Cognitive decline (CD) is common but often under-recognized in ALS due to the scarcity of adequate cognitive screening methods. In this scenario, the Amyotrophic Lateral Sclerosis Cognitive Behavioural Screen (ALS-CBS) is the most investigated instrument and presents high sensitivity to identify CD. Currently, there are no validated cognitive screening tools for ALS patients in the Brazilian population and little is known about the frequency of ALS related CD in the country. We assessed the accuracy of the Brazilian Portuguese version of ALS-CBS Cognitive Section (ALS-CBS-Br) for classifying the cognitive status of Brazilian patients compared to a standard neuropsychological battery, and estimated the prevalence of CD in the Brazilian ALS population. Among 73 initially recruited ALS patients, 49 were included. Twenty-four patients were excluded due to severe motor disability, FTD diagnosis or non-acceptance. Ten healthy controls were also included. Ten ALS patients (20%) were diagnosed with executive dysfunction (ALSci) based on the battery results. ALS-CBS-Br scores were significantly lower in the ALSci group (p < 0.001). The scale accuracy in detecting executive dysfunction was 0.906. Optimal cut-off score was 10/20 (specificity 0.872 and sensitivity 0.900). In conclusion, the ALS-CBS-Br may facilitate the recognition of CD in routine clinical care and complement future studies in our population.
Keywords: ALS; cognition; motor neuron disease; screening.