Pathobiology of neurosarcoidosis and clinicopathologic correlation.

In a retrospective study of 4,294 consecutive postmortem cases, there were 15 with histologically proved sarcoidosis, including 4 with CNS involvement. Whereas in previously reported autopsy series the prevalence of neurosarcoidosis was 15%, it is 27% in this review. Five cases with incidental, clinically inapparent sarcoidosis died at a mean age of 54.6 years; those six with systemic sarcoidosis, not involving the CNS, died at a mean age of 47.0 years; while those four with a variety of neurologic manifestations in addition to systemic sarcoidosis died at a mean age of 38.2 years. Thus, it appears that at one end of the spectrum of morbidity, sarcoidosis may cause no or only trivial symptoms and permit prolonged survival. At the other extreme, sarcoidosis may affect a younger population more severely. CNS involvement occurs relatively early in the course and its rather rapidly progressive, accounting for the poor prognosis, despite appropriate medical and neurosurgical management. In its turn, neurosarcoidosis may present with a variety of signs and symptoms, depending on the site of involvement along the craniospinal axis. This feature is illustrated by the manifestations of compression myelopathy, hydrocephalus with dementia, hydrocephalus with seizures and ataxia, and anosmia, blindness, seizures, and diabetes insipidus. In addition, one patient developed a Nocardia brain abscess as a complication of the altered immune system in sarcoidosis.