La BCcogSEP : une batterie courte d’évaluation des fonctions cognitives destinées aux patients souffrant de sclérose en plaques

Abstract

In French language, there is no standardized procedure to assess cognitive function in patients with multiple sclerosis (MS). Such an assessment is however very useful to determine the consequences of the disease on cognitive function, to evaluate the disease progression and the consequences of usual treatments on cognition. This study aimed to develop and validate a French language battery based on "the Brief Repeatable Battery of Neuropsychological tests for Multiple Sclerosis" (BRB-N) often used in other countries. In an initial phase, the battery was composed of the French version of the 5 BRB-N tests to which were added 4 tests assessing immediate and working memory as well as executive function. 52 healthy control subjects (20-50 years) participated in the study. A principal component analysis (PCA) of their data examined the contribution of each test into the battery. 93 other healthy subjects participated in a second phase where analyses of variance were carried out to investigate the effect of the main demographical variables. Finally, the performance of two patient groups (20 with a EDSS score<or=3 et 31 with a EDSS score>3) was compared to the healthy controls in order to investigate the ability of our battery to detect cognitive impairment in MS patients. The PCA showed that each test, except one, had a specific contribution to the battery. The final battery (BCcogSEP) was thus comprised of 8 tests. MANOVA and ANOVA showed significant effects of age, sex and educational level on performance. In consequence, a procedure allowing to take into account these factors was developed. The battery was able to detect cognitive impairment in MS patients, even when the disease is not severe. In this case, deficits were observed in tests assessing executive function, information processing speed, immediate and working memory. This short battery with reliable psychometric qualities allows the interpretation of a MS patient's performance considering his/her demographical characteristics and is able to detect cognitive abnormalities even in case of mild physical handicap.