Assessment of cognitive dysfunction in multiple sclerosis.

Cognitive deficit can be an early feature in the course of multiple sclerosis, may occur clinically isolated, impacts on social activities and could reflect disease progression that is independent of physical disability with potential therapeutical consequences. Neuropsychological tests should be independent of motor coordination or visuo-spatial ability, but sensitive to subtle cognitive changes, exploring attention speed and working memory They could be included in brief batteries with good normative data and alternative forms for future therapeutic trials. We recommend for a brief battery of neuropsychological tests the inclusion of PASAT and two memory tests: the learning stage of CVLT and backward Digit Span with a total time duration of 30 min. A complementary tool could be a cognitive questionnaire for informant. After a relapse, cognitive assessment should be performed at least 8 weeks afterwards. If the patient presents with psychiatric symptoms, a specific assessment should be proposed before starting a complete cognitive assessment. Finally, we propose some red flags warranting neuropsychological screening: patients with a mild physical disability, but unable to maintain their professional activities, pathological laughing-crying, increased age and low educational level.