Pneumocephalus: an unusual cause

SYNOPSIS A 60 year old male had an open thoracotomy for bronchogenic carcinoma. On the twelfth hospital day he became obtunded and complained of headache. Radiographs revealed intra-cranial air. It was thought that the pneumocephalus in this patient was most likely secondary to a tension pneumothorax continuously forcing air through a dural tear sustained at the time of initial surgery. The causes of pneumocephalus are reviewed and no similar case report has been found in the literature. Cranial aerocoele (pneumocephalus) was first fully described by Chiari (1844). Markham (1967), in a thorough review of the literature, listed the various causes as follows: trauma (frac-tures of the skull involving either the sinuses o