A Modified Reading the Mind in the Eyes Test Predicts Behavioral Variant Frontotemporal Dementia Better Than Executive Function Tests

Abstract

Behavioral variant frontotemporal dementia (bvFTD) is characterized by deep alterations in behavior and personality. Although revised diagnostic criteria agree for executive dysfunction as most characteristic, impairments in social cognition are also suggested. The study aimed at identifying those neuropsychological and behavioral parameters best discriminating between bvFTD and healthy controls. Eighty six patients were diagnosed with possible or probable bvFTD according to Rascovsky et al. (2011) and compared with 43 healthy age-matched controls. Neuropsychological performance was assessed with a modified Reading the Mind in the Eyes Test (RMET), Stroop task, Trail Making Test (TMT), Hamasch-Five-Point Test (H5PT), and semantic and phonemic verbal fluency tasks. Behavior was assessed with the Apathy Evaluation Scale, Frontal Systems Behavioral Scale, and Bayer Activities of Daily Living Scale. Each test's discriminatory power was investigated by Receiver Operating Characteristic curves calculating the area under the curve (AUC). bvFTD patients performed significantly worse than healthy controls in all neuropsychological tests. Discriminatory power (AUC) was highest in behavioral questionnaires, high in verbal fluency tasks and the RMET, and lower in executive function tests such as the Stroop task, TMT and H5PT. As fluency tasks depend on several cognitive functions, not only executive functions, results suggest that the RMET discriminated better between bvFTD and control subjects than other executive tests. Social cognition should be incorporated into diagnostic criteria for bvFTD in the future, such as in the International Classification of Diseases (ICD)-11, as already suggested in the Diagnostic and Statistical Manual for Mental Disorders (DSM)-5.

Keywords: behavioral variant frontotemporal dementia; diagnostic criteria; executive function; social cognition; theory of mind.

FIGURE 1

Receiver Operating Characteristic curves for the CDR, the CDR specified for FTLD (FTLD-CDR), and for the several neuropsychological tests, namely the Stroop test, H5PT, semantic and phonemic fluency, TMT, and the RMET.

FIGURE 2

Receiver Operating Characteristic curves for the behavioral questionnaires, in particular the AES, BADL, and the FrSBe. Informant- and self-report measures are shown.

FIGURE 3

Discriminatory power as measured with Areas Under the Curve (AUC) as revealed by ROC curves for the AES, BADL, CDR, CDR specified for FTLD (FTLD-CDR), FrSBe, H5PT, RMET, and TMT.

FIGURE 4

Discriminatory power as measured with Areas Under the Curve (AUC) as revealed by ROC curves for the total scale and the subscales of the FrSBe.