Spontaneous acute subdural haematoma caused by tension pneumocephalus

Summary We describe the first case of spontaneous acute subdural haematoma (SASH) caused by tension pneumocephalus in a patient who had undergone surgery for sinusitis followed by meningitis many years previously. The patient presented with a seizure and epistaxis. The haematoma was caused by a torn bridging vein. Tension pneumocephalus has to be added to the list of possible causes for SASH.