Autonomic Nervous System (Re)activity and Multiple Sclerosis-Related Fatigue: A Synthesis of Evidence and a Proposed Conceptual Extension
Year: 2026
Type: dissertation
Abstract: Fatigue is among the most common and disabling symptoms of multiple sclerosis (MS), yet its underlying mechanisms remain only partly understood. Building on the sickness behavior model and its autonomic extension, this dissertation examines the role of autonomic nervous system (ANS) dysfunction in MS-related fatigue. Across two reviews and two empirical studies using heart rate variability as a biomarker of autonomic activity, the findings identify reduced parasympathetic regulation and impaired autonomic adaptability as physiological correlates of fatigue. Although interventions such as progressive muscle relaxation, deep breathing, and self-alert training modulated autonomic activity, they did not significantly reduce fatigue. To explain this discrepancy, an extended conceptualization is proposed that incorporates “fatigue debt” and allostatic overload as secondary maintaining processes. Together, these mechanisms may contribute to the persistence and treatment resistance of fatigue beyond its initial neuroimmune-autonomic origins.
Author: Garis, Guadalupe
Language: English
Subfield: Clinical Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W7172232985