Spontaneous extensive pneumocephalus following frontal sinus defect.

We report an unexpected case of the spontaneous development of extensive pneumocephalus secondary to a frontal sinus defect in an adolescent with X-linked hydrocephalus and a ventriculoperitoneal (VP) shunt. The frontal sinus defect is likely to have developed due to the pressure effects of longstanding raised intracranial pressure. The patient had undergone an emergency shunt revision surgery 3 months prior to developing pneumocephalus. On further exploration, there was a history of a left-sided nasal cerebrospinal fluid leak for many months, suggestive of raised intracranial pressure contributing to the development of a sinus defect. To our knowledge, this is the first reported case of atraumatic spontaneous pneumocephalus secondary to a frontal sinus bone defect occurring as a result of raised intracranial pressure.Pneumocephalus is a rare but life-threatening condition. Despite developing extensive pneumocephalus, the patient only had nonspecific symptoms of poor appetite, vomiting, and slight changes in behaviour (lethargy and fatigue). As he was largely asymptomatic, this led to delays in picking up the pneumocephalus.