Cognitive impairment progresses continuously in multiple sclerosis (MS), associated with atrophy and lesion accumulation, according to a recent study, suggesting that interventions targeting these processes could be beneficial at all disease stages. Widespread cognitive functions are more profoundly affected, associated with lesions and corpus callosal atrophy, supporting the idea of an underlying disconnection mechanism for cognitive decline in MS. A cohort of 37 MS patients reflecting 5 decades of disease duration and all subtypes was followed over 17.5 years. Matched controls were recruited at the last follow-up. During the last 8.5 years of the study, brain MRI was performed to analyze normalized volumetrics of 3 global tissue compartments (white and gray matter, lesions) and strategic regions (corpus callosum, thalamus, hippocampus). Researchers found:

• Cognitive decline progressed continuously throughout the study paralleled by atrophy and lesion accumulation.
• The cognitive index partly correlated with Expanded Disability Status Scale and was mainly associated with the lesion fraction and callosal fraction in multiple linear regression analysis.
• The lesion fraction was an independent predictor of the cognitive performance 8.5 years later.