Multiple sclerosis (MS) is an inflammatory disease of the central nervous system. The central nervous system is made up of the brain, spinal cord and optic nerves. The precise reason(s) for the inflammation that occurs in MS are not yet known, and this remains an active area of research. We do know that the inflammation damages both neurons and the myelin that insulates neuronal processes (called axons).
The loss of myelin is a characteristic feature of MS and forms areas of scar tissue called sclerosis (also called plaques or lesions). When the myelin or nerve fiber is damaged, nerve impulses traveling to and from the brain and spinal cord are distorted or totally blocked. Whereas myelin is capable of partially regenerating with some recovery of nerve function, neurons and their processes (axons) are not able to regenerate once permanently damaged.
Progressive or ongoing injury from MS can be measured precisely using an automated image analysis system developed by UC San Diego researchers. Major areas of research include finding ways to protect neurons from permanent injury (called neuroprotective therapy) and how to enhance myelin repair after partial injury.
Multiple Sclerosis Symptoms
Most people experience their first symptoms of MS between the ages of 20 and 50, although up to one third of patients will be diagnosed at younger or older ages. The initial symptoms of MS are highly variable and often go unrecognized, especially when less severe, as is often the case at the beginning of the disease. Symptoms may go away quickly or last for months. The progression and severity of MS vary from person-to-person.
Symptoms may include:
- Muscle weakness, clumsiness or incoordination
- Visual loss or double vision
- Difficulty with walking and balance
- Paresthesia (burning, prickling or “pins and needles” sensation
- Spasticity (involuntary muscle spasms and feelings of stiffness)
- Pain, particularly neuralgia
- Speech impediments
- Cognitive changes (may include difficulties with concentration, attention, memory and judgment)
- Bowel and bladder problems
- Changes in sexual function
Although the subsequent course of MS is unpredictable and apt to changes, certain risk factors for more severe disease have been identified, helping us to make treatment decisions.
Multiple Sclerosis Attack
An exacerbation, also called an attack, flare-up, or relapse, occurs when a person experiences new or worsening symptoms for at least 24 hours (usually more than 72 hours) in the absence of an explanation, such as fever or infection. Researchers believe that exacerbations are associated with the development of newly damaged areas in the brain.
An attack of MS can range from mild to severe and last from several days, to several weeks or months. Severe attacks can interfere significantly with a person’s daily activities.
There are several
treatment options that can help reduce symptoms or facilitate recovery from an attack.
Causes and Risk Factors
Multiple sclerosis is considered part of the common, complex disorders, which means the disease is not determined by a single genetic cause. Complex disorders are known to involve numerous genes, non-genetic factors, and interactions between genes and environmental factors.
Although there is an increased risk for MS in areas farthest from the equator and in Caucasians of northern European descent, MS is found in most regions of the world and in most ethnic groups.
There are 350,000 to 500,000 people in the U.S. who have been diagnosed with MS, and over 2.5 million people living with the disease worldwide.
- Multiple Sclerosis Foundation
Multiple sclerosis is more common in women, appearing two to three times higher than in men. This sex difference, however, disappears in patients with progressive onset of the disease.