[Neurosarcoidosis]

Sarcoidosis is a chronic systemic disease of unknown causes characterized by noncauseating granuloma in various organs. Neurological involvement occurs in 5-6% of patients with sarcoidosis. Most patients with neurosarcoidosis have extraneurologic abnormalities and extraneurologic biopsies usually support the diagnosis, however, nearly half of the patients with neurosarcoidosis present with neurological manifestations without systemic symptoms. Several cases of isolated neurosarcoidosis have been reported, making the diagnosis difficult. Although several diagnostic criteria have been proposed, neuropathological examination is required for the definite diagnosis. Brain biopsy may still be required in selected patients. Since it is often difficult to perform, clinical assessment with various combinations of modern neuroimaging techniques is important. Lumbar puncture is useful to rule out other diseases but CSF changes are not specific. Elevated serum ACE level is also not a specific diagnosis test. Any part of the CNS can be involved, but there is predilection for hypothalamus, pituitary gland, leptomeninges, and cranial nerves particularly facial nerve. Although corticosteroids are the main stay of therapy, refractory cases can be treated by immunosuppressive and radiation therapy.