Oligoclonal bands are present in less than 85% of patients with clinically definite Multiple Sclerosis. Ideally serum and CSF should be tested simultaneously to distinguish between production of oligoclonal bands due to peripheral gammopathy from that due to local production in the CNS. Other conditions which show oligoclonal bands are Subacute sclerosing panencephalitis, Inflammatory polyneuropathy, CNS Lupus and Brain tumors.