By Ed Lash
Now seems like a good time to talk about the weather-specifically the effect that hot, wet weather can have on people with multiple sclerosis (MS).
Traditionally, the heat factor with MS has been explained as being due to temporary additional impairment of demyelinated nerve fibers in the central nervous system (CNS) due to a rise in body temperature. In other words, damaged nerve cells are much less efficient when the body’s core temperature rises and functions or sensations associated with those damaged nerve cells will then appear worse.
This does not fully explain, however, the appearance of new and prolonged symptoms emerging under heat conditions as happens to many individuals with MS.
To begin with, your doctor may have recommended limiting physical activity on hot days, or not taking hot baths. In addition, many individuals with MS notice a flare-up of symptoms during emotional upsets, otherwise known as “getting hot under the collar.” Being overheated with strenuous physical activity, even on a cool day, can sometimes do the same. Under all these conditions, body temperature is often raised and it’s this rise in body temperature which gives many people problems.
Body temperature is also raised during some illnesses. With illness, fever is good. It signals the immune system to become more active, to make protective white blood cells work faster, and to increase the number of anti-bodies in the blood. In other words, fever triggers the immune system to be more aggressive.
A University of Michigan researcher, Dr. Joseph Cannon, studied the effects of exercise on the immune system in rats and humans. He noted that the immune system may become more active in any situation when there’s a rise in body temperature (such as during strenuous activity); in other words, that exercise can have the same effect on the immune system as fever does. Since the immune system takes its cue from a rise in body temperature during illness, it evidently does the same when any rise in temperature occurs, such as during strenuous exercise, a hot day, a hot bath, or emotional stress.
Any increase in temperature, then, could result in a situation where white blood cells may be produced to fight an enemy—with no enemies around to fight! Imagine some of these white blood cells entering the CNS, gathering at various points along the nerves. These gatherings of white blood cells result in inflammation, or swelling, resulting in pressure, or a “squeeze” on nerve cells in the area. Depending on which nerve cells are being squeezed, new symptoms may appear in that part of the body associated with those nerve cells.
If this is true, then what can a vulnerable person with MS do?
First of all, it seems wise to avoid all heat situations to discourage your immune system from that kind of response as much as possible and to avoid even the slightest possible demyelination from the added inflammation.
In the case of infections, such as with the bladder, tooth abscess, or the flu, get good medical attention as soon as you begin to suspect a problem in order to help avoid or limit fever. Bladder infections can often be prevented by drinking plenty of fluids, especially water, and by being attentive to advice from your doctor. To minimize the effects of colds and flu, try not to get run-down. The best way not to get run-down is to build yourself up with proper diet, exercise and rest.
In hot weather, we all should know the many common tricks for keeping cool. If not, contact your local MS Chapter.
Note: Self-help is not intended to replace medical treatment. It should be used together with the help of appropriate professionals in a team effort.
Ed Lash is a United Spinal member who lives in Trumbull, Connecticut. This essay is adapted from his book, MULTIPLE SCLEROSIS, Self-help . . . A Patient’s View (Vantage Press 2001), which is available by e-mail from edlash.ms.selfhelp@juno.com, or by phone at 203-445-0118.
