Longitudinal Stability of Cognition in Early-Phase Relapsing-Remitting Multiple Sclerosis

Abstract Background: Up to 70% of people with multiple sclerosis (MS) experience cognitive impairment. Some remain cognitively intact despite advanced disease. Cognitive reserve (CR) theory postulates that individuals with higher levels of intellectual enrichment can tolerate more pathology than others before exhibiting cognitive impairment. Methods: Thirty-two individuals with early-phase relapsing-remitting MS with mild physical disability and disease duration less than 10 years and 32 controls were recruited. At baseline and after 3 years, participants completed neuropsychological tests evaluating several cognitive domains. The CR was assessed via a cognitive reserve index (CRI) using educational levels and North American Adult Reading Test scores. Change in cognition was assessed using a reliable change index. Results: At baseline, people with MS performed worse than controls on visual memory. There were no significant group differences on information processing speed, learning, language, and executiv...