Presence of intrathecal IgG synthesis suggests inflammatory disease of the CNS, such as caused by Multiple Sclerosis (MS).

According to the updated international guidelines, these revised criteria will notably allow diagnosing MS in asymptomatic individuals specifically, those who previously were classified as having radiologically isolated syndrome (RIS). People with RIS have MRI lesions suggestive of MS, but no clinical symptoms.

The latest recommendations emphasize that the detection of disease-specific oligoclonal bands in the cerebrospinal fluid can replace the need to demonstrate dissemination in time, allowing for a confirmed diagnosis even after a single clinical event in certain cases.