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THE REALITY OF MS FATIGUE
How many of you struggle with seemingly insurmountable fatigue? You know you have to do the bills, but it is too much effort to go into one room to find the bills and then into another to find your checkbook? Or you drive to the first store on your list, walk in from the parking lot, only to realize you don't have enough energy left to shop, turn around and go back to the car to drive home, having not accomplished any of your errands? It is a different fatigue than being bone-tired. Before you were ill, even if you were tired beyond tired you could still muster up enough energy to do what really had to be done. Now, sometimes you can't. Family, friends and coworkers do not understand and make comments about "trying harder." You begin to feel truly lazy. This inability to overcome "fatigue" sounds ridiculous even to ourselves. It gnaws away at our own self-image.
Fatigue is one of the three most disabling symptoms of MS and is the one most like to lead to early departure from the workplace. 80% to 90% of people with MS complain of severe fatigue at some point. For about 60% it is a constant companion.
Research with new MRI techniques is showing a correlation between "gray matter" (the thinking cells) injury, from very early on in the MS course, and both cognitive and fatigue problems. This "gray matter" fatigue further slows down the ability to accomplish anything and makes any action more difficult.
Fatigue in MS is not easy to explain to ourselves or to others.
Types of Fatigue
There are several types of fatigue at play in MS. Any or all of them may be working against a person's ability to move through their day effectively.
1) Usual everyday, every person fatigue of daily life. You do a lot and you get tired at the end of the day. It's no different for people with MS.
2) Increased fatigue of exertion. In people with muscle weakness, those muscles will fatigue faster in continued use. Nerves fibers affected by demyelination are susceptible to a) early exhaustion. This means they become tired with far less use. b) Rate-dependent signal block. This means that the faster you try to move, the more poorly the signal gets to the muscles. And, c) There can be complete conduction block with increased temperature. As a person exercises or is exposed to higher heat, the demyelinated nerve fiber may completely fail. All this boils down to decreased stamina that you cannot correct with conditioning exercise. It also can mean that whatever you are doing, you must do slowly in order to get it done at all. An attempt to move fast can cause failure of the muscles to even get the signal. Finally, the act of exercising itself can raise the body's core temperature slightly in all people. This increase in temperature accentuates the weakness, along with other MS symptoms. The same occurs no matter why a person gets too hot. "Too hot" may indicate just a fraction of a degree of increased core temperature.
3) Spasticity - the work of moving a given set of muscles is actually counteracted by the constantly increased tone (spasticity) of the muscles opposing them. For me it is like dragging a 10 lb. weight when I try to swing my R leg forward to walk because of the muscles that are constantly trying to swing my leg back. For people with spasticity sometimes it is a major effort to do the simplest motion.
4) Depression - depression is a "primary" product of MS. This means that the disease ITSELF causes the depression. Fatigue is a major side effect of depression.
5) Fatigue of a chronic, inflammatory disease - This is felt probably to be caused by the release of tissue by-products of inflammation. (Lupus, RA, major infection,, etc.) However, comparing self-reported fatigue, it is worse in MS, than in people who are far more disabled by some other chronic conditions.
6) Fatigue of sleep deprivation - Sleep-related complaints are about 3 times greater in people with MS than in healthy controls. Sleep problems are associated with higher levels of depression. Also, there are several sites in the brain that serve "supplementary motor areas" that have been linked to sleep complaints. This might possibly be related to the very common occurence of sleep-disturbing nocturnal spasms. Inadequate sleep leads to fatigue, sleepiness, and poor performance, both mental and physical.
7) Medication side effects. Many of the meds used in controlling MS symptoms cause fatigue and/or drowsiness as a prominent side effect. Some meds, especially those used for spasticity cause muscle weakness at higher doses.
8) This is one that is rarely mentioned, but my neurologist has discussed it. In MSer's who have significant vertigo, there is an added mental fatigue. The brainstem, combined with portions of the cortex, and the vestibular system all make sure that we remain upright, and that are bodies move in a coordinated way against gravity. All this stuff takes place in the deep, background of automated brain function. When part of this system is disrupted, the system that has to take up the slack is the visual system. This, however, is brain processing that is essentially on the conscious level. It robs the person of that much mental energy just to remain upright. Sort of like RAM having to do a functions normally handled by the CPU. Everything bogs down. How many of you with vertigo or balance problems find that visually "busy" environments (like traffic or store aisles) or sitting at a computer screen exhaust you way out of proportion to the "work" you are actually doing - or that reading actually seems to physically tire you?
THE FATIGUE OF MS
9) The exact nature of MS-Specific Fatigue is not completely understood. It appears to be more of a mental fatigue possibly due to overall slowing of nerve conduction and communication in the brain. In fact, it is not unusual to see “diffuse slowing” on an EEG of a person with MS. Some researchers feel that this fatigue is a failure of the brain to initiate activity. But, whatever the exact nature, it is a major stumbling block for many with MS in doing what they want or need to do. This fatigue can be over-powering in some people with MS.
So fatigue is one of the “invisible” disabilities of MS that lead to so much misunderstanding with family, friends, employers and sometimes even poorly educated doctors. They think, and often say outloud that "We’re just tired and not trying hard enough." The MS Society publishes a great pamphlet that you can order or print off called, “But You Look So Good!” And that really does sum it up.
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