Validation of criteria for frontotemporal dementia with right anterior temporal lobe predominance

Abstract

Introduction: Frontotemporal dementia (FTD) with right anterior temporal lobe (rATL) predominance lacks universally agreed-upon diagnostic criteria. This study validated the Amsterdam diagnostic tree (ADT) for right temporal variant FTD (rtvFTD) and the diagnostic criteria for semantic behavioral variant FTD (sbvFTD), examining clinical, behavioral, and imaging differences.

Methods: The study included 138 patients with behavioral variant FTD and 87 with semantic variant primary progressive aphasia who had 3D T1-weighted magnetic resonance imaging scans. The participants were grouped into rtvFTD and sbvFTD by respective imaging criteria.

Results: We identified 42 rtvFTD and 20 sbvFTD patients. ADT showed 81% sensitivity and 29% specificity, whereas sbvFTD criteria had 45% sensitivity and 55% specificity.

Discussion: The unfavorable validation of both diagnostic criteria in Korean FTD patients may result from socio-cultural differences, the lack of standardized tools for assessing abnormal behaviors, and the retrospective nature of the study. The perspectives on rATL also differed between the two studies.

Highlights: Frontotemporal dementia (FTD) with right anterior temporal lobe (rATL) predominance is a controversial FTD syndrome, also referred to as right temporal variant FTD (rtvFTD), or right predominant semantic variant primary progressive aphasia. Two clinical criteria for rATL have been proposed: One is the Amsterdam diagnostic tree for rtvFTD and the other is for semantic behavioral variant FTD (sbvFTD). Our validation study suggested the need for standardized tools and highlighted theoretical distinctions between rtvFTD and sbvFTD.

Keywords: diagnostic criteria; right temporal variant frontotemporal dementia; semantic behavioral variant frontotemporal dementia; semantic dementia.