Two cases of pneumocephalus are described, one after epidural anaesthesia and one after a steroid injection in the lumbar spine.

The first case was a 28-year-old woman who presented with a severe headache, numbness in the upper extremities, photophobia and vomiting 3 days post partum from a vaginal delivery and an epidural anaesthesia. The second case was a 37-year-old-man who had recently been treated in a local pain clinic with lumbar steroid injections and who presented 24 h later complaining of a severe headache, nausea, vomiting and photophobia. Both patients were afebrile, vital signs were unremarkable, they had no focal neurological deficits and were otherwise healthy individuals. Both cases were unique in that intraventricular air predominated in the head CT scan (figs 1 and 2). They were treated with oxygen and their condition resolved after 2–3 days in hospital.

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Figure 1 CT scan of the head in case 1.

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Figure 2 CT scan of the head in case 2.

A diagnosis of pneumocephalus was made in both patients. Pneumocephalus is more common after head or facial trauma that involves a leak of cerebrospinal fluid, occurring in up to one-third of such patients. Pneumocephalus after epidural steroid injections or epidural anaesthesia is very rare and only case reports have been reported in the literature.1 2 Although the absolute incidence of this condition is unknown, only 1–2 cases a year are reported in the literature. The mechanism involves inadvertent puncture of the dural layer during epidural injections for treatment of radiculopathy or induction of epidural anaesthesia with the introduction of air in the dural space. The headache of pneumocephalus is usually immediate in onset, aggravated by any motion, and is not relieved by lying down. As little as 2 ml of air can cause symptoms. The air is usually reabsorbed after 2 days and the headache usually resolves within 5 days of the dural puncture. The development of pneumocephalus following blood patches and epidural anaesthesia involving the placement of catheters has also been reported. Many of these procedures are performed in an outpatient setting and therefore it is important to include pneumocephalus in the differential diagnosis of sudden severe headache in a patient in the emergency department. No randomised trials have studied the treatment of pneumocephalus, but administration of 40–100% oxygen has been suggested. Patients should be admitted for observation if symptoms are severe.