Ask the Doctor: Overheating, Exercise, and Uhthoff’s Syndrome

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Dr. Jack Burks

By Dr. Jack Burks
Chief Medical Officer for MSAA

Overheating, Exercise, and Uhthoff’s Syndrome

Q: First, I would like to express my thanks for MSAA’s magazine and website, which are very informative for all of us with MS. I read the most recent issue of The Motivator, and was happy to see a section on vision. However, there was no mention of Uhthoff’s syndrome. I know it is less common than the other vision issues and few experience this. Could you provide some information on this syndrome?

A: Uhthoff’s syndrome is actually rather common, although it gets little “press.” It indicates partial myelin damage in the optic nerve as the visual signal goes from the eye to the brain. It is described by patients as a dimming or reduced vision, usually associated with exercise or overheating. The visual problem improves with rest.

The treatment is to avoid overheating, which varies from patient to patient. Once you learn your limits, you may plan ahead and arrange your activities accordingly. For instance, if you enjoy participating in sports or other physical activities when outdoors, plan to do so when the weather is cooler (such as in the morning). This will help to reduce your risk of overheating. Knowing when to stop and take a break from physical activity is also important.

Q: I have several questions. (a) Can myelin-sheath damage be reversed? (b) Can you differentiate demyelination on a CAT scan versus an MRI? (c) Is it normal to have an aneurysm on the brain? (d) Is MS affected by humidity and heat? (e) What type of climate and environment is best to live in to avoid relapses?

A: (a) Can myelin-sheath damage be reversed? Yes, especially in early MS, your body has the ability to reverse (or repair) myelin-sheath damage. This is why people get better after a relapse. Ample evidence in animal models shows this is true. Clinical trials in progress right now are testing experimental treatments to stimulate remyelination, when the body no longer can do so on its own. We are all very hopeful that these types of treatments will soon become a reality for the MS population.

(b) Can you differentiate demyelination on a CAT scan versus an MRI? The CT or CAT scan is not a good way to measure demyelination; the MRI is far better.

(c) Is it normal to have an aneurysm on the brain? No, an aneurysm in the brain is not a normal finding, but some people have aneurysms and don’t know that they do. Inadvertently, when tests are performed for other indications, this type of unexpected finding can be discovered. If you have an aneurysm, you and your doctor will need to discuss your situation and decide upon the best plan of action. The treatment is often dictated by the location, size, and shape of the aneurysm.

(d) Is MS affected by humidity and heat? Humidity and heat are a major cause of a temporary worsening of symptoms for many but not all MS patients. We often refer to this as being “heat-sensitive.” That is why, for individuals who are heat-sensitive, we recommend that they avoid the heat whenever possible and use cooling apparel and accessories to minimize the affects of heat and humidity.

These types of items may be obtained through MSAA’s Cooling Program
(certain limitations apply; please see cooling for more information) or through vendors who can offer similar options. These include cooling vests as well as wraps that can be put around your neck, waist, wrists, and ankles.

Some people will take a cool bath or shower during the heat of the day to refresh themselves. Sucking on ice chips or occasionally enjoying a frozen, non-alcoholic drink can also help to keep you cool during the warmest time of day.

(e) What type of climate and environment is best to live in to avoid relapses?

Aside from relapses after an infection, we don’t know what precipitates relapses. Many patients consider moving from a hot and humid climate to a cooler and dryer one. Unfortunately, that usually requires a relocation of jobs and a separation from family, which can significantly reduce one’s quality of life. Therefore, most patients adapt to their less-than-ideal environment.

How can you adapt? Air conditioning, for example, for some people with MS, may be paid for by medical insurance. Avoiding the outdoors during the middle of the day and employing other strategies (such as the use of cooling apparel) can minimize the effects of a hot environment.

Keep in mind that many patients also have trouble with cold environments. This is especially true when snow and ice are involved, which can increase the risk of falling. Additionally, I recommend following a routine for a healthy lifestyle, including good nutrition, exercise, stress reduction, and adhering to MS medications prescribed by your doctor.

Q: I have been struggling with an embarrassing problem. My MS meds had been changed; first to Aubagio, then to Tecfidera. Beginning in April, I started having bowel accidents. Often there is no or very little advance notice and my bowels just empty themselves. My primary care doctor and I both feel it is the MS that is causing the problem; my neurologist insists it is not MS. My health history likely impacts this as I have had several surgeries on my intestines and lower abdomen.

A: A good bowel regimen from your doctor is a good start. Anti-diarrhea medications may or may not help; this is difficult to predict. I would inquire about Tecfidera, which may cause GI upsets in some people, including diarrhea similar to what you describe. This is usually temporary, but not always. Did your uncontrollable diarrhea start after you began Tecfidera? I would also inquire about other causes of diarrhea, such as parasitic infections. MS alone is an unlikely cause of this type of diarrhea. Our cover story discusses bowel dysfunction in MS. Please refer to page 15 for additional information, which may be of help to you.

Q: My question concerns optical coherence tomography (OCT). I understand that changes in retinal thickness mirror cortical gray matter changes, which in turn reflect the changes of progressive MS far better than MRI. I have secondary progressive MS and will be seeing my Mayo Clinic neurologist in about two months. Should I request a baseline OCT at my next neuro visit?

A: OCT is being used in many MS clinical trials and changes in the OCT are correlated with MS injury. However, it is not yet used by most neurologists in a non-research setting, although it is gaining popularity. I would ask the Mayo Clinic neurologist if he or she recommends OCT and ask if your insurance will pay for it. When an FDA-approved treatment for SPMS becomes available sometime in the future, I believe OCT might be helpful in evaluating the treatment.

Q: I was diagnosed with MS in June 2011. I was also diagnosed with breast cancer in March 2012. I had chemo and radiation treatments, plus a mastectomy in September 2012. I have horrible fatigue, balance difficulties, and slurred speech, which all worsened in October. I have seen my neurologist and had an MRI in October (no changes). I began Avonex in July 2011. I take Ritalin®, vitamin D3, B vitamins, and tamoxifin (for cancer). Do you have any suggestions to help relieve my symptoms?

A: I do not know if the chemotherapy (chemo) is amplifying your MS. For some patients, chemo has helped their MS. Certainly, fatigue can be aggravated by MS and chemo. I might recommend getting another MRI, since it is approaching one year since your last one. If your MRI shows more damage, that might help to explain your fatigue as well as your increased balance and speech problems.

Two other medications might be worth discussing with your doctor, if you have not done so already. First, while Provigil is not FDA-approved for MS-induced fatigue (or from fatigue related to chemo), my colleagues and I have found it to be helpful in many of our MS patients. Ask your neurologist. Second, Ampyra is a drug that is FDA-approved to increase walking speed in MS. While it does not help all individuals with MS, it might be worth considering with your doctor. It is important for your neurologist and your oncologist to work together in evaluating and treating your symptoms.

To Submit Questions to Ask the Doctor…

If you have a question that you would like to ask, please submit your question to:

Questions for Ask the Doctor
c/o Dr. Jack Burks
375 Kings Highway North
Cherry Hill, NJ 08034

Readers may also send in questions via email to Please be sure to write “Ask the Doctor” in the subject line.

A Note About the Shingles Vaccine

A few people have written to me asking about the safety of the shingles vaccine for individuals with MS. Because the shingles vaccine uses a live virus, the answer is not the same for everyone. I advise anyone with MS who is 60 years of age or older (this is the age group for which the shingles vaccine is recommended) to discuss the risks and benefits of this vaccine with his or her doctor. For more information, please see page 42 for the “Health and Wellness” column in this issue.

Dr. Jack Burks is an international MS neurologist, writer, lecturer, and researcher, who assists with the development of new MS therapies and advises patients, families, MS organizations, and healthcare groups. Dr. Burks is a clinical professor of neurology at the Florida International University in Miami. He has written and edited three MS textbooks, as well as numerous chapters and articles on MS.