Clinimetrics of the Italian version of the Montreal Cognitive Assessment (MoCA) in adult-onset idiopathic focal dystonia

Abstract

This study aimed at assessing the clinimetrics of the Montreal Cognitive Assessment (MoCA) in an Italian cohort of patients with adult-onset idiopathic focal dystonia (AOIFD). N = 86 AOIFD patients and N = 92 healthy controls (HCs) were administered the MoCA. Patients further underwent the Trail-Making Test (TMT) and Babcock Memory Test (BMT), being also screened via the Beck Depression Inventory-II (BDI-II) and the Dimensional Apathy Scale (DAS). Factorial structure and internal consistency were assessed. Construct validity was tested against TMT, BMT, BDI-II and DAS scores, whilst diagnostics against the co-occurrence of a defective performance on at least one TMT measure and on the BMT. Case-control discrimination was examined. The association between MoCA scores and motor-functional measures was explored. The MoCA was underpinned by a mono-component structure and acceptably reliable at an internal level. It converged towards TMT and BMT scores, as well as with the DAS, whilst diverging from the BDI-II. Its adjusted scores accurately detected cognitive impairment (AUC = .86) at a cut-off of < 17.212. The MoCA discriminated patients from HCs (p < .001). Finally, it was unrelated to disease duration and severity, as well as to motor phenotypes. The Italian MoCA is a valid, diagnostically sound and feasible cognitive screener in AOIFD patients.

Keywords: Cognitive screening; Dystonia; Hyperkinetic; Montreal Cognitive Assessment; Movement disorders; Neuropsychology.

Fig. 1

ROC curves for raw and adjusted MoCA scores. ROC receiver-operating characteristics, MoCA Montreal Cognitive Assessment. Raw scores (cut-off: ≤ 20): AUC = 0.89; SE = 0.05; CI 95% [0.79, 0.99]; adjusted scores (cut-off: < 17.212): AUC = 0.86; SE = 0.07; CI 95% [0.74, 0.99]. MoCA scores were adjusted according to Aiello et al. (2022a)