Post-traumatic tension pneumocephalus

Case contributed by Dr Anastasia Koutsogianni


Head trauma with loss of consciousness and later irritability.

Patient Data

Age: 40-year-old
Gender: Male

CT Brain

Extended pneumocephalus occurring in subdural, subarachnoid and intraventricular space due to blunt head trauma.

In this case, a large amount of air occupies the subdural space at the level of the frontal lobes, between the tips of the frontal lobes giving the appearance of Mount Fuji, thus suggesting tension pneumocephalus.

There is also the appearance of mild brain swelling on both hemispheres.

Intracranial air entrapment in the form of small bubbles is seen diffusely in the subaracnoid space and in several cisterns (‘‘air bubble sign’’), with a preference at the left side of the brain. Air has also filled part of the left lateral ventricle.

On the bone window, an extended fracture of the left temporal and sphenoid bone is seen, crossing the midline up to the right lateral wall of the sphenoid sinus, which is opacified by hyperdense (hemorrhagic) material. 


Case Discussion

In our case, the cause of the entrapped air into the subarachnoid space could be due to the fracture of the sphenoid sinus and mastoid bone.

The bilateral distribution of the entrapped air that separates and compresses the frontal lobes has been described as "Mount Fuji sign" which combined with the "air bubble sign" is helpful in the diagnosis of tension pneumocephalus. Presumably, the air bubbles enter the subarachnoid space through a tear in the arachnoid membrane caused by increased tension of air in the subdural space.

Contributed by:

George Beretis1, Anastasia Koutsogianni2, A. Eugenia Zmpogko1

(1) Consultant Radiologist, (2) Radiology ResidentCT Department of General Hospital of Athens "G.Gennimatas", Greece.

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Case information

rID: 42844
Published: 14th Feb 2016
Last edited: 25th Sep 2018
Inclusion in quiz mode: Included

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