Multiple Sclerosis Relapse or Pseudoexacerbation? Part Two

Patient Expert

In Multiple Sclerosis Relapse or Pseudoexacerbation? Part One, we discussed the difference between a relapse and a pseudoexacerbation.   Here is a brief review:

"Most exacerbations last from a few days to several weeks or even months," states the National Multiple Sclerosis Society.

The presence of worsened symptoms does not always signal a new relapse, as there are many triggers that can lead to a reappearance of old MS symptoms or bring on new symptoms that mimic a relapse.   Since the central nervous system doesn't work as well at high temperatures in most people with MS, symptoms can emerge with a rise in body temperature due to triggers such as stress, infection, or a warm environment.

Heat-Sensitivity and the Pseudoexacerbation

Many people with MS experience a temporary worsening of their symptoms when the weather is very hot or humid or they run a fever, sunbathe, get overheated from exercise, or take very hot showers or baths. For example, some people notice that their vision becomes blurred when they get overheated a phenomenon known as Uhthoff's sign. These temporary changes can result from even a very slight elevation in core body temperature (one-quarter to one-half of a degree) because an elevated temperature further impairs the ability of a demyelinated nerve to conduct electrical impulses.

The 'Hot Bath' Test Used for Years to Diagnose MS

For many years, the "Hot Bath" test was used to diagnose MS. A person suspected of having MS was immersed in a hot tub of water, and the appearance of neurologic symptoms or their worsening was taken as evidence that the person had MS.   So heat is a very effective method of bringing out or increasing the symptoms of multiple sclerosis.

Heat-Related Symptoms are Temporary

It is important to remember that heat generally produces only temporary worsening of symptoms and does not cause more disease activity (demyelination or damage to the nerves themselves). The symptoms are generally rapidly reversed when the source of increased temperature is removed. People with MS who are planning to move to a very warm climate should try to visit first; plans may have to be changed if the weather seriously worsens MS symptoms.

Strategies for Easing the Effects of Heat

* Stay in an air-conditioned environment during periods of extreme heat and humidity. [If an air conditioner is needed to help minimize the symptoms of MS, the cost of this equipment may be tax deductible if the physician has written a prescription for it.]

* Use cooling products (vests, neck wraps, bandanas, etc.) during exercise or outdoor activity, or pre- and post-cool.

* Wear lightweight, loose, "breathe-able" clothing.

* Icy drinks such as "slurpees" or popsicles can provide temporary relief.

* Drink plenty of water and avoid caffeine, as it acts is a diuretic.

* Use an oscillating fan during indoor exercise.

* Exercise in a cool pool (<85 degrees) or during cool parts of the day.

Active and Passive Cooling Systems

Active cooling is considered a therapy and requires both a doctor's prescription and supervision for usage. "Active Suits" have a separate cooling unit that circulates cool liquid through a vest and cap worn by the user. Clinical research has shown that active cooling systems can significantly reduce the temperature in certain areas of the body. When areas of the central nervous system that have been demyelinated are cooled, the conductivity across the damaged area is greatly enhanced. This increased conductivity allows more effective transmission of signals, which can reduce some symptoms.

Passive cooling systems help maintain a cooler body temperature. "Passive" cooling apparel includes vests, collars, bandanas, and wristbands that either hold cool inserts or contain special material that remains cool for up to two hours.   These can be used outdoors in hot weather or during exercise regimens. These passive systems do not reduce body temperature, and are not considered a therapy. They do provide relief from heat for short periods of time.

Cold Can Also Be a Problem Too

Some people with MS notice that symptoms, particularly spasticity, become worse in cold weather. It is generally recommended that people with MS who are sensitive to temperature try to avoid extremes of either hot or cold, and that people who are considering a move to a "better" climate try to visit first to see if the climate change is, indeed, beneficial.

SOURCES: Practical Insights for Multiple Sclerosis Patients, MS Perspectives, Fall 2008

"Heat and Temperature Sensitivity" as discussed by National Multiple Sclerosis Society.

"Cooling Equipment Distribution" by Multiple Sclerosis Association of America.

For Further Information:

MS Essentials 01: Managing Relapses presented by MS Society UK, 2007.