Posted on: May 18, 2017
What Is Multiple Sclerosis?
- Multiple sclerosis (MS) is a chronic disease that affects the central nervous system. MS is thought to be an autoimmune disease. In MS, the body’s immune system produces cells and proteins (antibodies) that attack myelin, a fatty substance that protects nerve fibers. The cause of MS is unknown. It is not an inherited disease, but it appears that genetic factors play a role in making some people more susceptible to developing it.
- MS affects significantly more women than men. Most patients first begin to have symptoms between the ages of 20 – 50.
- The course of MS varies among patients. The disease may be mild, moderate, or severe. Most patients have the relapsing-remitting form of MS in which flare-ups (also called relapses or exacerbations) of symptoms are followed by periods of remission.
- Symptoms of MS include fatigue; vision problems; difficulty walking; muscle weakness, stiffness, and spasms; and bladder and bowel problems. Not all patients have all symptoms.
4 Major Types of Multiple Sclerosis
- Relapsing-Remitting MS. Relapse-remitting MS (RMSS) is the most common form of multiple sclerosis. About 85% of patients are first diagnosed with this type of MS. RMSS is marked by flare-ups (also called relapses or exacerbations) of symptoms followed by periods of remission when symptoms improve or disappear.
- Secondary-Progressive MS. Some patients with RMSS go on to develop secondary-progressive (SPMS). (For many patients, treatment with disease-modifying medications helps delay this progression.) In SPMS, the disease course continues to worsen with or without periods of remission or leveling off of symptom severity (plateaus).
- Primary-Progressive MS. About 10% of patients are diagnosed with primary-progressive MS (PPMS). In PPMS, symptoms continue to worsen gradually from the very beginning. PPMS has no relapses or remissions. There may be periods of occasional plateaus. This type of multiple sclerosis is more resistant to the medications typically used to treat the illness.
- Progressive-Relapsing MS. Progressive-relapsing MS (PRMS) is a rare form of MS, occurring in less than 5% of patients. It is progressive from the start with intermittent flare-ups of worsening symptoms along the way. There are no periods of remission.
As with other autoimmune disorders, the exact cause of MS is unknown. A combination of environmental and genetic factors likely plays a role.
Multiple sclerosis is not hereditary, but genetic factors appear to play a role in making some people susceptible to the disease process leading to the condition. The most significant genetic link to MS occurs in the major histocompatability complex (MHC), a cluster of genes on chromosome 6 that are essential for immune system function. A much smaller percentage of MS cases may be due to variations in interleukin-7 (IL-7) and interleukin-2 (IL-2) gene receptors, which are also related to immune system regulation.
Multiple sclerosis is more common in certain geographical areas of the world, particularly areas that are farther from the equator. Prevalence is generally highest in northern European and North American countries. The clustering of MS cases in these regions has led researchers to investigate whether certain toxins, infections, or vitamin deficiencies (such as vitamin D) may play a factor in triggering MS in genetically susceptible people.
Infectious organisms, mainly viruses, have long been suspects. They include Epstein-Barr virus (the cause of mononucleosis), herpesvirus 6, herpes simplex virus, influenza, measles, mumps, varicella-zoster virus, cytomegalovirus, respiratory syncytial virus, and Chlamydia pneumoniae. However, no direct link has been proven between these infections and multiple sclerosis. There is no evidence that any type of vaccination causes multiple sclerosis.
- Vision Problems. Optic neuritis, inflammation of the nerves in the eye, is a common early symptom. Patients may initially experience blurred or double vision, usually because of problems with one eye.
- Tingling and Numbness Sensations. Tingling, crawling or burning sensations, or loss of sensation can occur. Patients may feel sensations of intense heat or cold.
- Muscle Weakness and Spasms. Patients can feel weakness, clumsiness, or heaviness in the limbs. They may have difficulty with finger dexterity. Muscle spasms and stiffness (spasticity), particularly in the legs, occur in an initial attack of MS in nearly half of patients.
- Problems with Balance and Coordination. Patients have an unsteady gait and difficulty walking normally and keeping their balance. They may have trouble grasping small objects.
- Fatigue. Fatigue is the most common and debilitating symptom of MS and often occurs early in the disease.
Other Common Symptoms
- Bladder and Bowel Problems. Some patients have problems emptying their bladder (urinary retention) and bowels (constipation) or find they cannot control their bladderand bowels (incontinence). Patients with urge incontinence need to urinate frequently or are unable to reach the bathroom before leakage occurs. Bladder problems, and catheterization for urinary retention, can lead to urinary tract infections.
- Most patients have pain at some point during the course of the disease, and many are never completely pain free. MS causes many pain syndromes; some occur for a short time while others continue for a long time. Some worsen with age and disease progression. Pain syndromes associated with MS include trigeminal (facial) pain, powerful spasms and cramps, pressure pain, stiffened joints, and a variety of sensations, including feelings of itching, burning, and shooting pain.
- Sexual Dysfunction. Sexual dysfunction is a common problem. Men are likely to have erectile dysfunction, and women often have problems with vaginal lubrication. Sexual dysfunction appears to be highly associated with urinary dysfunction.
- Speech and Swallowing Problems. Up to half of patients have trouble chewing or swallowing. Some patients have slurred speech and problems speaking clearly.
- Thinking, Concentration, and Memory Problems. Cognitive problems, such as having trouble concentrating, reasoning, and solving problems, affect about half of patients.
- Mood Swing. Depressionis very common and is sometimes very severe.
Most patients first seek medical help after an initial attack of symptoms, called a clinically isolated syndrome (CIS). Not all patients who have a CIS go on to develop MS, and it is difficult to predict which patients will or will not.
Multiple sclerosis can be challenging to diagnose as there is no one test for it, and a number of other conditions may mimic its symptoms. To confirm a diagnosis of multiple sclerosis the doctor needs to find:
- Evidence of nerve damage in at least two different areas of the central nervous system (brain, spinal cord, and optic nerves)
- Evidence that the damage occurred in episodes that happened at least one month apart
- No evidence that the damage is caused by other conditions
A diagnosis of multiple sclerosis is based on results from a combination of various tests. These include the patient’s medical history, neurological exam, magnetic resonance imaging (MRI) scans, evoked potential tests, and possibly a spinal fluid test.
The goals of treatment for multiple sclerosis are:
- Modify the disease course by reducing the number and severity of relapses (also called exacerbations or flares), reducing accumulation of lesions, and slowing the progression of disability
- Treat relapses on a short-term as-needed basis
- Manage symptoms
Patients are recommended to seek care from a neurologist experienced in treating multiple sclerosis.
Early Treatment. Evidence strongly suggests that the most destructive changes from multiple sclerosis in the brain occur very early on in the disease process — and may cause considerable damage even before symptoms begin.
Many doctors recommend treatment after a first neurological episode of MS (a clinically isolated syndrome) using disease-modifying drugs. The best current approach is to use specific findings from MRI scans to determine patients at highest risk for progression, making them likely candidates for early treatment with these drugs.
Over a third of patients will progress even with immediate treatment, but without early treatment about half of patients will progress to clinically identifiable multiple sclerosis.
Treatment with Disease-Modifying Drugs
Patients with multiple sclerosis are treated with medications and rehabilitation. Eight disease-modifying drugs are approved by the FDA for treatment of multiple sclerosis. These drugs can help reduce the frequency and severity of relapses and slow disease progression and disability. Drugs approved by the Food and Drug Administration (FDA) are:
- Interferon beta-1b (Betaseron, Extavia). Given in subcutaneous (under the skin) injections every other day.
- Interferon beta-1a (Avonex). Given as weekly intramuscular injections.
- Interferon beta-1a (Rebif). Given in subcutaneous injections three times a week.
- Glatiramer acetate (Copaxone). Given daily in subcutaneous injections.
- Natalizumab (Tysabri). Given by intravenous infusion once every four weeks.
- Mitoxantrone (Novantrone). Given intravenously once every three months for 2 – 3 years at most.
- Fingolimod (Gilenya). Taken daily as a pill.
- Teriflunomide (Aubagio). Taken daily as a pill.
You can read more about Multiple Sclerosis from The University of Maryland Medical Center here.