Clinically Isolated Syndrome (CIS)

Clinically isolated syndrome (CIS) is the first clinical presentation of disease characterized by inflammatory demyelination. CIS, a neurologic episode that lasts at least 24 hours, could indicate a first course in multiple sclerosis (MS) disease.

Natural history studies and clinical trials of MS disease-modifying therapies have shown that an episode of CIS and an MRI brain scan that shows lesions will likely predict a second episode of neurologic symptoms. A diagnosis of relapsing-remitting MS could come several years later.

If brain lesions are not detected, the odds of developing MS are much lower.

CIS is more common in women than men, and occurs more frequently among people ages 20 to 40.

If CIS is accompanied by MRI findings that show a past episode had occured, an MS diagnosis can be made. Meanwhile, people with CIS and brain lesions may be treated with disease-modifying medicines because early treatment could delay the onset of MS or prevent a second neurologic episode.

Some medicines approved for CIS by the U.S. Food and Drug Administration (FDA) are:






CIS can be monofocal or multifocal. Monofocal CIS is a single neurologic sign or symptom caused by a single lesion (such as optic neuritis, brain dysfunction, or partial myelitis). Multifocal CIS is the experience of one or more symptoms caused by more than one lesion.

Most of the time, CSI occurs with no fever orinfection. Revovery may be complete or partial.

Note: Multiple Sclerosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.




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