Uncovering the association between fatigue and fatigability in multiple sclerosis using cognitive control

Area of Science:

• Neuroscience
• Clinical Psychology

Background:

• Fatigue and cognitive dysfunction are prevalent in multiple sclerosis (MS).
• The connection between subjective fatigue and objective fatigability in MS remains unclear.
• Cognitive control tasks may reveal fatigability and link subjective/objective cognitive fatigue in MS.

Purpose of the Study:

• To investigate the association between objective fatigability, subjective fatigue, and baseline cognitive function in MS patients.
• To utilize the Blocked Cyclic Naming Task (BCNT) to induce and measure cognitive fatigability.
• To explore the relationship between performance on a cognitive control task and self-reported fatigue levels.

Main Methods:

• Twenty-one MS patients completed baseline assessments including cognitive tests (MoCA), fatigue, sleep, and depression questionnaires, and disability scales (EDSS).
• Participants performed the BCNT, a task involving naming pictures from related and unrelated blocks, with response times (RTs) recorded.
• State momentary fatigue was assessed before and after the BCNT; data analyzed using ANOVA and Pearson correlations.

Main Results:

• MS patients exhibited performance decline in related picture blocks and reduced repetition priming over time.
• Objective cognitive fatigability was observed, with increased differences between related and unrelated conditions in later task stages.
• A strong correlation was found between objective fatigability measured by the BCNT and subjective momentary fatigue (r=0.612, p=0.007).

Conclusions:

• The study demonstrates a significant association between subjective and objective cognitive fatigue in individuals with MS.
• The BCNT is a valuable tool for assessing cognitive fatigue and control in MS.
• Further research with larger cohorts is recommended to validate these findings in the MS population.