Tension pneumocephalus as a complication of lumbar drainage for cerebral aneurysm surgery--case report.

A 66-year-old man developed tension pneumocephalus after failed lumbar drainage before clipping surgery for a ruptured anterior communicating artery aneurysm. After puncture with a Tuohy needle, the spinal catheter could not be inserted into the spinal dura, so surgery proceeded without the catheter placement. The patient's neurological status deteriorated suddenly into coma within 15 hours after uneventful clipping of the aneurysm. Computed tomography revealed tension pneumocephalus with marked brain shift. Intracranial hypotension was probably caused by continuous cerebrospinal fluid leakage from the iatrogenic spinal dural tear, resulting in air entry and accumulation into the cranium from an unidentified opening of the cranial dura. The patient was immediately treated with autologous epidural blood patch administration in the lumbar spine, followed by reopening of the craniotomy incision and flap to evacuate the accumulated air. The patient made a quick and uneventful neurological recovery after the rescue procedure.