By Trevis Gleason – For Life With Multiple Sclerosis – Reviewed: December 29, 2022
Have you ever felt like you can’t think straight when you’re overly tired or physically fatigued? Sure, a lot of people could say yes to that question, but people with multiple sclerosis (MS) — and in particular, people with progressive forms of the disease — are more likely than most to understand this phenomenon.
We get fatigued, and any cognitive symptoms we may have seem to worsen. And as we find ourselves more burdened by this cog fog, we seem to become even more overwhelmed and fatigued.
It’s like the ascending and descending staircases of an M.C. Escher lithograph: We don’t know if we’re going up or down or even if we’re moving at all.
The Worse the MS, the More the Impact of Fatigue
A recent study helped researchers identify why it is that people with progressive MS in particular experience what they deemed “fatigue and dual-task impairment of walking and cognition.” Fatigue was judged on the Modified Fatigue Impact Scale (MFIS).
Using structural and functional MRI sequences, they observed a probable cause for this impairment.
It’s not just in our heads, as it were (though, of course, it is in our heads), that we find ourselves cognitively taxed when we’re fatigued. Both structural and functional frontal cortico-subcortical abnormalities were observed. (The cortex is the outer layer of the brain, and the subcortex comprises brain structures beneath the cortex.)
The worse a person’s MS was — judged by higher Expanded Disability Status Scale (EDSS) score, higher lesion load, and lower cortical volume (or more extensive brain atrophy) — the more significant the effect of fatigue on both the physical and cognitive symptoms of the disease.
It may seem obvious that the “worse” a person’s multiple sclerosis (the disease) is, the more something like fatigue would affect other symptoms. That there is another way to judge how “bad” the disease is by using these MRI techniques gives us proof of the physical relationship between how we feel and how we perform.
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