Lateral skull radiograph in a patient with post-traumatic tension pneumocephalus complicated by late epilepsy

After recovering from a motorbike head injury, a 49-year-old man developed headache, double incontinence and subsequently coma. Because he could not afford the cost of a cranial CT scan, a lateral skull radiograph (fig 1) was done which revealed air trapped within the region of the left frontal lobe (pneumocephalus) and grossly dilated lateral and third ventricles (pneumoventricle). He recovered fully following conservative management but, at 8-month follow-up, he was found to have developed grand mal epilepsy.

Figure 1. Lateral skull radiograph showing air trapped within the region of the left frontal lobe (pneumocephalus) and grossly dilated lateral and third ventricles (pneumoventricle).

Epilepsy is an established complication of head injury but, because a cortical/subcortical lesion represents the main risk factor for delayed post-traumatic epilepsy,¹ and a model has demonstrated rapid air influx into the cerebral parenchyma raising intracranial pressure and displacing neural tissue, tension pneumocephalus presumably constitutes a secondary risk factor for epilepsy. This case highlights the value of a simple, cheap and readily available investigation for the diagnosis of a life-threatening condition in a poor resource African country.