Introduction: Mastoid hyperpneumatisation predisposes to intracranial pneumatocoele development, due to the risk of rupture of the thin, bony walls. Intracranial pneumatocoele may be precipitated by even minor head trauma or an abrupt change in middle-ear pressure, with the potential risk of infectious or compressive intracranial complications.

Case report: A 19-year-old man with mastoid hyperpneumatisation developed a chronic intracranial–epidural pneumatocoele of traumatic origin in the right parieto-occipital area, in contiguity with the posterior mastoid cells. Eighteen months later, after a common cold, the patient developed signs of intracranial hypertension, due to the pneumatocoele spreading to the right epidural anterior fossa. A large right mastoidectomy extended to the retrosigmoid cells was performed, and a watertight seal applied over a large retrosigmoid cell using bovine pericardium and a mixture of bone powder and fibrin glue.

Results: The patient was discharged on post-operative day three with no symptoms. Ten days after surgery, computed tomography monitoring showed complete reabsorption of the pneumatocoele.

Conclusion: In cases of chronic, otogenic, epidural pneumatocoele, the possibility of the sudden onset of serious complications suggests the need for early repair of the communication between the temporal bone and the intracranial compartments. Closure of the fistula using autogenic and/or allogenic materials is usually adequate to resolve the pneumatocoele.