Diagnostic accuracy of behavioral variant frontotemporal dementia consortium criteria (FTDC) in a clinicopathological cohort.

Abstract

The aims of this study were to assess the sensitivity of the International Behavioural Variant FTD Criteria Consortium (FTDC) revised criteria of behavioural variant frontotemporal dementia (bvFTD) in a pathological cohort and to determine their predictive values in a clinical context suggestive of bvFTD. In addition, the study aimed to assess the influence of the age at onset and underlying pathology in the clinicopathological correlations. Retrospective, blinded review of the clinical and neuropathological data from the Neurological Tissue Bank of the Biobank Hospital Clinic-IDIBAPS, Barcelona (Spain) was conducted, assessing the fulfilment of the diagnostic criteria on a case-by-case basis. Two separate nonexclusive cohorts were selected: Cohort 1 (n = 58) subjects with pathological diagnosis of frontotemporal lobar degeneration (FTLD) and Cohort 2 (n = 66) subjects with the premortem diagnosis of bvFTD. The FTDC criteria reached a sensitivity of 93% for possible and 80% for probable bvFTD. Early-onset cases displayed significantly more disinhibition, loss of empathy and compulsive behaviour with respect to late-onset bvFTD, leading to a slightly higher sensitivity of the diagnostic criteria (97% vs. 91%). There were no differences in the diagnostic performance between tau-positive and tau-negative cases. In subjects clinically diagnosed as bvFTD, a 'possible bvFTD' diagnosis reached a positive predictive value for FTLD pathology of 90%, irrespective of underlying proteinopathy. False-positive clinical diagnoses were mainly Alzheimer's disease. These cases were significantly older, had less family history of dementia and had a predominantly apathetic clinical picture. The revised bvFTD criteria present good sensitivity and positive predictive value in both early- and late-onset cases and regardless of the underlying FTLD pathology.