Forms of Multiple Sclerosis
There are several different forms of MS. Approximately 85% of individuals with MS initially have what is known as relapsing-remitting MS. Patients with this type of the disease experience a fairly sudden onset of symptoms (known as an attack, relapse, flare, or exacerbation), such as blurred or double vision, weakness, numbness, tingling, balance problems, or dizziness. These symptoms, which usually develop over a few days and often improve with time, are typically followed by periods of remissions. MS relapses vary from mild to severe. Some people have few attacks from which they make full recoveries. However, approximately 35 percent of the time, the symptoms from a relapse do not resolve completely. This is why it is important to try to prevent MS attacks with the disease-modifying drugs. Unfortunately, an excellent recovery from a previous relapse does not ensure a similar outcome for subsequent attacks.
When relapsing-remitting MS is left untreated, a significant proportion of patients will enter a progressive phase of the disease with gradual deterioration and reduced functioning. This is known as secondary progressive MS. About 15% of individuals have primary progressive MS, which is characterized by a gradual decline in functioning in the absence of exacerbations or remissions.