Behcet's syndrome and the nervous system

Patients with Behcet’s Syndrome (BS) may present with different neurological problems, which are either primary or secondary consequences of the systemic disease. The clinical and imaging evidence suggests that primary neurological involvement in BS may be divided into two major forms: The first form, seen in the majority of patients, is the parenchymal central nervous system (CNS) involvement. This is likely to be due to inflammatory small vessel disease, and may present as an acute disorder or may have a chronic progressive form. It’s named as intra-axial “neuro-Behcet’s syndrome” (NBS). The second form, which has few symptoms and a better neurological prognosis, is caused by isolated cerebral venous sinus thrombosis and presents with symptoms and signs of intracranial hypertension, and it’s named as extra-axial “neuro-Behcet’s syndrome.” These two types rarely occur in the same individual, and their pathogenesis is likely to be different. Isolated behavioral syndromes and peripheral nervous system involvement are rare, whereas a nonstructural vascular type headache is relatively common and independent from neurological involvement. Neurologic complications secondary to systemic involvement of BS such as cerebral emboli from cardiovascular complications of BS and increased intracranial pressure due to superior vena cava syndrome, as well as neurologic complications related to BS treatments such as CNS neurotoxicity with cyclosporine and peripheral neuropathy with the use of thalidomide or colchicine are considered as secondary neurological complications. Acute episodes of NBS are treated with high-dose i.v. methylprednisolone followed by an oral tapering. As the neurological involvement in this syndrome is so heterogeneous, it is difficult to predict its course and prognosis, and response to treatment. A number of immunosuppressive agents as well as the immunomodulatory agent interferon-alpha have been used for the long-term treatment of intra-axial NBS, but none of them have been shown to be specifically beneficial. The monoclonal anti-TNF alpha antibody treatment emerges as a new option for the same purpose, but further data is needed. Currently, treatment options are limited to attack and symptomatic therapies, with no evidence for the efficacy of any long-term preventive treatment.