Sensitivity and Specificity of the ECAS in Parkinson’s Disease and Huntington’s Diseases

Background and aims: The study aims to investigate psychometric properties of the ECAS, recently validated in the Italian language, in Parkinson’s (PD) and Huntington’s (HD) diseases. In particular, the sensitivity and specificity of the ECAS in highlighting HD and PD cognitivebehavioural features and in differentiating between these two populations and from healthy controls (HC) were evaluated. Methods: Participants were administered the ECAS, together with other cognitive screening tools (FAB, MoCA, RME) and psychological questionnaires (BDI, STAI/Y, I-DAS). Patients’ possible changes in behaviour were evaluated by carers interview (ECAS Carer Interview). 73 PD, 38 HD patients and 49 HC were recruited at the San Luca Hospital, IRCCS Istituto Auxologico Italiano and at CSS-Mendel and LIRH Foundation site, Rome. Correlations between the ECAS and traditional cognitive measures, together with core clinical features were analysed. Results: The ECAS distinguished between HD patients and HC (p<0.001) and between the 2 clinical syndromes (p< 0.001) with high sensitivity and specificity. Even if diagnostic accuracy of the ECAS in distinguishing between PD and HC was very low (p=0.05), the PD cognitive phenotype was very well described by the ECAS. Convergent validity of the ECAS against other traditional cognitive screening was observed, as well as correlations with psychological aspects and typical clinical features, especially for the HD group. Conclusion: The ECAS represents a rapid, feasible and sensitive tool, useful also in different neurodegenerative disorders affecting verbal-motor abilities other than ALS. Clinical applications in these neurodegenerative conditions require further investigations.