How to detect affect recognition alterations in amyotrophic lateral sclerosis.

OBJECTIVE

To define the clinical usability of an affect recognition (AR) battery-the Comprehensive Affect Testing System (CATS)-in an Italian sample of patients with amyotrophic lateral sclerosis (ALS).

METHODS

96 ALS patients and 116 healthy controls underwent a neuropsychological assessment including the AR subtests of the abbreviated version of the CATS (CATS-A). CATS-A AR subtests and their global score (CATS-A AR Quotient, ARQ) were assessed for their factorial, convergent, and divergent validity. The diagnostic accuracy of each CATS-A AR measure in discriminating ALS patients with cognitive impairment from cognitively normal controls and patients was tested via receiver-operating characteristics analyses. Optimal cut-offs were identified for CATS-A AR measures yielding an acceptable AUC value (≥ .70). The ability of CATS-A ARQ to discriminate between different ALS cognitive phenotypes was also tested. Gray-matter (GM) volumes of controls, ALS with normal (ALS-nARQ), and impaired ARQ score (ALS-iARQ) were compared using ANCOVA models.

RESULTS

CATS-A AR subtests and ARQ proved to have moderate-to-strong convergent and divergent validity. Almost all considered CATS-A measures reached acceptable accuracy and diagnostic power (AUC range = .79-.83). ARQ showed to be the best diagnostic measure (sensitivity = .80; specificity = .75) and discriminated between different ALS cognitive phenotypes. Compared to ALS-nARQ, ALS-iARQ patients showed reduced GM volumes in the right anterior cingulate, right middle frontal, left inferior temporal, and superior occipital regions.

CONCLUSIONS

The AR subtests of the CATS-A, and in particular the CATS-A ARQ, are sound measures of AR in ALS. AR deficits may be a valid marker of frontotemporal involvement in these patients.