Benign multiple sclerosis: cognitive, psychological and social aspects in a clinical cohort

A study of cognitive, psychological and social aspects in benign multiple sclerosis (MS). Methods One hundred and sixty three patients with benign MS (defined as disease duration > or = 15 years and Expanded Disability Status Scale (EDSS) score < or = 3.0 ) underwent neuropsychological testing on the Rao's Brief Repeatable Battery (BRB) and the Stroop test, evaluation of depression on the Montgomery and Asberg Depression Rating Scale (MADRS), of fatigue on the Fatigue Severity Scale (FSS) and of handicap on the Environmental Status Scale (ESS). Patients' cognitive performance was compared with that of 111 demographically matched healthy controls. Cognitive impairment was defined as the failure in at least 3 tests, using the fifth percentile of controls' performance as the cut-off point. Clinical correlates of cognitive impairment were determined by multiple logistic regression analysis.

Cognitive assessment led to the identification of 74 subjects (45%) with cognitive impairment. Significant fatigue was found in 80 subjects (49%) and depression in 88 patients (54%). In comparison with cognitively preserved subjects, cognitively impaired patients exhibited higher handicap scores on the ESS (p = 0.005). In the regression analysis, only EDSS scores were significantly associated with cognitive impairment (OR 1.8, 95%CI 1.2-2.6).

Current definitions of benign MS may overestimate this entity, since they are mainly weighted for the patients' motor abilities and fail to capture relevant disease-related cognitive, psychological and social problems.