Hyperorality in Frontotemporal Dementia: How Psychiatric and Neural Correlates Change During the Disease Course.

Objective: Hyperorality is a core feature of behavioral variant frontotemporal dementia (bvFTD); however, the cognitive, psychiatric, and neuroanatomical correlates of hyperorality across the bvFTD stages remain unclear. The authors explored these associations in early- and advanced-stage bvFTD.

Methods: Participants with sporadic or genetic bvFTD were enrolled in the ARTFL LEFFTDS Longitudinal Frontotemporal Lobar Degeneration (ALLFTD) consortium study. Baseline cognitive and psychiatric symptoms of participants with or without hyperorality were compared after stratification by disease severity. Linear multivariable regressions adjusted for age and total intracranial volume were used to examine associations between regional gray matter volume (GMV) and hyperorality status. Five anatomical regions of interest were preselected for analysis on the basis of previously identified neuroanatomical correlates of hyperorality in bvFTD.

Results: Hyperorality was present in 50% of early-stage bvFTD participants (N=136) and was associated with higher rates of ritualistic-compulsive behavior and difficulty detecting social-emotional expressions. Hyperorality was present in 63% of advanced-stage participants (N=208) and was associated with higher rates of apathy, ritualistic-compulsive behavior, and socially aberrant behavior. Regional GMV was similar for those with or without hyperorality among early-stage participants. Among advanced-stage participants, hyperorality was associated with lower GMV in the right dorsal and ventral striatum.

Conclusions: Hyperorality emerged early in bvFTD and was accompanied by deficits in social cognition and complex-ritualistic behavior before clinically significant GMV loss. These findings suggest that early identification and management of hyperorality could improve neuropsychiatric trajectories in bvFTD.