REM Sleep Behavior Disorder May Portend Impairments

TORONTO — People who act out their dreams as a result of having REM Sleep Behavior Disorder have an increased risk of developing mild cognitive impairment or parkinsonism within 3 years of follow-up, according to researchers affiliated with the Mayo Clinic Study of Aging.

Evidence also suggests that knowledge of a REM sleep behavior disorder (RBD) diagnosis might enhance the accuracy of diagnosing associated dementia, in addition to predicting future cognitive or motor impairment.

“We already knew from studies of clinic-based samples that between 45% and 85% of patients with RBD develop one of the synucleinopathies [Parkinson's disease, Parkinson's disease with dementia, dementia with Lewy bodies (DLB), or multiple system atrophy],” said Dr. Brendon P. Boot, a fellow at the Mayo Clinic in Rochester, Minn. “We were interested to know what the risk is for the elderly living in the community.”

The synucleinopathies are a group of neurodegenerative disorders characterized by aggregation of alpha-synuclein, a protein normally found in neuronal synapses.

Diagnosing RBD requires polysomnographic testing. However, the researchers used the Mayo Sleep Questionnaire (MSQ) to screen for RBD by asking the subject's bed partner: Has your spouse ever “acted out his or her dreams” while sleeping? This includes punching or flailing arms in the air or shouting or screaming.

In one of the Mayo Clinic studies presented at the annual meeting of the American Academy of Neurology, Dr. Boot reported that the MSQ has a sensitivity of 100% and a specificity of 95% for the diagnosis of RBD, based on testing of 96 cognitively normal, 29 mildly cognitively impaired, and 3 mildly demented community-dwelling elderly individuals from Olmsted County, Minn.

Dr. Boot and his colleagues then administered the MSQ in another study of 543 cognitively normal individuals between 70 and 89 years old and found that 44 had probable RBD. After a median follow-up of 33 months, 1 of these 44 patients developed Parkinson's disease and 13 developed mild cognitive impairment (MCI).

Those with MCI are at increased risk of developing dementia, and so RBD plus MCI may represent an early sign of a synucleinopathy. After adjustment for age, sex, education, and medical comorbidity, patients with probable RBD had 2.5 times greater risk of developing MCI or a synucleinopathy than did those without RBD.

In a related study, these investigators found that older, cognitively normal people with probable RBD had significantly worse olfaction than those without probable RBD, using the University of Pennsylvania Brief Smell Identification Test.

Hyposmia frequently precedes other symptoms of the synucleinopathies, Dr. Boot said.

In another study, Tanis J. Ferman, Ph.D., from the Mayo Clinic in Jacksonville, Fla., explored the diagnostic value of RBD in 82 patients with DLB and 64 patients with Alzheimer's disease.

According to the 2005 Consensus Criteria, diagnosis of DLB requires dementia plus one or more core clinical features fluctuating alertness and cognition, visual hallucinations, and parkinsonism. The criteria were modified in 2005 to include RBD as a suggestive feature, where the presence of RBD plus one core feature yields a diagnosis of probable DLB (Neurology 2005;65:1863–72).

In autopsy examinations of patients with dementia, the presence of RBD was associated with nearly sixfold higher odds of having DLB rather than Alzheimer's disease.

RBD appears to be a useful early clinical indicator of DLB, Dr. Ferman said.

Dr. Boot and Dr. Ferman said they had no relevant disclosures.

TORONTO — People who act out their dreams as a result of having REM Sleep Behavior Disorder have an increased risk of developing mild cognitive impairment or parkinsonism within 3 years of follow-up, according to researchers affiliated with the Mayo Clinic Study of Aging.

Evidence also suggests that knowledge of a REM sleep behavior disorder (RBD) diagnosis might enhance the accuracy of diagnosing associated dementia, in addition to predicting future cognitive or motor impairment.

“We already knew from studies of clinic-based samples that between 45% and 85% of patients with RBD develop one of the synucleinopathies [Parkinson's disease, Parkinson's disease with dementia, dementia with Lewy bodies (DLB), or multiple system atrophy],” said Dr. Brendon P. Boot, a fellow at the Mayo Clinic in Rochester, Minn. “We were interested to know what the risk is for the elderly living in the community.”

The synucleinopathies are a group of neurodegenerative disorders characterized by aggregation of alpha-synuclein, a protein normally found in neuronal synapses.

Diagnosing RBD requires polysomnographic testing. However, the researchers used the Mayo Sleep Questionnaire (MSQ) to screen for RBD by asking the subject's bed partner: Has your spouse ever “acted out his or her dreams” while sleeping? This includes punching or flailing arms in the air or shouting or screaming.

In one of the Mayo Clinic studies presented at the annual meeting of the American Academy of Neurology, Dr. Boot reported that the MSQ has a sensitivity of 100% and a specificity of 95% for the diagnosis of RBD, based on testing of 96 cognitively normal, 29 mildly cognitively impaired, and 3 mildly demented community-dwelling elderly individuals from Olmsted County, Minn.

Dr. Boot and his colleagues then administered the MSQ in another study of 543 cognitively normal individuals between 70 and 89 years old and found that 44 had probable RBD. After a median follow-up of 33 months, 1 of these 44 patients developed Parkinson's disease and 13 developed mild cognitive impairment (MCI).

Those with MCI are at increased risk of developing dementia, and so RBD plus MCI may represent an early sign of a synucleinopathy. After adjustment for age, sex, education, and medical comorbidity, patients with probable RBD had 2.5 times greater risk of developing MCI or a synucleinopathy than did those without RBD.

In a related study, these investigators found that older, cognitively normal people with probable RBD had significantly worse olfaction than those without probable RBD, using the University of Pennsylvania Brief Smell Identification Test.

Hyposmia frequently precedes other symptoms of the synucleinopathies, Dr. Boot said.

In another study, Tanis J. Ferman, Ph.D., from the Mayo Clinic in Jacksonville, Fla., explored the diagnostic value of RBD in 82 patients with DLB and 64 patients with Alzheimer's disease.

According to the 2005 Consensus Criteria, diagnosis of DLB requires dementia plus one or more core clinical features fluctuating alertness and cognition, visual hallucinations, and parkinsonism. The criteria were modified in 2005 to include RBD as a suggestive feature, where the presence of RBD plus one core feature yields a diagnosis of probable DLB (Neurology 2005;65:1863–72).

In autopsy examinations of patients with dementia, the presence of RBD was associated with nearly sixfold higher odds of having DLB rather than Alzheimer's disease.

RBD appears to be a useful early clinical indicator of DLB, Dr. Ferman said.

Dr. Boot and Dr. Ferman said they had no relevant disclosures.

TORONTO — People who act out their dreams as a result of having REM Sleep Behavior Disorder have an increased risk of developing mild cognitive impairment or parkinsonism within 3 years of follow-up, according to researchers affiliated with the Mayo Clinic Study of Aging.

Evidence also suggests that knowledge of a REM sleep behavior disorder (RBD) diagnosis might enhance the accuracy of diagnosing associated dementia, in addition to predicting future cognitive or motor impairment.

“We already knew from studies of clinic-based samples that between 45% and 85% of patients with RBD develop one of the synucleinopathies [Parkinson's disease, Parkinson's disease with dementia, dementia with Lewy bodies (DLB), or multiple system atrophy],” said Dr. Brendon P. Boot, a fellow at the Mayo Clinic in Rochester, Minn. “We were interested to know what the risk is for the elderly living in the community.”

The synucleinopathies are a group of neurodegenerative disorders characterized by aggregation of alpha-synuclein, a protein normally found in neuronal synapses.

Diagnosing RBD requires polysomnographic testing. However, the researchers used the Mayo Sleep Questionnaire (MSQ) to screen for RBD by asking the subject's bed partner: Has your spouse ever “acted out his or her dreams” while sleeping? This includes punching or flailing arms in the air or shouting or screaming.

In one of the Mayo Clinic studies presented at the annual meeting of the American Academy of Neurology, Dr. Boot reported that the MSQ has a sensitivity of 100% and a specificity of 95% for the diagnosis of RBD, based on testing of 96 cognitively normal, 29 mildly cognitively impaired, and 3 mildly demented community-dwelling elderly individuals from Olmsted County, Minn.

Dr. Boot and his colleagues then administered the MSQ in another study of 543 cognitively normal individuals between 70 and 89 years old and found that 44 had probable RBD. After a median follow-up of 33 months, 1 of these 44 patients developed Parkinson's disease and 13 developed mild cognitive impairment (MCI).

Those with MCI are at increased risk of developing dementia, and so RBD plus MCI may represent an early sign of a synucleinopathy. After adjustment for age, sex, education, and medical comorbidity, patients with probable RBD had 2.5 times greater risk of developing MCI or a synucleinopathy than did those without RBD.

In a related study, these investigators found that older, cognitively normal people with probable RBD had significantly worse olfaction than those without probable RBD, using the University of Pennsylvania Brief Smell Identification Test.

Hyposmia frequently precedes other symptoms of the synucleinopathies, Dr. Boot said.

In another study, Tanis J. Ferman, Ph.D., from the Mayo Clinic in Jacksonville, Fla., explored the diagnostic value of RBD in 82 patients with DLB and 64 patients with Alzheimer's disease.

According to the 2005 Consensus Criteria, diagnosis of DLB requires dementia plus one or more core clinical features fluctuating alertness and cognition, visual hallucinations, and parkinsonism. The criteria were modified in 2005 to include RBD as a suggestive feature, where the presence of RBD plus one core feature yields a diagnosis of probable DLB (Neurology 2005;65:1863–72).

In autopsy examinations of patients with dementia, the presence of RBD was associated with nearly sixfold higher odds of having DLB rather than Alzheimer's disease.

RBD appears to be a useful early clinical indicator of DLB, Dr. Ferman said.

Dr. Boot and Dr. Ferman said they had no relevant disclosures.