A short-circuit of the nervous systemComment on this story
Multiple sclerosis (MS) is a disease of unknown cause that affects the brain, optic nerves and spinal cord (the central nervous system).
It affects women more than men and is most commonly diagnosed between the ages of 20 and 40, but can occur at any age.
Non Smit, the national director of the MS Society in SA, said she thought of it as a circuit.
“Imagine a simple wiring circuit. Each wire (your nerve) has a rubber insulation (called myelin) to prevent electrical impulses jumping and short-circuiting. If you were to strip off a part of the rubber insulation, the wire might still work and carry electrical impulses, but it wouldn’t do it efficiently and if there was another wire close to it, you might get a short or broken circuit,” she said.
Smit said this was basically what caused the many, varied symptoms of MS.
“Without myelin, our nerves can’t carry electrical signals efficiently (or sometimes at all). If you think about it, everything we do is controlled by our central nervous system and so any function can be affected, depending on which nerve or nerves are affected.”
Durban neurologist Professor Ahmed Bhigjee said: “Depending on the part of the central nervous system affected by MS, patients may have difficulty in walking owing to weakness and stiffness, disturbed balance, abnormal sensation and bladder and bowel dysfunction. One of the most common symptoms is chronic fatigue. Recent studies have increasingly recognised cognitive abnormalities and personality changes as important causes of disability.
“Although the cause of MS is unknown, it is believed that interaction between genetic predisposition, immune disturbance and the environment leads to MS,” he said
“The environmental factor may be an infection such as the Epstein Barr virus, which is a virus of the herpes family and is one of the most common viruses in humans. It is best known as the cause of infectious mononucleosis. It is also associated with particular forms of cancer, particularly Hodgkin’s lymphoma, Burkitt’s lymphoma, nasopharyngeal carcinoma and central nervous system lymphomas associated with HIV,” said Smit.
PATTERNS OF MS
According to Bhigjee, there are four recognised patterns of MS:
* Benign MS: People have only mild symptoms and very few relapses (new or worsening symptoms). Between relapses, they recover fully and don’t have more than mild disability.
* Relapsing-remitting MS (RRMS): People have a number of relapses. Between relapses, they recover partially or fully. Disability can get worse over time.
* Secondary progressive MS (SPMS) with or without relapses: This starts out as RRMS, but then patients get irreversible cumulative deficits. About 70 percent of people with RRMS move on to SPMS within 10 years.
* Primary progressive MS (PPMS): The MS becomes steadily worse from the outset, with no real relapses or recoveries. There may be small temporary improvements and occasional periods when the disease does not worsen. This type is not common.
SYMPTOMS OF MS
Multiple sclerosis is an insidious disease with varying symptoms that may include:
Loss of balance
Weakness in one or more limbs
Blurred or double vision
Sudden onset of paralysis
Lack of co-ordination
As the disease progresses, other symptoms may include muscle spasms, sensitivity to heat, fatigue, changes in thinking or perception and sexual disturbances.
Having some of these symptoms does not mean you have MS. The correct diagnosis depends on a careful neurological assessment and appropriate investigations such as MRI scans of the brain and spinal cord and cerebro-spinal fluid analysis.
It’s not uncommon for people with MS to experience new symptoms, or feel that their old symptoms are getting worse. When this happens, it is called a relapse or flare-up, flare, attack, or exacerbation. This is caused by inflammation in the central nervous system, which causes demyelination.
These are unpredictable and mostly occur without warning. Perhaps you have not had vision problems before, and suddenly you can’t see out of your left eye. They may be more common after a viral or upper respiratory infection. They may also occur slightly more often in women in the three months after pregnancy.
Relapses can interfere with your daily life, which is why staying on track with your MS medication is advised.
You may recover completely, with the symptom going away entirely, or there may be some permanent loss of function or sensation.
Most exacerbations evolve over a period of days, sometimes over weeks. They can go on for as long as a year.
There is no known cure for multiple sclerosis. However, there are disease-modifying therapies that decrease the number of relapses and may slow the progression of the disease.
The mainstays of treatment are the beta interferons, which are given by injections. However, there are exciting oral therapies on the horizon. One awaiting registration with the MCC is fingolimod. - The Mercury