Radiologically isolated syndrome (RIS)
Although not considered a course of MS, radiologically isolated syndrome (RIS) has been used to classify those with:
- Lesions on the brain or spinal cord — not explained by another diagnosis — consistent with lesions of MS and
- No past or current neurological symptoms or abnormalities found on a neurological exam
Often these individuals have had an MRI because of other symptoms, such as headache, and the results showed lesions similar to those seen in MS.
A 2020 study found that little more than half of those with RIS go on to develop MS within 10 years. There are no specific treatment guidelines for RIS. Additional research is needed to further define what factors increase the likelihood that someone with RIS will develop MS. Monitoring of MRI and neurological symptoms, as well as neurological examination, are generally recommended to quickly identify changes. If the diagnosis is MS, you can begin treatment early.
Research interest in RIS is high, and several studies are ongoing that could provide more guidance for monitoring and treatment. In fact, a 2022 study showed that dimethyl fumarate (Tecfidera®, Biogen) extended the time before the development of a first neurological symptom significantly more than a placebo. This adds to the idea that early treatment is protective and supports the idea that MS can begin well before symptoms emerge. Further study is needed, in larger numbers of people with RIS. Additional trials are underway.
More than a dozen disease-modifying therapies have been approved by the U.S. Food and Drug Administration (FDA) to treat the different types of MS. The FDA indicates which type of MS each drug can treat. More treatments are available for relapsing forms of MS than for progressive forms. Scientists around the world are actively looking for more effective treatments for progressive forms of MS. Addressing the challenges of progressive MS is a primary target of the Society’s research strategy.