Right Temporal Variant Frontotemporal Dementia Presenting With Prosopagnosia: Insights From 18 F-FDG PET and MRI.

Abstract

Right temporal variant frontotemporal dementia (rtvFTD) is a rare subtype of the FTD spectrum that typically presents with early deficits in person recognition rather than language impairment. We describe a 62-year-old man with progressive prosopagnosia and memory impairment whose T2-weighted MRI demonstrated atrophy in the right anterior temporal region. Subsequent 18 F-FDG PET revealed marked right temporal hypometabolism with additional involvement of the right frontal and anterior cingulate cortices, findings supported by quantitative SPM Z-score analysis. This structural-metabolic pattern is characteristic of rtvFTD, which primarily affects right temporal networks responsible for person recognition. Although right temporal atrophy has been documented in imaging studies of rtvFTD, detailed 18 F-FDG PET characterization remains scarce. This case contributes to the limited literature by providing a clear multimodal depiction of the characteristic metabolic signature of rtvFTD.