What is MS—Multiple Sclerosis?
Multiple sclerosis (MS) is a disease in which the nerves of the central nervous system (brain and spinal cord) degenerate. Myelin, which provides a covering or insulation for nerves, improves the conduction of impulses along the nerves and also is important for maintaining the health of the nerves. In multiple sclerosis, inflammation causes the myelin to disappear. Consequently, the electrical impulses that travel along the nerves decelerate, that is, become slower. This damage slows down or blocks messages between your brain and your body, leading to the symptoms of MS. They can include:
1. Visual disturbances
2. Muscle weakness
3. Trouble with coordination and balance
4. Sensations such as numbness, prickling, or "pins and needles"
5. Thinking and memory problems
6. Speech Impediment
7. Attention deficits
10. Impairment in judgment
11. Memory loss
It is not easy to diagnose multiple sclerosis as it has symptoms common to other diseases. The McDonald criteria which are in use now include clinical, radiologic and laboratory data collected from lesions caused by multiple sclerosis. Diagnostic tools commonly used are neuro-imaging, analysis of cerebrospinal fluid , magnetic resonance imaging , testing of cerebrospinal fluid. There are four main varieties as defined in an international survey of neurologists (All the graphs show level of disability over time - where two lines appear in the graph it denotes two possible courses of that form of MS.)
1. Relapsing/Remitting (RRMS)
This is characterised by relapses (also known as exacerbations) during which time new symptoms can appear and old ones resurface or worsen. The relapses are followed by periods of remission, during which time the person fully or partially recovers from the deficits acquired during the relapse. Relapses can last for days, weeks or months and recovery can be slow and gradual or almost instantaneous. The vast majority of people presenting with Multiple Sclerosis are first diagnosed with relapsing/remitting. This is typically when they are in their twenties or thirties, though diagnoses much earlier or later are known. Around twice as many women as men present with this variety.
2. Secondary Progressive (SPMS)
After a number of years many people who have had relapsing/remitting MS will pass into a secondary progressive phase of the disease. This is characterized by a gradual worsening of the disease between relapses. In the early phases of Secondary Progressive, the person may still experience a few relapses but after a while these merge into a general progression. People with secondary progressive, may experience good and bad days or weeks, but, apart from some remission following relapsing episodes, no real recovery. After 10 years, 50% of people with relapsing/remitting MS will have developed secondary progressive By 25 to 30 years, that figure will have risen to 90%
3. Progressive Relapsing Multiple Sclerosis (PRMS)
This form of MS follows a progressive course from onset, punctuated by relapses. There is significant recovery immediately following a relapse but between relapses there is a gradual worsening of symptoms.
4. Primary Progressive (PPMS)
This type of MS is characterized by a gradual progression of the disease from its onset with no remissions at all. There may be periods of a leveling off of disease activity and, as with secondary progressive; there may be good and bad days or weeks. PPMS differs from Relapsing/Remitting and Secondary Progressive in that onset is typically in the late thirties or early forties, men are as likely women to develop it and initial disease activity is in the spinal cord and not in the brain. Primary Progressive MS often migrates into the brain, but is less likely to damage brain areas than relapsing/remitting or secondary progressive - for example, people with Primary Progressive are less likely to develop cognitive problems.
The cause of multiple sclerosis is still unknown. Multiple sclerosis affects women more than men. It often begins between the ages of 20 and 40. Usually, the disease is mild, but some people lose the ability to write, speak or walk. Medications used to treat MS can be classified as immunomodulating or symptom-management medications. For acute exacerbations, methylprednisolone (Solu-Medrol) is given and has been shown to hasten recovery from the given attack, but it has uncertain long-term effects. In addition, plasma exchange (plasmapheresis) can be used short term for severe attacks if steroids are contraindicated or ineffective. The 2011 American Academy of Neurology (AAN) guideline for plasmapheresis in neurological diseases calls plasmapheresis “probably effective” as second-line treatment for relapsing MS exacerbations that do not respond to steroids.