The Relationship between Fatigue and a Clinically Accessible Measure of Switching in Individuals with Multiple Sclerosis

Abstract

Objective We examined whether fatigue in multiple sclerosis (MS) is linked to switching processes when switching is measured by the Trail Making Test (TMT). Method Eighty-three participants with MS were administered a battery of standardized tests of switching, working memory, and processing speed. Ordinary least squares regression models were used to estimate the association between fatigue severity and switching above and beyond attention, working memory, and processing speed. Results We found a negative association between TMT performance and fatigue severity score. When measures of processing speed and working memory were included in the model, the switching measure continued to uniquely contribute to fatigue severity. Conclusions There may be a unique relationship between fatigue and switching processes identifiable by clinical measures of switching. Future research should continue to investigate this relationship by using both behavioral and neural markers to test models of fatigue to eventually identify specific intervention targets.

Role of selective attention in fatigue in neurological disorders

“…Slowed oral responses may also be driven by overt motor deficits related to speech production or altered sensorimotor processing. Such uncertainties were laid to rest in another study [ 13 ] where the difference in response time between a demanding attentional task and a less demanding attentional task was directly related to self‐reported fatigue levels, even after controlling for measures of memory and processing speed. This study used the difference between Trail Making Test B (TMT‐B) and TMT‐A as a measure of task switching.…”