Multiple Sclerosis : Remyelination, Diet, Unproven Therapies

by National Institute of Health

(Page 8 of 9)

Remyelination

Some studies focus on strategies to reverse the damage to myelin and oligodendrocytes (the cells that make and maintain myelin in the central nervous system), both of which are destroyed during MS attacks. Scientists now know that oligodendrocytes may proliferate and form new myelin after an attack. Therefore, there is a great deal of interest in agents that may stimulate this reaction. To learn more about the process, investigators are looking at how drugs used in MS trials affect remyelination. Studies of animal models indicate that monoclonal antibodies and two immunosuppressant drugs, cyclophosphamide and azathioprine, may accelerate remyelination, while steroids may inhibit it. The ability of intravenous immunoglobulin (IVIg) to restore visual acuity and/or muscle strength is also being investigated.

Diet

Over the years, many people have tried to implicate diet as a cause of or treatment for MS. Some physicians have advocated a diet low in saturated fats; others have suggested increasing the patient's intake of linoleic acid, a polyunsaturated fat, via supplements of sunflower seed, safflower, or evening primrose oils. Other proposed dietary "remedies" include megavitamin therapy, including increased intake of vitamins B12 or C; various liquid diets; and sucrose-, tobacco-, or gluten-free diets. To date, clinical studies have not been able to confirm benefits from dietary changes; in the absence of any evidence that diet therapy is effective, patients are best advised to eat a balanced, wholesome diet.

Unproven Therapies

MS is a disease with a natural tendency to remit spontaneously, and for which there is no universally effective treatment and no known cause. These factors open the door for an array of unsubstantiated claims of cures. At one time or another, many ineffective and even potentially dangerous therapies have been promoted as treatments for MS. A partial list of these "therapies" includes: injections of snake venom, electrical stimulation of the spinal cord's dorsal column, removal of the thymus gland, breathing pressurized (hyperbaric) oxygen in a special chamber, injections of beef heart and hog pancreas extracts, intravenous or oral calcium orotate (calcium EAP), hysterectomy, removal of dental fillings containing silver or mercury amalgams, and surgical implantation of pig brain into the patient's abdomen. None of these treatments is an effective therapy for MS or any of its symptoms.

Are Any MS Symptoms Treatable?

While some scientists look for therapies that will affect the overall course of the disease, others are searching for new and better medications to control the symptoms of MS without triggering intolerable side effects.

Many people with MS have problems with spasticity, a condition that primarily affects the lower limbs. Spasticity can occur either as a sustained stiffness caused by increased muscle tone or as spasms that come and go, especially at night. It is usually treated with muscle relaxants and tranquilizers. Baclofen (Lioresal), the most commonly prescribed medication for this symptom, may be taken orally or, in severe cases, injected into the spinal cord. Tizanidine (Zanaflex), used for years in Europe and now approved in the United States, appears to function similarly to baclofen. Diazepam (Valium), clonazepam (Klonopin), and dantrolene (Dantrium) can also reduce spasticity. Although its beneficial effect is temporary, physical therapy may also be useful and can help prevent the irreversible shortening of muscles known as contractures. Surgery to reduce spasticity is rarely appropriate in MS.

Weakness and ataxia (incoordination) are also characteristic of MS. When weakness is a problem, some spasticity can actually be beneficial by lending support to weak limbs. In such cases, medication levels that alleviate spasticity completely may be inappropriate. Physical therapy and exercise can also help preserve remaining function, and patients may find that various aids-such as foot braces, canes, and walkers-can help them remain independent and mobile. Occasionally, physicians can provide temporary relief from weakness, spasms, and pain by injecting a drug called phenol into the spinal cord, muscles, or nerves in the arms or legs. Further research is needed to find or develop effective treatments for MS-related weakness and ataxia.

Although improvement of optic symptoms usually occurs even without treatment, a short course of treatment with intravenous methylprednisolone (Solu-Medrol) followed by treatment with oral steroids is sometimes used. A trial of oral prednisone in patients with visual problems suggests that this steroid is not only ineffective in speeding recovery but may also increase patients' risk for future MS attacks. Curiously, prednisone injected directly into the veins-at ten times the oral dose-did seem to produce short-term recovery. Because of the link between optic neuritis and MS, the study's investigators believe these findings may hold true for the treatment of MS as well. A follow-up study of optic neuritis patients will address this and other questions.

Fatigue, especially in the legs, is a common symptom of MS and may be both physical and psychological. Avoiding excessive activity and heat are probably the most important measures patients can take to counter physiological fatigue. If psychological aspects of fatigue such as depression or apathy are evident, antidepressant medications may help. Other drugs that may reduce fatigue in some, but not all, patients include amantadine (Symmetrel), pemoline (Cylert), and the still-experimental drug aminopyridine.

People with MS may experience several types of pain. Muscle and back pain can be helped by aspirin or acetaminophen and physical therapy to correct faulty posture and strengthen and stretch muscles. The sharp, stabbing facial pain known as trigeminal neuralgia is commonly treated with carbamazapine or other anticonvulsant drugs or, occasionally, surgery. Intense tingling and burning sensations are harder to treat. Some people get relief with antidepressant drugs; others may respond to electrical stimulation of the nerves in the affected area. In some cases, the physician may recommend codeine.

About the Author

NIH is the nation's medical research agency - making important medical discoveries that improve health and save lives. The National Institutes of Health (NIH), a part of the U.S. Department of Health and Human Services, is the primary Federal agency for conducting and supporting medical research.