Intracranial hypotension as a complication of lumbar puncture prior to elective aneurysm clipping

Background: Lumbar dural defects are an uncommon but important cause of persistent intracranial hypotension in the neurosurgical population. We present a case of intracranial hypotension after elective craniotomy due to a lumbar puncture performed 3 weeks earlier. Case Description: A 55-year-old female underwent uneventful craniotomy for clipping of an unruptured left middle cerebral artery bifurcation aneurysm. Postoperatively, the patient showed a gaze deviation and failed to wake up. Computed tomography demonstrated significant postoperative pneumocephalus. Family members indicated that the patient underwent a lumbar puncture 3 weeks prior to surgery to rule out a subarachnoid hemorrhage. The excessive pneumocephalus was initially interpreted as a result of spinal cerebrospinal fluid leak, and the patient was placed in the Trendelenburg position. This positioning resulted in some improvement in her mental status, although she was unable to tolerate any subsequent elevation in the head of her bed. Magnetic resonance imaging analysis of her spinal axis did not demonstrate any evidence of cerebrospinal fluid leak, but a subsequent lumbar blood patch resulted in rapid and dramatic improvement in the patient's status. She was subsequently discharged after an uneventful hospital stay. Conclusion: Although uncommon, persistent intracranial hypotension caused by lumbar dural defects must be considered in patients who have recently undergone procedures that compromise the lumbar dura because prompt intervention can significantly improve the patient's condition.