Cognitive impairment in clinically isolated syndromes: A control-case study

Introduction - Cognitive impairment is common in multiple sclerosis (MS) but its diagnosis is often made late, at the stage of social and professional disinsertion. Studies of the cognitive aspects in early forms of MS such as clinically isolated syndrome (CIS) and radiologically isolated syndrome (RIS) are rare.Objectives - To analysis the cognitive functions of a first demyelinating event and identify the areas that would be most affected early.                            Patients and methods - The cognitive profile of a homogeneous population of 13 patients with a CIS was evaluated, and compared with 15 healthy controls, matched according to age, sex and level of education. A battery of neuropsychological tests (BCCogSEP, Short battery for cognitive assessment of MS) validated in MS,was used. Its components explore memory and verbal skills, attention, information processing speed (IPS) and executive functions.Results - The overall cognitive performance was reduced in the CIS group,compared to control group. Five out of thirteen CIS patients (38%) had an overall cognitive impairment, demonstrated by the achievement of at least two or three battery tests. The Paced Auditory Serial Addition Test (PASAT) was the most altered test (84.6% impairment). IPS and working memory were the most affected functions in the patients.Conclusion - Cognitive dysfunctions can be seen very early and can severely affect the prognosis of MS