Yoo A, Lee JY, Kim YK, et al. - This study attempted to explore the cognitive functions and mild cognitive impairment (MCI) in a prospective isolated rapid-eye-movement sleep behavior disorder (iRBD) cohort and investigated their association with disease-specific brain metabolic patterns. Researchers enrolled a total of 44 patients with polysomnography-confirmed iRBD performing a standardized battery of neuropsychological examinations every two years. They compared those expressions between iRBD with normal cognition and with mild cognitive impairment(iRBD-MCI) and assessed if they predicted progressive cognitive deterioration. It was shown that elevated disease-specific brain metabolic patterns are correlated with iRBD-MCI and impending cognitive deterioration with the risk of progression to Lewy body dementia.