MULTIPLE SCLEROSIS (MS)

MS is a disease affecting the ‘white matter’ of the brain and spinal cord. This white matter, which lies mainly in the interior of the brain, is made up of the nerve fibers or axons and their surrounding insulating material, myelin. It is the myelin which is primarily affected, causing a breakdown in transmission of nerve impulses. Because the myelin can be affected anywhere in the brain or spinal cord, symptoms vary.

MS is common in temperate climates, affecting about 1 in 500 people. There is a higher incidence in women than in men. Onset is usually between age 20 and 40.

What Causes MS?

The cause of MS is unknown. Both genetic and environmental factors appear to be important in triggering the immune system to attack myelin.

Different Types of MS:

MS is divided into several types. The relapsing-remitting form is most common, affecting 80% of patients. In this form, symptoms come and go in the form of 'attacks'.  An MS attack is characterized by abrupt worsening, usually lasting greater than 24 hours and often for weeks or months, followed by a remission. Symptoms may include sudden visual loss, weakness, numbness, or vertigo. Remissions can also last for weeks, months or even years.

Primary progressive MS, which affects about 20% of patients, causes a gradual decline in neurologic function from disease onset without remission.

Diagnosis:

The diagnosis is made on the basis of a history of 2 or more attacks with abnormalities on examination indicating effects in different parts of the brain and spinal cord. Most patients with MS have abnormal Magnetic Resonance Imaging (MRI) scans.

Treatment of MS:

Interferons and Copaxone are used in individuals with clinically definite MS with active disease, i.e., frequent attacks. Contraindications for their use include pregnancy, breast feeding and prior allergic reaction. Patient education regarding the drugs (and the disease) is important. Blood counts and liver function can be affected by the drugs and are monitored. The drugs are often introduced gradually. Acetaminophen or non-steroidal anti-inflammatory drugs (NSAIDs, e.g. ibuprophen) can be used to control side effects.

Interferons and Copaxone decrease attacks and their severity. They have also been shown to reduce lesion burden on the MRI.

The interferons include Betaseron, Rebif and Avonex. Betaseron and Rebif are the  highest-dosed preparations. Avonex has the least interferon. Both Rebif and Betaseron seem to have more effect in MS.

Copaxone is a mixture of 4 amino-acids designed to look like a myelin protein. It has modest effects on reducing attacks and MRI scanning changes.

Interferon side effects include the flu, low white blood cell counts, abnormalities in liver function, and injection site reactions.

To date, interferons seem to have a very modest effect on disability. Azathioprine and  mitoxantrone may also have a modest efficacy In progressive MS.

New treatment developments under study include bone marrow transplantation, combination of interferons with immunosuppression, and earlier treatment.

The most important part of MS patient care is treating MS symptoms. Fatigue, the commonest symptom, can be treated with modafinil (Alertec) or amantadine (Symmetrel). Drugs that are effective for spasticity include diazepam (Valium), Lioresal (Baclofen) and Tizanidine (Zanaflex). Treatment options for pain include Amitriptyline (Elavil), Gabapentin (Neurontin), or Carbamazepine (tegretol). Escalating doses of analgesics can also be tried.

Bladder difficulties are common. Ditropan, urispas, or Dotrol can be tried for upper motor neuron type bladder difficulties. Intermittent catheterization is sometimes necessary. 

Depression is common in MS. Drugs such as Prozac seem to be effective. 

In British Columbia MS clinics located at the University of British Columbia, Kelowna, Victoria and Prince George can help consolidate a diagnosis, launch treatment programs, and are also involved in research.

The Canadian MS Society provides excellent information resources for patients. 

Ongoing research in MS is helping us to understand the disease better. MS treatment has improved considerably over the last few years.

Dr. M. Berry

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