Remote cerebellar hemorrhage after foramen magnum decompression surgery for Chiari I malformation--case report

A 47-year-old woman underwent decompressive suboccipital craniectomy and C1 laminectomy with duroplasty in the prone position for Chiari malformation type I and syringomyelia. The arachnoid membrane was not injured. Intraoperative echography showed good enlargement of the subarachnoid space. No closed subcutaneous drain was used. The patient complained of repeated nausea and vomiting 3 hours after the operation, and computed tomography revealed remote cerebellar hemorrhage on postoperative day 1. The cerebellar hemorrhage was treated conservatively, and the symptoms continued only for 3 days after surgery. Dural opening with rapid loss of cerebrospinal fluid (CSF) has occurred in every reported case of remote cerebellar hemorrhage complicating intracranial and spinal procedures. Loss of CSF is the main pathogenesis of this condition. In our case, the most probable pathomechanism seems to involve stretching of the infratentorial cerebellar bridging veins due to cerebellar sagging because of dural opening in the prone position and drop in CSF pressure. Such a complication is rare but should be considered after foramen magnum decompression surgery if the patient shows unusual symptoms of repeated vomiting.