[Clinical features of late onset dementia with Lewy bodies]

We conducted a retrospective study to elucidate clinical features of late onset dementia with Lewy bodies (DLB). Nineteen patients with DLB of neocortical category were neuropathologically diagnosed out of 500 consecutive autopsies at Yokufukai Hospital by using the pathological criteria of the consortium on DLB International Workshop. Medical history and clinical signs and symptoms were reviewed from the medical records. The age at onset was 55-88 years (mean 75.9 years), the age at death was 62-91 years, and duration of illness was 1-14 years. The initial symptoms were memory disturbance (10 cases), delirium (6 cases), gait disturbance (3 cases), visual hallucination (3 cases). We divided nineteen cases of DLB into two group: the age of onset was under 75 years (9 cases) and over 76 years (10 cases). The early onset group showed parkinsonism (67%), and visual hallucination (55%). The sensitivity of the clinical diagnosis of probable DLB based on DLB international workshop consensus criteria was 67%. On the other hand, the late onset group (10cases) presented with delirium (70%), parkinsonism (20%), and visual hallucination (30%). The sensitivity of a clinical diagnosis of probable DLB was 30%. Our results indicated considerable difficulty of the diagnosis of late onset DLB cases by the consensus criteria, requiring more sensitive criteria and diagnostic tests for DLB.