When MS Is Really a Pain.

"It hurts so to walk. It feels like a huge ball pressing against the heel of my foot." That's how one woman, a former office manager, describes the feeling. She also feels an awful tightness around her knees when she is sitting down, so much so that she gets up to move around--only to have the heel pain kick in.

Pain and tightness around the knees also bothers a practicing Philadelphia architect. "It started in my thighs," he commented, "and now it's moved down to my lower legs."

People with pain from MS often refer to a tightness or a girdling pressure on the torso. But not always. A retired Head Start registered nurse has pain in her shoulders and neck that began a year ago, 6 years after she was diagnosed. "It's a dull, achy feeling that's pretty much continuous, but worse in the morning." A volunteer for the Society said that it feels as if a hunk of concrete is attached to her knees when she walks. "It's so draining that I'm exhausted after a block." But she goes on to express sympathy for another woman with MS she. knows who is devastated by episodes of trigeminal neuralgia--which feels like lightning bolts of pain across her face.

These individuals are a sample of people who recently came to the MS Clinic of MCP Hahnemann in Philadelphia. Some of them have relapsing-remitting MS; others have progressive disease. They are all getting medications that help relieve their pain.

But other people who receive care at the same MS clinic have no painful symptoms--indeed, they've never experienced any pain with their MS. As with other aspects of this disease, every individual's MS is unique.

There is no way to predict who will suffer pain or how serious it will be. However, surveys suggest that pain of one sort or another affects one-half to two-thirds of all people with MS in the course of their disease. Of that group, half again will describe their pain as severe.

"Pain of one sort or another"

If you feel pain, it's important to communicate that information to your physician. Describe the symptoms and the degree of severity you feel as clearly as possible--because treatments vary. And treatment is important.

Pain that occurs as a result of nervous system disease is abnormal. It's different from the "good" pain that serves to protect you. You have nerve endings sensitive to pain all over your body which normally sound an alarm to the brain when something is harming or about to harm your body. And normally your brain responds so fast that you have already withdrawn your fingers from the hot stovetop before you realize consciously what happened.

In more serious events--a sprained ankle or a broken bone--pain sounds a more general alarm designed to make you rest and let the body heal. Sprained ankles or broken bones produce acute pain. So do toothaches that drive us to the dentist or stomachaches we may remedy with an antacid tablet.

In contrast, chronic or recurrent pain--especially pain that occurs because of disease or injury of the nervous system--serves no useful purpose. It robs sleep, saps energy, dampens mood, and curbs appetite. In some chronic pain conditions, the constant barrage of pain nerve signals sensitizes the central nervous system (the brain and spinal cord) so that a bad pain feels worse and even a light touch can hurt. It's not clear whether that also happens in the "centrally mediated pain" associated with central nervous system damage caused by multiple sclerosis. MS symptoms wax and wane and often there is no simple association between the location and number of MS lesions (or damaged areas) and the kind of pain the person may be experiencing.

What to do

First, it's important for you and your primary-care doctor to distinguish between MS pain and other kinds of pain. Having MS doesn't make you immune to headaches, menstrual cramps, arthritis, or low back pain. At a Veterans Administration MS clinic in West Haven, Connecticut, for example, a number of veterans had had physically demanding jobs in the military or later in civilian life. Their chronic neck or low back pain may relate more to their former jobs than to their MS.

In arriving at a diagnosis, you and your doctor will need to consider whether your pain comes from lack of movement or from abnormal pressures you may be putting on your limbs or torso in response to weakness, difficulties keeping your balance, or other mobility symptoms. These positional or pressure pain--even disc pain--may respond to exercise, massage, and physical therapy approaches. Mild-to-moderate pain relievers, including nonsteroidal anti-inflammatory drugs, such as ibuprofen or aceteminophen, may also help.

Burning, tingling, and numbness

That said, there are MS-related symptoms that are irritating to some people and reach the level of severe pain in others. These are sensations of numbness and tingling called paresthesias, most often felt in the legs and feet, and distorted or disagreeable sensations, called dysesthesias, which sometimes accompany paresthesias. One man with dysesthetic leg pain said it was "like a toothache" throbbing and burning in his feet. The pain was worse at night and when the weather changed. In one study of individuals with this kind of leg pain, MRI scans showed plaques, or scarred areas, on the motor nerves that run down the back or posterior part of the spinal cord to supply the leg muscles. Some people in this study also had plaques in the sensory pathways that run along the sides of the cord and transmit incoming messages of pain and temperature.

The physician's first choice for treatment of burning leg or foot pain is usually one of the tricyclic drugs, such as amitriptyline or imipramine. Conventional over-the-counter pain relievers such as ibuprofen or aceteminophen will not work. While the tricyclic drugs were initially used to treat depression, investigators have discovered that these same drugs at different dosage levels have pain-relieving effects. They act on nerve pathways descending from the brain that inhibit incoming messages of pain.

The feeling of a tight band or girdle, typically constricting the upper chest, is a common MS-related dysesthesia. Again, over-the-counter pain relievers have no effect on this awful sensation, but it is often successfully controlled with an anticonvulsant prescription drug, carbamazepine.

Stiffness and spasticity 

Cramps, stiffness in the legs, and spasticity are also common sources of pain in MS. They are all signs of uneven activity in the nerves that send signals to the muscles that flex or extend your limbs. The drug baclofen calms the nerves and relaxes the muscles and is usually considered first. The diazepam family of drugs, which includes Valium and Klonopin, may also be prescribed. These drugs, too, have muscle-relaxing actions. Tizanidine is the latest drug to become available for spasticity. It inhibits nerve signals from the brain to limb muscles.

Ideally, medications should prevent spasticity without inducing muscle weakness. In practice, you may need to work with your doctor in trying out drugs in various dosages and combinations until a good balance is reached. Tizanidine can be used safely in combination with baclofen, as can the tricyclic drugs.

Trigeminal neuralgia

Early in her career, a physician assistant conducted a neurological exam on a woman with MS and wrote this description of trigeminal neuralgia, which often goes by its old name, tic douloureux: "When I touched her tongue with a tongue depressor, she froze and tears streamed down her face. Had she been able to rise from her wheelchair, she would have jumped out of her seat."

The episodes of sudden, intense pain that occur in trigeminal neuralgia can take place for no apparent reason or can sometimes be initiated by stimulating trigger points in and around the face. When this woman has an attack, she cannot open her mouth to talk or eat, the pain is so great. Fortunately, her neuralgia is controlled most of the time by carbamazepine. Like other anticonvulsant drugs, carbamazepine acts by suppressing electrical activity in the brain. In the case of trigeminal neuralgia, it is activity in the brainstem that is the culprit. This part of the brain, tucked under the cerebral hemispheres, is where many of the cranial nerves originate, including the trigeminal nerves, which are the source of sensation to the face.

While the number of people with MS who have trigeminal neuralgia is not large, the condition is estimated to be 400 times more common in people with MS than in the general population. In the general population there is no evidence of a brain lesion, and it is considered a condition of unknown origin. Nevertheless, the same drugs can be effective for both groups of people.

Research and research results

MRI and even newer imaging and microscopic technologies have been a boon to pain research, revealing the widespread distribution of pain pathways and pain centers within the brain. At the molecular level, pain researchers can now distinguish certain cells that transmit the normal "good" pain signals from the cells that are prominent in chronic pain. Investigators are tracking each step in the chemical chain that begins when a molecule makes contact with a receptor on a nerve cell membrane and ends with signals inside the cell directing specific genes in the cell's nucleus to turn on or turn off.

With each new pain molecule or gene discovery comes the potential for developing a drug that might selectively target that molecule to suppress pain. The more selective the target, the less likely are undesirable side effects like constipation, nausea, or sedation. New pain-relieving drugs are signs of the progress taking place in neurology research.

Recently, for example, a new anticonvulsant drug called gabapentin has come on the market. It is increasingly being used as an alternative to carbamazepine to treat dysesthesias due to MS, trigeminal neuralgia, and other types of nerve injury. The prefix "gaba" refers to gammaaminobutyric acid, or GABA--a major brain chemical that acts as an inhibitory neurotransmitter.

While gabapentin is structurally related to the natural neurotransmitter GABA, how the drug works is not yet completely understood. It is known to be safe and effective, which is the bottom line for someone with "nerve" pain.

Other new and potent pain relievers now being tested include drugs that act on a class of nicotinic receptor (the receptor that reacts to tobacco) and a drug that selectively blocks a gate that opens when a pain nerve cell fires an impulse.

The fifth vital sign 

New facts about chronic pain and its consequences are sparking changes in how physicians will practice medicine. The Department of Veterans Affairs has begun a major initiative asking VA physicians to record pain level as "the fifth vital sign". An inquiry about pain will be added to the traditional 4 vital signs--temperature, blood pressure, and heart and respiration rates--noted during a standard physical exam. Among other measures, the VA plans to use a 10-point scale to measure pain, with zero equivalent to no pain and 10 being the most severe pain imaginable.

Acknowledging that pain should be documented--and hence treated--is a major step in overcoming the all too common belief that pain is "all in your head". Of course it is--that's where your brain is. This is often accompanied by a "blame the victim" attitude that people who complain of pain are weak, depressed, want attention, or worse yet, want drugs. The new initiative recognizes that pain is real and harmful. It can delay healing, increase stress, lower resistance to disease, and it can certainly lead to depression.

The National MS Society is also collaborating on a major pain management program as part of a larger initiative. The Society is one of 23 organizations along with the VA in the Council for Multiple Sclerosis Clinical Practice Guidelines. This organization, sponsored by Paralyzed Veterans of America, has already completed 2 guidelines--on fatigue and on bladder dysfunction--and is in the process of developing several more. Work on pain guidelines begins this summer. Dr. Deborah Miller of the Cleveland Clinic's Mellen MS Center, who is chairing the project, commented, "We select topics for guideline development based on the priority concerns of MS experts. The inclusion of pain definitely indicates that the community of MS specialists understands the importance of pain management in MS."

This sea change in attitude comes at a time when the prospects for better pain treatments are also dramatically better.

Complementary approaches, too

The development of new drugs does not rule out alternative or complementary approaches to relieving pain. Meditation, relaxation, hypnosis, massage, and even exercise are among the approaches that help some people. (Transcutaneous electrical nerve stimulation, or TENS, applied over the area of pain occasionally provides relief, but more frequently for people with MS has the opposite effect, and it is rarely recommended.)

The retired Head Start nurse finds applying a loufa sponge and massaging with the soft ball of plastic netting supplied with some body lotions helps relieve her shoulder and neck pain. The Society volunteer works out with a personal trainer to ease her painful leg spasticity and keep her muscles in good shape. Indeed, it is characteristic of many people with MS to look for ways to help themselves and to take action to reduce their pain.

They can rest assured that more than ever before, MS specialists and their colleagues in pain research are also taking action with the aim of ultimately eliminating all that unnecessary pain.

Joan Wilentz is a freelance science writer following a career at the National Institutes of Health, where, most recently, she served as chief of the Planning, Evaluation, and Legislation Branch of the National Institute of Dental and Craniofacial Research.