Clinically isolated syndrome is a first episode of neurologic symptoms caused by demyelination and inflammation in the central nervous system. These neurologic symptoms, similar to those of multiple sclerosis, must last at least 24 hours with no accompanying fever or infection for CIS to be diagnosed. In people who have experienced CIS, MRI findings may show a lesion on the brain or spinal cord like those seen in MS.
To better understand the difference between CIS and MS, MyMSTeam sat down with Dr. Jacqueline Nicholas. Dr. Nicholas is a fellowship-trained MS specialist and board-certified neurologist who directs the OhioHealth Multiple Sclerosis Center and MS research in Columbus, Ohio.
“CIS occurs when an individual experiences a single episode of neurologic symptoms due to demyelination within the brain or spinal cord in which no other cause or explanation is found,” Dr. Nicholas explained.
“We perform an extensive evaluation to review the patient’s story of their symptoms, which need to have lasted 24 hours or longer, perform a mimics work-up — including labs, MRI, and sometimes a lumbar puncture for spinal fluid evaluation — to clarify the diagnosis. A special criteria called the 2017 McDonald Criteria are used to determine if the patient has CIS,” Dr. Nicholas added.
According to the 2017 revisions to the McDonald diagnostic criteria for MS, when CIS is accompanied by MRI evidence that another episode has occurred, the diagnosis of MS can be made. The presence of oligoclonal bands in a person’s cerebrospinal fluid can also help make the diagnosis.
An episode of CIS can be followed by partial, full, or no recovery. Some people who experience CIS may never have another occurrence of neurologic symptoms.
The International Advisory Committee on Clinical Trials of MS considers CIS one of four main MS disease courses. CIS becomes definite MS when a second occurrence of symptoms or a worsening of lesions happens — or both.
“To read this article in its entirety click this link: Clinically Isolated Syndrome (CIS) vs. MS.”