What’s Your Type? What You Need to Know About the Different Forms of MS
Multiple sclerosis, also known as MS, is an unpredictable and potentially disabling disease affecting the central nervous system; however, all cases of MS are not created equal. The disease can actually manifest in four distinct types or courses. These classifications are based on the severity and progression of symptoms in each patient.
The Four Types of MS
The four unique types of MS recognized by the National Multiple Sclerosis Society include:
- RRMS — Relapsing-remitting multiple sclerosis
- PPMS — Primary-progressive multiple sclerosis
- SPMS — Secondary-progressive multiple sclerosis
- PRMS — Progressive-relapsing multiple sclerosis
Relapsing-remitting MS is the most common form of the disease and accounts for approximately 90 percent of cases. This form of the disease is characterized by episodic flares or relapses where neurological function worsens followed by periods of complete or partial recovery or remission. The periods of flares and remission can last anywhere from a few days to even months. Symptoms can range in severity from mild to severe.
Progressive Forms of MS
Only about 10 percent of patients with MS have a progressive form of the disease at the time of diagnosis.
- PPMS — With primary-progressive MS, symptoms continuously worsen. The rate of progression is typically slow and steady, but it can vary during the course of the disease. On rare occasions, patients with PPMS may experience mild improvements or plateaus in the progression of their symptoms.
- SPMS — Patients with secondary-progressive MS may experience fluctuations in their symptoms similar to relapsing-remitting MS; however, the disease does not completely disappear between these episodes, and the disease continues to progress. RRMS can advance to SPMS if not treated.
- PRMS — Progressive-relapsing MS is a relatively rare form of the disease. Both PRMS and RRMS have clear periods where symptoms can flare-up or relapse. The two forms differ in that in PRMS, the symptoms continue to progress between relapses.
Diagnosing and treating RRMS early may prevent it from developing into a progressive form of the disease. Several disease-modifying drugs are available to treat RRMS and progressive forms of the disease where the patient continues to have episodic relapses. There are currently no approved treatments for PPMS without relapses; however, this is a primary focus of the National MS Society’s research strategy.