Multiple Sclerosis (MS)
Multiple Sclerosis (MS) is an inflammatory disease affecting the central nervous system (CNS). The CNS consists of the brain, spinal cord, and the optic nerves. Surrounding and insulating the nerve fibers of the CNS is a fatty tissue called myelin. Myelin protects nerve fibers and allows them to function normally. MS causes myelin to be lost, and scar tissue called sclerosis forms in its place, causing plaques or lesions to form. Damaged nerve fibers disrupt the ability of the nerves to conduct electrical impulses to and from the brain. The damaged areas known as plaques or lesions produce the various symptoms of MS.
Many experts believe that MS is an autoimmune disease – one in which the body, through its immune system, launches a defensive attack against its own tissues. With MS, it is the nerve-insulating myelin that comes under attack. Such attacks may be linked to an external factor, such as a viral infection.
Prevalence and Incidence
MS is the most common neurological disorder diagnosed in young adults. According to the National Multiple Sclerosis Society, there are approximately 400,000 reported cases of MS in the United States. This estimate suggests that nearly 200 new cases are diagnosed each week. There are an estimated 2.5 million people worldwide with the disease. MS is five times more prevalent in cooler climates – such as those found in the northern United States, Canada, and Europe. The closer one lives to the equator, the less prevalent MS appears to be.
Although MS can strike anyone, most people experience their first symptoms of MS between the ages of 20 and 40. Women are affected two to three times more often than men. The average risk of developing MS is one in 1,000, but this risk increases to 3 to 4 percent if you have a first-degree relative with MS. Caucasians are more than twice as likely as other races to develop MS.
The symptoms of MS vary greatly from person to person, depending on the area of the nervous system affected. Some people experience symptoms for a short period of time and then may remain symptom-free for years, while others may experience a more steady progression of the disease. Symptoms may be mild, such as numbness in the limbs, or severe, such as paralysis or loss of vision.
Common symptoms may include:
Periods of active MS symptoms are called attacks, exacerbations, or relapses. These can be followed by quiet periods called remissions.
MS ranges from very mild and intermittent to steadily progressive. At diagnosis, about 80 percent of people have the relapsing-remitting form of MS. People at this stage have attacks followed by periods of partial or total remission, which may last months or even years. Others experience a progressive disease course with steadily worsening symptoms. The disease may worsen steadily from the onset (primary-progressive MS) or may become progressive after a relapsing-remitting course (secondary-progressive MS).
No single neurological or laboratory test can confirm or rule out MS. Before your doctor can recommend a course of treatment, he or she will:
- Review your medical history, and perform a general physical examination
- Ask specific questions to determine if your symptoms may be caused by MS
- Perform a complete neurological examination, identifying the neurological signs of MS, such as damage to the optic nerve, abnormal reflexes, or poor coordination
- Perform diagnostic testing as needed
Your doctor may recommend a spinal tap. In this procedure, a needle is inserted into the spinal column and spinal fluid is removed for analysis. The presence of white blood cells in the fluid may be indicative of an inflammatory reaction resulting from MS. The presence of a pattern of antibodies called oligoclonal bands in the spinal fluid is also common in MS.
In addition, more specialized diagnostic procedures may be performed such as evoked potential tests that record the brain's response to visual, auditory and pain stimuli; computed tomography (CT or CAT scan) that can detect areas of demyelination; and magnetic resonance imaging (MRI) that provides a specialized image of the CNS that cannot be captured through traditional x-rays or a CT scan.
At present, there is no cure for MS. There are, however, effective treatments that can help reduce the severity and frequency of attacks and help manage the symptoms. Two common courses of treatment include drug therapy or alternative healing modalities, commonly known as holistic treatments. The earlier one is treated, the more effective treatment appears to be. Early treatment may potentially limit the amount of nerve damage incurred and also delay the onset of subsequent attacks.
Currently, there are five FDA-approved drugs utilized to treat MS. Avonex® (interferon beta-1a), Betaseron® (interferon beta-1a) and Copaxone® (glatiramer acetate). Research has shown that these medications are effective for many patients over long periods of time. The fourth drug, Novantrone® (mitoxantrone) is used for relapsing-remitting and secondary-progressive MS. The fifth drug, Rebif® is the same drug as Avonex, but is injected differently in more frequent and higher doses.
All of these drugs have side effects, but they are usually manageable. Novantrone has a set number of doses, as heart damage may occur when doses are administered over too long a period of time. It is only administered via intravenous injection once every three months for a maximum of three years.
The other four drugs are injected via syringes, and many patients may self-administer these in the comfort of their own home. These four drugs are injected anywhere from once a week to once a day, depending on which one is prescribed.
For severe attacks, a high-dose, short-term course of corticosteroids may be prescribed. This can help reduce the severity and length of the attack by decreasing inflammation, and potentially minimize the damage caused by the attack.
For MS patients who develop trigeminal neuralgia, a severe facial pain syndrome, there are several drug therapies or surgeries that may help reduce pain. When MS affects the cerebellum or the cerebellum's connections to other parts of the brain, severe tremor can result. Tremor may be treated using deep brain stimulation (DBS), a surgical procedure in which a hair-thin wire is implanted in the thalamus and connected to a neurostimulator implanted under the collarbone. The neurostimulator sends electrical impulses along the wire to the thalamus, interrupting signals that cause tremor.
Some MS sufferers opt for alternative therapies including acupuncture, osteopathy, homeopathy, aromatherapy, and reflexology. Many people find a combination of drug therapy, physical therapy and alternative methods achieve the best results. There are local support groups throughout the United States that can help patients and family members address problems which arise from coping with MS.
Copyright, the American Association of Neurological Surgeons, November 2005.