Vasculitis of the central nervous system.

Central nervous system (CNS) vasculitis occurs in a variety of clinical settings. Some exhibit a distinct age preference; others a tissue tropism. Most frequently encountered are giant cell arteritis (temporal arteritis) and vasculitis secondary to infections. The CNS may be involved in the systemic vasculitides, and neurologic abnormalities occasionally appear as a presenting manifestation of disease. Isolated angiitis of the CNS, a rare form of vasculitis restricted to the CNS, must be distinguished from other causes of CNS inflammation and from noninflammatory vascular disease. We are learning a great deal about the cellular mechanisms of vascular inflammation in the brain. Some manifestations of the clinical disease result from histologic features of the infiltrate and the size of affected vessel. However, the local consequences of inflammation such as increased coagulation and altered vasomotor tone, as well as the systemic consequences such as activation of the central noradrenergic systems, trigeminovascular system, and hypothalamic pituitary adrenal axis contribute to both pathogenesis of disease and recovery. Two central issues that confront us now are improving the accuracy of the diagnosis (including identifying any underlying infectious causes) and limiting the long-term damage both from disease and its therapies.