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Advanced Neurology Fatigue management in patients with MS

40 years. MS is an autoimmune disease that affects twice as regarding this condition. These hypotheses divide fatigue
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many women as men. While the etiology of MS is not fully in MS into two subcategories: primary fatigue, caused
understood, it is believed that genetic and environmental directly by MS itself, and secondary fatigue, caused by
factors play a role. Due to damage to the myelin sheath by the other factors contributing to fatigue or MS symptoms. 10,11
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individual’s immune system, nerve conduction is disrupted, Multiple pathophysiological mechanisms have been
resulting in acute attacks, impaired physical mobility, and suggested to underlie primary fatigue. These mechanisms
various other long-term symptoms. Commonly reported include structural damage to the white and gray matter in
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symptoms include urinary problems, constipation, the brain, immune system involvement due to inflammatory
spasticity, pain, motor problems, cognitive dysfunction, processes, impairment of neural connectivity pathways
sexual dysfunction, and fatigue. Fatigue is a prevalent due to lesions and inflammation, and impairment of
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symptom among MS patients, affecting approximately 75 – metacognition due to disruption of homeostatic balance.
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90% of them. In fact, the majority of patients report fatigue MS is characterized by an increasing burden of lesions
as one of their top three symptoms, and more than half over time, particularly in the brain, brainstem, and spinal
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describe it as one of the most debilitating symptoms of the cord. These lesions cause neural damage, inflammation,
disease, significantly impairing their quality of life. Fatigue and demyelination, which are the underlying cause of
not only affects daily activities but also has a significant fatigue. Several studies have shown that the lesion load
impact on their work, family, and social life.
in white matter is associated with fatigue. 13-15 Lesion load
Fatigue is defined as the lack of physical or mental energy in the white matter has been reported to slow conduction
required to carry out daily activities. The characteristics of velocity, contributing to fatigue in both motor and cognitive
fatigue in individuals with MS differ from those in healthy functions. Lesions in the gray matter can affect structures
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individuals. 6 related to alertness, arousal, and motivation. In addition,
The fatigue experienced by individuals with MS can be lesions in dopaminergic, serotonergic, or noradrenergic
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characterized as follows: nuclei in the brainstem can contribute to fatigue. Gray
(i) Fatigue typically begins in the middle of the day and matter lesions in the brainstem can contribute to endocrine
intensifies toward the evening hours. and autonomic disorders through the disruption of the
(ii) Its severity may not correspond to the level of physical hypothalamic-pituitary-adrenal axis, resulting in fatigue. 18
or mental activity. An individual may describe him/ Secondary fatigue is exacerbated by various symptoms
herself as tired even if he/she is not engaging in any or conditions. Clinical variables associated with fatigue
activity. include stress, heavy exercise, neuropsychiatric symptoms
(iii) It can easily worsen with stress and temperature (such as anxiety and depression), infections, urinary
increase, such as during a fever. system problems, insomnia, pain, spasticity, and drug
(iv) Fatigue can have a significant negative impact on an side effects. 19,20 Although these symptoms do not directly
individual’s activities of daily living and quality of life. cause or initiate fatigue, they significantly exacerbate it.
(v) Its severity may be much higher than that of normal Therefore, since fatigue in MS patients is multifactorial, a
fatigue. single method for its management is unlikely.
(vi) It is possible to experience the effects of physical
activity in the morning, even if no activity was 3. Fatigue management in patients with MS
performed. 8 Managing fatigue in individuals with MS begins with
Although fatigue is a common symptom in individuals identifying it. Patients may not be aware that fatigue can be
with MS, it may be overlooked and left untreated if patients a symptom of MS and needs to be managed. In addition,
do not report it. It is important for health-care providers to they may not realize the impact of fatigue on their daily
ask about fatigue and for patients to express any symptoms lives, often prioritizing other issues during physician
they may be experiencing. This underreporting can happen appointments. Therefore, the first step is to ask patients if
due to reasons such as an incomplete understanding of they are experiencing fatigue. When patients report fatigue,
its pathophysiology or difficulty in diagnosing it through it is appropriate to use a scale to determine its severity. The
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neurological examinations or laboratory findings. 9 Fatigue Severity Scale and the Fatigue Impact Scale
are the most commonly used tools for this purpose. The
2. Pathophysiology of fatigue and scores obtained from these scales help determine both the
associated factors severity of fatigue and its impact on individuals’ lives.
The pathophysiology of fatigue in patients with MS has not After defining fatigue, it is important to identify any
been fully explained. However, there are strong hypotheses contributing factors. Comorbid diseases, such as anemia

Volume 3 Issue 2 (2024) 2 doi: 10.36922/an.2576