Cognitive deficits have only limited influence on health-related quality of life in amyotrophic lateral sclerosis

Objective: To explore the association between cognitive deficits and health-related quality of life in amyotrophic lateral sclerosis (ALS). Methods: The revised ALS Functional Rating Scale (ALSFRS-R for physical impairment), the ALS Assessment Questionnaire (ALSAQ-40 for health-related quality of life) and the Edinburgh Cognitive and Behavioral ALS Screen (ECAS for cognition) were assessed in 125 patients with ALS. Correlations between ALSAQ-40 domains and ECAS functions were tested using Spearman correlation. Linear regression was used to evaluate the relationship between dysphagia, depression, hopelessness, pain (all derived from corresponding items from the ALSFRS-R or ALSAQ-40), ALSFRS-R, ECAS and the ALSAQ-40. Results: Verbal fluency, language and executive function were disturbed in 69 (55%), 54 (43%) and 41 (33%) patients, respectively. In the ALS non-specific domains the memory and visuospatial function were impaired in 44 (35%) and 12 (10%) patients. In the non-demented group the five ECAS functions did not correlate with the ALSAQ-40 subdomains. The ALSFRS-R score, hopelessness, pain, and depression explained 65% of the ALSAQ-40 SI variance; the ECAS total score did not significantly predict ALSAQ-40 summary index. The ECAS visuospatial, executive function and fluency significantly predicted emotional well-being (adjusted R ² = 0.08). When the model was controlled for depression, hopelessness and pain none of the ECAS functions (visuospatial, executive function and fluency) were significant predictors of emotional well-being. Conclusion: Deficits in visuospatial function, executive function and fluency constrain the ability to manage activities of daily living and this might cause decline in well-being.