Introduction: Hydrocephalus due to aqueductal stenosis following mumps meningoencephalitis is a rare condition, reported only in 16 cases in the literature. The pathogenetic role of the mumps virus in inducing aqueductal stenosis has been demonstrated experimentally in animal models and clinically proven in a few cases. Although obstructive in nature, the post-infectious etiology raises the question as to whether third ventriculostomy is the appropriate treatment.
Patient: We report a case of hydrocephalus due to pure aqueductal stenosis occurring in an 11-year-old boy who suffered from mumps meningoencephalitis 9 years previously. The boy was successfully treated by endoscopic third ventriculostomy.
Conclusions: The present case offers further evidence of the purely obstructive nature of the hydrocephalus induced by paramyxovirus meningoencephalitis, even if it did occur several years after the infectious disease. The pathogenesis of mumps-induced hydrocephalus and the rationale of treatment are discussed, and the literature is reviewed.