Categories of multiple sclerosis
Relapsing-Remitting MS
In relapsing-remitting MS, symptoms come (relapses) and go (remissions). Symptoms may evolve over several days and then disappear, although some symptoms may remain. The course varies from person to person, but on average, relapses appear every 2 years. The period between relapses can be very long, as much as 20 years or more. A small percentage of people have only a single attack in their lifetime.
Relapsing-remitting MS is the most common form of the disease and is most frequently diagnosed between the ages of 20 and 40. Up to 80 percent of people with MS are diagnosed with the relapsing-remitting type. Only 50 percent of people with RR MS develop secondary-progressive MS within the first 10 years.
Secondary-Progressive MS
The change from relapsing-remitting MS to secondary-progressive MS generally occurs 5 to 15 years after the disease begins. With secondary-progressive MS, neurological symptoms tend to worsen progressively, with or without superimposed relapses. Over time, it is common for secondary-progressive patients to have fewer attacks (sometimes none at all), despite continual progression. About 30 percent of people with MS have secondary-progressive disease.
Primary-Progressive MS
With primary-progressive MS, symptoms get worse over time, but there are no relapses or remissions. Some people with primary-progressive MS have brief periods of time during which their symptoms either stay the same or improve slightly. This type of MS is most often diagnosed in people over the age of 40.Progressive-Relapsing MS
Progressive-relapsing MS is a rare form of MS with a gradual worsening of symptoms from the beginning, with superimposed relapses and remissions.
It should be stated that this overview of the four diagnostic categories of MS is intended, in part, to simplify a complex disease. There may be additional diagnostic categories or subcategories, such as chronic progressive, that patients and health professionals use to further define the disease in individuals.
