Delayed resolution of Chiari I-associated hydromyelia after posterior fossa decompression: case report and review of the literature.

Objective And Importance: The expected time interval for resolution of hydromyelia after Chiari I decompression is lacking in the literature. This case report highlights one instance of delayed resolution of Chiari-induced hydromyelia.

Clinical Presentation: We report an adolescent girl with a Chiari I malformation and hydromyelia.

Intervention: A suboccipital craniectomy and C1 laminectomy with intradural exploration and duraplasty were performed. Serial imaging at 1 and 2 years after posterior cranial fossa decompression with duraplasty demonstrated no change in the size of the hydromyelia. At 3 years after surgery and before reoperation for continued hydromyelia, repeat magnetic resonance imaging demonstrated significant diminution of the fluid cavity. If this hydromyelia did resolve as a result of surgery, the interval for radiological observation clearly needs to be reconsidered.

Conclusion: Unfortunately, this is an area in which the literature is lacking. With this case as a nidus, studies are now necessary to determine the range of time necessary for Chiari I malformation-related hydromyelia to resolve.