Fatigue in Multiple Sclerosis: A Multifaceted Approach
Open Access
- Author:
- Mc Nett, Sienna
- Area of Honors:
- Biology
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Peter Andrew Arnett, Thesis Supervisor
Richard W Ordway, Thesis Honors Advisor - Keywords:
- Fatigue
Depression
Multiple Sclerosis
MS
Autoimmune
Neuropsychology
Biology
Neuroimaging
Psychology
Chronic Disease
Clinical
Response Time Variance
Cognitive Fatigue - Abstract:
- INTRODUCTION: Fatigue is a debilitating symptom that affects the quality of life for many individuals living with multiple sclerosis (MS). The nature of this elusive disease feature is still not well understood, leaving possibility for further exploration and potential for clinical intervention. While depression has been tied to fatigue in the MS population, research has suggested that recovery of depression does not lead to recovery from high levels of fatigue. The purpose of this thesis is to examine fatigue from psychological, structural, and behavioral angles in order to better understand fatigue and its relationship with depression in MS. METHODS: (a) The sample (n=54) was sorted into three depression groups (never depressed, remitted depression, and currently depressed). Total, physical, social, and cognitive fatigue impacts were examined among depression groups using a series of ANOVAs. (b) A series of Pearson Correlations were conducted between proportioned structural volumes (hippocampus, third ventricle, and thalamus) and cognitive fatigue as well as total fatigue. This analysis was done for the overall sample (n=51) and the three-group divided sample. The relationship between proportioned hippocampus volume and level of depression was also examined. (c) Response time variance and mean response time were calculated from the Computerized Assessment of Response Bias (CARB) and analyzed in relation to different fatigue indices for the overall sample (n=48). RESULTS: (a) Never and remitted depressed groups were found to have significantly lower levels of total fatigue severity, total fatigue impact, physical fatigue impact, and social fatigue impact than the currently depressed group. Cognitive fatigue impact levels were significantly higher in the ever-depressed groups compared to the never depressed group. (b) Hippocampal volume was the one structural region found to meaningfully correlate with total fatigue impact and cognitive fatigue impact. No significant correlations were found between fatigue indices and hippocampus volumes for any of the divided three-groups. DISCUSSION: (a) Findings suggest cognitive fatigue and depression have a different relationship than depression and other fatigue types. It is clinically relevant that cognitive fatigue does not appear to remit with depression. (b) Findings support hippocampal volume involvement in total and cognitive fatigue but not level of depression, despite fatigue’s high correlation with depression. (c) Findings were limited in statistical power due to small sample sizes. While no significant findings were found, fatigue severity positively trended with response time variance and mean response time, suggesting potential for these measures to serve as objective measures of total fatigue.