Neurological complications of Behçet's syndrome.

In this review of the neurological complications of Behçet's syndrome, the clinical features and epidemiology of the systemic disease are summarised before a discussion of the neurological syndromes which may develop is made. Neurological involvement occurs in 9% of cases, and is equally prevalent in each geographical area. Vascular complications occur in 14%, in whom thrombosis of the venous sinuses or cerebral veins occurs, and intracranial hypertension, venous infarction and parenchymal haemorrhage may develop. There is a correlation with the prevalence of peripheral venous thrombosis. Concurrent inflammatory disease of the brain is most uncommon. Inflammation may affect any part of the central nervous system, but most commonly involves a subacute meningoencephalitis of the brainstem and diencephalon. Inflammatory lesions elsewhere in the brain and in the spinal cord may occur, and tumefactive lesions may arise from the diencephalon. Cognitive dysfunction and affective symptoms, including psychosis, may occur, and there are high levels of anxiety and fatigue which are related to the severity of the systemic disease, all of which are more severe in those with neurological involvement. Imaging shows enhancing lesions which often disappear after treatment, but atrophy is common. The CSF is active when there is a meningoencephalitis, and oligoclonal bands do not occur. Treatment is with steroids and immunosuppression. Those with treatment resistant disease respond to biological agents, including TNF alpha, IL-1 and IL-6 antagonists.