Researchers link task length with cognitive fatigue in MS

Kessler Foundation researchers have authored a new article that provides insight into the factors that contribute to cognitive fatigue in individuals with multiple sclerosis (MS).

The article, "Subjective cognitive fatigue in MS depends on task length," was epublished ahead of print on October 27 in Frontiers in Neurology. The authors are Joshua Sandry, PhD, Helen Genova, PhD, Ekaterina Dobryakova, PhD, John DeLuca, PhD, and Glenn Wylie, DPhil, of Kessler Foundation. This study was supported by the National MS Society and the New Jersey Commission for Brain Injury Research.

Cognitive fatigue, which is common in MS, has subjective and objective manifestations. Treatment for fatigue is hindered by the lack of understanding of contributing factors. This study examined how the variables of processing speed, working memory, time on task and cognitive load influence cognitive fatigue in 32 individuals with MS and 24 controls. The investigators found that subjective and objective fatigue were independent of one another, and that subjective cognitive fatigue increased as time on task increased. This increase in cognitive fatigue was greater in the MS group. No relationship was found between cognitive fatigue and the other cognitive variables.

"In our study, task length was the factor associated with subjective cognitive fatigue," said Dr. Sandry, lead author, "which supports the hypothesis of Temporal Fatigue. This finding should be considered when designing cognitive studies in MS populations." Dr. Sandry noted, "More research is needed to look at these parameters in people with different types of MS, different levels of cognitive impairment and in more advanced stages."