Neurosarcoidosis: a study of 30 new cases

The frequency, nature, relationship to systemic features, value of investigation findings and outcomes for a cohort of patients with neurosarcoidosis (NS) were studied by performing a retrospective survey of case records from nine District General or Regional Centre hospitals in south-west England and south Wales over a 12-year period (1990-2002). Thirty patients (29 Caucasians) were included--16 (53%) males and 14 (47%) females, including 13 with histological confirmation of CNS disease, making this one of the largest series of biopsy-confirmed NS; the remaining cases had "Probable" NS according to the Zajicek criteria. The male preponderance is of interest particularly considering the female predominance of systemic sarcoidosis.

The indicative prevalence of NS in this geographical area was estimated at one per 100,000, given an approximate population of 3 million. The most frequent features were headaches, visual failure, ataxia and vomiting. Cranial neuropathy occurred in 80% of patients, and as a presenting feature in 50%--though facial nerve involvement was seen in only 23%, and in none of those with definite disease. Unsurprisingly, no diagnostic clinical patterns emerged overall when only definite cases were analysed, but within our definite group of patients, meningeal and/or parenchymal lesion enhancement was observed in all but one case, while distinction from multiple sclerosis might also be aided by the observation that in all NS cerebrospinal fluid (CSF) samples with positive oligoclonal bands (27%), banding was accompanied by elevations of CSF protein.

From a prognostic perspective, the reported association of seizures in NS with a poor long-term outcome was not supported, while the suggestion that myelopathy also predicts an adverse prognosis was confirmed.