Schistosomiasis

Neuroschistosomiasis results from infection with one of the five human Schistosoma parasites. Symptomatic neurological manifestations are seen in approximately 4% of the hundreds of millions of people infected by these parasites. Acute schistosomal encephalopathy occurs early in the course of the infection as a result of what seems to be an eosinophil-mediated vasculitis. Chronic schistosomiasis can present as encephalopathy due to granulomatous reactions around parasite eggs deposited in the brain or as myelopathy due to similar reactions in the spinal canal. The diagnosis usually involves imaging of the central nervous system and identification of eggs. Treatment with praziquantel and, often, steroids is effective.