Tension pneumocephalus: the neurosurgical emergency equivalent of tension pneumothorax

Abstract

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.

Figure 1.

Unenhanced axial CT brain slice on brain windows demonstrating the “Mount Fuji” sign. There is a large volume of subdural air (long arrows) which is compressing and causing separation (star) of both frontal lobes away from the midline falx cerebri, pathognomic of tension pneumocephalus. A small heamorrhagic contusion (short arrow) is also seen.

Figure 2.

Sagittal CT brain image on bone windows demonstrating a large frontal subdural air collection (arrows) compressing the frontal lobe. The dependent air/fluid level in the sphenoid sinus raises the suspicion of an occult fracture (star).