Mild cognitive impairment in rapid eye movement sleep behavior disorder and Parkinson's disease.
OBJECTIVE
To investigate the frequency and subtypes of mild cognitive impairment (MCI) in idiopathic rapid eye movement sleep behavior disorder (RBD) and Parkinson's disease (PD) in association with RBD.


METHODS
One hundred and twelve subjects without dementia or major depression including 32 idiopathic RBD patients, 22 PD patients with polysomnography-confirmed RBD, 18 PD patients without RBD, and 40 healthy control subjects, underwent a comprehensive neuropsychological evaluation. We compared the proportion of patients with MCI between groups using standard diagnostic criteria.


RESULTS
MCI was found in 50% of idiopathic RBD patients and 73% of PD patients with RBD. In contrast, only 11% of PD patients without RBD and 8% of control subjects had MCI. The presence of MCI was significantly greater in idiopathic RBD patients and PD patients with RBD than in PD patients without RBD and control subjects. PD patients with RBD also performed worse than idiopathic RBD patients on neuropsychological tests assessing visuoconstructional and visuoperceptual abilities.


CONCLUSIONS
In both its association with PD and its idiopathic form, RBD is an important risk factor for MCI. Except for visuoconstructional and visuoperceptual problems, RBD may be an important determinant of cognitive impairment in PD. Ann Neurol 2009;66:39-47.
Gagnon
Jean-François
JF
Centre d'étude du Sommeil et des Rythmes Biologiques, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada. jean-francois.gagnon.5@umontreal.ca
Vendette
Mélanie
M
Postuma
Ronald B
RB
Desjardins
Catherine
C
Massicotte-Marquez
Jessica
J
Panisset
Michel
M
Montplaisir
Jacques
J
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003072:Cognition Disorders / Q000209:etiology*; D004569:Electroencephalography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications*; D011569:Psychiatric Status Rating Scales; D020187:REM Sleep Behavior Disorder / Q000150:complications*; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric