Frontotemporal-spectrum disorders and functional independence in non-demented ALS patients

Background: The present study aimed at determining whether, net of motor confounders, neuropsychological features affect functional independence (FI) in activities of daily living (ADLs) in non-demented amyotrophic lateral sclerosis (ALS) patients. Methods: N = 88 ALS patients without frontotemporal dementia were assessed for FI—Katz’s Basic ADL Scale (BADL) and Lawton-Brody’s Instrumental ADL Scale (IADL)—, cognition—Edinburgh Cognitive and Behavioural ALS Screen (ECAS)—and behaviour—Beaumont Behavioural Inventory and Dimensional Apathy Scale. The association between cognitive and behavioural measures and BADL/IADL scores was assessed by covarying for demographics, anxiety and depression levels, disease duration and motor confounders—i.e. ALS Functional Rating Scale-Revised (ALSFRS-R) scores, progression rate and both King’s and Milano-Torino stages. Results: Higher scores on the ECAS-Language were associated with higher IADL scores (p = 0.005), whilst higher apathetic features—as measured by the Dimensional Apathy Scale (DAS)—were inversely related to the BADL (p = 0.003). Whilst IADL scores were related to all ECAS-Language tasks, the DAS-Initiation was the only subscale associated with BADL scores. Patients with abnormal ECAS-Language (p = 0.023) and DAS (p = 0.008) scores were more functionally dependent than those without. Discussion: Among non-motor features, language changes and apathetic features detrimentally affect FI in non-demented ALS patients.