[Recent aspects of Neuro-Behcet's disease].

The central nervous system involvement in Behcet's disease, usually called neuro-Behcet's disease (NBD), includes acute type and chronic progressive type. Acute NBD is characterized by acute meningoencephalitis with focal lesions, presenting high-intensity areas on T2-weighted images or FLAIR images on magnetic resonance imaging (MRI). Cyclosporin A (CyA)-related acute NBD is almost identical to CyA-unrelated acute NBD in terms of clinical manifestations, laboratory data, and responses to steroids, except for the paucity of relapse on discontinuation of CyA. Chronic progressive NBD is characterized by intractable slowly progressive dementia, ataxia, and dysarthria with persistent elevation of the cerebrospinal fluid (CSF) IL-6 activity and progressive brain stem atrophy on MRI. Chronic progressive NBD is strongly associated with male gender, HLA-B51, and cigarette smoking. Diagnostic criteria have been proposed on the basis of the results of a retrospective multicenter cohort study, using CSF cell counts for acute NBD, and CSF IL-6 activity with brain stem atrophy on MRI for chronic progressive NBD, respectively. Attacks of acute NBD respond well to moderate-to-high doses of corticosteroids. Moreover, colchicine is effective in preventing relapses of acute NBD, especially in patients who developed the disease in the absence of CyA. Chronic progressive NBD is resistant to conventional treatment with steroid, cyclophosphamide, or azathioprine, but responds to low-dose methotrexate. Infliximab has also been found to be effective in patients with chronic progressive NBD when the response to methotrexate is inadequate.