Intracranial neurosarcoidosis.

Neuroradiological findings in two cases of histologically confirmed intracranial sarcoidosis are presented, one with periaqueductal granulomata causing aqueduct obstruction. The granulomatous aggregation was of slightly greater attenuation than normal brain parenchyma and did enhance homogeneously following contrast medium administration. No direct signs of basal arachnoiditis could be found on computed tomography (CT) in the other case in which hydrocephalus was produced by a granulomatous infiltration of the fourth ventricle and cisterna magna. The neuropathological and pertinent clinical and laboratory manifestations of neurosarcoidosis are reviewed as a means of predicting recognizable CT patterns of the entity.