Mentalizing in frontotemporal dementia and progressive supranuclear palsy

Background: Mentalizing and emotion recognition are impaired in behavioral variant frontotemporal dementia (bvFTD). It is not clear whether these abilities are disturbed in progressive supranuclear palsy (PSP). Objective: To investigate social cognition (SC) between bvFTD and PSP. The neural basis of SC in PSP and bvFTD groups were also investigated by neuroimaging. Methods: Data from the notification sheet were collected and patients were classified according to current clinical and pathological criteria. Results: Groups did not differ on age, schooling and sex. Compared to controls, bvFTD and PSP patients had reduced scores in all tests of SC. bvFTD and PSP did not differ on measures of SC. PSP and bvFTD had cerebral atrophy in critical regions for SC. The cortical correlates of emotion recognition overlapped in bvFTD and PSP, correlating with frontal medial cortex, insula and limbic structures. PSP and bvFTD patients also displayed similar patterns of brain correlations (anterior temporal lobes) for social norms. The neural correlates of mentalizing were associated with frontal and temporal poles bilaterally, in both bvFTD and PSP. Conclusion:PSP patients exhibit impairment in mentalizing. PSP and bvFTD share clinical, cognitive and neuroimaging features.