Article

Mild cognitive impairment in rapid eye movement sleep behavior disorder and Parkinson's disease

Centre d'étude du Sommeil et des Rythmes Biologiques, Hôpital du Sacré-Coeur de Montréal, Montréal, Québec, Canada.
Annals of Neurology (Impact Factor: 11.91). 07/2009; 66(1):39-47. DOI: 10.1002/ana.21680
Source: PubMed

ABSTRACT 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.
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.
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.
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.

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    • "Moreover, the absence of these associations in the controls suggests that the associations between EEG measures and cognitive performance found in our study are specific to iRBD patients. Poor performance on the Trail Making Test Part B and the Block Design subtest has been reported in DLB and PD with cognitive impairment [6] [29] [30]. This observation suggests that both EEG slowing and impaired performance on these tasks could be early manifestations of cognitive decline in iRBD patients. "
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    ABSTRACT: Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is a well-documented risk factor for synucleinopathies such as Parkinson disease (PD) and dementia with Lewy bodies (DLB). Moreover, approximately 50% of iRBD patients have mild cognitive impairment (MCI). The purpose of our study was to investigate waking electroencephalogram (EEG) abnormalities specific to iRBD patients with MCI. Forty-two polysomnographically confirmed iRBD patients, including 23 iRBD [+]MCI patients 19 patients without MCI (iRBD [-]MCI), and 37 healthy subjects participated in the study. All participants underwent a complete neuropsychologic assessment for MCI diagnosis and a waking quantitative EEG recording. iRBD [+]MCI patients had a higher slow-to-fast frequency ratio than iRBD [-]MCI patients and controls in the parietal, temporal, and occipital regions. iRBD [+]MCI patients also had higher relative θ power in the parietal, temporal, and occipital regions and lower relative α power in the occipital region compared to iRBD [-]MCI patients and controls. Moreover, iRBD [+]MCI patients had higher relative θ power in the frontal and central areas and lower relative β power in the central, parietal, and temporal regions compared to controls. The dominant occipital frequency also was slower in iRBD [+]MCI patients compared to controls. No between-group differences were observed between iRBD [-]MCI patients and controls. In iRBD patients, only those with concomitant MCI showed waking EEG slowing in the posterior cortical regions, providing a potential marker for an increased risk for developing DLB or PD.
    Sleep Medicine 09/2013; 14(11). DOI:10.1016/j.sleep.2013.06.013 · 3.10 Impact Factor
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    • "Criteria should be developed for how iRBD patients are tested and how the results can influence entry into the study. (F) RBD patients with mild cognitive impairment [34] [35] [36]. This inclusion is in line with the previous inclusion of RBD patients with soft neurologic dysfunction. "
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    Sleep Medicine 07/2013; 15(1). DOI:10.1016/j.sleep.2013.02.016 · 3.10 Impact Factor
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    • "Cognitive impairment has been associated with nocturnal psychosis, hallucination, depressive symptoms and excessive daytime sleepiness [3] [4]. Furthermore, it has been reported that patients with PD and RBD showed more frequent mild cognitive impairment [5] and poorer performance on tests of episodic verbal memory, executive functions and visuospatial and visuoperceptual processing compared with patients with PD without RBD [6]. Although the coexistence of RLS in PD patients has been reported with a frequency ranging from 0 to 50% [7], a relationship between RLS and PD is still controversial [8] [9] [10] [11]. "
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    Journal of the neurological sciences 04/2012; 318(1-2):76-81. DOI:10.1016/j.jns.2012.03.022 · 2.26 Impact Factor
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