A diagnosis of multiple sclerosis is not enough of a description to accurately represent the different types of the disease which are currently identified. Multiple sclerosis, and inflammatory and chronic degenerative disorder that affects nerves in the brain and spinal cord, is a result of the destruction of myelin that insulates the nerves and facilitates the conduction of electronic impulses. This removal of the myelin sheath results in symptoms such as muscle weakness, muscle tremors and visual impairment.
The damage done to the myelin sheath around the nerves is not a consistent event but rather happens intermittently. This demyelination causes scarring and hardening of the nerve tissue in the spinal cord, brain and optic nerves. Multiple sclerosis can progress steadily or cause acute attacks followed by a partial or complete remission. Most patients who suffer from multiple sclerosis will have a somewhat normal life span. Women may experience a decreased lifespan by approximately 6 years and men may have a decreased lifespan of approximately 11 years.
There are several types of multiple sclerosis. The first is called primary progressive and causes a steady progression of symptoms with only a few periods of remission. This particular type of aggressive multiple sclerosis is relatively rare and often ultimately ends in death.
Another type of multiple sclerosis is relapsing-remitting disease. In this case the individual will experience worsening of symptoms, called exacerbations, that occur with increasing frequency along with periods of reduce symptoms, called a remission. This is the most common form of multiple sclerosis with approximately 85% of people who begin their disease process with this type.
Secondary progressive multiple sclerosis looks initially similar to relapsing remitting but eventually follows the course of progressive MS without any remission. Attacks and partial recoveries may continue to occur. Of the 85% who start with relapsing remitting disease more than 60% will develop secondary progressive.
Relapsing progress of multiple sclerosis will cause cumulative damage during the exacerbations and remission.
Multiple sclerosis is the most common neurological cause of debilitation in young people and estimates today are there are approximately 500,000 people in the United States and potentially 2 million worldwide who suffer from this disease.
Another category in the disease of multiple sclerosis is benign multiple sclerosis. Unfortunately this is a highly misleading term since it implies that the severity will be slight. Initially this may be true but over time this form of the disease can be as debilitating as any of the others. Approximately 20% of patients will be initially diagnosed with benign multiple sclerosis but over time physicians will find that only 5% actually fall into this category.
While knowing the particular type of multiple sclerosis at the time of diagnosis is helpful with prognosis of the disease it is also important to note that this disease can also change course after several years. The truly aggressive and progress of form of multiple sclerosis is ultimately very rare in the vast majority of patients go on to live a life span which is shortened by only a couple of years.
RESOURCES
Multiple Sclerosis: Types
X-Plain Patient Education: Multiple Sclerosis
National Multiple Sclerosis Society: What is Multiple sclerosis
Cleveland Clinic: Multiple Sclerosis
Queensland: Four Different types of Multiple Sclerosis
Stanford School of Medicine: Two Kinds of Multiple Sclerosis