Prevalence of vascular lesions in dementia with Lewy bodies. A postmortem study

The frequency of vascular lesions in dementia with Lewy bodies (DLB) has been suggested to be less common than for Parkinson disease (PD), but exact data on the relationship between DLB and stroke are not available. 387 consecutive cases of autopsy-proven Lewy body disease - 291 cases of idiopathic PD (Lewy body disease of brainstem type) and 96 cases of DLB - and 390 age-matched controls were compared using current routine stains and immunohistological methods. The frequency of cerebrovascular lesions of various intensity (lacunes, amyloid angiopathy, old ischemic infarcts and hemorrhages) was lower in DLB than in both PD and controls (34.4% vs. 36.7% and 33.3%) (p > 0.03). While acute ischemic strokes and hemorrhages were rarely present in both PD and controls (4.1 vs. 3.3%), no such lesions were observed in DLB. At variance to previous findings in autopsy-proven PD and Alzheimer disease (AD), these data suggest a protective effect against stroke and no greater susceptibility to death from stroke in the DLB population studied, but the reasons remain unclear. On the other hand, like in PD and AD, cognitive impairment in DLB appears to be independent from coexisting vascular pathology and is mainly related to neuritic Alzheimer pathology.