The Cerebrospinal Fluid Presentations of Neuro-Behçet Disease

In parenchymal neuro-Behcet disease (NBD), CSF opening pressure is usually normal. CSF pleocytosis is usually less than 200/mm3. Pleocytosis could be lymphocyte dominant or less frequently PMN dominant. However, CSF cytochemistry could be completely normal. CSF protein content is usually increased, but it could be normal. CSF glucose is often normal, which can be helpful in differentiation of acute NBD from infectious processes. In NBD presenting with cerebral venous sinus thrombosis, it is better to withhold the lumbar puncture; however, if CSF is taken, CSF opening pressure is elevated, but CSF constituents are usually normal. Intrathecal oligoclonal IgG bands are infrequently found in neuro-Behcet disease. The absence of more than two oligoclonal IgG bands may help differentiate NBS from multiple sclerosis (MS). Oligoclonal bands are less stable in the setting of NBD compared with MS and can be easily suppressed by corticosteroid treatment. However, rarely in young MS patients, oligoclonal IgG bands could be absent in the early stages of the disease or can present as a weak single band. Therefore, the presence of oligoclonal bands cannot rule out NBD. CSF IL-6 might be a marker of disease activity in parenchymal NBD patients. That IL-6 is more increased in chronic progressive NBD patients is a matter of debate. Also, CSF IL-6 is not increased in patients with non-parenchymal NBD.