Objective: To compare the extrapyramidal features of pathologically confirmed cases of diffuse Lewy body disease (DLBD) and Parkinson's disease (PD).
Background: The proportion of pathologically confirmed cases of DLBD diagnosed clinically as PD is as high as 88%. Few papers focus specifically on the extrapyramidal features of DLBD. Further characterization of these features might facilitate antemortem diagnosis, in particular, distinguishing DLBD from PD.
Methods: Review of prospective and retrospective clinical data on a large series of pathologically diagnosed cases of DLBD (N = 31) and PD (N = 34) seen between 1984 and 1995 at Columbia-Presbyterian Medical Center or the University of Rochester.
Results: Those with DLBD had an older mean age of onset (67.9 years) than PD (62.0 years) (z = 6.5, p < 0.0001). Rest tremor was more common in PD (85.0%) than DLBD (55.0%) (chi 2 = 4.3, p = 0.038). Myoclonus was more common in DLBD (18.5%) than PD (0%) (Fisher's p = 0.021). There were no differences in rigidity, bradykinesia, dystonia, or gaze palsies. Clinical response to levodopa may have been more common in PD (100%) than DLBD (70.0%) (Fisher's p = 0.059). The occurrence of any one of four clinical features (myoclonus, absence of rest tremor, no response to levodopa, or no perceived need to treat with levodopa) was 10 times more likely in DLBD than PD (odds ratio = 10.29, 95% confidence interval = 2.58-41.11).
Conclusions: We demonstrated that several clinical features distinguish DLBD from PD. These features, in combination with reported differences in cognitive and psychiatric manifestations, may be used for diagnostic purposes in distinguishing DLBD from PD in prospective longitudinal cohort studies of DLBD.