The occurrence of Lewy bodies has a prevalence rate of 2%–9% in elderly people1 and dementia with Lewy bodies (DLB) accounts for 12%–27% of cases previously diagnosed as dementia of the Alzheimer type (DAT).2 3 The core features of DLB are fluctuating cognition with pronounced variation in attention and alertness, recurrent visual hallucinations, and spontaneous parkinsonian signs; probable DLB requires two of these features. There is considerable overlap between DLB and DAT,4 but there have been only a few comparative neuropsychological studies. Various neuropsychological issues were addressed in the papers by Lambon Ralphet al 5 (this issue, pp …