Lewy Body Dementia

Lewy bodies are intracytoplasmic inclusion bodies comprised largely of the intermediate filament protein, ubiquitin a heat-shock protein1. In the brain stem they are a characteristic feature of Parkinson's disease (PD). The first cases of dementia with cortical Lewy bodies were reported by Okazaki et al.2. Since then about 300 further cases have been described. Lewy body dementia (LBD) is common in post-mortem series, the mean frequency in six post-mortem series being 12.5%. In vivo LBD has been found in 23% of patients with dementia attending a day-hospital3 and in 12% of patients presenting to psychogeriatric service4. Although it has been designated a disease entity, a variety of Alzheimer's disease (AD) and a spectrum disorder5, the nosological status of LBD is not yet resolved. There are two main reasons for this. One is the heterogeneity of the pathological findings; the majority of cases have Lewy bodies in the brain stem and cerebral cortex (a few cases have been reported with cortical Lewy bodies only Kosaka et al.6) together with a variable degree of Alzheimer's histology, senile plaques and neurofibrillary tangles. The second is the heterogeneity of the clinical features, some cases resembling AD other PD and others vascular dementia (VaD)7.