Cognitive impairment in patients with multiple sclerosis using the Brief Repeatable Battery-Neuropsychology test

Abstract
Aims To assess the cognitive impairment of multiple sclerosis (MS) patients using the Brief Repeatable Battery-Neuropsychology (BRB-N) test. Methods The performance of 59 patients with MS in the BRB-N test was assessed and compared with 152 matched healthy controls (HC). Results In most tests, MS patients performed worse than controls. Age and educational level strongly influenced the performance of the subjects. The Symbol Digit Modality Test (SDMT) best correlated with the other individual tests and contributed most to the general BRB-N factor. Furthermore, a correlation between physical disability and performance in some BRB-N tests was observed. Indeed, patients with progressive MS and greater physical disability performed worse in some tests than less disabled patients with relapsing MS. By creating a global BRB-N Z score, we found that patients generally performed 0.7 standard deviation (SD) below the level of controls. We obtained cut-off values stratified by age and education to determinate cognitive impairment in MS patients. Conclusions Our data show that cognitive impairment is prevalent amongst MS patients, and that a single cognitive measurement might be useful for monitoring patients during the progression of this illness.