Tension Pneumocephalus Caused by a Communicating Pneumothorax via a Nerve Root Avulsion.

Tension pneumocephalus (TP) is an unusual and potentially life-threatening condition characterized by a large volume of intracranial air causing compression and displacement of the underlying cerebral cortex. The symptoms of TP are non-specific. Diagnosis is generally made by demonstration of the classic "Mount Fuji" sign on computed tomography imaging. TP is most commonly seen in the early postoperative period after craniotomy or trauma involving fractures through the pneumatized sinuses. We present a rare case of TP which resulted from an inadequately decompressed pneumothorax communicating with root avulsions of C8 and T1.