Cognitive and behavioral impairments in German and Chinese ALS populations - a post-hoc comparison of national study data.

This study aimed to clarify whether differences between German and Chinese studies using the standardized Edinburgh Cognitive and Behavioural ALS Screen (ECAS), might be explained by differences in translated versions of ECAS, by patient demographic or clinical characteristics or by population-specific factors. Comparisons were performed on data from two previous studies in Germany and China. We found except for spelling task (p = 0.05), no differences between control groups of two countries were detected after adjusting for demographics. In contrast, differences were observed in scores on total ECAS, ALS-specific function such as different executive functions (all p < 0.01) and language (p = 0.02), even after correcting for demographic and clinical variables. Chinese ALS cohort performed worse in executive subfunction scores for sentence completion, alternation, social cognition, digit span and language comprehension; they performed better in spelling. Chinese ALS cohort more frequently exhibited disinhibition (p = 0.02), whereas German cohort more frequently exhibited loss of sympathy (p = 0.01) and stereotyped behavior (p = 0.03). Chinese and German ALS cohorts showed a distinctly different pattern in executive and language function. Most of the differences might be related to distinct differences between populations as only spelling might be affected by different language versions of ECAS. Socio-cultural factors might explain behavioral profile differences.