Symptomatic posterior fossa and supratentorial subdural hygromas as a rare complication following foramen magnum decompression for Chiari malformation Type I.

Symptomatic subdural hygroma due to foramen magnum decompression for Chiari malformation Type I is extremely rare. The authors present their experience with 2 patients harboring such lesions and discuss treatment issues. They conclude that the possibility of subdural hygromas should be considered in all patients presenting with increased intracranial tension following foramen magnum decompression for Chiari malformation Type I. Immediate neuroimaging and appropriate surgical intervention provides a good outcome.