To investigate the effect of social and leisure activity engagement on cortical thickness in patients with behavioral variant frontotemporal degeneration.

Behavioral variant frontotemporal degeneration (bvFTD) is a progressive neurodegenerative disease that primarily affects social and executive functioning. Consistent with cognitive reserve theory, we hypothesized that an enriched lifetime of social engagement and leisure activity would provide resilience to pathogenic loss of cortical thickness (CT) in regions associated with social cognition.

32 patients with bvFTD (Age: M=61.2(8.10), Â鶹´«Ã½Ó³»­: M=17.1(1.94), MMSE: M=23.7(5.75)) underwent a T1-weighted volumetric MRI scan. Patients were screened for amyloid negativity using published cutoffs (>192pg/mL) for amyloid-beta levels in cerebrospinal fluid. Caregivers for patients completed the Lifetime of Experiences Questionnaire (LEQ). We examined the association between social engagement and leisure activities on the LEQ and CT. CT in regions of interest (ROIs) were calculated using the Lausanne atlas. A subset of 19 patients were investigated longitudinally. Linear mixed effects assessed the effect of LEQ on decline in whole-brain CT, covarying for age, sex, and disease duration, corrected for multiple comparisons. All patients underwent cognitive testing after which examiners completed the Social Behavior Observer Checklist (SBO), measuring behavioral comportment.

Higher social engagement and leisure activity was associated with greater CT in superior anterior temporal including amygdala. In our longitudinal analysis, we observed an association with a slower rate of CT loss in the insula. This finding was supported by behavioral evidence, as we found highly engaged individuals also had slower decline on social behavior ratings.

We found that social engagement and leisure activity are associated with relatively preserved CT early in disease trajectory, as well as a slower rate of cortical thinning in regions important for social functioning. These findings suggest that lifetime social engagement and leisure activity may provide a form of resilience against pathologic effects of disease.