Neurologic involvement in Beh double dagger et's disease (BD) is seen in about 5% to 10% of all BD patients. Clinical and imaging data suggest that neurologic involvement in BD presents in two major forms. The first, central nervous system (CNS) parenchymal involvement with a predilection to brainstem-diencephalic regions, is seen in the majority of patients with neuro-BD (NBD). The second form is cerebral venous sinus thrombosis (CVST), which is seen in up to 20% of cases. BD is very rare in children, but when it does occur, the patterns are reversed: most children with NBD present with CVST. Other syndromes such as spinal cord involvement, arterial CNS involvement, optic neuritis, aseptic meningitis, and peripheral neuropathies may be seen, but are rare. Venous sinus thrombosis in BD has a significantly better neurologic prognosis than parenchymal CNS involvement. There is no Class I evidence regarding treatment of parenchymal CNS involvement or CVST in BD. Current treatment applications are based largely on expert opinion; none are evidence-based. Acute parenchymal CNS involvement should be treated with high-dose intravenous methylprednisolone (IVMP), 1 g per day, for 5 to 10 days, followed by either a prolonged oral taper or intermittent IVMP pulses with a low oral dose between the pulses, over 6 months. After treatment of the acute attack, long-term maintenance with immunosuppressive agents should be considered in patients with parenchymal CNS involvement, as this form may follow a relapsing or secondary progressive course and may result in significant physical and cognitive deficits leading to severe neurologic disability. A number of randomized controlled studies have tested treatments for systemic manifestations of BD. Colchicine was found to be effective for mucocutaneous symptoms, thalidomide was found to be effective in erythema nodosum-like skin lesions, azathioprine and cyclosporine were shown to be effective in BD uveitis, and cyclophosphamide was shown to be effective for major vascular involvement. More recently, interferon alfa and anti-TNF agents were also shown to be effective in BD uveitis. Although randomized controlled studies have not been performed in NBD, the most widely used long-term therapeutic agent is azathioprine. Recent observations suggest that the addition and long-term use of azathioprine in NBD could be associated with a more favorable course. A growing number of case reports in recent years suggest that anti-TNF agents may be an effective alternative in NBD, but current experience with these agents is limited. CVST in BD is also treated with steroids. The addition to glucocorticoids of anticoagulation, including short-term fractionated heparin, is controversial, as these patients have a higher probability of harboring pulmonary or other aneurysms, which may be associated with an increased risk of bleeding. Long-term oral anticoagulation is unnecessary. Interestingly, the prognosis of CVST due to BD seems to be much more favorable than the prognosis of CVST due to other causes, with much less tendency for venous infarcts and seizures. However, as recurrences may occur, long-term treatment with azathioprine is recommended.
