The Effect of a Single Bout of Physical Exertion on Language Skills in Individuals with Multiple Sclerosis
A dominant symptom of MS is fatigue, with 75% of individuals with MS reporting extreme fatigue. The impact of MS fatigue upon language function is less documented than cognition & this research on expressive language function in patients with MS was intended to contribute to closing the literature gap. Although fatigue, implicit as the outcome of physical exertion is well recognized, its impact upon language is notably under researched.
Does a single bout of physical exertion cause a decline in 1) expressive language & 2) word finding skills in individuals with MS? 3) Does a single bout physical exertion increase the duration of time needed to complete confrontation-naming measures?
The study had a total of 24 participants, n=17 (intervention) and n=7 (controls). In the intervention group, all participants had clinically diagnosed MS, 5 had PPMS while 12 had RMMS. Participants were assessed in a range of language tasks after undergoing one bout of cardio-vascular exercise & asked to provide a subjective fatigue score in addition to objective tests. The tasks were then replicated in a counter-balanced fashion after a fatigue-equivalent rest period.
Q1. Groups differed with regard to EVT-2 scale scores, p = .005. A Tukey HSD post hoctest determined that the Intervention Fatigue Group had a significantly higher confrontation naming errors on the EVT-2 in comparison to all other groups.
Q2. Groups significantly differed on their ability to generate words when given a letter of the alphabet (PS1M), p = .025. A Tukey HSD post hoc test determined that the Intervention Fatigue Group had a significantly lower PS1M score comapred to all other groups. A Tukey HSD post hoc test also determined significant group differences on the sematic category task in which subjects were instructed to generate the name of countries within 60 seconds, p< .001. The Intervention Fatigue Group had a significantly lower score compared to all other groups.
Q3. Tests of between-subjects on the CTOPP, a test of rapid identification of letters, number, colors & objects, showed that 2 of 3 variables were significant. Groups significantly differed on the Rapid Color Naming Total Time, p = .042. A Tukey HSD post hoc test determined that the Intervention Fatigue Group had a significantly higher score to complete the task. Groups also significantly differed on the Rapid Object Naming Total Time, p = .032.
The results of the study illustrate that after a single bout of fatigue individuals with MS, unlike the control group, demonstrated statistically significant changes in their language skills most notably in the areas of confrontation naming, phonemic & semantic verbal fluency, and the total amount of time necessary to name familiar objects & colors. Although the current study had a conservative sample size, the results indicate the need for larger studies investigating the relationships between fatigue & language in individual with MS.