Although individuals with multiple sclerosis (MS) continue to be vulnerable to cognitive fatigue at follow-up, severity does not seem to increase with time, according to a recent study. Researchers aimed to evaluate cognitive fatigue over a 3-year interval in individuals with early-phase relapsing-remitting RRMS. The sensitivity of the Paced Auditory Serial Addition Test (PASAT) at detecting cognitive fatigue was evaluated, as was the impact of scoring method. 32 people with MS and 32 controls completed the 3- and 2-second PASAT (PASAT-3″ and -2″) as a measure of sustained attention at baseline and 3-year follow-up. Researchers found:

• Performance on the PASAT remained stable across time, with improvement noted on the PASAT-2″ likely due to practice and the small sample size.
• Cognitive fatigue was noted at both times, although sensitivity varied based on scoring method.
• No evidence of worsening cognitive fatigue was noted over time.
• The MS group performed worse only when cognitive fatigue was the outcome variable.