Cognitive impairment in clinically isolated syndrome: A systematic review

The pattern of cognitive abnormalities in multiple sclerosis (MS) has been extensively studied and well characterized. However, little is known about the cognitive involvement in patients with the clinically isolated syndrome (CIS). OBJECTIVES: To perform a systematic review of the results of the studies on cognitive dysfunction in CIS patients. METHODS: Cochrane, Lilacs, PubMed/Medline and SciELO databases were searched for studies involving patients with clinically isolated syndrome submitted to neuropsychological evaluation. RESULTS: Seven studies fulfilled the selection criteria adopted in this review. The pattern of cognitive abnormalities in CIS resembles that found in patients with MS and is characterized by attention deficit, reduced information processing speed and impaired working memory and executive functions. The frequency of cognitive impairment in CIS seems to be lower than in MS. CONCLUSIONS: Cognition should be evaluated in patients with CIS. Future studies are required to evaluate the impact of cognitive abnormalities and to correlate them with axonal damage findings in patients with CIS.