What is multiple sclerosis?
Multiple sclerosis is a demyelinating (inflammatory) disease of the central nervous system. The central nervous system consists of the brain, optic nerves and the spinal cord. Multiple sclerosis produces degenerative changes in the white matter of the central nervous system. White matter contains the nerve fibers and is responsible for transmitting the neural signals to various parts of the body and the brain. Myelin is an insulating material covering of the nerve fibers. Multiple sclerosis produces multiple patchy lesions called plaques in the central nervous system. In this disease, the myelin in lost in the affected areas of the brain. The lesions may be due to an autoimmune response.
The usual age of onset is 10-59 years, with the greatest peak between ages 20 - 40 years. Males are slightly more affected than females. Approximately 30-40 persons per 100,000 population are affected by multiple sclerosis in northern U.S and Canada.
What are the types of multiple sclerosis?
There are four types of multiple sclerosis:
What are the symptoms of a patient who is having multiple sclerosis?
- Relapsing- remitting: Here there will be episodes of acute neurological worsening with recovery and a stable course between the attacks.
- Secondary progressive: Here there is gradual deterioration of the neurological status of the patient who had relapsing remitting type of multiple sclerosis initially.
- Primary progressive: Here there is gradual and nearly continuous neurological deterioration from the onset of symptoms.
- Progressive relapsing: Here the patient will have gradual neurological deterioration from the onset of symptoms, but with subsequent superimposed relapses.
Typically the symptoms come and go over a period of time. Common symptoms are:
How to diagnose multiple sclerosis?
- Visual disturbances: The lesion affects the optic nerve. Visual disturbances may be the common complaint in 15% of the multiple sclerosis patients. Sometimes, acute loss of vision in one or both eyes can occur. Double vision, blurring of vision and visual field defects are the other visual symptoms.
- Weakness of limbs and difficulty in walking are the most common symptoms in a patient with multiple sclerosis.
- Difficulty in speaking due to cerebellar involvement can occur.
- Numbness and tingling sensation over the face, trunk and limbs may be there.
- Trigeminal neuralgia can occur.
- Psychological symptoms like euphoria or depression can occur.
- Sexual disturbances like impotence in males and reduced libido in both males and females are common in multiple sclerosis.
- Muscle spasms, spasticity, cramps and pain.
- Urinary symptoms like incontinence, urinary urgency or hesitancy.
- Loss of balance.
- Fatigue, short term memory problems, and other forms of cognitive dysfunction.
- Difficulty in swallowing the food.
- Difficulty if breathing.
Diagnosis is confirmed by clinical examination, MRI findings and the lab investigations. CSF study shows the presence of oligoclonal bands. MRI of the brain with contrast will show the demyelinating plaques as white signal intensities. Visual evoked potentials may show the damage to the visual pathways.
What are the treatment options available?
Till date there are no drugs available for the cure of multiple sclerosis. The following drugs are useful only to treat the acute attack of the disease and to slow down the disease process.
- Interferon beta-1b injections reduces the frequency of relapses by 30%
- Interferon beta 1a can also be given
- Glatiramer injections reduces the annual relapses by 30%
- Immunoglobulins may be useful but are very costly
- Methotrexate has some short term benefits
- Corticosteroids like ACTH and methylprednisolone are the most commonly used drugs during the acute attacks.