A Case of Semantic Dementia with Picks Pathology (P1.231)

OBJECTIVE: To identify clinical and imaging features in semantic dementia which differentiate Pick’s disease from TDP-43 pathology. BACKGROUND: Semantic dementia, a clinical syndrome associated with FTLD, is typically associated with TDP-C proteinopathy. Of the 14[percnt] of SD cases without TDP pathology, most have Pick’s disease. Identifying clinical and imaging features predictive of Pick’s pathology in SD would have important implications for protein-specific treatments. DESIGN/METHODS: The clinical and imaging features in a 66-year-old man with SD due to Pick’s disease were compared with those in two groups: one with SD due to TDP-43 pathology and the other with Pick’s disease pathology but not SD. RESULTS: The SD patients performed significantly worse on tests of language, such as the Peabody Picture Vocabulary Test and the Boston Naming Task, compared to the Pick’s disease patients. On these tests, our case performed better than the SD group and worse than the Pick’s disease group. Voxel-based morphometry demonstrated that the regions with the most significant atrophy in Pick’s disease were the right caudate and the right middle frontal gyrus, whereas SD was associated with predominantly temporal atrophy. The pattern of atrophy in this case was more similar to the pattern seen in Pick’s than in TDP-C. CONCLUSIONS: Our results suggest that clinical and imaging features, such as less language involvement and a pattern of atrophy more localized to the right caudate and right middle frontal gyrus, can be used to identify semantic dementia due to Pick’s disease. Disclosure: Dr. Caplan has nothing to disclose. Dr. Elofson has nothing to disclose. Dr. Lis has nothing to disclose. Dr. Rosen has nothing to disclose. Dr. Gorno Tempini has nothing to disclose. Dr. Grinberg has nothing to disclose. Dr. Miller has received personal compensation in an editorial capacity for Cambridge University Press, Guilford Publications, Inc., and Neurocase.