Cognitive impairment in multiple sclerosis can be predicted by imaging early in the disease

Background: Cognitive impairment is common in multiple sclerosis ( MS) and adds significantly to the burden of the disease. The ability to predict future cognitive impairment from imaging obtained at disease onset has not been investigated. Methods: 62 patients imaged within 3 months of a clinically isolated syndrome were assessed neuropsychologically 7 years later. Baseline and periodic MRI measures of lesions, atrophy and normal-appearing white and grey matter were regressed against neuropsychological scores to explore the best predictors of cognitive outcome. Results: 28 patients had developed clinically definite MS at follow-up and a further nine met revised McDonald criteria for MS. Deficits in speed of information processing and executive function were the most common abnormalities. Poor performance correlated with high anxiety ratings. Baseline T-1 lesion metrics predicted executive deficits, and new T-2 lesions at the 3-month follow-up predicted slowed information processing. An increase in myo-inositol concentration in normal- appearing white matter over the first 3 years was associated with poor executive function. Conclusions: MRI variables obtained at the onset of a clinically isolated syndrome can predict future development of cognitive abnormalities. Our findings may have implications in monitoring and treating patients.