Traumatic Posterior Fossa Subdural Hygroma and Secondary Occlusive Hydrocephalus

Background: Infratentorial subdural hygromas causing secondary occlusive hydrocephalus are extremely rare in children. Only a handful of cases have been reported in the literature. Methods: We present a case of a 6-month-old infant with an occipital fracture and slow enlargement of a posterior fossa subdural hygroma that culminated in obstructive hydrocephalus. We give a review of the literature on post-traumatic posterior fossa hygroma with secondary occlusive hydrocephalus and discuss its pathogenesis and the mechanism of its later resolution, as well as the available treatment options. Results: A temporary external ventricular drain led to acute relief of the hydrocephalus and subsequent complete resolution of the subdural hygroma. Conclusion: Temporary external ventricular drain placement led to complete resolution of the subdural hygroma and hydrocephalus. We recommend close clinical follow-up, and imaging if indicated, for as long as 4 weeks after trauma with occipital skull fractures.