Oligoclonal bands are present in the CSF of more than 85% of patients with clinically definite
multiple sclerosis (MS). To distinguish between
oligoclonal bands in the CSF due to a peripheral gammopathy and oligoclonal bands due to local production in the CNS,
serum and CSF should be tested simultaneously. Oligoclonal bands can however be observed in a variety
of other diseases, e.g., subacute sclerosing pan-encephalitis, inflammatory polyneuropathy, CNS lupus, and brain tumors and infarctions.