Mild cognitive impairment and abnormal brain metabolic expression in idiopathic REM sleep behavior disorder. (September 2021)

• Record Type: Journal Article
• Authors: Yoo, Dallah; Lee, Jee-Young; Kim, Yu Kyeong; Yoon, Eun Jin; Kim, Heejung; Kim, Ryul; Nam, Hyunwoo; Jeon, Beomseok
• Is Part Of: Parkinsonism & related disorders. Volume 90(2021)
• Page Start: 1
• Page End: 7
• Publication Date: 2021-09
• Subjects: REM sleep behavior disorder -- Mild cognitive impairment -- Positron emission tomography -- Lewy body dementia; Parkinson's disease -- Periodicals; Movement disorders -- Periodicals; Movement Disorders -- Periodicals; Nerve Degeneration -- Periodicals; Nervous System Diseases -- Periodicals; Parkinson Disease -- Periodicals; Tremor -- Periodicals; Parkinson, Maladie de -- Périodiques; Parkinson's disease; 616.833
• DOI: 10.1016/j.parkreldis.2021.07.022
• Languages: English
• ISSNs: 1353-8020

Abstract

Abstract: Background: Mild cognitive impairment (MCI) is a common feature of isolated rapid-eye-movement sleep behavior disorder (iRBD). Here, we assessed cognitive functions and MCI in a prospective iRBD cohort and investigated their association with disease-specific brain metabolic patterns. Methods: Forty-four patients with polysomnography-confirmed iRBD performed a standardized battery of neuropsychological examinations every two years. We used previously established spatial covariance patterns from de novo drug-naïve Parkinson's disease with concomitant RBD (denovo PDRBD-RP) and iRBD (iRBD-RP) using 18 F-fluorodeoxyglucose PET scan. We compared those expressions between iRBD with normal cognition (iRBD-NC) and with mild cognitive impairment (iRBD-MCI), and evaluated whether they predict progressive cognitive deterioration. Results: Twenty iRBD patients (45 %) had MCI at baseline and 12 patients (27 %, about 7 % per year) had clinically significant cognitive deterioration after 4 years. The iRBD-MCI and iRBD-NC groups showed similar rates of cognitive change, but iRBD-MCI consistently performed worse in the domains of verbal memory and executive function. Elevated denovo PDRBD-RP expression predicted cognitive deterioration (hazard ratio = 5.98 [1.70–21.06]), whereas iRBD-RP did not. Conclusions: Increased disease-specific brain metabolic patterns are associated with iRBD-MCI and impending cognitive deterioration with the risk of progression to Lewy body dementia. Highlights: The iRBD-MCI consistently shows verbal memory and executive dysfunctions. The iRBD-MCI and iRBD-NC show similar rate of cognitive decline. The denovo PDRBD-RP expression is significantly increased in iRBD-MCI group. Elevated denovo PDRBD-RP expression predicts cognitive deterioration of iRBD.