Cognitive function in amyotrophic lateral sclerosis: Is the ECAS a valid instrument for screening cognitive function in ALS?
Summary
The main goal of this study was to validate the Edinburg cognitive and behavioural ALS screen (ECAS) in a Dutch sample. The ECAS is a cognitive instrument developed especially for patients with Amyotrophic lateral sclerosis (ALS) that measures executive function, language, verbal fluency, memory and visuospatial functions (Abrahams et al., 2015). Up to 50% of ALS patients suffer from cognitive impairment, which is associated with a lower quality of life. In order to validate the ECAS, three goals were set. First, normal scores were calculated that were corrected for age and education. The cognitive performance of 298 ALS patients was analysed according to these normal scores. Second, the reliability of the five cognitive domains was assessed. Third, the ECAS was compared with other validated neuropsychological research to obtain construct validity. The hypothesis was that the ALS patients would demonstrate cognitive impairment on the domains executive functions, language and verbal fluency compared with healthy control subjects. A preserved memory and visuospatial functions were expected. Also, a high reliability and construct validity were predicted. In contrast with the hypothesis, the results of the performance in ALS patients on the ECAS deviated from what was expected. Furthermore, reliability and construct validity were not achieved. In conclusion: The ECAS could not be validated in this study due to the limited number of participants with signs of cognitive impairment. Further research with larger sample size is needed to validate the ECAS in the Dutch population.