Multiple sclerosis affects people in many different ways. Every person diagnosed with MS will have a unique experience. However, there are two common patterns to the disease which can be described as relapsing or progressive. The course of MS tends to follow one of these two patterns, or a combination of each.
What is relapsing MS?
Relapsing MS is the most common form of MS, affecting more than 8 out of 10 people with MS. Relapsing MS is characterized by episodic worsening of symptoms or the sudden appearance of new symptoms interfering with normal neurologic function. These episodes are called relapses, attacks, exacerbations, or flare-ups. Relapses are typically followed by partial or complete recovery (called remission). Forms of relapsing MS include relapsing-remitting MS (RRMS) and progressive-relapsing MS (PRMS).
What is progressive MS?
Progressive MS affects far fewer people than relapsing MS, with only about 10% to 15% of people originally diagnosed with the progressive form of the disease. Progressive MS is characterized by a gradual and steady increase in disability without distinct relapses and remissions. With progressive MS, the increase in disability may be gradual, slow, quick, or fluctuate over time. Forms of progressive MS include primary-progressive MS (PPMS), secondary-progressive MS (SPMS), and progressive-relapsing MS (PRMS).
In PPMS and PRMS, the disease causes an gradual increase in disability from the beginning at disease onset. In SPMS, patients began their MS journey with the RRMS form of the disease which later transitions into progressive disease with fewer and fewer relapses over time. Note that PRMS, which is very rare, combines relapsing and progressive characteristics of the disease. Patients with PPMS do not experience relapses.
What is pediatric MS?
Out of the approximately 400,000 people who live with MS in the US, about 8,000 to 10,000 are children or adolescents. These children are diagnosed with pediatric MS. An additional 10,000 to 15,000 children experience one or more MS-like symptoms that may or may not eventually lead to a diagnosis of MS.
Symptoms of MS can appear in infants as young as 13 months. MS has been diagnosed in children as young as 2 years of age. However, most diagnoses of pediatric MS are made during adolescence in the teenage years.
As with adults, the course of MS in children is unpredictable and may progress quickly or slowly.