Neurosarcoidosis.

Sarcoidosis is a multisystem granulomatous disorder of unknown etiology first named and described in the 19th century. The diagnosis usually requires the finding of noncaseating epithelioid cell granulomas in more than one organ and exclusion of other disorders known to cause granulomatous disease. The incidence of nervous system involvement in sarcoidosis is about 5%. Sarcoidosis may involve any part of the nervous system. Corticosteroids remain the mainstay of treatment of neurosarcoidosis.