Sarcoid of the nervous system.

Sarcoid is a granulomatous disease of undetermined etiology characterized by the presence of epithelioid cell aggregates without caseation which proceeds to conversion to hyaline fibrous tissue or resolution. The sites of nervous system involvement include the meninges, cranial, and peripheral nerves, hypothalamus and pituitary gland, muscles, and, more rarely, brain and spinal cord parenchyma. In nervous system involvement there is usually cerebrospinal fluid lymphocytic pleocytosis and elevated protein but these findings are not specific. When other systems are involved with sarcoid the diagnosis of neurosarcoidosis is obvious. When an unusual neurological symptom complex presents, sarcoid should be considered. The author reviews the literature and presents 22 cases of sarcoid involvement of the nervous system.