Multiple sclerosis (MS) is the most common neurological disorder among young adults, afflicting an estimated 2.3 million people worldwide. An abnormal immune system response is thought to be the cause of multiple sclerosis, although several other factors likely influence the disorder, too.
Multiple sclerosis occurs when the immune system mistakenly attacks the central nervous system.
The central nervous system is comprised of the brain and spinal cord. This system is responsible for relaying and interpreting information from the body to the brain and vice versa. The central nervous system is made up of nerve fibers, which are surrounded by a fatty substance called myelin.
In multiple sclerosis, the immune system attacks the myelin and causes damage. The damaged myelin forms scar tissue, or sclerosis, which is where the disorder’s name comes from. This process can eventually cause damage to the nerve fibers themselves. Nerve impulses traveling along scarred or damaged nerves in the central nervous system become interrupted or distorted.
The symptoms of multiple sclerosis can vary, depending on which nerves are affected. Some of the possible symptoms include:
- Numbness or weakness in one or more limbs, usually occurring in the legs and trunk or on one side of the body at a time
- Partial or total loss of vision, often with painful eye movement, typically occurring in one eye at a time
- Blurred or double vision
- Electric-shock sensations with certain neck movements, particularly bending the neck forward
- Tingling or pain
- Tremor, unsteady gait, or lack of coordination
- Fatigue or dizziness
- Slurred speech
During a relapse (also called an attack, exacerbation, or flare), symptoms can worsen, or new symptoms can appear. During a remission, symptoms may lessen or even disappear. A relapse typically lasts for days or weeks, while a remission can last weeks, months, or even years.
There are four types of multiple sclerosis.
Most people are initially diagnosed with relapse-remitting multiple sclerosis (RRMS), meaning that they suffer definite relapses of worsened symptoms followed by periods of remission. During remission, there is no noticeable progression of the disease.
Eventually, most people diagnosed with relapse-remitting multiple sclerosis will progress to secondary-progressive multiple sclerosis (SPMS), which is characterized by a more steady progression of the disease. The progression may not necessarily be faster in SPMS, however, just more steady.
Primary-progressive multiple sclerosis (PPMS) is a steady worsening of neurological symptoms from the beginning. Unlike secondary-progressive multiple sclerosis, it does not follow relapse-remitting multiple sclerosis. Instead, there is a steady rate of progression from the beginning, with no distinct remissions or relapses.
The most uncommon form of the disease is progressive-relapsing multiple sclerosis (PRMS). PRMS is characterized by a steady worsening of neurological symptoms, in addition to occasional relapses, but with no remissions.
Multiple sclerosis is thought to be caused by a combination of genetic and environmental factors.
While developing multiple sclerosis isn’t necessarily genetic, a vulnerability to multiple sclerosis is genetic. In fact, a recent study conducted by scientists at the International Multiple Sclerosis Genetics Consortium (IMSGC) has identified 48 new susceptibility variants, or gene variations that increase vulnerability to multiple sclerosis.
This means that genes don’t determine whether or not an individual has multiple sclerosis, but his or her genes do determine whether or not he is likely to develop it if other factors trigger the disease. Approximately 15% of people with multiple sclerosis have at least one relative who also has the disease. While the average citizen of the United States has about a 0.1% chance of developing the disease, a first-degree relative of someone with multiple sclerosis has a risk of 2.5-5%.
However, the identical twin of someone with multiple sclerosis has a 25% chance of developing multiple sclerosis. As stated by the National MS Society:
“If genes were solely responsible for determining who gets MS, an identical twin of someone with MS would have a 100% chance of developing the disease; the fact that the risk is only one in four demonstrates that other factors, including geography, ethnicity and the elusive infectious trigger, are likely involved as well.”
Geography, ethnicity, and some infections have indeed been identified as risk factors for multiple sclerosis. For example, living somewhere with a temperate climate, such as southern Canada, the northern United States, New Zealand, and southeastern Australia and Europe, increases the risk of multiple sclerosis. People of almost any ethic group can develop multiple sclerosis, but it’s most widespread among Caucasians.
Other risk factors include:
- Age: Most people are diagnosed with multiple sclerosis between 20 and 50
- Sex: Women are approximately twice as likely to develop multiple sclerosis
- Certain autoimmune diseases: People with type 1 diabetes, inflammatory bowel disease, or thyroid disease are at higher risk
- Smoking: A smoker who experiences a multiple sclerosis attack is much more likely than a non-smoker to experience a second, diagnosis-confirming attack
As far as infectious diseases as a risk factor for multiple sclerosis, the virus that causes mononucleosis, Epstein-Barr, is the most commonly suggested. Other infectious viruses and bacteria that have been or are being studied in relation to multiple sclerosis include Chlamydia, pneumonia, measles, canine distemper, and human herpes virus-6. However, none—not even Epstein-Barr—have been definitively proven as triggers for multiple sclerosis.
Successfully managing multiple sclerosis requires a comprehensive treatment plan.
An individual with multiple sclerosis should have a team of different medical professionals, such as neurologists, therapists, and general physicians, to manage help manage his or her disease.
A comprehensive treatment plan for multiple sclerosis has five elements:
- Slowing the disease progression
- Treating relapses
- Managing symptoms
- Improving function and safety
- Addressing mental health
Different medications are utilized for each of these goals. For example, steroids have been successful at treating relapses. Traditionally, intravenous (IV) methylprednisolone (a steroid) has been used for this purpose, but recent research has suggested that oral steroids might work just as well. This could be good news for people with multiple sclerosis, since it would mean that relapse treatment could be done on an outpatient basis, rather than the required hospitalization for IV steroids.
Various types of rehabilitative therapy can also be beneficial, such as physical, occupational, speech, or cognitive therapies. If the gait is affected, assistive devices can help individuals with multiple sclerosis stay on their feet.
Also, eating a healthy diet, getting enough rest, avoiding extreme temperatures, and avoiding stress can help. If multiple sclerosis makes swallowing difficult, make changes in food and drink choices, such as drinks with thickeners added or noodles instead of rice. Additionally, talk to a physician about supplements that might help multiple sclerosis symptoms, especially vitamin D.
If you have multiple sclerosis, how do you manage your symptoms?
Image by Lisa Brewster via Flickr