REM-SLEEP BEHAVIOR DISORDER AND DEGENERATIVE DEMENTIA - AN ASSOCIATION LIKELY REFLECTING LEWY BODY DISEASE

Background: REM sleep behavior disorder (RBD) has been reported with v arious neurodegenerative disorders, most frequently in disorders with Lewy body pathology. RBD often precedes the onset of PD, and a recent prospective study showed that 38% of patients with RBD eventually deve loped PD. Methods: We identified 37 patients with degenerative dementi a and a history of bursts of vigorous movement of the arms and legs wi th vocalization during sleep and associated with dream recall. Patient s with and without two or more signs of parkinsonism were compared. Cl inical, laboratory, and neuropsychometric features were analyzed, and criteria for the clinical diagnosis of dementia with Lewy bodies (DLB) were applied to all patients. Results: Thirty-four of the 37 patients were male with mean age at onset of 61.5 years for RBD and 68.1 years for cognitive decline. RBD commenced before or concurrently with deme ntia in all patients but two. Parkinsonism (two or more signs) occurre d in 54% of the sample (20/37), with a mean age at onset of 69.1 years . Polysomnography (PSG) confirmed RBD in all patients studied. Neurops ychological testing demonstrated impaired perceptual-organizational sk ills, verbal fluency: and marked constructional dyspraxia in more than one-half the patients. There were no statistically significant differ ences in the frequency of clinical features or in neuropsychological p erformance between patients with and without parkinsonism. Thirty-four patients (92%) met criteria for clinically possible or probable DLB. Three patients were autopsied; all had limbic with or without neocorti cal Lewy bodies. Conclusions: We report a group of predominantly male patients with a characteristic association of RBD and degenerative dem entia. The clinical and neuropsychometric features of the groups of pa tients with and. without parkinsonism are similar. We hypothesize that the underlying pathology in these patients is DLB.