Multiple sclerosis (MS) is the most common neurological disease. About one in a 1,000 people are affected.
MS is a disease that targets the central nervous system- brain and spinal cord. Messages from the brain travel down the spinal cord and to muscles in the body and limbs. Messages also travel back to the brain up to the spinal cord. These messages are sent along the nerves as electrical impulses. Some tell muscles to move and control how they work together. Other nerves alert the brain to sensations such as pain and temperature.
Nerves are protected by a fatty, insulating substance called myelin. People with MS have damaged myelin. This causes electrical impulses to be blocked in different parts of the brain, spinal cord and nerves. This “insulation” breaks down in the process of demyelination so that the associated neuron becomes dysfunctional. This process can occur anywhere in the nervous system.
Why this demyelination occurs is more of a puzzle. What we do know for sure is that MS is an autoimmune disease that, for some reason, our body fails to recognise the myelin as its own and so starts destroying it.
There seem to be two main broad types of a pattern of lesions: a form that affects the spine and is usually associated with a greater physical disability and a form that affects the brain and leads to a greater cognitive impairment.
The early symptoms of MS occur when nerves are unable to carry their signals effectively. These include:
- Weakness of limbs especially of legs
- Numbness and “pins and needles”
- Loss of balance
- Loss of vision
- Severe fatigue
Other common early symptoms include optic neuritis (inflammation of the optic nerve leading to blurred vision, loss of acuity and pain), double vision and urgency to urinate.
There are also prominent effects on memory with an impaired ability to learn and recall and more rapid forgetting with interference, with recognition less affected than recall. MS patients also have disturbances of mood. Depression is common with MS patients and suicide risk is up by 15%.
Patients with advanced cases may be dependent on a wheelchair or special seating system, produce staccato and slurred speech that may be very difficult to understand, have abnormal eye movements, upper limb weakness and ataxia, severe spastic paraplegia with spasms, and sensory loss, and be double incontinent. They may be completely dependent for all their physical care.
Unlike other diseases the symptoms of MS are unpredictable, they are different for every person with the disease. In mild cases, a person may just have intense tiredness or in severe cases become paralysed.
– Need to know Multiple Sclerosis, Alexander Burnfield, 2004, page 6,7,16,17, 18,19
– Introduction to Neuropsychology second edition, J. Graham Beaumont, 2008, page 160-162
By Sonia and Riya