Tension pneumocephalus: the neurosurgical emergency equivalent of tension pneumothorax.

Tension pneumocephalus (TP) is the intracranial equivalent of tension pneumothorax. It is an unusual but life-threatening neurosurgical emergency, which has been described following head trauma, epidural injections or complicating neurological, spinal, craniofacial or sinus surgery. Unfortunately, the signs and symptoms of TP are non-specific and the diagnosis must be made by prompt recognition of the classic imaging signs of TP, allowing lifesaving emergency decompression. We present a trauma patient demonstrating the "Mount Fuji" sign on an unenhanced CT scan of the brain, which is reportedly specific for TP.