Cognitive problems have limited impact on overall health-related quality of life (QoL) in people with amyotrophic lateral sclerosis (ALS) — but verbal fluency and space orientation are among the factors linked to patients’ emotional well-being, according to new research.
The study, “Cognitive deficits have only limited influence on health-related quality of life in amyotrophic lateral sclerosis,” appeared in the journal Aging & Mental Health.
Health-related QoL is a measure of how individuals perceive their health, including physical factors and emotional well-being. Researchers say that, in ALS, psychological and supportive factors also should be addressed when studying QoL. However, the impact of cognitive deficits on health-related QoL remains to be properly evaluated.
A team at Jena University Hospital, in Germany, addressed this gap in 125 people with ALS — median age 64 years, 52 women — recruited between May 2013 and December 2016. The participants had been living with ALS for a median of 19 months.
Physical impairment was assessed with the revised ALS Functional Rating Scale (ALSFRS-R). Health-related QoL was evaluated with the ALS Assessment Questionnaire (ALSAQ-40), which assesses domains of mobility, activities of daily living, eating, communication, and emotional well-being.
Cognition was assessed with the Edinburgh Cognitive and Behavioral ALS Screen (ECAS). This screener includes ALS-specific domains — fluency, language, and executive function, or goal-directed actions and adaptation to novel situations — and ALS non-specific domains. These include memory and visuospatial function, which refers to space orientation, and motion and target localization.
The researchers then evaluated the potential links between dysphagia — difficulty swallowing — depression, hopelessness, pain, total ALSFRS-R and ECAS scores, and the ALSAQ-40 summary index (SI) of overall health-related QoL.
The results showed that verbal fluency was impaired in 69 patients (55%). Difficulties in language were found in 54 patients (43%), while executive function impairment was found in 41 (33%). Among non-specific domains, memory problems were found in 44 patients (35%) and visuospatial dysfunction, or difficulties, in 12 (10%).
No differences in cognition and behavior were found between bulbar patients — those with first manifestations in speech and swallowing — and limb-onset individuals, who first see symptoms in the arms and legs. There also were no differences seen between men and women, or when comparing patients with high and low scores of emotional well-being.
No correlation was found between cognitive deficits and patients with high or low scores of health-related QoL and emotional well-being. Therefore, the investigators then restricted the analysis to the 103 patients without cognitive impairment. This further showed no significant links between the five ECAS functions and the ALSAQ-40 domains.
“The present analysis shows that cognitive deficits (ECAS total score) have no impact on overall health-related QoL … in non-demented ALS patients,” the researchers said.
The results further revealed that the ALSFRS-R score, hopelessness, pain and depression explained 65% of the ALSAQ-40 SI variance.
Fluency and visuospatial and executive functions significantly predicted emotional well-being. However, when the scientists accounted for differences in depression, hopelessness and pain, they found that only hopelessness and depression were significant predictors.
“Whether there is a general association between well-being on cognition or vice versa remains uncertain,” the researchers said.
“Longitudinal studies … could improve our understanding and the potential positive influence of high emotional well-being on cognitive function in ALS,” the team added.