CNS toxoplasmosis presenting with obstructive hydrocephalus in patients of retroviral disease--a case series.

CNS toxoplasmosis presenting as hydrocephalus is a very rare entity. We present three cases of HIV positive patients whose brain imaging revealed hydrocephalus and who improved with anti toxoplasma medication along with intravenous steroids and did not require any CSF shunting procedures. The mechanism of hydrocephalus in CNS toxoplasmosis is usually due to compression of CSF outflow pathway by ring enhancing lesions but even in their absence hydrocephalus can be rarely seen due to ventriculitis. Hence in HIV positive patients with unexplained hydrocephalus CNS toxoplasmosis should be considered and such patients if started on treatment early have a good prognosis without requiring neurosurgical intervention.