Pneumocephalus (Intracranial aerocele), defined as intracranial air, is an uncommon complication in head injury patients. It can present immediately following head trauma or be delayed for many days before clinical symptoms occur. We present two cases of extensive pneumocephalus after trauma. The diagnosis was made by computed tomography (CT). When pneumocephalus is suspected, CT can play a vital role in determining the precise location of the gas collection, its relationship to the basal skull fracture site or air sinuses and the amount of mass effect on the brain.
Pneumocephalus or collection of air in the intracranial cavity can occur after trauma or surgery. However, delayed pneumocephalus occurring months after the initial injury is not common. We would like to report a case of spontaneous traumatic pneumoencephalocele presenting with transient recurrent hemiparesis 14 months after the initial trauma.
The authors describe a case of pneumocephalus following epidural anaesthesia for total knee arthroplasty. Multiple attempts in locating the epidural space for the anaesthesia and the use of loss of resistance to air (LORA) technique were identified as the source of air entry. Supportive management was given including high flow oxygenation therapy and spontaneous reabsorption of air was noted five days after surgery. The presence of pneumocephalus should be kept in mind if patient develops neurological complications postoperatively following epidural anaesthesia.
This study investigates the effects of aircraft cabin pressure on intracranial pressure (ICP) elevation of a pneumocephalus patient. We propose an experimental setup that simulates the intracranial hydrodynamics of a pneumocephalus patient during flight. It consists of an acrylic box (skull), air-filled balloon [intracranial air (ICA)], water-filled balloon (cerebrospinal fluid and blood) and agarose gel (brain). The cabin was replicated using a custom-made pressure chamber. The setup can measure the rise in ICP during depressurization to levels similar to that inside the cabin at cruising altitude. ΔICP, i.e. the difference between mean cruising ICP and initial ICP, was found to increase with ICA volume and ROC. However, ΔICP was independent of the initial ICP. The largest ΔICP was 5 mmHg; obtained when ICA volume and ROC were 20 ml and 1,600 ft/min, respectively. The postulated ICA expansion and the subsequent increase in ICP in pneumocephalus patients during flight were successfully quantified in a laboratory setting. Based on the quantitative and qualitative analyses of the results, an ICA volume of 20 ml and initial ICP of 15 mmHg were recommended as conservative thresholds that are required for safe air travel among pneumocephalus patients. This study provides laboratory data that may be used by doctors to advise post-neurosurgical patients if they can safely fly.
Tension pneumocephalus is rare but has been well documented following trauma and neurosurgical procedures. It is a surgical emergency as it can lead to neurological deterioration, brainstem herniation and death. Unlike previous cases where tension pneumocephalus developed postoperatively, we describe a case of intraoperative tension pneumocephalus leading to sudden, massive open brain herniation out of the craniotomy site. The possible causative factors are outlined. It is imperative to rapidly identify possible causes of acute intraoperative brain herniation, including tension pneumocephalus, and institute appropriate measures to minimize neurological damage.