Life-Threatening Intracranial Hypotension after Skull Base Surgery with Lumbar Drainage

Although lumbar drainage (LD) is widely used in skull base surgery (SBS), no cases with intracranial hypotension (IH) following LD-assisted SBS have been reported, and skull base surgeons lack awareness of this potentially life-threatening condition. We report two cases of IH after LD-assisted SBS, a spheno-orbital meningioma and an osteosarcoma in the orbit. Despite a minimal amount of cerebrospinal fluid (CSF) drainage and early LD removal, severe postural headache and even a deteriorating consciousness level were observed in the early postoperative course. Neuroimages demonstrated epidural fluid collections, severe midline shift, and tonsillar sag compatible with IH. Epidural blood patch (EBP) immediately and completely reversed the clinical and radiologic findings in both patients. IH should be included in the differential diagnosis of postural headache after LD-assisted SBS that can be managed successfully with EBP. Persistent leakage of CSF at the LD-inserted site leads to IH. Broad dural dissection and wide removal of bony structure may be involved in the midline shift. EBP should be performed soon after conservative management fails. Further reports will determine the risk factors for IH development following LD-assisted SBS.