Cognitive Function in Patients with Multiple Sclerosis: Impairment and Treatment

Abstract

Cognitive impairment is common in multiple sclerosis (MS), with up to 65% of patients exhibiting some type of neuropsychological dysfunction. The cognitive domains most affected by MS are learning and memory, attention, information processing, visuospatial abilities, and executive functioning. It is difficult to detect cognitive dysfunction in patients with MS during routine neurologic examinations because conventional measures of neurologic disability are not sensitive enough to detect cognitive impairment. Furthermore, cognitive dysfunction is only weakly correlated with the type of MS, disease duration, or physical disability. However, brain imaging studies show that a relatively strong correlation exists between cognitive dysfunction and overall lesion burden and brain atrophy in MS. This paper reviews the natural history of cognitive dysfunction, areas of cognition affected, the correlation between MRI measures and cognitive dysfunction, issues related to neuropsychological assessment, and treatment of cognitive impairment with disease-modifying MS drugs.