Mark’s post: Measuring fatigue in MS



Fatigue is complicated and multifactorial. It may be classified as:

Primary fatigue 

Primary fatigue is apparently directly related to neurological damage, affecting one’s ability to activate or control muscle groups. It commonly affects walking. 
This is where damage to the central nervous system directly contributes to physical disability and means that the person affected must increase their efforts to make desired movements, and this will be fatiguing. 
In addition, damaged central nervous system circuitry can also give rise to spasticity and muscle stiffness.

Secondary fatigue 

Secondary fatigue is related to a variety of problems caused by the disease, including: lack of sleep; having to use the toilet in the night due to bladder issues; altered mood; muscle weakness owing to the effects of reduced exercise; and muscle spasm or stiffness.
In some circumstances symptoms may arise for both primary and secondary reasons, for example where there is a raised core temperature during an infection, that may have an impact on nerve impulse conduction (primary) but also making the person feel unwell (secondary). 
Increased temperature in the body caused for example by exercise or a change in the weather (Uhthoff’s phenomenon), is well known to exacerbate symptoms and would therefore be expected to increase the feeling of fatigue.
One possibility is that it is the inflammatory component of the disease itself that gives rise to the feeling of fatigue, some pwMS treated with Tysabri tell us that in addition to relapse cessation, their fatigue is also notably improved. 
Neurologists are trying to find biomarkers, for example IL-1b, that are both raised during inflammation and that can be measured in saliva. They could then be used as a way of quantifying both ongoing immune activity and fatigue.
by Dr Mark Baker

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  • Don’t people say post hsct fatigue is reduced? Wouldn’t that be a clean way to measure fatigue based on damage that has occurred and what is still occurring?

  • My fatigue seems to be strongly influenced by oxygen levels in the air. Houswork fatigues me very quickly, even if the house is cool, whereas I can do much more work outdoors in the fresh air. I have PPMS.

  • Thank you so much for this publication! Incredibly it seems that physical activity prevents me from feeling fatigue.

    When I have fatigue, for now (with MS we never know anything), maybe it's the secondary type, more related to mood swings, lack of sleep and going to the bathroom at night.



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