About Multiple Sclerosis
Multiple sclerosis (MS) is a chronic autoimmune disease that causes inflammation of certain parts of the brain and spinal cord. In people with MS, the immune system has become sensitized to proteins called myelin proteins, which are present on nerve cells.
The prevailing theory on the cause of MS is that T lymphocytes become reactive to myelin proteins, and are able to cross the blood-brain barrier once they become activated. Normally, immune cells cannot cross this barrier, because inflammation in the brain and spinal cord is destructive to delicate brain and nerve tissue.
Once immune cells cross the blood-brain barrier they are able to attack myelin proteins on the surface of spinal cord cells, as well as cells in certain parts of the brain, including optic nerves. Over time, the immune response to myelin proteins leads to the formation of lesions on the spinal cord, which prevents the transmission of nerve impulses from the brain to muscles. These lesions are responsible for the signs and symptoms of MS.
MS is a progressive disease, which means that the symptoms grow worse over time. The course of the disease is highly variable, however. For some people the course of the disease is steadily and rapidly progressive, while for others, progression might be slow. In still other cases, progression is punctuated by periods of remission in which symptoms lessen in severity or even disappear altogether.
Early Warning Signs of Multiple Sclerosis
There are many signs and symptoms that can occur early in the course of MS. However, many of these symptoms are fairly non-specific, and as a result diagnosis can be difficult.
Possible early symptoms of MS include:
- Numbness or weakness in limbs. Usually this affects on the lower limbs, or affects the limbs on one side of the body. This symptom is one of the most common early MS warning signs.
- Blurring of vision, or double vision
- Muscle tremors
- Reduced muscle coordination
- Pain and tingling in various parts of the body
- Electric shock-like sensations in the head
- Reduced attention span, memory loss, impaired judgment
All of the above symptoms can appear early in the progression of the disease. Many of these can also manifest much later in progression. This list of symptoms is only a general guide: not all symptoms will be noted in any individual case, and the diversity and severity of symptoms at any stage of progression is highly individual.
Because MS is a progressive disease, all of the above symptoms have the potential to become more severe over time. Other symptoms can also develop. These include symptoms such as bladder or bowel dysfunction, sexual dysfunction, depression, speech disorders, swallowing problems, breathing problems, vision loss, chronic pain, and seizures.
Many of these progressive symptoms appear much later in progression, and are unlikely to develop in all cases. For example, around 40% of people with MS develop speech problems, and 5% have seizures. In contrast, some progressive symptoms are more common. Bladder dysfunction occurs in 80% of cases of MS, and around 55% of people experience chronic pain.
Fernando Dangond, MD, for eMedicine: Inflammatory and Demyelinating Diseases: Multiple Sclerosis
National Institute of Health Medline Plus: Multiple Sclerosis
The Mayo Clinic: Multiple Sclerosis
U.S. National Multiple Sclerosis Society: About MS