Background: A case of spinal subdural hematoma (SSDH) following subarachnoid hemorrhage (SAH) because of a ruptured internal carotid aneurysm is described. Such a case has never been reported.
Case description: A 52-year-old woman underwent a craniotomy for a ruptured internal carotid aneurysm. A computed tomography scan showed that SAH existed predominantly in the posterior fossa and subdural hematoma beneath the cerebellar tentorium. Intrathecal administration of urokinase, IV administration of fasudil hydrochloride, and continuous cerebrospinal fluid (CSF) evacuation via cisternal drainage were performed as prophylactic treatments for vasospasm. On the sixth postoperative day, the patient complained of severe lower back and buttock pain. Magnetic resonance imaging showed a subdural hematoma in the lumbosacral region. Although the mass effect was extensive, the patient showed no neurologic symptoms other than the sciatica. She was treated conservatively. The hematoma dissolved gradually and had diminished completely 15 weeks later. Her pain gradually subsided, and she was discharged 7 weeks later without any neurologic deficit.
Conclusion: Although the exact mechanism of SSDH in this case is unclear, we speculate that this SSDH was a hematoma that migrated from the intracranial subdural space. Low CSF pressure because of continuous drainage and intrathecal thrombolytic therapy may have played an important role in the migration of the hematoma through the spinal canal. It is important to recognize the SSDH as a possible complication of the SAH accompanied with intracranial subdural hematoma.