To determine whether dementia with Lewy bodies with or without probable rapid eye movement sleep behavior disorder differ clinically or pathologically.
Patients with dementia with Lewy bodies who have probable rapid eye movement sleep behavior sleep disorder (n=71) were compared to those without it (n=19) on demographics, clinical variables (core features of dementia with Lewy bodies, dementia duration, rate of cognitive/motor changes) and pathologic indices (Lewy body distribution, neuritic plaque score, Braak neurofibrillary tangle stage).
Individuals with probable rapid eye movement sleep behavior disorder were predominantly male (82% versus 47%), and had a shorter duration of dementia (mean 8 years versus 10 years), earlier onset of parkinsonism (mean 2 years versus 5 years), and earlier onset of visual hallucinations (mean 3 years versus 6 years). These patients also had a lower Braak neurofibrillary tangle stage (Stage IV versus Stage VI) and lower neuritic plaque scores (18% frequent versus 85% frequent), but no difference in Lewy body distribution. When probable rapid eye movement sleep behavior disorder developed early (at or before dementia onset), the onset of parkinsonism and hallucinations was earlier and Braak neurofibrillary tangle stage was lower compared to those who developed the sleep disorder after dementia onset. Women with autopsy-confirmed DLB without a history of dream enactment behavior during sleep had a later onset of hallucinations and parkinsonism and a higher Braak NFT stage.
Probable rapid eye movement sleep behavior disorder is associated with distinct clinical and pathologic characteristics of dementia with Lewy bodies.