Clustering of Pick bodies in patients with Pick's disease

Clustering of Pick bodies (PB) was studied in the frontal and temporal robe in 10 cases of Pick's disease (PD). Pick bodies exhibited clustering in 47/50 (94 %) brain areas analysed. In 20/50 (40 %) brain areas, PB were present in a single large cluster greater than or equal to 6400 mu m in diameter, in 27/50 (54 %) PB occurred in smaller clusters (200 - 3200 mu m in diameter) which exhibited a regular periodicity relative to the tissue boundary, in 1/50 (2 %) there was a regular distribution of individual PB and in 2/50 (4 %), PB were randomly distributed. Mean cluster size of the PB was greater in the dentate gyrus compared with the inferior temporal gyrus and lateral occipitotemporal gyrus. Mean cluster size of PB in a brain region was positively correlated with the mean density of PB. Hence, PB exhibit essentially the same spatial patterns as senile plaques and neurofibrillary tangles in Alzheimer's disease (AD) and Lewy bodies in Dementia with Lewy bodies (DLB). (C) 1998 Elsevier Science Ireland Ltd.