Multiple sclerosis is a disease that may affect any area of the nervous system, thus causing a wide variety of symptoms such as visual problems, weakness, or numbness. Although the exact cause is unknown, it is thought to be an inflammatory process that attacks a substance in the nervous system called myelin. Myelin is the material that surrounds neurons (the cells of the nervous system). Myelin acts to facilitate the rapid transmission of signals up and down neurons, much like insulation around electrical wiring. When the myelin is broken down, the nerve impulses do not travel as efficiently, causing the symptoms that are characteristic of MS.
Who gets MS?
There are approximately 350,000 people in the U.S. and 2.5 million people worldwide with MS. MS typically affects young people. It most commonly starts between the ages of 20 and 40, although less commonly, it can occur later. It affects women more often than men, by a ratio of nearly two to one. People living in the northern latitudes have an increased risk over those living in the southern hemisphere. This suggests an environmental trigger. People who change geographic locations prior to the age of 15 acquire the risk of the region they move to. Although it is not directly inherited, there is some genetic predisposition; there is a one- to three-percent risk of developing MS if a parent or sibling has the disease. Identical twins of a person who has MS have a 25-percent chance of getting the disease. The theory is that there is a genetic predisposition that may be triggered by environmental influences, although we still lack a clear explanation. It is thought that there may be a virus that ultimately acts to trigger the inflammatory or immune response that results in myelin destruction. The main concept is that the immune system recognizes a part of the virus that is similar to that of myelin. Although a number of viruses have been implicated, none have been proven with certainty to be the triggering cause of MS.
Symptoms of MS
MS can affect any area of the central nervous system (the brain and spinal cord), and as such, there are a wide variety of symptoms.
- Weakness: Weakness can occur anywhere in the body. It may come on rather suddenly (and may be confused with a stroke) or it can occur more gradually.
- Spasms: The same process that causes the weakness may also cause spasms and stiffness, making it difficult to use the affected limb or to walk. The spasms can be painful, much like getting a charley horse while exercising.
- Sensory symptoms: MS can cause numbness anywhere in the body. It may also cause abnormal sensations, for instance, a “pins-and-needles” sensation, much like when your arm falls asleep, but the sensation lasts much longer. A typical MS attack lasts for more than 24 hours.
- Visual symptoms: A very common feature of MS is optic neuritis. This is a condition caused by inflammation of the optic nerve, resulting in decreased vision. The visual loss can vary from very mild (for instance, only involving color discrimination) to severe. Typically, the visual loss starts slowly, followed by a more rapid decline in vision. It is often accompanied by pain in the eye and light sensitivity. The visual loss may persist from days to weeks and then gradually improves over weeks to months. The majority of patients have almost complete recovery of their vision, but some may continue to notice subtle changes that persist in the vision. Symptoms may return during exercise, exertion, or with increased body temperatures, such as during a hot shower. This is a temporary phenomenon and the symptoms resolve when the body temperature returns to baseline. Alternatively, people can develop eye movement abnormalities that can lead to double vision, or “jumpy” vision. This can happen in a number of ways, either affecting the coordination of eye movements, or the signals that help to move both eyes at once.
- Walking problems: Walking may become difficult for several reasons. First, there may be weakness or stiffness in the legs. Spasms can make walking quite difficult, but they are treatable. There may be difficulty with coordination or balance. People with MS may describe feeling like they're walking as if they were drunk. Alternatively, decreased sensation makes walking difficult because it is difficult to judge where your feet are in space. There are many techniques for overcoming these problems, and a physical therapist can be of great assistance in this particular area.
- Urologic dysfunction: Urinary symptoms may include difficulty starting a stream or completely emptying the bladder. On the other hand, some people have difficulty with urinary incontinence. Men can have problems with erectile dysfunction and women may experience decreased libido or difficulty having an orgasm. It is important to share these concerns with your doctor because a urologist or gynecologist may be able to help.
- Fatigue: Fatigue is a very frequent complaint. In many inflammatory disorders such as MS, people describe generalized fatigue that may affect one's ability to accomplish common tasks in an average day. It may be the result of some of the chemical mediators that are released in inflammatory diseases. Heat may exacerbate these symptoms—people often complain of feeling “blah” when it is hot and humid. This feeling of fatigue is because nerves do not transmit their signals as well when body temperatures are increased. In addition, given the physical limitations that may occur with MS, it often takes more energy to accomplish the same activities as before.
- Pain: Many people, including physicians, do not believe that pain is a significant part of MS, but it actually is. New MS lesions can cause inflammation around the linings of nerves and cause acute pain, as in optic neuritis. Spasms can be painful, but are treatable. There may also be neuropathic pain , which is a chronic condition that involves an uncomfortable sensitivity, such as a pins and needles, or burning sensation. This too, is treatable.
- Depression: Depression is common in people with MS, and may occur in up to 75 percent of patients. It is often situational; in other words, brought on by a new diagnosis or increased disability.
- Cognitive disturbances: Although understudied, and often overlooked, cognitive difficulties commonly occur in MS. Some studies estimate it to be as high as 50 to 75 percent of patients. The symptoms are usually quite subtle, and most often involve a slowing of information processing, short-term memory loss, and impaired visuospatial skills (e.g., depth perception). These problems usually do not arise until late in the course of the illness, presumably after many demyelinating lesions have accrued.
How Does a Doctor Make a Diagnosis of MS?
MS is a disease that is disseminated over time and space. In other words, your doctor must find proof of more than one attack in different parts of the nervous system. This proof includes the clinical history that you provide, the neurologic exam that your doctor performs (which examines the functioning of the brain and its nerves), magnetic resonance imaging (MRI) results (which uses a magnetic field to view internal soft tissue such as organs, muscle, nerves), and perhaps spinal tap results. A spinal tap may be done for two reasons. First, it is often necessary to rule out other diseases that mimic MS, such as Lyme disease. Second, if the spinal fluid contains distinct proteins called oligoclonal bands, it helps to support the diagnosis of MS. A normal spinal tap does not exclude MS, as it may be normal, especially in the early stages of the illness.
It is also very important to perform blood-work to rule out other disease processes that mimic MS. These include infections such as Lyme disease, autoimmune problems such as lupus, inflammatory diseases, thyroid abnormalities, and vitamin deficiencies (specifically B12 and folate).
Health
MRI scans may be helpful to follow patients with MS. We now know that there may be lesions that appear on MRI that do not cause overt clinical symptoms. In this way, MRI can be used to measure disease activity. Although we are still trying to perfect the best way to use MRI as a tool for following patients (i.e., how often to get them), it is sometimes helpful in deciding how or when therapy should be utilized.
Prognosis After an MS Diagnosis
The course of MS is quite variable from person to person and even from year to year in the same person. The frustrating part about MS, both for the patient and the physician, is the fact that MS is so unpredictable. It has been estimated that within fifteen years of onset of MS, 50 percent of patients will require a cane for ambulation. It is very important to note, however, that that number was established prior to the advent of the new immunomodulating drugs, and it remains to be seen how these medications will affect the prognosis over the long haul. The immunomodulating drugs, also know as the ABC drugs (Avonex, Betaseron, and Copaxone), act on the immune system to “quiet it down.” These medications have been shown to decrease the number of MS attacks by keeping the immune system in check. While we don't yet have a cure for MS, for the first time we do have medications that can alter the course of the disease.
What's the Best Way to Stay Healthy and Avoid Attacks?
Avoid heat
There are several things you can do to feel better if you have MS. First, try to avoid the triggers that make you feel worse. Although heat does not further damage the nervous system, it may bring out old symptoms that you haven't had in a while, as well as deplete your energy levels. As such, it is generally a good idea to avoid overexerting yourself on hot and humid days and stay as cool as possible in the summer months. While taking hot showers or baths will not cause damage to your nervous system, the previously damaged neurons do not function quite as efficiently while your body temperature is up, thus making you notice your old symptoms, such as weakness and visual problems.
Good sleep habits
It is extremely important to develop good sleep habits. While none of us does well with sleep-deprivation, it is particularly important in people with MS, because it may affect how well you function the next day. While not proven to cause MS flares in general, sleep-deprivation, getting run down, and stress may affect how your body's immune system works in ways we don't yet understand.
Diet
People often ask if there is a special diet that they can follow to stay well. While there are no vitamins or special foods proven to prevent flares, we do recommend that people eat a well-balanced diet. If people find it difficult to eat a well-balanced diet, it is a good idea to take a daily multi-vitamin to get the vitamins and minerals that they may be missing. People should avoid aggressive weight-loss plans and fasting, as that may limit their energy level.
Calcium supplements
Osteoporosis (thinning of the bones) can be a particular problem in MS. Women, who comprise the majority of people with MS, are at a general increased risk of developing osteoporosis. In addition, decreased weight-bearing activity, which is often a problem in MS, can increase your risk. Finally, the long-term use of steroids (over months and years, not in the short term) can lead to osteoporosis as well. It is particularly important to get an adequate amount of calcium in your diet. If you can't do so by eating enough dairy products, then you should take a calcium supplement.
Another question people often ask is how to exercise. In general, physical activity is a good thing in MS. It keeps people flexible, helps to prevent spasms, and keeps up muscle mass. But, as with anything else, too much of a good thing can be bad. Overexertion can lead to problems with fatigue and muscle weakness. You can stick to whatever exercise regimen worked for you in the past, but remember that you must pay special attention to your body signals. If you're feeling like you're pushing yourself too hard, then ease up. It is also important to discuss your exercise regimen with your doctor first. If you weren't a runner before you were diagnosed, then it may not be the best time to start. Swimming is an excellent exercise: it keeps you flexible, is a great cardiovascular workout, builds muscle mass, and keeps your body temperature low while you exercise. Physical therapists are great at helping you to plan an exercise regimen that works for you.
Pregnancy and MS
Although whether or not you should become pregnant is a question you need to ask your doctor, and more importantly yourself, there are some general words of wisdom that may help. It used to be a widely held notion that women with MS shouldn't get pregnant. In general, that is not currently accepted. Again, it is important to tailor that thought to your own level of disease and what you think you can manage in terms of energy levels and the difficulty of child-rearing. For example, you may want to have a small family, but again that is a personal decision, and one to take into consideration in thinking how much your energy will allow. For the most part, pregnancy does not lead to increased disability in MS. In fact, recent studies have shown that there are actually fewer exacerbations during pregnancy. However, there do tend to be more attacks in the post-partum period (especially between three and six months after delivery), although not drastically more than the general MS population. Overall, there is no change in the level of disability. It is a good idea to restart immunomodulating therapy as soon after delivery as possible. These medications are not used during pregnancy, as the effects to the fetus are unknown, and should be stopped several months (we advise three) prior to conception. If you are planning to conceive, you should discuss these issues with your neurologist and gynecologist. Again, this is a very personal decision, and one that should be tailored to your level of disease and to your lifestyle.
Conclusion
As you can see, multiple sclerosis is a variable disease. The exact cause of MS remains unknown, but many factors are thought to play a role in its development. We now have several medications available to treat the symptoms of MS and to prevent them from developing. Your experience with MS may be quite different from other people with whom you speak. It is important to keep that in perspective and to bring up any questions you might have with your physician.
