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Researchers examine potential causes of dementia in CTE
, according to a cross-sectional study published online Aug. 5 in JAMA Neurology.
The study of older, deceased former American football players with CTE showed that more years of play were associated with more severe white matter rarefaction and greater burden of neurofibrillary tau tangles in the dorsolateral frontal cortex, wrote Michael L. Alosco, PhD, assistant professor of neurology at Boston University’s CTE Center, and colleagues.
An analysis of donated brains
Repetitive head impacts are associated with CTE. The clinical presentation of CTE includes cognitive, behavioral, and mood changes that can progress to dementia. The contributions of pathologic changes in phosphorylated tau, white matter degeneration, and cerebrovascular disease to dementia in the context of CTE are poorly understood. Dr. Alosco and colleagues examined arteriosclerosis, infarcts, microinfarcts, microbleeds, and white matter rarefaction in donated brains to illuminate these contributions.
The researchers examined data from the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) Study and Veterans Affairs–Boston University–Concussion Legacy Foundation brain bank. The population included deceased men who had played football and had received a neuropathologic diagnosis of CTE. Eligible participants had a history of repetitive head impacts. Brains that had been donated after a prolonged time postmortem and those with poor tissue quality were excluded.
Neuropathologists blinded to clinical data analyzed patients’ CTE stage and severity of neurofibrillary tangle burden in the dorsolateral frontal cortex as semiquantitative scales of phosphorylated tau severity. Neurofibrillary tangle burden was dichotomized as none or mild versus moderate or severe. The neuropathologists also rated white matter rarefaction and arteriolosclerosis severity using a scale of 0 points (i.e., none) to 3 points (i.e., severe changes). The investigators obtained clinical data through online surveys and retrospective telephone interviews with informants. They adjudicated consensus diagnoses of dementia based on modified criteria from DSM-IV.
White matter rarefaction was common
Dr. Alosco and colleagues included 180 individuals in their analysis, excluding those aged younger than 40 years because of low pathologic burden and minimal presence of dementia. Mean age at death was nearly 68 years. Fifty patients had no or mild neurofibrillary tangle burden, and 130 had moderate to severe burden. Thirty-five patients had CTE at stage I or II, and 145 had CTE at stage III or IV. In all, 120 patients were determined to have had dementia. About 47% of the sample had moderate to severe white matter rarefaction, and about 47% had arteriolosclerosis. Infarcts, microinfarcts, and microbleeds were uncommon.
When the investigators created a simultaneous equations regression model and controlled for age and race, they found that more years of play was associated with more severe white matter rarefaction, greater phosphorylated tau accumulation, and high CTE stage. Furthermore, white matter rarefaction and dorsolateral frontal cortex neurofibrillary tangles were associated with dementia. The association of years of play with dementia was mediated by white matter rarefaction and neurofibrillary tangle burden. Arteriolosclerosis was not associated with years of play, but arteriolosclerosis was independently associated with dementia.
The odds ratio for dementia was 1.69 among participants with more severe white matter rarefaction and 1.81 among patients with arteriolosclerosis. After the researchers controlled for age and race, the odds ratio of dementia was 2.65 among participants with a high neurofibrillary tangle burden, compared with participants with a low burden.
“Studies that include direct cardiovascular disease and repetitive head impacts metrics and refined measures of white matter integrity are needed to improve understanding of the pathogenesis of white matter rarefaction and cerebral small vessel changes in CTE,” Dr. Alosco and colleagues wrote.
The study was funded by grants from the National Institute on Aging, National Institute of Neurological Disorders and Stroke, the Department of Veterans Affairs, the Nick and Lynn Buoniconti Foundation, and the National Center for Advancing Translational Sciences. Some of the authors reported financial ties to the pharmaceutical industry and serving on professional sports committees.
SOURCE: Alosco ML et al. JAMA Neurol. 2019 Aug 5. doi: 10.1001/jamaneurol.2019.2244.
The study by Alosco et al. provides new insights into the pathogenesis of dementia in deceased former football players with chronic traumatic encephalopathy (CTE), Julie A. Schneider, MD, professor of neuropathology at Rush University, Chicago, wrote in an accompanying editorial (JAMA Neurol. 2019 Aug 5. doi: 10.1001/jamaneurol.2019.1089).
Significant and widespread white matter injury is an established result of head trauma resulting from acceleration-deceleration injuries. In addition, studies of single and repetitive traumatic brain injury have shown disruption of axons and white matter. The findings of Alosco et al. “underscore the importance of studying the risk factors and mechanisms for the white matter rarefaction, in addition to the tauopathy, in individuals who have played U.S. football and have CTE,” Dr. Schneider wrote.
The comprehensive neuropathologic examinations, advanced statistical techniques, and multiple sensitivity analyses that the investigators performed are among the study’s strengths. An important limitation, however, is selection bias. “The frequency of pathologic characteristics in this group should not be generalized to estimate the prevalence of neuropathologic conditions in living individuals who have played or are playing U.S. football,” Dr. Schneider wrote. “Moreover, individuals who played football who were selected for autopsy and found to have CTE may differ in other important ways from those who did not undergo autopsy or did not have CTE.” Recall bias could alter associations between years of play and dementia diagnosis, and the study’s semiquantitative assessments could result in decreased power to observe relevant associations, she said.
“In spite of these limitations, the authors should be applauded for elegant work and compelling support for multiple pathologic pathways to dementia in football players with CTE,” Dr. Schneider concluded.
Dr. Schneider is with the Rush Alzheimer’s Disease Center at Rush University, Chicago. She has been an expert consultant for the National Football League and the National Hockey League.
The study by Alosco et al. provides new insights into the pathogenesis of dementia in deceased former football players with chronic traumatic encephalopathy (CTE), Julie A. Schneider, MD, professor of neuropathology at Rush University, Chicago, wrote in an accompanying editorial (JAMA Neurol. 2019 Aug 5. doi: 10.1001/jamaneurol.2019.1089).
Significant and widespread white matter injury is an established result of head trauma resulting from acceleration-deceleration injuries. In addition, studies of single and repetitive traumatic brain injury have shown disruption of axons and white matter. The findings of Alosco et al. “underscore the importance of studying the risk factors and mechanisms for the white matter rarefaction, in addition to the tauopathy, in individuals who have played U.S. football and have CTE,” Dr. Schneider wrote.
The comprehensive neuropathologic examinations, advanced statistical techniques, and multiple sensitivity analyses that the investigators performed are among the study’s strengths. An important limitation, however, is selection bias. “The frequency of pathologic characteristics in this group should not be generalized to estimate the prevalence of neuropathologic conditions in living individuals who have played or are playing U.S. football,” Dr. Schneider wrote. “Moreover, individuals who played football who were selected for autopsy and found to have CTE may differ in other important ways from those who did not undergo autopsy or did not have CTE.” Recall bias could alter associations between years of play and dementia diagnosis, and the study’s semiquantitative assessments could result in decreased power to observe relevant associations, she said.
“In spite of these limitations, the authors should be applauded for elegant work and compelling support for multiple pathologic pathways to dementia in football players with CTE,” Dr. Schneider concluded.
Dr. Schneider is with the Rush Alzheimer’s Disease Center at Rush University, Chicago. She has been an expert consultant for the National Football League and the National Hockey League.
The study by Alosco et al. provides new insights into the pathogenesis of dementia in deceased former football players with chronic traumatic encephalopathy (CTE), Julie A. Schneider, MD, professor of neuropathology at Rush University, Chicago, wrote in an accompanying editorial (JAMA Neurol. 2019 Aug 5. doi: 10.1001/jamaneurol.2019.1089).
Significant and widespread white matter injury is an established result of head trauma resulting from acceleration-deceleration injuries. In addition, studies of single and repetitive traumatic brain injury have shown disruption of axons and white matter. The findings of Alosco et al. “underscore the importance of studying the risk factors and mechanisms for the white matter rarefaction, in addition to the tauopathy, in individuals who have played U.S. football and have CTE,” Dr. Schneider wrote.
The comprehensive neuropathologic examinations, advanced statistical techniques, and multiple sensitivity analyses that the investigators performed are among the study’s strengths. An important limitation, however, is selection bias. “The frequency of pathologic characteristics in this group should not be generalized to estimate the prevalence of neuropathologic conditions in living individuals who have played or are playing U.S. football,” Dr. Schneider wrote. “Moreover, individuals who played football who were selected for autopsy and found to have CTE may differ in other important ways from those who did not undergo autopsy or did not have CTE.” Recall bias could alter associations between years of play and dementia diagnosis, and the study’s semiquantitative assessments could result in decreased power to observe relevant associations, she said.
“In spite of these limitations, the authors should be applauded for elegant work and compelling support for multiple pathologic pathways to dementia in football players with CTE,” Dr. Schneider concluded.
Dr. Schneider is with the Rush Alzheimer’s Disease Center at Rush University, Chicago. She has been an expert consultant for the National Football League and the National Hockey League.
, according to a cross-sectional study published online Aug. 5 in JAMA Neurology.
The study of older, deceased former American football players with CTE showed that more years of play were associated with more severe white matter rarefaction and greater burden of neurofibrillary tau tangles in the dorsolateral frontal cortex, wrote Michael L. Alosco, PhD, assistant professor of neurology at Boston University’s CTE Center, and colleagues.
An analysis of donated brains
Repetitive head impacts are associated with CTE. The clinical presentation of CTE includes cognitive, behavioral, and mood changes that can progress to dementia. The contributions of pathologic changes in phosphorylated tau, white matter degeneration, and cerebrovascular disease to dementia in the context of CTE are poorly understood. Dr. Alosco and colleagues examined arteriosclerosis, infarcts, microinfarcts, microbleeds, and white matter rarefaction in donated brains to illuminate these contributions.
The researchers examined data from the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) Study and Veterans Affairs–Boston University–Concussion Legacy Foundation brain bank. The population included deceased men who had played football and had received a neuropathologic diagnosis of CTE. Eligible participants had a history of repetitive head impacts. Brains that had been donated after a prolonged time postmortem and those with poor tissue quality were excluded.
Neuropathologists blinded to clinical data analyzed patients’ CTE stage and severity of neurofibrillary tangle burden in the dorsolateral frontal cortex as semiquantitative scales of phosphorylated tau severity. Neurofibrillary tangle burden was dichotomized as none or mild versus moderate or severe. The neuropathologists also rated white matter rarefaction and arteriolosclerosis severity using a scale of 0 points (i.e., none) to 3 points (i.e., severe changes). The investigators obtained clinical data through online surveys and retrospective telephone interviews with informants. They adjudicated consensus diagnoses of dementia based on modified criteria from DSM-IV.
White matter rarefaction was common
Dr. Alosco and colleagues included 180 individuals in their analysis, excluding those aged younger than 40 years because of low pathologic burden and minimal presence of dementia. Mean age at death was nearly 68 years. Fifty patients had no or mild neurofibrillary tangle burden, and 130 had moderate to severe burden. Thirty-five patients had CTE at stage I or II, and 145 had CTE at stage III or IV. In all, 120 patients were determined to have had dementia. About 47% of the sample had moderate to severe white matter rarefaction, and about 47% had arteriolosclerosis. Infarcts, microinfarcts, and microbleeds were uncommon.
When the investigators created a simultaneous equations regression model and controlled for age and race, they found that more years of play was associated with more severe white matter rarefaction, greater phosphorylated tau accumulation, and high CTE stage. Furthermore, white matter rarefaction and dorsolateral frontal cortex neurofibrillary tangles were associated with dementia. The association of years of play with dementia was mediated by white matter rarefaction and neurofibrillary tangle burden. Arteriolosclerosis was not associated with years of play, but arteriolosclerosis was independently associated with dementia.
The odds ratio for dementia was 1.69 among participants with more severe white matter rarefaction and 1.81 among patients with arteriolosclerosis. After the researchers controlled for age and race, the odds ratio of dementia was 2.65 among participants with a high neurofibrillary tangle burden, compared with participants with a low burden.
“Studies that include direct cardiovascular disease and repetitive head impacts metrics and refined measures of white matter integrity are needed to improve understanding of the pathogenesis of white matter rarefaction and cerebral small vessel changes in CTE,” Dr. Alosco and colleagues wrote.
The study was funded by grants from the National Institute on Aging, National Institute of Neurological Disorders and Stroke, the Department of Veterans Affairs, the Nick and Lynn Buoniconti Foundation, and the National Center for Advancing Translational Sciences. Some of the authors reported financial ties to the pharmaceutical industry and serving on professional sports committees.
SOURCE: Alosco ML et al. JAMA Neurol. 2019 Aug 5. doi: 10.1001/jamaneurol.2019.2244.
, according to a cross-sectional study published online Aug. 5 in JAMA Neurology.
The study of older, deceased former American football players with CTE showed that more years of play were associated with more severe white matter rarefaction and greater burden of neurofibrillary tau tangles in the dorsolateral frontal cortex, wrote Michael L. Alosco, PhD, assistant professor of neurology at Boston University’s CTE Center, and colleagues.
An analysis of donated brains
Repetitive head impacts are associated with CTE. The clinical presentation of CTE includes cognitive, behavioral, and mood changes that can progress to dementia. The contributions of pathologic changes in phosphorylated tau, white matter degeneration, and cerebrovascular disease to dementia in the context of CTE are poorly understood. Dr. Alosco and colleagues examined arteriosclerosis, infarcts, microinfarcts, microbleeds, and white matter rarefaction in donated brains to illuminate these contributions.
The researchers examined data from the Understanding Neurologic Injury and Traumatic Encephalopathy (UNITE) Study and Veterans Affairs–Boston University–Concussion Legacy Foundation brain bank. The population included deceased men who had played football and had received a neuropathologic diagnosis of CTE. Eligible participants had a history of repetitive head impacts. Brains that had been donated after a prolonged time postmortem and those with poor tissue quality were excluded.
Neuropathologists blinded to clinical data analyzed patients’ CTE stage and severity of neurofibrillary tangle burden in the dorsolateral frontal cortex as semiquantitative scales of phosphorylated tau severity. Neurofibrillary tangle burden was dichotomized as none or mild versus moderate or severe. The neuropathologists also rated white matter rarefaction and arteriolosclerosis severity using a scale of 0 points (i.e., none) to 3 points (i.e., severe changes). The investigators obtained clinical data through online surveys and retrospective telephone interviews with informants. They adjudicated consensus diagnoses of dementia based on modified criteria from DSM-IV.
White matter rarefaction was common
Dr. Alosco and colleagues included 180 individuals in their analysis, excluding those aged younger than 40 years because of low pathologic burden and minimal presence of dementia. Mean age at death was nearly 68 years. Fifty patients had no or mild neurofibrillary tangle burden, and 130 had moderate to severe burden. Thirty-five patients had CTE at stage I or II, and 145 had CTE at stage III or IV. In all, 120 patients were determined to have had dementia. About 47% of the sample had moderate to severe white matter rarefaction, and about 47% had arteriolosclerosis. Infarcts, microinfarcts, and microbleeds were uncommon.
When the investigators created a simultaneous equations regression model and controlled for age and race, they found that more years of play was associated with more severe white matter rarefaction, greater phosphorylated tau accumulation, and high CTE stage. Furthermore, white matter rarefaction and dorsolateral frontal cortex neurofibrillary tangles were associated with dementia. The association of years of play with dementia was mediated by white matter rarefaction and neurofibrillary tangle burden. Arteriolosclerosis was not associated with years of play, but arteriolosclerosis was independently associated with dementia.
The odds ratio for dementia was 1.69 among participants with more severe white matter rarefaction and 1.81 among patients with arteriolosclerosis. After the researchers controlled for age and race, the odds ratio of dementia was 2.65 among participants with a high neurofibrillary tangle burden, compared with participants with a low burden.
“Studies that include direct cardiovascular disease and repetitive head impacts metrics and refined measures of white matter integrity are needed to improve understanding of the pathogenesis of white matter rarefaction and cerebral small vessel changes in CTE,” Dr. Alosco and colleagues wrote.
The study was funded by grants from the National Institute on Aging, National Institute of Neurological Disorders and Stroke, the Department of Veterans Affairs, the Nick and Lynn Buoniconti Foundation, and the National Center for Advancing Translational Sciences. Some of the authors reported financial ties to the pharmaceutical industry and serving on professional sports committees.
SOURCE: Alosco ML et al. JAMA Neurol. 2019 Aug 5. doi: 10.1001/jamaneurol.2019.2244.
FROM JAMA NEUROLOGY
Tranexamic acid may not improve neurologic outcomes in patients with TBI
PHILADELPHIA – according to an investigation presented at the annual meeting of the American Academy of Neurology. For patients with TBI and intracranial hemorrhage (ICH), however, treatment with a 2-gram bolus of tranexamic acid within 42 minutes of injury significantly improves the rate of 28-day survival. Tranexamic acid therefore “is the first therapeutic with evidence for benefit in acute TBI,” said Susan Rowell, MD, trauma medical director at Duke University in Durham, North Carolina.
No effective treatment is available for TBI, which is a major cause of death after trauma. In 2010, the CRASH-2 trial (Lancet. 2010 Jul 03;376[9734]:23-32), suggested that tranexamic acid, a lysine analogue that decreases the breakdown of clots, safely reduced the rate of death from hemorrhage in patients with trauma and bleeding. Patients treated within 1 hour of injury were significantly more likely to survive than those treated at 1 hour or more after injury.
Two small, prospective trials failed to show that tranexamic acid reduced in-hospital mortality, improved neurologic function at discharge, or reduced the progression of ICH. A meta-analysis of both trials, however, showed a trend toward a benefit of treatment with this therapy.
A multicenter, prehospital trial
Dr. Rowell and colleagues hypothesized that prehospital administration of tranexamic acid to patients with moderate to severe TBI early after injury would increase the likelihood of a favorable neurologic outcome. Between March 2015 and March 2017, they enrolled 1,280 participants in a multicenter, prehospital trial. Eligible participants had moderate to severe TBI, were not in shock (as evidenced by a systolic blood pressure greater than 90 mm Hg before randomization), and were enrolled within 2 hours of injury.
Patients were randomized to one of three treatment arms and followed for 6 months. The first treatment arm received a 1-gram bolus of tranexamic acid before hospital admission and an 8-hour, 1-gram infusion of tranexamic acid in the hospital. The second arm received a 2-gram bolus of tranexamic acid before hospital admission and a placebo infusion in the hospital. The third arm received a placebo bolus and placebo infusion. Paramedics and participants were blinded to treatment assignment. The trial was conducted at 20 hospitals and 39 emergency medical services agencies in the United States and Canada.
The study’s primary outcome was functional neurologic outcome at 6 months, as measured by the Glasgow Outcomes Scale – Extended (GOSE). The investigators dichotomized results into favorable and poor categories. Other prespecified outcomes included early and late mortality, the disability rating scale (DRS), and progression of ICH.
Treatment was administered early
The researchers identified 1,280 eligible patients, of whom 1,063 were randomized. The modified intention-to-treat analysis included 309 participants in the placebo group, 312 in the bolus-maintenance group (the 1-gram group), and 345 in the bolus-only group (the 2-gram group). The population’s average age was approximately 42 years, and 75% of the sample was male. About half of the patients had a Glasgow Coma Scale score between 3 and 8. Injury severity and prehospital care were similar among the groups.
The researchers provided the drug infusion at an average of 0.7 hours (42 minutes) after injury, “which is actually quite early,” said Dr. Rowell. They observed few infusion-related deviations, and the entire bolus was infused in about 95% of patients. Approximately 70% of patients received the full 8-hour infusion. This result was influenced partly by stopping rules and by providers who requested unblinding to give open-label tranexamic acid. Overall, 57% of patients in the trial had an ICH on head CT, which was approximately the proportion that the researchers had anticipated.
Dr. Rowell and colleagues completed the 6-month follow-up for 85% of patients. They saw no difference in the 6-month neurologic outcome between the group of all patients who received tranexamic acid and those who received placebo. The investigators also saw no differences between groups in early and late mortality and the DRS.
About half of patients with ICH were evaluated for progression. Progression occurred in 20% of the placebo arm, 17% of the bolus-maintenance arm, and 15% of the bolus-only arm. The differences between groups were not statistically significant. Participants in the bolus-only group, however, were significantly less likely to die, compared with the placebo and the bolus-maintenance groups. The odds ratio of death for the bolus-only group, compared with the others, was about 0.5. The absolute mortality rate for the placebo and bolus-maintenance groups was 17%, compared with 12% for the bolus-only group. Most deaths were attributable to TBI, and few patients died of exsanguination.
In addition, the bolus-only group also had improved long-term neurologic outcome, as assessed by the 6-month DRS and the 6-month GOSE, compared with the bolus maintenance group.
Among patients with ICH, survival increased by approximately 12% at 10 hours after injury in the bolus-only group, compared with the bolus-maintenance and placebo groups. This difference persisted throughout the follow-up period, said Dr. Rowell.
Among predefined major adverse events, seizure-like activity occurred in 5% of the bolus-only group, compared with 2% of the placebo and bolus-maintenance groups. The researchers found no significant differences in any thrombotic event between the bolus-only group and the placebo group.
The study was sponsored by University of Washington, Seattle. Collaborators included the National Heart, Lung, and Blood Institute; the U.S. Army Medical Research and Development Command; and the American Heart Association. Dr. Rowell had no relevant disclosures.
SOURCE: Rowell S et al. AAN 2019, Abstract.
PHILADELPHIA – according to an investigation presented at the annual meeting of the American Academy of Neurology. For patients with TBI and intracranial hemorrhage (ICH), however, treatment with a 2-gram bolus of tranexamic acid within 42 minutes of injury significantly improves the rate of 28-day survival. Tranexamic acid therefore “is the first therapeutic with evidence for benefit in acute TBI,” said Susan Rowell, MD, trauma medical director at Duke University in Durham, North Carolina.
No effective treatment is available for TBI, which is a major cause of death after trauma. In 2010, the CRASH-2 trial (Lancet. 2010 Jul 03;376[9734]:23-32), suggested that tranexamic acid, a lysine analogue that decreases the breakdown of clots, safely reduced the rate of death from hemorrhage in patients with trauma and bleeding. Patients treated within 1 hour of injury were significantly more likely to survive than those treated at 1 hour or more after injury.
Two small, prospective trials failed to show that tranexamic acid reduced in-hospital mortality, improved neurologic function at discharge, or reduced the progression of ICH. A meta-analysis of both trials, however, showed a trend toward a benefit of treatment with this therapy.
A multicenter, prehospital trial
Dr. Rowell and colleagues hypothesized that prehospital administration of tranexamic acid to patients with moderate to severe TBI early after injury would increase the likelihood of a favorable neurologic outcome. Between March 2015 and March 2017, they enrolled 1,280 participants in a multicenter, prehospital trial. Eligible participants had moderate to severe TBI, were not in shock (as evidenced by a systolic blood pressure greater than 90 mm Hg before randomization), and were enrolled within 2 hours of injury.
Patients were randomized to one of three treatment arms and followed for 6 months. The first treatment arm received a 1-gram bolus of tranexamic acid before hospital admission and an 8-hour, 1-gram infusion of tranexamic acid in the hospital. The second arm received a 2-gram bolus of tranexamic acid before hospital admission and a placebo infusion in the hospital. The third arm received a placebo bolus and placebo infusion. Paramedics and participants were blinded to treatment assignment. The trial was conducted at 20 hospitals and 39 emergency medical services agencies in the United States and Canada.
The study’s primary outcome was functional neurologic outcome at 6 months, as measured by the Glasgow Outcomes Scale – Extended (GOSE). The investigators dichotomized results into favorable and poor categories. Other prespecified outcomes included early and late mortality, the disability rating scale (DRS), and progression of ICH.
Treatment was administered early
The researchers identified 1,280 eligible patients, of whom 1,063 were randomized. The modified intention-to-treat analysis included 309 participants in the placebo group, 312 in the bolus-maintenance group (the 1-gram group), and 345 in the bolus-only group (the 2-gram group). The population’s average age was approximately 42 years, and 75% of the sample was male. About half of the patients had a Glasgow Coma Scale score between 3 and 8. Injury severity and prehospital care were similar among the groups.
The researchers provided the drug infusion at an average of 0.7 hours (42 minutes) after injury, “which is actually quite early,” said Dr. Rowell. They observed few infusion-related deviations, and the entire bolus was infused in about 95% of patients. Approximately 70% of patients received the full 8-hour infusion. This result was influenced partly by stopping rules and by providers who requested unblinding to give open-label tranexamic acid. Overall, 57% of patients in the trial had an ICH on head CT, which was approximately the proportion that the researchers had anticipated.
Dr. Rowell and colleagues completed the 6-month follow-up for 85% of patients. They saw no difference in the 6-month neurologic outcome between the group of all patients who received tranexamic acid and those who received placebo. The investigators also saw no differences between groups in early and late mortality and the DRS.
About half of patients with ICH were evaluated for progression. Progression occurred in 20% of the placebo arm, 17% of the bolus-maintenance arm, and 15% of the bolus-only arm. The differences between groups were not statistically significant. Participants in the bolus-only group, however, were significantly less likely to die, compared with the placebo and the bolus-maintenance groups. The odds ratio of death for the bolus-only group, compared with the others, was about 0.5. The absolute mortality rate for the placebo and bolus-maintenance groups was 17%, compared with 12% for the bolus-only group. Most deaths were attributable to TBI, and few patients died of exsanguination.
In addition, the bolus-only group also had improved long-term neurologic outcome, as assessed by the 6-month DRS and the 6-month GOSE, compared with the bolus maintenance group.
Among patients with ICH, survival increased by approximately 12% at 10 hours after injury in the bolus-only group, compared with the bolus-maintenance and placebo groups. This difference persisted throughout the follow-up period, said Dr. Rowell.
Among predefined major adverse events, seizure-like activity occurred in 5% of the bolus-only group, compared with 2% of the placebo and bolus-maintenance groups. The researchers found no significant differences in any thrombotic event between the bolus-only group and the placebo group.
The study was sponsored by University of Washington, Seattle. Collaborators included the National Heart, Lung, and Blood Institute; the U.S. Army Medical Research and Development Command; and the American Heart Association. Dr. Rowell had no relevant disclosures.
SOURCE: Rowell S et al. AAN 2019, Abstract.
PHILADELPHIA – according to an investigation presented at the annual meeting of the American Academy of Neurology. For patients with TBI and intracranial hemorrhage (ICH), however, treatment with a 2-gram bolus of tranexamic acid within 42 minutes of injury significantly improves the rate of 28-day survival. Tranexamic acid therefore “is the first therapeutic with evidence for benefit in acute TBI,” said Susan Rowell, MD, trauma medical director at Duke University in Durham, North Carolina.
No effective treatment is available for TBI, which is a major cause of death after trauma. In 2010, the CRASH-2 trial (Lancet. 2010 Jul 03;376[9734]:23-32), suggested that tranexamic acid, a lysine analogue that decreases the breakdown of clots, safely reduced the rate of death from hemorrhage in patients with trauma and bleeding. Patients treated within 1 hour of injury were significantly more likely to survive than those treated at 1 hour or more after injury.
Two small, prospective trials failed to show that tranexamic acid reduced in-hospital mortality, improved neurologic function at discharge, or reduced the progression of ICH. A meta-analysis of both trials, however, showed a trend toward a benefit of treatment with this therapy.
A multicenter, prehospital trial
Dr. Rowell and colleagues hypothesized that prehospital administration of tranexamic acid to patients with moderate to severe TBI early after injury would increase the likelihood of a favorable neurologic outcome. Between March 2015 and March 2017, they enrolled 1,280 participants in a multicenter, prehospital trial. Eligible participants had moderate to severe TBI, were not in shock (as evidenced by a systolic blood pressure greater than 90 mm Hg before randomization), and were enrolled within 2 hours of injury.
Patients were randomized to one of three treatment arms and followed for 6 months. The first treatment arm received a 1-gram bolus of tranexamic acid before hospital admission and an 8-hour, 1-gram infusion of tranexamic acid in the hospital. The second arm received a 2-gram bolus of tranexamic acid before hospital admission and a placebo infusion in the hospital. The third arm received a placebo bolus and placebo infusion. Paramedics and participants were blinded to treatment assignment. The trial was conducted at 20 hospitals and 39 emergency medical services agencies in the United States and Canada.
The study’s primary outcome was functional neurologic outcome at 6 months, as measured by the Glasgow Outcomes Scale – Extended (GOSE). The investigators dichotomized results into favorable and poor categories. Other prespecified outcomes included early and late mortality, the disability rating scale (DRS), and progression of ICH.
Treatment was administered early
The researchers identified 1,280 eligible patients, of whom 1,063 were randomized. The modified intention-to-treat analysis included 309 participants in the placebo group, 312 in the bolus-maintenance group (the 1-gram group), and 345 in the bolus-only group (the 2-gram group). The population’s average age was approximately 42 years, and 75% of the sample was male. About half of the patients had a Glasgow Coma Scale score between 3 and 8. Injury severity and prehospital care were similar among the groups.
The researchers provided the drug infusion at an average of 0.7 hours (42 minutes) after injury, “which is actually quite early,” said Dr. Rowell. They observed few infusion-related deviations, and the entire bolus was infused in about 95% of patients. Approximately 70% of patients received the full 8-hour infusion. This result was influenced partly by stopping rules and by providers who requested unblinding to give open-label tranexamic acid. Overall, 57% of patients in the trial had an ICH on head CT, which was approximately the proportion that the researchers had anticipated.
Dr. Rowell and colleagues completed the 6-month follow-up for 85% of patients. They saw no difference in the 6-month neurologic outcome between the group of all patients who received tranexamic acid and those who received placebo. The investigators also saw no differences between groups in early and late mortality and the DRS.
About half of patients with ICH were evaluated for progression. Progression occurred in 20% of the placebo arm, 17% of the bolus-maintenance arm, and 15% of the bolus-only arm. The differences between groups were not statistically significant. Participants in the bolus-only group, however, were significantly less likely to die, compared with the placebo and the bolus-maintenance groups. The odds ratio of death for the bolus-only group, compared with the others, was about 0.5. The absolute mortality rate for the placebo and bolus-maintenance groups was 17%, compared with 12% for the bolus-only group. Most deaths were attributable to TBI, and few patients died of exsanguination.
In addition, the bolus-only group also had improved long-term neurologic outcome, as assessed by the 6-month DRS and the 6-month GOSE, compared with the bolus maintenance group.
Among patients with ICH, survival increased by approximately 12% at 10 hours after injury in the bolus-only group, compared with the bolus-maintenance and placebo groups. This difference persisted throughout the follow-up period, said Dr. Rowell.
Among predefined major adverse events, seizure-like activity occurred in 5% of the bolus-only group, compared with 2% of the placebo and bolus-maintenance groups. The researchers found no significant differences in any thrombotic event between the bolus-only group and the placebo group.
The study was sponsored by University of Washington, Seattle. Collaborators included the National Heart, Lung, and Blood Institute; the U.S. Army Medical Research and Development Command; and the American Heart Association. Dr. Rowell had no relevant disclosures.
SOURCE: Rowell S et al. AAN 2019, Abstract.
REPORTING FROM AAN 2019
Key clinical point: Early administration of tranexamic acid after TBI does not improve neurologic outcome at 6 months.
Major finding: Patients with TBI and ICH who received a 2-g bolus of tranexamic acid had a 50% lower rate of mortality.
Study details: A multicenter, prehospital trial that enrolled 1,063 patients with moderate to severe TBI.
Disclosures: The study was sponsored by University of Washington, Seattle. Collaborators included the National Heart, Lung, and Blood Institute; the U.S. Army Medical Research and Development Command; and the American Heart Association. Dr. Rowell had no relevant disclosures.
Source: Rowell S et al. AAN 2019, Abstract.
Can serum inflammatory markers predict concussion recovery?
Levels of interleukin-6 (IL-6) and IL-1 receptor antagonist (IL-1RA) are significantly elevated 6 hours after concussion, and higher IL-6 levels are associated with slower recovery, according to a study of 41 high school and college football players with concussion. The findings were published online ahead of print July 3 in Neurology.
“With so many people sustaining concussions and a sizeable number of them having prolonged symptoms and recovery, any tools we can develop to help determine who would be at greater risk of problems would be very beneficial,” said study author Timothy B. Meier, PhD, assistant professor of neurosurgery at the Medical College of Wisconsin in Milwaukee, in a news release. “These results are a crucial first step.”
Symptoms of sport-related concussion typically resolve within 1-2 weeks but may last longer. Although prior studies have focused on biomarkers that are specific to brain injury, nonspecific inflammatory markers also may hold promise in predicting recovery after a mild traumatic brain injury, the authors said.
To examine whether acute elevations in serum inflammatory markers predict symptom recovery following sport-related concussion, Dr. Meier and his research colleagues enrolled 857 high school and college football players into a prospective cohort study. They included in their analyses 41 concussed athletes and 43 matched control athletes with an average age of 18 years. None of the concussed athletes lost consciousness, two had posttraumatic amnesia, and one had retrograde amnesia. The concussed athletes had a mean symptom duration of 8.86 days.
The researchers measured serum levels of IL-6, IL-1RA, IL-1 beta, IL-10, tumor necrosis factor, C-reactive protein, and interferon-gamma and recorded Sport Concussion Assessment Tool, 3rd edition, symptom severity scores.
Participants with concussion underwent testing at the start of the season, within 6 hours of injury, 24-48 hours after injury, and at 8, 15, and 45 days after injury. Control athletes underwent testing at similar times.
Among athletes with concussion, IL-1RA and IL-6 were elevated at 6 hours, compared with all other postinjury visits and with controls. IL-6 and IL-1RA significantly discriminated concussed from control athletes at 6 hours postconcussion with an area under the receiver operating characteristic curve of 0.79 for IL-6 and 0.79 for IL-1RA. Furthermore, IL-6 levels at 6 hours significantly correlated with symptom duration, “with a 1-unit increase in natural log-transformed IL-6 associated with 39% lower hazard of symptom recovery,” the researchers reported.
The extent to which these results generalize to females, youth athletes, or athletes who develop postconcussion syndrome is unclear, and larger studies may be needed to adequately assess inflammatory markers as clinical biomarkers of sport-related concussion, the authors noted.
“Eventually, these results may help us better understand the relationship between injury and inflammation and potentially lead to new treatments,” Dr. Meier said.
The research was supported by the U.S. Department of Defense, National Institute of Neurological Disorders and Stroke, National Institute of General Medical Sciences, National Institute of Mental Health, and the National Center for Advancing Translational Sciences. The authors had no relevant disclosures.
SOURCE: Nitta ME et al. Neurology. 2019 Jul 3. doi: 10.1212/WNL.0000000000007864.
Levels of interleukin-6 (IL-6) and IL-1 receptor antagonist (IL-1RA) are significantly elevated 6 hours after concussion, and higher IL-6 levels are associated with slower recovery, according to a study of 41 high school and college football players with concussion. The findings were published online ahead of print July 3 in Neurology.
“With so many people sustaining concussions and a sizeable number of them having prolonged symptoms and recovery, any tools we can develop to help determine who would be at greater risk of problems would be very beneficial,” said study author Timothy B. Meier, PhD, assistant professor of neurosurgery at the Medical College of Wisconsin in Milwaukee, in a news release. “These results are a crucial first step.”
Symptoms of sport-related concussion typically resolve within 1-2 weeks but may last longer. Although prior studies have focused on biomarkers that are specific to brain injury, nonspecific inflammatory markers also may hold promise in predicting recovery after a mild traumatic brain injury, the authors said.
To examine whether acute elevations in serum inflammatory markers predict symptom recovery following sport-related concussion, Dr. Meier and his research colleagues enrolled 857 high school and college football players into a prospective cohort study. They included in their analyses 41 concussed athletes and 43 matched control athletes with an average age of 18 years. None of the concussed athletes lost consciousness, two had posttraumatic amnesia, and one had retrograde amnesia. The concussed athletes had a mean symptom duration of 8.86 days.
The researchers measured serum levels of IL-6, IL-1RA, IL-1 beta, IL-10, tumor necrosis factor, C-reactive protein, and interferon-gamma and recorded Sport Concussion Assessment Tool, 3rd edition, symptom severity scores.
Participants with concussion underwent testing at the start of the season, within 6 hours of injury, 24-48 hours after injury, and at 8, 15, and 45 days after injury. Control athletes underwent testing at similar times.
Among athletes with concussion, IL-1RA and IL-6 were elevated at 6 hours, compared with all other postinjury visits and with controls. IL-6 and IL-1RA significantly discriminated concussed from control athletes at 6 hours postconcussion with an area under the receiver operating characteristic curve of 0.79 for IL-6 and 0.79 for IL-1RA. Furthermore, IL-6 levels at 6 hours significantly correlated with symptom duration, “with a 1-unit increase in natural log-transformed IL-6 associated with 39% lower hazard of symptom recovery,” the researchers reported.
The extent to which these results generalize to females, youth athletes, or athletes who develop postconcussion syndrome is unclear, and larger studies may be needed to adequately assess inflammatory markers as clinical biomarkers of sport-related concussion, the authors noted.
“Eventually, these results may help us better understand the relationship between injury and inflammation and potentially lead to new treatments,” Dr. Meier said.
The research was supported by the U.S. Department of Defense, National Institute of Neurological Disorders and Stroke, National Institute of General Medical Sciences, National Institute of Mental Health, and the National Center for Advancing Translational Sciences. The authors had no relevant disclosures.
SOURCE: Nitta ME et al. Neurology. 2019 Jul 3. doi: 10.1212/WNL.0000000000007864.
Levels of interleukin-6 (IL-6) and IL-1 receptor antagonist (IL-1RA) are significantly elevated 6 hours after concussion, and higher IL-6 levels are associated with slower recovery, according to a study of 41 high school and college football players with concussion. The findings were published online ahead of print July 3 in Neurology.
“With so many people sustaining concussions and a sizeable number of them having prolonged symptoms and recovery, any tools we can develop to help determine who would be at greater risk of problems would be very beneficial,” said study author Timothy B. Meier, PhD, assistant professor of neurosurgery at the Medical College of Wisconsin in Milwaukee, in a news release. “These results are a crucial first step.”
Symptoms of sport-related concussion typically resolve within 1-2 weeks but may last longer. Although prior studies have focused on biomarkers that are specific to brain injury, nonspecific inflammatory markers also may hold promise in predicting recovery after a mild traumatic brain injury, the authors said.
To examine whether acute elevations in serum inflammatory markers predict symptom recovery following sport-related concussion, Dr. Meier and his research colleagues enrolled 857 high school and college football players into a prospective cohort study. They included in their analyses 41 concussed athletes and 43 matched control athletes with an average age of 18 years. None of the concussed athletes lost consciousness, two had posttraumatic amnesia, and one had retrograde amnesia. The concussed athletes had a mean symptom duration of 8.86 days.
The researchers measured serum levels of IL-6, IL-1RA, IL-1 beta, IL-10, tumor necrosis factor, C-reactive protein, and interferon-gamma and recorded Sport Concussion Assessment Tool, 3rd edition, symptom severity scores.
Participants with concussion underwent testing at the start of the season, within 6 hours of injury, 24-48 hours after injury, and at 8, 15, and 45 days after injury. Control athletes underwent testing at similar times.
Among athletes with concussion, IL-1RA and IL-6 were elevated at 6 hours, compared with all other postinjury visits and with controls. IL-6 and IL-1RA significantly discriminated concussed from control athletes at 6 hours postconcussion with an area under the receiver operating characteristic curve of 0.79 for IL-6 and 0.79 for IL-1RA. Furthermore, IL-6 levels at 6 hours significantly correlated with symptom duration, “with a 1-unit increase in natural log-transformed IL-6 associated with 39% lower hazard of symptom recovery,” the researchers reported.
The extent to which these results generalize to females, youth athletes, or athletes who develop postconcussion syndrome is unclear, and larger studies may be needed to adequately assess inflammatory markers as clinical biomarkers of sport-related concussion, the authors noted.
“Eventually, these results may help us better understand the relationship between injury and inflammation and potentially lead to new treatments,” Dr. Meier said.
The research was supported by the U.S. Department of Defense, National Institute of Neurological Disorders and Stroke, National Institute of General Medical Sciences, National Institute of Mental Health, and the National Center for Advancing Translational Sciences. The authors had no relevant disclosures.
SOURCE: Nitta ME et al. Neurology. 2019 Jul 3. doi: 10.1212/WNL.0000000000007864.
FROM NEUROLOGY
Key clinical point: Serum biomarkers of inflammation may help identify which athletes will take longer to recover after a sport-related concussion.
Major finding: IL-6 and IL-1RA significantly discriminated concussed from control athletes at 6 hours postconcussion with an area under the receiver operating characteristic curve of 0.79 for IL-6 and 0.79 for IL-1RA. Furthermore, IL-6 levels at 6 hours significantly correlated with symptom duration.
Study details: A prospective cohort study of high school and college football players. The analyses included 41 concussed athletes and 43 matched control athletes with an average age of about 18 years.
Disclosures: The research was supported by the U.S. Department of Defense, National Institute of Neurological Disorders and Stroke, National Institute of General Medical Sciences, National Institute of Mental Health, and the National Center for Advancing Translational Sciences. The authors had no relevant disclosures.
Source: Nitta ME et al. Neurology. 2019 Jul 3. doi: 10.1212/WNL.0000000000007864.
Emergency Protocol Improves Survival After Severe Head Injury
Preventing low oxygen, low blood pressure, and hyperventilation in people with head injury has been shown to improve survival, according to observational studies. The guidelines for prehospital management of traumatic brain injury (TBI), developed in 2000, were updated in 2007 to reflect those findings. But are they being followed? And if followed, do they help?
The Excellence in Prehospital Injury Care (EPIC) study, the first time the guidelines were assessed in real-world conditions, trained EMS responders in Arizona and compared patient outcomes before and after the guideline implementation.
The study researchers found “a therapeutic sweet spot” in that the guidelines had an “enormous impact” on people with severe TBI. Implementing the guidelines did not affect overall survival of the entire group, which included > 21,000 patients with moderate, severe, and critical injuries. But further analysis showed that they helped double the survival rate of people with severe TBI and tripled the survival rate in severe TBI patients who had to have a breathing tube inserted by EMS personnel.
Daniel Spaite, MD, who led the study, said the patients with moderate injuries would most likely have survived anyway, and those in critical condition may have had injuries too serious to overcome.
The guidelines also were associated with an overall increase in survival to hospital admission.
According to Bentley Bobrow, MD, co-principal investigator, “It was exciting to see such dramatic outcomes resulting from a simple 2-hour training session with EMS personnel.”
The study “demonstrates the significance of conducting studies in real-world settings and brings a strong evidence base to the guidelines,” said Patrick Bellgowan, PhD, program director at the National Institute of Neurological Disorders and Stroke, which supported the study. “It suggests we can systematically increase the chances of saving lives of thousands of people who suffer severe traumatic brain injuries.”
Preventing low oxygen, low blood pressure, and hyperventilation in people with head injury has been shown to improve survival, according to observational studies. The guidelines for prehospital management of traumatic brain injury (TBI), developed in 2000, were updated in 2007 to reflect those findings. But are they being followed? And if followed, do they help?
The Excellence in Prehospital Injury Care (EPIC) study, the first time the guidelines were assessed in real-world conditions, trained EMS responders in Arizona and compared patient outcomes before and after the guideline implementation.
The study researchers found “a therapeutic sweet spot” in that the guidelines had an “enormous impact” on people with severe TBI. Implementing the guidelines did not affect overall survival of the entire group, which included > 21,000 patients with moderate, severe, and critical injuries. But further analysis showed that they helped double the survival rate of people with severe TBI and tripled the survival rate in severe TBI patients who had to have a breathing tube inserted by EMS personnel.
Daniel Spaite, MD, who led the study, said the patients with moderate injuries would most likely have survived anyway, and those in critical condition may have had injuries too serious to overcome.
The guidelines also were associated with an overall increase in survival to hospital admission.
According to Bentley Bobrow, MD, co-principal investigator, “It was exciting to see such dramatic outcomes resulting from a simple 2-hour training session with EMS personnel.”
The study “demonstrates the significance of conducting studies in real-world settings and brings a strong evidence base to the guidelines,” said Patrick Bellgowan, PhD, program director at the National Institute of Neurological Disorders and Stroke, which supported the study. “It suggests we can systematically increase the chances of saving lives of thousands of people who suffer severe traumatic brain injuries.”
Preventing low oxygen, low blood pressure, and hyperventilation in people with head injury has been shown to improve survival, according to observational studies. The guidelines for prehospital management of traumatic brain injury (TBI), developed in 2000, were updated in 2007 to reflect those findings. But are they being followed? And if followed, do they help?
The Excellence in Prehospital Injury Care (EPIC) study, the first time the guidelines were assessed in real-world conditions, trained EMS responders in Arizona and compared patient outcomes before and after the guideline implementation.
The study researchers found “a therapeutic sweet spot” in that the guidelines had an “enormous impact” on people with severe TBI. Implementing the guidelines did not affect overall survival of the entire group, which included > 21,000 patients with moderate, severe, and critical injuries. But further analysis showed that they helped double the survival rate of people with severe TBI and tripled the survival rate in severe TBI patients who had to have a breathing tube inserted by EMS personnel.
Daniel Spaite, MD, who led the study, said the patients with moderate injuries would most likely have survived anyway, and those in critical condition may have had injuries too serious to overcome.
The guidelines also were associated with an overall increase in survival to hospital admission.
According to Bentley Bobrow, MD, co-principal investigator, “It was exciting to see such dramatic outcomes resulting from a simple 2-hour training session with EMS personnel.”
The study “demonstrates the significance of conducting studies in real-world settings and brings a strong evidence base to the guidelines,” said Patrick Bellgowan, PhD, program director at the National Institute of Neurological Disorders and Stroke, which supported the study. “It suggests we can systematically increase the chances of saving lives of thousands of people who suffer severe traumatic brain injuries.”
Biomarkers support impact of concussions on cognitive function
Former athletes with a history of concussion averaged higher levels of total tau in their cerebrospinal fluid than did healthy controls, and those with the highest levels showed signs of reduced cognitive function in a case-control study.
Chronic traumatic encephalopathy (CTE) remains a postmortem diagnosis, but “the potential for treating postconcussion degeneration such as CTE depends on being able to detect the in vivo pathology at an early stage to intervene before the disease progresses to an irreversible stage,” wrote Foad Taghdiri, MD, of the University of Toronto and colleagues.
In a study published in Neurology, the researchers measured concentrations of phosphorylated tau181, total tau (t-tau), and beta-amyloid in the cerebrospinal fluid (CSF) of three groups: 22 former professional athletes who had suffered multiple concussions, 5 healthy controls, and 12 individuals diagnosed with Alzheimer’s disease (AD). The average ages of the groups were 56 years, 57 years, and 60 years, respectively. All the athletes were male, and their sports included snowboarding, hockey, and football.
The average t-tau level in the CSF of the athletes was significantly higher than that of controls (349.3 pg/mL vs. 188.8 pg/mL) and significantly lower than that of AD patients (857.0 pg/mL).
Normal CSF t-tau was defined as 300 pg/mL, and 12 former athletes (45%) had high t-tau levels, with an average of 499.3 pg/mL. In this group of high t-tau former athletes, the average score on the Trail Making Test (TMT) Part B was significantly lower than the average score among the 10 former athletes with normal CSF t-tau levels (t scores 45.6 vs. 62.3; P = .017).
In addition, results from MRI scans showed that fractional anisotropy values across all the tracts were significantly lower for those with high CSF t-tau levels, compared with those who had normal CSF t-tau levels (P = .036).
The findings were limited by several factors, including the small sample size, lack of female athletes, and limited ability to compare white matter integrity between high and normal CSF t-tau groups, the researchers noted.
However, the results suggest that “multiple concussive or subconcussive events may trigger neurodegeneration to a greater degree than expected on the basis of age alone,” they said. Although the study did not allow for diagnosing the participants with CTE, “we are engaged in longitudinal studies to track neurologic and neuropsychological function, CSF biomarkers, and structural brain changes over time to further assess the delayed effects of multiple concussions on the brain,” the researchers wrote.
The study was funded by the Toronto General and Western Hospital Foundation, PSI Foundation, and the Canadian Institute of Health Research. The researchers had no financial conflicts to disclose.
SOURCE: Taghdiri F et al. Neurology. 2019 May 8. doi: 10.1212/WNL.0000000000007608
Former athletes with a history of concussion averaged higher levels of total tau in their cerebrospinal fluid than did healthy controls, and those with the highest levels showed signs of reduced cognitive function in a case-control study.
Chronic traumatic encephalopathy (CTE) remains a postmortem diagnosis, but “the potential for treating postconcussion degeneration such as CTE depends on being able to detect the in vivo pathology at an early stage to intervene before the disease progresses to an irreversible stage,” wrote Foad Taghdiri, MD, of the University of Toronto and colleagues.
In a study published in Neurology, the researchers measured concentrations of phosphorylated tau181, total tau (t-tau), and beta-amyloid in the cerebrospinal fluid (CSF) of three groups: 22 former professional athletes who had suffered multiple concussions, 5 healthy controls, and 12 individuals diagnosed with Alzheimer’s disease (AD). The average ages of the groups were 56 years, 57 years, and 60 years, respectively. All the athletes were male, and their sports included snowboarding, hockey, and football.
The average t-tau level in the CSF of the athletes was significantly higher than that of controls (349.3 pg/mL vs. 188.8 pg/mL) and significantly lower than that of AD patients (857.0 pg/mL).
Normal CSF t-tau was defined as 300 pg/mL, and 12 former athletes (45%) had high t-tau levels, with an average of 499.3 pg/mL. In this group of high t-tau former athletes, the average score on the Trail Making Test (TMT) Part B was significantly lower than the average score among the 10 former athletes with normal CSF t-tau levels (t scores 45.6 vs. 62.3; P = .017).
In addition, results from MRI scans showed that fractional anisotropy values across all the tracts were significantly lower for those with high CSF t-tau levels, compared with those who had normal CSF t-tau levels (P = .036).
The findings were limited by several factors, including the small sample size, lack of female athletes, and limited ability to compare white matter integrity between high and normal CSF t-tau groups, the researchers noted.
However, the results suggest that “multiple concussive or subconcussive events may trigger neurodegeneration to a greater degree than expected on the basis of age alone,” they said. Although the study did not allow for diagnosing the participants with CTE, “we are engaged in longitudinal studies to track neurologic and neuropsychological function, CSF biomarkers, and structural brain changes over time to further assess the delayed effects of multiple concussions on the brain,” the researchers wrote.
The study was funded by the Toronto General and Western Hospital Foundation, PSI Foundation, and the Canadian Institute of Health Research. The researchers had no financial conflicts to disclose.
SOURCE: Taghdiri F et al. Neurology. 2019 May 8. doi: 10.1212/WNL.0000000000007608
Former athletes with a history of concussion averaged higher levels of total tau in their cerebrospinal fluid than did healthy controls, and those with the highest levels showed signs of reduced cognitive function in a case-control study.
Chronic traumatic encephalopathy (CTE) remains a postmortem diagnosis, but “the potential for treating postconcussion degeneration such as CTE depends on being able to detect the in vivo pathology at an early stage to intervene before the disease progresses to an irreversible stage,” wrote Foad Taghdiri, MD, of the University of Toronto and colleagues.
In a study published in Neurology, the researchers measured concentrations of phosphorylated tau181, total tau (t-tau), and beta-amyloid in the cerebrospinal fluid (CSF) of three groups: 22 former professional athletes who had suffered multiple concussions, 5 healthy controls, and 12 individuals diagnosed with Alzheimer’s disease (AD). The average ages of the groups were 56 years, 57 years, and 60 years, respectively. All the athletes were male, and their sports included snowboarding, hockey, and football.
The average t-tau level in the CSF of the athletes was significantly higher than that of controls (349.3 pg/mL vs. 188.8 pg/mL) and significantly lower than that of AD patients (857.0 pg/mL).
Normal CSF t-tau was defined as 300 pg/mL, and 12 former athletes (45%) had high t-tau levels, with an average of 499.3 pg/mL. In this group of high t-tau former athletes, the average score on the Trail Making Test (TMT) Part B was significantly lower than the average score among the 10 former athletes with normal CSF t-tau levels (t scores 45.6 vs. 62.3; P = .017).
In addition, results from MRI scans showed that fractional anisotropy values across all the tracts were significantly lower for those with high CSF t-tau levels, compared with those who had normal CSF t-tau levels (P = .036).
The findings were limited by several factors, including the small sample size, lack of female athletes, and limited ability to compare white matter integrity between high and normal CSF t-tau groups, the researchers noted.
However, the results suggest that “multiple concussive or subconcussive events may trigger neurodegeneration to a greater degree than expected on the basis of age alone,” they said. Although the study did not allow for diagnosing the participants with CTE, “we are engaged in longitudinal studies to track neurologic and neuropsychological function, CSF biomarkers, and structural brain changes over time to further assess the delayed effects of multiple concussions on the brain,” the researchers wrote.
The study was funded by the Toronto General and Western Hospital Foundation, PSI Foundation, and the Canadian Institute of Health Research. The researchers had no financial conflicts to disclose.
SOURCE: Taghdiri F et al. Neurology. 2019 May 8. doi: 10.1212/WNL.0000000000007608
FROM NEUROLOGY
Brain volumes after TBI correlate with clinical features
PHILADELPHIA – ” according to a study presented at the annual meeting of the American Academy of Neurology.
Traumatic brain injury (TBI) damages brain tissue and causes subsequent volume loss, which may result in clinical symptoms. It is a prevalent worldwide health problem caused by a mechanical insult to the head, resulting in transient or permanent alteration to brain tissue and/or function. Standard neuroimaging with computerized cranial tomography (CT) and structural magnetic resonance imaging (MRI) is often unrevealing during the evaluation of patients with TBI, particularly those classified as mild TBI. I
In this study, James Rock, MD, of Penn Presbyterian Medical Center and the University of Pennsylvania, and his colleagues sought to examine the value of quantitative analysis of regional brain volumes in the evaluation of TBI. The investigators reviewed the medical records and MRI imaging from 44 patients with TBI evaluated at a Level I trauma center. They also read clinical notes to assess reported symptoms and physical findings.
Regional volumes from TBI subjects were derived using the software package Freesurfer image analysis suite, which utilizes a T1-weighted structural scan to calculate volumetric information. A machine learning algorithm, random forests, was employed across volume measurements from 25 regions of interest to determine the most important regions for classifying subjects based on clinical outcome and symptomology.
Basal ganglia volume showed the highest variable importance with regards to classifying subjects who exhibited symptoms of cognitive dysfunction (Mean Decrease in Gini = 1.067, Mean Decrease in Accuracy = 5.966e-03) in quantitative analysis. Left lateral ventricle volume was important in classifying subjects with motor and vestibular alterations (Mean Decrease in Gini = 2.037, Mean Decrease in Accuracy = 2.92e-02). Left choroid plexus volume was the most important region for classifying subjects with sensation and somatic dysfunction (Mean Decrease in Gini = 0.271, Mean Decrease in Accuracy = 4.82e-03).
The researchers noted that their study is ongoing, in an abstract. “It will be extended to a larger cohort to determine whether volume changes in specific [regions of interest] can act as useful clinical biomarkers for chronic symptoms,” they said.
Dr. Diaz-Arrastia received personal compensation from Neural Analytics, Inc, BrainBox Solutions, Inc, and Bioscience Pharma Partners. Dr. Diaz-Arrastia holds stock and/or stock options in Neural Analytics, Inc. and has received research support from BrainBox Solutions. The other authors reported not having anything to disclose..
SOURCE: Rock J et al. AAN 2019. Abstract S2.006 .
PHILADELPHIA – ” according to a study presented at the annual meeting of the American Academy of Neurology.
Traumatic brain injury (TBI) damages brain tissue and causes subsequent volume loss, which may result in clinical symptoms. It is a prevalent worldwide health problem caused by a mechanical insult to the head, resulting in transient or permanent alteration to brain tissue and/or function. Standard neuroimaging with computerized cranial tomography (CT) and structural magnetic resonance imaging (MRI) is often unrevealing during the evaluation of patients with TBI, particularly those classified as mild TBI. I
In this study, James Rock, MD, of Penn Presbyterian Medical Center and the University of Pennsylvania, and his colleagues sought to examine the value of quantitative analysis of regional brain volumes in the evaluation of TBI. The investigators reviewed the medical records and MRI imaging from 44 patients with TBI evaluated at a Level I trauma center. They also read clinical notes to assess reported symptoms and physical findings.
Regional volumes from TBI subjects were derived using the software package Freesurfer image analysis suite, which utilizes a T1-weighted structural scan to calculate volumetric information. A machine learning algorithm, random forests, was employed across volume measurements from 25 regions of interest to determine the most important regions for classifying subjects based on clinical outcome and symptomology.
Basal ganglia volume showed the highest variable importance with regards to classifying subjects who exhibited symptoms of cognitive dysfunction (Mean Decrease in Gini = 1.067, Mean Decrease in Accuracy = 5.966e-03) in quantitative analysis. Left lateral ventricle volume was important in classifying subjects with motor and vestibular alterations (Mean Decrease in Gini = 2.037, Mean Decrease in Accuracy = 2.92e-02). Left choroid plexus volume was the most important region for classifying subjects with sensation and somatic dysfunction (Mean Decrease in Gini = 0.271, Mean Decrease in Accuracy = 4.82e-03).
The researchers noted that their study is ongoing, in an abstract. “It will be extended to a larger cohort to determine whether volume changes in specific [regions of interest] can act as useful clinical biomarkers for chronic symptoms,” they said.
Dr. Diaz-Arrastia received personal compensation from Neural Analytics, Inc, BrainBox Solutions, Inc, and Bioscience Pharma Partners. Dr. Diaz-Arrastia holds stock and/or stock options in Neural Analytics, Inc. and has received research support from BrainBox Solutions. The other authors reported not having anything to disclose..
SOURCE: Rock J et al. AAN 2019. Abstract S2.006 .
PHILADELPHIA – ” according to a study presented at the annual meeting of the American Academy of Neurology.
Traumatic brain injury (TBI) damages brain tissue and causes subsequent volume loss, which may result in clinical symptoms. It is a prevalent worldwide health problem caused by a mechanical insult to the head, resulting in transient or permanent alteration to brain tissue and/or function. Standard neuroimaging with computerized cranial tomography (CT) and structural magnetic resonance imaging (MRI) is often unrevealing during the evaluation of patients with TBI, particularly those classified as mild TBI. I
In this study, James Rock, MD, of Penn Presbyterian Medical Center and the University of Pennsylvania, and his colleagues sought to examine the value of quantitative analysis of regional brain volumes in the evaluation of TBI. The investigators reviewed the medical records and MRI imaging from 44 patients with TBI evaluated at a Level I trauma center. They also read clinical notes to assess reported symptoms and physical findings.
Regional volumes from TBI subjects were derived using the software package Freesurfer image analysis suite, which utilizes a T1-weighted structural scan to calculate volumetric information. A machine learning algorithm, random forests, was employed across volume measurements from 25 regions of interest to determine the most important regions for classifying subjects based on clinical outcome and symptomology.
Basal ganglia volume showed the highest variable importance with regards to classifying subjects who exhibited symptoms of cognitive dysfunction (Mean Decrease in Gini = 1.067, Mean Decrease in Accuracy = 5.966e-03) in quantitative analysis. Left lateral ventricle volume was important in classifying subjects with motor and vestibular alterations (Mean Decrease in Gini = 2.037, Mean Decrease in Accuracy = 2.92e-02). Left choroid plexus volume was the most important region for classifying subjects with sensation and somatic dysfunction (Mean Decrease in Gini = 0.271, Mean Decrease in Accuracy = 4.82e-03).
The researchers noted that their study is ongoing, in an abstract. “It will be extended to a larger cohort to determine whether volume changes in specific [regions of interest] can act as useful clinical biomarkers for chronic symptoms,” they said.
Dr. Diaz-Arrastia received personal compensation from Neural Analytics, Inc, BrainBox Solutions, Inc, and Bioscience Pharma Partners. Dr. Diaz-Arrastia holds stock and/or stock options in Neural Analytics, Inc. and has received research support from BrainBox Solutions. The other authors reported not having anything to disclose..
SOURCE: Rock J et al. AAN 2019. Abstract S2.006 .
REPORTING FROM AAN 2019
VA Weighs Improvements to Disability Determination Process
The severity of traumatic brain injury (TBI) is typically defined at the time of the initial injury, but a diagnosis may not come for months or even years later. Given the complexities of diagnosing what might be a slowly revealed condition, with signs and symptoms that may manifest over time; the need for self-report of symptoms; and the time that might have elapsed since the original injury, a diagnostician needs not only to have experience with TBI but to stay abreast of the state of the science.
As of now, only health care professionals in 4 specialties—neurologist, neurosurgeon, physiatrist, or psychiatrist—are allowed to diagnose TBI in the VA’s disability compensation process. A new congressionally mandated report by the National Academies of Sciences, Engineering, and Medicine, though, is advising that it’s training and experience that count, not necessarily the specialty.
In Evaluation of the Disability Determination Process for Traumatic Brain Injury in Veterans, a committee of experts in emergency medicine, neurology, neurosurgery, psychiatry, psychology, physical medicine and rehabilitation, and epidemiology and biostatistics review the process and current literature on TBI. The committee advises that any health care professional with “pertinent and ongoing brain injury training and experience” and up-to-date knowledge about TBI should be included in the diagnostic process.
The disability compensation is a tax-free benefit paid to veterans with disabilities resulting from disease or injury incurred or aggravated during active military service. The amount is determined in a 6-step process beginning when the veteran (or a proxy) files a claim. An approved clinician typically must diagnose and evaluate the degree of impairment, functional limitation, and disability.
Between 2000 and 2018, an estimated 384,000 incidents of TBI occurred in the military. That increasing prevalence means more medical specialties now include TBI training in their curriculum. The committee notes that at least 18 brain injury programs are accredited by the Accreditation Council for Graduate Medical Education to train physicians in many specialties to diagnose, treat, and rehabilitate patients with brain injury.
Among other recommendations, the committee advised that the VA take specific actions to increase transparency at both individual and systemwide levels, such as providing veterans full access to the details of their examinations, allowing veterans to rate the quality of their evaluations, and providing public access to detailed systemwide data on the outcomes of evaluations and outcome quality. Those changes will represent a “fundamental enhancement” in the quality of disability evaluations, the committee says, which added that shifting from a focus on the consistency of the process and practitioner qualifications to a focus on the accuracy of the outcome of the evaluation will help identify steps or components in the process that warrant improvement.
It also suggested regularly updating the Veteran Affairs Schedule for Rating Disabilities and the Disability Benefits Questionnaires (DBQs) for residuals of TBI to “better reflect the current state of medical knowledge.” The committee found that 3 important residuals of TBI are not adequately covered by any of the existing DBQs: insomnia, vestibular dysfunction, and near-vision dysfunction. Although 4 DBQs (mental disorder, chronic fatigue syndrome, PTSD, and sleep apnea) contain isolated questions related to insomnia and sleep disruption, no single DBQ, the committee says, combines them all “in a way that captures the full extent of disability associated with post-TBI sleep disruption.” Similarly, no single DBQ captures the full extent of disability associated with post-TBI vestibular dysfunction or the disability associated with near-vision dysfunction.
The committee sums up: “[B]y adopting an explicit learning structure in which the reliability and validity of disability determinations are directly assessed, the VA will be able to devote its resources to those modifications and enhancements … that will have the greatest impact in improving the service provided to injured veterans.”
The severity of traumatic brain injury (TBI) is typically defined at the time of the initial injury, but a diagnosis may not come for months or even years later. Given the complexities of diagnosing what might be a slowly revealed condition, with signs and symptoms that may manifest over time; the need for self-report of symptoms; and the time that might have elapsed since the original injury, a diagnostician needs not only to have experience with TBI but to stay abreast of the state of the science.
As of now, only health care professionals in 4 specialties—neurologist, neurosurgeon, physiatrist, or psychiatrist—are allowed to diagnose TBI in the VA’s disability compensation process. A new congressionally mandated report by the National Academies of Sciences, Engineering, and Medicine, though, is advising that it’s training and experience that count, not necessarily the specialty.
In Evaluation of the Disability Determination Process for Traumatic Brain Injury in Veterans, a committee of experts in emergency medicine, neurology, neurosurgery, psychiatry, psychology, physical medicine and rehabilitation, and epidemiology and biostatistics review the process and current literature on TBI. The committee advises that any health care professional with “pertinent and ongoing brain injury training and experience” and up-to-date knowledge about TBI should be included in the diagnostic process.
The disability compensation is a tax-free benefit paid to veterans with disabilities resulting from disease or injury incurred or aggravated during active military service. The amount is determined in a 6-step process beginning when the veteran (or a proxy) files a claim. An approved clinician typically must diagnose and evaluate the degree of impairment, functional limitation, and disability.
Between 2000 and 2018, an estimated 384,000 incidents of TBI occurred in the military. That increasing prevalence means more medical specialties now include TBI training in their curriculum. The committee notes that at least 18 brain injury programs are accredited by the Accreditation Council for Graduate Medical Education to train physicians in many specialties to diagnose, treat, and rehabilitate patients with brain injury.
Among other recommendations, the committee advised that the VA take specific actions to increase transparency at both individual and systemwide levels, such as providing veterans full access to the details of their examinations, allowing veterans to rate the quality of their evaluations, and providing public access to detailed systemwide data on the outcomes of evaluations and outcome quality. Those changes will represent a “fundamental enhancement” in the quality of disability evaluations, the committee says, which added that shifting from a focus on the consistency of the process and practitioner qualifications to a focus on the accuracy of the outcome of the evaluation will help identify steps or components in the process that warrant improvement.
It also suggested regularly updating the Veteran Affairs Schedule for Rating Disabilities and the Disability Benefits Questionnaires (DBQs) for residuals of TBI to “better reflect the current state of medical knowledge.” The committee found that 3 important residuals of TBI are not adequately covered by any of the existing DBQs: insomnia, vestibular dysfunction, and near-vision dysfunction. Although 4 DBQs (mental disorder, chronic fatigue syndrome, PTSD, and sleep apnea) contain isolated questions related to insomnia and sleep disruption, no single DBQ, the committee says, combines them all “in a way that captures the full extent of disability associated with post-TBI sleep disruption.” Similarly, no single DBQ captures the full extent of disability associated with post-TBI vestibular dysfunction or the disability associated with near-vision dysfunction.
The committee sums up: “[B]y adopting an explicit learning structure in which the reliability and validity of disability determinations are directly assessed, the VA will be able to devote its resources to those modifications and enhancements … that will have the greatest impact in improving the service provided to injured veterans.”
The severity of traumatic brain injury (TBI) is typically defined at the time of the initial injury, but a diagnosis may not come for months or even years later. Given the complexities of diagnosing what might be a slowly revealed condition, with signs and symptoms that may manifest over time; the need for self-report of symptoms; and the time that might have elapsed since the original injury, a diagnostician needs not only to have experience with TBI but to stay abreast of the state of the science.
As of now, only health care professionals in 4 specialties—neurologist, neurosurgeon, physiatrist, or psychiatrist—are allowed to diagnose TBI in the VA’s disability compensation process. A new congressionally mandated report by the National Academies of Sciences, Engineering, and Medicine, though, is advising that it’s training and experience that count, not necessarily the specialty.
In Evaluation of the Disability Determination Process for Traumatic Brain Injury in Veterans, a committee of experts in emergency medicine, neurology, neurosurgery, psychiatry, psychology, physical medicine and rehabilitation, and epidemiology and biostatistics review the process and current literature on TBI. The committee advises that any health care professional with “pertinent and ongoing brain injury training and experience” and up-to-date knowledge about TBI should be included in the diagnostic process.
The disability compensation is a tax-free benefit paid to veterans with disabilities resulting from disease or injury incurred or aggravated during active military service. The amount is determined in a 6-step process beginning when the veteran (or a proxy) files a claim. An approved clinician typically must diagnose and evaluate the degree of impairment, functional limitation, and disability.
Between 2000 and 2018, an estimated 384,000 incidents of TBI occurred in the military. That increasing prevalence means more medical specialties now include TBI training in their curriculum. The committee notes that at least 18 brain injury programs are accredited by the Accreditation Council for Graduate Medical Education to train physicians in many specialties to diagnose, treat, and rehabilitate patients with brain injury.
Among other recommendations, the committee advised that the VA take specific actions to increase transparency at both individual and systemwide levels, such as providing veterans full access to the details of their examinations, allowing veterans to rate the quality of their evaluations, and providing public access to detailed systemwide data on the outcomes of evaluations and outcome quality. Those changes will represent a “fundamental enhancement” in the quality of disability evaluations, the committee says, which added that shifting from a focus on the consistency of the process and practitioner qualifications to a focus on the accuracy of the outcome of the evaluation will help identify steps or components in the process that warrant improvement.
It also suggested regularly updating the Veteran Affairs Schedule for Rating Disabilities and the Disability Benefits Questionnaires (DBQs) for residuals of TBI to “better reflect the current state of medical knowledge.” The committee found that 3 important residuals of TBI are not adequately covered by any of the existing DBQs: insomnia, vestibular dysfunction, and near-vision dysfunction. Although 4 DBQs (mental disorder, chronic fatigue syndrome, PTSD, and sleep apnea) contain isolated questions related to insomnia and sleep disruption, no single DBQ, the committee says, combines them all “in a way that captures the full extent of disability associated with post-TBI sleep disruption.” Similarly, no single DBQ captures the full extent of disability associated with post-TBI vestibular dysfunction or the disability associated with near-vision dysfunction.
The committee sums up: “[B]y adopting an explicit learning structure in which the reliability and validity of disability determinations are directly assessed, the VA will be able to devote its resources to those modifications and enhancements … that will have the greatest impact in improving the service provided to injured veterans.”
Symptomatic former NFL players may have tau deposition consistent with CTE
according to research published online ahead of print April 10 in the New England Journal of Medicine. The distribution of tau in the players’ brains appears to be similar to that in persons with chronic traumatic encephalopathy (CTE).
CTE is a neurodegenerative disease that has been associated with a history of repetitive head impacts, such as those withstood in contact sports. The basis for the neuropathological diagnosis of CTE is a distinct pattern of tau deposition with minimal deposition of amyloid-beta. Paired helical filament tau aggregates are first observed in the frontal, temporal, and parietal cortices. They later spread throughout the cerebral cortex, medial temporal lobe, diencephalon, and brainstem. CTE is diagnosed only through post mortem neuropathological examinations.
To examine whether tau and amyloid deposition can be detected in the brains of living people at risk for CTE, Robert A. Stern, PhD, and his colleagues studied living former NFL players and asymptomatic controls with flortaucipir PET (to detect tau) and 18F-florbetapir PET (to detect amyloid-beta). Dr. Stern is director of clinical research at the CTE Center at Boston University. Eligible former players were male, aged 40-69 years, had played football in the NFL for at least 2 years, had had at least 12 years of total tackle football experience, and reported cognitive, behavioral, and mood symptoms through telephone screening. Eligible controls were male, aged 40-69 years, and had no cognitive symptoms or history of traumatic brain injury.
All subjects underwent flortaucipir PET, florbetapir PET, and T1-weighted volumetric MRI of the head. Dr. Stern and his colleagues used automated image-analysis algorithms to compare the regional tau standardized uptake value ratio (SUVR) between the two patient groups and to evaluate potential associations between that ratio and symptom severity or years of football play.
The investigators included 26 former players and 31 controls in their analysis. The group of former players had a higher percentage of black participants and a lower mean Mini-Mental State Examination score, compared with controls. The mean flortaucipir SUVR was higher among former players than among controls in the bilateral superior frontal (1.09 vs. 0.98), bilateral medial temporal (1.23 vs. 1.12), and left parietal (1.12 vs. 1.01) regions. Dr. Stern and his colleagues found no association between tau deposition in those regions and results on cognitive and neuropsychiatric tests. In a post hoc analysis, they calculated the correlation coefficients in the three brain regions between the SUVRs and years of play to be 0.58 in the bilateral superior frontal region, 0.45 in the bilateral medial temporal region, and 0.50 in the left parietal region. Mean cortical:cerebellar florbetapir SUVRs did not differ significantly between groups.
“These findings suggest that the cognitive difficulties reported by the former players were not related to Alzheimer’s disease amyloid-beta deposition,” said the authors. The study may have been insufficiently powered to detect associations between flortaucipir uptake and the clinical measures, they added. Also, paired helical filament tau pathology alone may not be associated with the former players’ neuropsychiatric symptoms and cognitive impairment. “Although this study showed between-group differences in flortaucipir PET measurements, our analyses do not pertain to detection of tau pathology in individual participants,” the authors concluded.
The study was supported by an investigator-initiated grant from Avid Radiopharmaceuticals. The National Institutes of Health, the state of Arizona, and the U.S. Department of Defense also supported the study.
SOURCE: Stern RA et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMoa1900757 (Epub ahead of print).
The study by Stern et al offers valuable information, but the relationships between various features of chronic traumatic encephalopathy (CTE) still are not well understood, said Allan H. Ropper, MD, executive vice chair of neurology at Harvard Medical School in Boston, in an accompanying editorial (N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMe1903746). The risk of CTE associated with a long period of playing football does not correspond with the number, severity, or serial occurrence of concussions, he observed. In addition, “individual factors such as the player’s size, head-to-neck configuration, style of play, and position, as well as biologic attributes, may influence the deposition of tau.” Because of the absence of an association between neuropsychological test results and tau deposition, neurologists can draw few conclusions based on the presence of neuropsychological abnormalities in athletes who are at risk for CTE, said Dr. Ropper.
“As with Alzheimer’s disease, the CTE field is in a phase of fumbling with circumstantial evidence for a connection between tau deposition and a clinical syndrome. ... The report in this issue certainly does strengthen the case that tau is the offender early in CTE, but other links remain to be clarified,” he concluded.
Dr. Ropper reported no relevant conflicts of interest. He is deputy editor of the New England Journal of Medicine.
The study by Stern et al offers valuable information, but the relationships between various features of chronic traumatic encephalopathy (CTE) still are not well understood, said Allan H. Ropper, MD, executive vice chair of neurology at Harvard Medical School in Boston, in an accompanying editorial (N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMe1903746). The risk of CTE associated with a long period of playing football does not correspond with the number, severity, or serial occurrence of concussions, he observed. In addition, “individual factors such as the player’s size, head-to-neck configuration, style of play, and position, as well as biologic attributes, may influence the deposition of tau.” Because of the absence of an association between neuropsychological test results and tau deposition, neurologists can draw few conclusions based on the presence of neuropsychological abnormalities in athletes who are at risk for CTE, said Dr. Ropper.
“As with Alzheimer’s disease, the CTE field is in a phase of fumbling with circumstantial evidence for a connection between tau deposition and a clinical syndrome. ... The report in this issue certainly does strengthen the case that tau is the offender early in CTE, but other links remain to be clarified,” he concluded.
Dr. Ropper reported no relevant conflicts of interest. He is deputy editor of the New England Journal of Medicine.
The study by Stern et al offers valuable information, but the relationships between various features of chronic traumatic encephalopathy (CTE) still are not well understood, said Allan H. Ropper, MD, executive vice chair of neurology at Harvard Medical School in Boston, in an accompanying editorial (N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMe1903746). The risk of CTE associated with a long period of playing football does not correspond with the number, severity, or serial occurrence of concussions, he observed. In addition, “individual factors such as the player’s size, head-to-neck configuration, style of play, and position, as well as biologic attributes, may influence the deposition of tau.” Because of the absence of an association between neuropsychological test results and tau deposition, neurologists can draw few conclusions based on the presence of neuropsychological abnormalities in athletes who are at risk for CTE, said Dr. Ropper.
“As with Alzheimer’s disease, the CTE field is in a phase of fumbling with circumstantial evidence for a connection between tau deposition and a clinical syndrome. ... The report in this issue certainly does strengthen the case that tau is the offender early in CTE, but other links remain to be clarified,” he concluded.
Dr. Ropper reported no relevant conflicts of interest. He is deputy editor of the New England Journal of Medicine.
according to research published online ahead of print April 10 in the New England Journal of Medicine. The distribution of tau in the players’ brains appears to be similar to that in persons with chronic traumatic encephalopathy (CTE).
CTE is a neurodegenerative disease that has been associated with a history of repetitive head impacts, such as those withstood in contact sports. The basis for the neuropathological diagnosis of CTE is a distinct pattern of tau deposition with minimal deposition of amyloid-beta. Paired helical filament tau aggregates are first observed in the frontal, temporal, and parietal cortices. They later spread throughout the cerebral cortex, medial temporal lobe, diencephalon, and brainstem. CTE is diagnosed only through post mortem neuropathological examinations.
To examine whether tau and amyloid deposition can be detected in the brains of living people at risk for CTE, Robert A. Stern, PhD, and his colleagues studied living former NFL players and asymptomatic controls with flortaucipir PET (to detect tau) and 18F-florbetapir PET (to detect amyloid-beta). Dr. Stern is director of clinical research at the CTE Center at Boston University. Eligible former players were male, aged 40-69 years, had played football in the NFL for at least 2 years, had had at least 12 years of total tackle football experience, and reported cognitive, behavioral, and mood symptoms through telephone screening. Eligible controls were male, aged 40-69 years, and had no cognitive symptoms or history of traumatic brain injury.
All subjects underwent flortaucipir PET, florbetapir PET, and T1-weighted volumetric MRI of the head. Dr. Stern and his colleagues used automated image-analysis algorithms to compare the regional tau standardized uptake value ratio (SUVR) between the two patient groups and to evaluate potential associations between that ratio and symptom severity or years of football play.
The investigators included 26 former players and 31 controls in their analysis. The group of former players had a higher percentage of black participants and a lower mean Mini-Mental State Examination score, compared with controls. The mean flortaucipir SUVR was higher among former players than among controls in the bilateral superior frontal (1.09 vs. 0.98), bilateral medial temporal (1.23 vs. 1.12), and left parietal (1.12 vs. 1.01) regions. Dr. Stern and his colleagues found no association between tau deposition in those regions and results on cognitive and neuropsychiatric tests. In a post hoc analysis, they calculated the correlation coefficients in the three brain regions between the SUVRs and years of play to be 0.58 in the bilateral superior frontal region, 0.45 in the bilateral medial temporal region, and 0.50 in the left parietal region. Mean cortical:cerebellar florbetapir SUVRs did not differ significantly between groups.
“These findings suggest that the cognitive difficulties reported by the former players were not related to Alzheimer’s disease amyloid-beta deposition,” said the authors. The study may have been insufficiently powered to detect associations between flortaucipir uptake and the clinical measures, they added. Also, paired helical filament tau pathology alone may not be associated with the former players’ neuropsychiatric symptoms and cognitive impairment. “Although this study showed between-group differences in flortaucipir PET measurements, our analyses do not pertain to detection of tau pathology in individual participants,” the authors concluded.
The study was supported by an investigator-initiated grant from Avid Radiopharmaceuticals. The National Institutes of Health, the state of Arizona, and the U.S. Department of Defense also supported the study.
SOURCE: Stern RA et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMoa1900757 (Epub ahead of print).
according to research published online ahead of print April 10 in the New England Journal of Medicine. The distribution of tau in the players’ brains appears to be similar to that in persons with chronic traumatic encephalopathy (CTE).
CTE is a neurodegenerative disease that has been associated with a history of repetitive head impacts, such as those withstood in contact sports. The basis for the neuropathological diagnosis of CTE is a distinct pattern of tau deposition with minimal deposition of amyloid-beta. Paired helical filament tau aggregates are first observed in the frontal, temporal, and parietal cortices. They later spread throughout the cerebral cortex, medial temporal lobe, diencephalon, and brainstem. CTE is diagnosed only through post mortem neuropathological examinations.
To examine whether tau and amyloid deposition can be detected in the brains of living people at risk for CTE, Robert A. Stern, PhD, and his colleagues studied living former NFL players and asymptomatic controls with flortaucipir PET (to detect tau) and 18F-florbetapir PET (to detect amyloid-beta). Dr. Stern is director of clinical research at the CTE Center at Boston University. Eligible former players were male, aged 40-69 years, had played football in the NFL for at least 2 years, had had at least 12 years of total tackle football experience, and reported cognitive, behavioral, and mood symptoms through telephone screening. Eligible controls were male, aged 40-69 years, and had no cognitive symptoms or history of traumatic brain injury.
All subjects underwent flortaucipir PET, florbetapir PET, and T1-weighted volumetric MRI of the head. Dr. Stern and his colleagues used automated image-analysis algorithms to compare the regional tau standardized uptake value ratio (SUVR) between the two patient groups and to evaluate potential associations between that ratio and symptom severity or years of football play.
The investigators included 26 former players and 31 controls in their analysis. The group of former players had a higher percentage of black participants and a lower mean Mini-Mental State Examination score, compared with controls. The mean flortaucipir SUVR was higher among former players than among controls in the bilateral superior frontal (1.09 vs. 0.98), bilateral medial temporal (1.23 vs. 1.12), and left parietal (1.12 vs. 1.01) regions. Dr. Stern and his colleagues found no association between tau deposition in those regions and results on cognitive and neuropsychiatric tests. In a post hoc analysis, they calculated the correlation coefficients in the three brain regions between the SUVRs and years of play to be 0.58 in the bilateral superior frontal region, 0.45 in the bilateral medial temporal region, and 0.50 in the left parietal region. Mean cortical:cerebellar florbetapir SUVRs did not differ significantly between groups.
“These findings suggest that the cognitive difficulties reported by the former players were not related to Alzheimer’s disease amyloid-beta deposition,” said the authors. The study may have been insufficiently powered to detect associations between flortaucipir uptake and the clinical measures, they added. Also, paired helical filament tau pathology alone may not be associated with the former players’ neuropsychiatric symptoms and cognitive impairment. “Although this study showed between-group differences in flortaucipir PET measurements, our analyses do not pertain to detection of tau pathology in individual participants,” the authors concluded.
The study was supported by an investigator-initiated grant from Avid Radiopharmaceuticals. The National Institutes of Health, the state of Arizona, and the U.S. Department of Defense also supported the study.
SOURCE: Stern RA et al. N Engl J Med. 2019 Apr 10. doi: 10.1056/NEJMoa1900757 (Epub ahead of print).
FROM THE NEW ENGLAND JOURNAL OF MEDICINE
Trial to Test Effectiveness of CBT Phone Sessions for Chronic Pain After TBI
As many as 81.5% of veterans may experience chronic pain, pain that lasts beyond the point of healing and for at least 3 months. It is also particularly prevalent among veterans with traumatic brain injury (TBI) , often accompanied by comorbid conditions. Nearly 90% of veterans with a history of TBI have a psychiatric diagnosis, about 75% have insomnia, and 70% have a pain diagnosis, say researchers from University of Washington and Veterans Administration Puget Sound Health Care System (VAPSHCS).
Cognitive behavioral therapy (CBT) has been shown to help reduce pain, as well as pain-related disability and distress, but no randomized controlled trials (RCT) have examined CBT’s efficacy for pain after TBI in veterans, the researchers say.
In response, the VAPSHCS researchers have designed an RCT to compare telephone-based CBT with telephone-delivered pain education for veterans with TBI and chronic pain. The single-center 2-group trial will enroll up to 160 veterans with TBI to examine the relative efficacy of the interventions on average pain intensity, pain interference, sleep, depression, and life satisfaction.
The participants will be drawn from VAPSHCS, and can be enrolled via clinician referral, electronic health record review, and self-referral. Outcome variables will be collected pre-, mid-, and posttreatment, and 6 months following randomization.
Both interventions will consist of 8 hour-long phone sessions over approximately 8 to 12 weeks, scheduled at times convenient for the participants. Both interventions will also use a participant treatment workbook, with session-specific content to be discussed during the telephone sessions, and audio-recordings to augment material covered. Clinicians will make brief “booster” calls 2, 6, and 10 weeks after the final treatment session.
The trial is innovative, the researchers say, in that it is tailored to veterans, through relatable examples, and to those with TBI, by reducing content and providing multiple methods of engaging with information, as well as using known strategies to help with recall. If effective, the intervention could be disseminated throughout the VHA system, potentially to other personnel who have difficulty accessing specialty pain care.
The trial is registered at ClinicalTrials.gov, protocol NCT01768650.
As many as 81.5% of veterans may experience chronic pain, pain that lasts beyond the point of healing and for at least 3 months. It is also particularly prevalent among veterans with traumatic brain injury (TBI) , often accompanied by comorbid conditions. Nearly 90% of veterans with a history of TBI have a psychiatric diagnosis, about 75% have insomnia, and 70% have a pain diagnosis, say researchers from University of Washington and Veterans Administration Puget Sound Health Care System (VAPSHCS).
Cognitive behavioral therapy (CBT) has been shown to help reduce pain, as well as pain-related disability and distress, but no randomized controlled trials (RCT) have examined CBT’s efficacy for pain after TBI in veterans, the researchers say.
In response, the VAPSHCS researchers have designed an RCT to compare telephone-based CBT with telephone-delivered pain education for veterans with TBI and chronic pain. The single-center 2-group trial will enroll up to 160 veterans with TBI to examine the relative efficacy of the interventions on average pain intensity, pain interference, sleep, depression, and life satisfaction.
The participants will be drawn from VAPSHCS, and can be enrolled via clinician referral, electronic health record review, and self-referral. Outcome variables will be collected pre-, mid-, and posttreatment, and 6 months following randomization.
Both interventions will consist of 8 hour-long phone sessions over approximately 8 to 12 weeks, scheduled at times convenient for the participants. Both interventions will also use a participant treatment workbook, with session-specific content to be discussed during the telephone sessions, and audio-recordings to augment material covered. Clinicians will make brief “booster” calls 2, 6, and 10 weeks after the final treatment session.
The trial is innovative, the researchers say, in that it is tailored to veterans, through relatable examples, and to those with TBI, by reducing content and providing multiple methods of engaging with information, as well as using known strategies to help with recall. If effective, the intervention could be disseminated throughout the VHA system, potentially to other personnel who have difficulty accessing specialty pain care.
The trial is registered at ClinicalTrials.gov, protocol NCT01768650.
As many as 81.5% of veterans may experience chronic pain, pain that lasts beyond the point of healing and for at least 3 months. It is also particularly prevalent among veterans with traumatic brain injury (TBI) , often accompanied by comorbid conditions. Nearly 90% of veterans with a history of TBI have a psychiatric diagnosis, about 75% have insomnia, and 70% have a pain diagnosis, say researchers from University of Washington and Veterans Administration Puget Sound Health Care System (VAPSHCS).
Cognitive behavioral therapy (CBT) has been shown to help reduce pain, as well as pain-related disability and distress, but no randomized controlled trials (RCT) have examined CBT’s efficacy for pain after TBI in veterans, the researchers say.
In response, the VAPSHCS researchers have designed an RCT to compare telephone-based CBT with telephone-delivered pain education for veterans with TBI and chronic pain. The single-center 2-group trial will enroll up to 160 veterans with TBI to examine the relative efficacy of the interventions on average pain intensity, pain interference, sleep, depression, and life satisfaction.
The participants will be drawn from VAPSHCS, and can be enrolled via clinician referral, electronic health record review, and self-referral. Outcome variables will be collected pre-, mid-, and posttreatment, and 6 months following randomization.
Both interventions will consist of 8 hour-long phone sessions over approximately 8 to 12 weeks, scheduled at times convenient for the participants. Both interventions will also use a participant treatment workbook, with session-specific content to be discussed during the telephone sessions, and audio-recordings to augment material covered. Clinicians will make brief “booster” calls 2, 6, and 10 weeks after the final treatment session.
The trial is innovative, the researchers say, in that it is tailored to veterans, through relatable examples, and to those with TBI, by reducing content and providing multiple methods of engaging with information, as well as using known strategies to help with recall. If effective, the intervention could be disseminated throughout the VHA system, potentially to other personnel who have difficulty accessing specialty pain care.
The trial is registered at ClinicalTrials.gov, protocol NCT01768650.
Functional MRI detects consciousness after brain damage
Functional MRI can measure patterns of connectivity to determine levels of consciousness in nonresponsive patients with brain injury, according to results from a multicenter, cross-sectional, observational study.
Blood oxygen level–dependent (BOLD) fMRI showed that brain-wide coordination patterns of high complexity became increasingly common moving from unresponsive patients to those with minimal consciousness to healthy individuals, reported lead author Athena Demertzi, PhD, of GIGA Research Institute at the University of Liège in Belgium, and her colleagues.
“Finding reliable markers indicating the presence or absence of consciousness represents an outstanding open problem for science,” the investigators wrote in Science Advances.
In medicine, an fMRI-based measure of consciousness could supplement behavioral assessments of awareness and guide therapeutic strategies; more broadly, image-based markers could help elucidate the nature of consciousness itself.
“We postulate that consciousness has specific characteristics that are based on the temporal dynamics of ongoing brain activity and its coordination over distant cortical regions,” the investigators wrote. “Our hypothesis stems from the common stance of various contemporary theories which propose that consciousness relates to a dynamic process of self-sustained, coordinated brain-scale activity assisting the tuning to a constantly evolving environment, rather than in static descriptions of brain function.”
There is a need for a reliable way of distinguishing consciousness from unconscious states, the investigators said. “Given that nonresponsiveness can be associated with a variety of brain lesions, varying levels of vigilance, and covert cognition, we highlight the need to determine a common set of features capable of accounting for the capacity to sustain conscious experience.”
To search for patterns of brain signal coordination that correlate with consciousness, four independent research centers performed BOLD fMRI scans of participants at rest or under anesthesia with propofol. Of 159 total participants, 47 were healthy individuals and 112 were patients in a vegetative state/with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS), based on standardized behavioral assessments. The main data analysis, which included 125 participants, assessed BOLD fMRI signal coordination between six brain networks known to have roles in cognitive and functional processes.
The researchers’ analysis revealed four distinct and recurring brain-wide coordination patterns ranging on a scale from highest activity (pattern 1) to lowest activity (pattern 4). Pattern 1, which exhibited most long-distance edges, spatial complexity, efficiency, and community structure, became increasingly common when moving from UWS patients to MCS patients to healthy control individuals (UWS < MCS < HC, rho = 0.7, Spearman rank correlation between rate and group, P less than 1 x 10-16).
In contrast, pattern 4, characterized by low interareal coordination, showed an inverse trend; it became less common when moving from vegetative patients to healthy individuals (UWS > MCS > HC, Spearman rank correlation between rate and group, rho = –0.6, P less than 1 x 10-11). Although patterns 2 and 3 occurred with equal frequency across all groups, the investigators noted that switching between patterns was most common and predictably sequential in healthy individuals, versus patients with UWS, who were least likely to switch patterns. A total of 23 patients who were scanned under propofol anesthesia were equally likely to exhibit pattern 4, regardless of health status, suggesting that pattern 4 depends upon fixed anatomical pathways. Results were not affected by scanning site or other patient characteristics, such as age, gender, etiology, or chronicity.
“We conclude that these patterns of transient brain signal coordination are characteristic of conscious and unconscious brain states,” the investigators wrote, “warranting future research concerning their relationship to ongoing conscious content, and the possibility of modifying their prevalence by external perturbations, both in healthy and pathological individuals, as well as across species.”
The study was funded by a James S. McDonnell Foundation Collaborative Activity Award, INSERM, the Belgian National Funds for Scientific Research, the Canada Excellence Research Chairs program, and others. The authors declared having no conflicts of interest.
SOURCE: Demertzi A et al. Sci Adv. 2019 Feb 6. doi: 10.1126/sciadv.aat7603.
Functional MRI can measure patterns of connectivity to determine levels of consciousness in nonresponsive patients with brain injury, according to results from a multicenter, cross-sectional, observational study.
Blood oxygen level–dependent (BOLD) fMRI showed that brain-wide coordination patterns of high complexity became increasingly common moving from unresponsive patients to those with minimal consciousness to healthy individuals, reported lead author Athena Demertzi, PhD, of GIGA Research Institute at the University of Liège in Belgium, and her colleagues.
“Finding reliable markers indicating the presence or absence of consciousness represents an outstanding open problem for science,” the investigators wrote in Science Advances.
In medicine, an fMRI-based measure of consciousness could supplement behavioral assessments of awareness and guide therapeutic strategies; more broadly, image-based markers could help elucidate the nature of consciousness itself.
“We postulate that consciousness has specific characteristics that are based on the temporal dynamics of ongoing brain activity and its coordination over distant cortical regions,” the investigators wrote. “Our hypothesis stems from the common stance of various contemporary theories which propose that consciousness relates to a dynamic process of self-sustained, coordinated brain-scale activity assisting the tuning to a constantly evolving environment, rather than in static descriptions of brain function.”
There is a need for a reliable way of distinguishing consciousness from unconscious states, the investigators said. “Given that nonresponsiveness can be associated with a variety of brain lesions, varying levels of vigilance, and covert cognition, we highlight the need to determine a common set of features capable of accounting for the capacity to sustain conscious experience.”
To search for patterns of brain signal coordination that correlate with consciousness, four independent research centers performed BOLD fMRI scans of participants at rest or under anesthesia with propofol. Of 159 total participants, 47 were healthy individuals and 112 were patients in a vegetative state/with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS), based on standardized behavioral assessments. The main data analysis, which included 125 participants, assessed BOLD fMRI signal coordination between six brain networks known to have roles in cognitive and functional processes.
The researchers’ analysis revealed four distinct and recurring brain-wide coordination patterns ranging on a scale from highest activity (pattern 1) to lowest activity (pattern 4). Pattern 1, which exhibited most long-distance edges, spatial complexity, efficiency, and community structure, became increasingly common when moving from UWS patients to MCS patients to healthy control individuals (UWS < MCS < HC, rho = 0.7, Spearman rank correlation between rate and group, P less than 1 x 10-16).
In contrast, pattern 4, characterized by low interareal coordination, showed an inverse trend; it became less common when moving from vegetative patients to healthy individuals (UWS > MCS > HC, Spearman rank correlation between rate and group, rho = –0.6, P less than 1 x 10-11). Although patterns 2 and 3 occurred with equal frequency across all groups, the investigators noted that switching between patterns was most common and predictably sequential in healthy individuals, versus patients with UWS, who were least likely to switch patterns. A total of 23 patients who were scanned under propofol anesthesia were equally likely to exhibit pattern 4, regardless of health status, suggesting that pattern 4 depends upon fixed anatomical pathways. Results were not affected by scanning site or other patient characteristics, such as age, gender, etiology, or chronicity.
“We conclude that these patterns of transient brain signal coordination are characteristic of conscious and unconscious brain states,” the investigators wrote, “warranting future research concerning their relationship to ongoing conscious content, and the possibility of modifying their prevalence by external perturbations, both in healthy and pathological individuals, as well as across species.”
The study was funded by a James S. McDonnell Foundation Collaborative Activity Award, INSERM, the Belgian National Funds for Scientific Research, the Canada Excellence Research Chairs program, and others. The authors declared having no conflicts of interest.
SOURCE: Demertzi A et al. Sci Adv. 2019 Feb 6. doi: 10.1126/sciadv.aat7603.
Functional MRI can measure patterns of connectivity to determine levels of consciousness in nonresponsive patients with brain injury, according to results from a multicenter, cross-sectional, observational study.
Blood oxygen level–dependent (BOLD) fMRI showed that brain-wide coordination patterns of high complexity became increasingly common moving from unresponsive patients to those with minimal consciousness to healthy individuals, reported lead author Athena Demertzi, PhD, of GIGA Research Institute at the University of Liège in Belgium, and her colleagues.
“Finding reliable markers indicating the presence or absence of consciousness represents an outstanding open problem for science,” the investigators wrote in Science Advances.
In medicine, an fMRI-based measure of consciousness could supplement behavioral assessments of awareness and guide therapeutic strategies; more broadly, image-based markers could help elucidate the nature of consciousness itself.
“We postulate that consciousness has specific characteristics that are based on the temporal dynamics of ongoing brain activity and its coordination over distant cortical regions,” the investigators wrote. “Our hypothesis stems from the common stance of various contemporary theories which propose that consciousness relates to a dynamic process of self-sustained, coordinated brain-scale activity assisting the tuning to a constantly evolving environment, rather than in static descriptions of brain function.”
There is a need for a reliable way of distinguishing consciousness from unconscious states, the investigators said. “Given that nonresponsiveness can be associated with a variety of brain lesions, varying levels of vigilance, and covert cognition, we highlight the need to determine a common set of features capable of accounting for the capacity to sustain conscious experience.”
To search for patterns of brain signal coordination that correlate with consciousness, four independent research centers performed BOLD fMRI scans of participants at rest or under anesthesia with propofol. Of 159 total participants, 47 were healthy individuals and 112 were patients in a vegetative state/with unresponsive wakefulness syndrome (UWS) or in a minimally conscious state (MCS), based on standardized behavioral assessments. The main data analysis, which included 125 participants, assessed BOLD fMRI signal coordination between six brain networks known to have roles in cognitive and functional processes.
The researchers’ analysis revealed four distinct and recurring brain-wide coordination patterns ranging on a scale from highest activity (pattern 1) to lowest activity (pattern 4). Pattern 1, which exhibited most long-distance edges, spatial complexity, efficiency, and community structure, became increasingly common when moving from UWS patients to MCS patients to healthy control individuals (UWS < MCS < HC, rho = 0.7, Spearman rank correlation between rate and group, P less than 1 x 10-16).
In contrast, pattern 4, characterized by low interareal coordination, showed an inverse trend; it became less common when moving from vegetative patients to healthy individuals (UWS > MCS > HC, Spearman rank correlation between rate and group, rho = –0.6, P less than 1 x 10-11). Although patterns 2 and 3 occurred with equal frequency across all groups, the investigators noted that switching between patterns was most common and predictably sequential in healthy individuals, versus patients with UWS, who were least likely to switch patterns. A total of 23 patients who were scanned under propofol anesthesia were equally likely to exhibit pattern 4, regardless of health status, suggesting that pattern 4 depends upon fixed anatomical pathways. Results were not affected by scanning site or other patient characteristics, such as age, gender, etiology, or chronicity.
“We conclude that these patterns of transient brain signal coordination are characteristic of conscious and unconscious brain states,” the investigators wrote, “warranting future research concerning their relationship to ongoing conscious content, and the possibility of modifying their prevalence by external perturbations, both in healthy and pathological individuals, as well as across species.”
The study was funded by a James S. McDonnell Foundation Collaborative Activity Award, INSERM, the Belgian National Funds for Scientific Research, the Canada Excellence Research Chairs program, and others. The authors declared having no conflicts of interest.
SOURCE: Demertzi A et al. Sci Adv. 2019 Feb 6. doi: 10.1126/sciadv.aat7603.
FROM SCIENCE ADVANCES
Key clinical point:
Major finding: A brain-wide coordination pattern of high complexity became increasingly common when moving from patients with unresponsive wakefulness syndrome (UWS) to patients in a minimally conscious state (MCS) to healthy control individuals.
Study details: A study involving blood oxygen level–dependent (BOLD) fMRI scans at rest or under anesthesia in 159 participants at four independent research facilities.
Disclosures: The study was funded by a James S. McDonnell Foundation Collaborative Activity Award, INSERM, the Belgian National Funds for Scientific Research, the Canada Excellence Research Chairs program, and others. The authors declared having no conflicts of interest.
Source: Demertzi A et al. Sci Adv. 2019 Feb 6. doi: 10.1126/sciadv.aat7603.