Adult-onset Sacral Meningocele Causing a Specific Headache Triggered by Compression or Adoption of a Sitting or Supine Posture.

We report a rare case of adult-onset sacral meningocele where compression triggered a specific headache. A 46-year-old woman presented with a headache, which worsened when she was in a sitting or supine position. A subcutaneous mass was observed on her left buttock, the compression of which also induced headache. No neurological deficits were evident. Lumbar and sacral magnetic resonance imaging demonstrated a meningocele in the left dorsal buttock, connecting to the sacral cerebrospinal fluid (CSF) space, and spinal computed tomography revealed sacral dysplasia. Initial meningocele resection improved the patient's headache, but the cyst recurred 2 years later. Following repeated surgery to reinforce the meningocele orifice, the headache was relieved and has been absent for more than 6 years. The headache was due to intracranial pressure fluctuations due to CSF influx into and drainage from the meningocele. Meningocele development in adulthood can be owing to a spinal bone defect and pressure load on the spinal dura. Surgical resection can improve symptoms resulting from meningocele, and reinforcement of the orifice using an artificial surgical membrane effectively prevents recurrence.