Delayed Tension Pneumocephalus following Gunshot Wound to the Head: A Case Report and Review of the Literature

Abstract

Tension pneumocephalus is a rare complication of head trauma and neurosurgical procedures, amongst other causes. It is defined by the combination of intracranial air, increased intracranial pressure, and mass effect. Although it often presents soon after surgery, it can also rarely present in a delayed fashion. We present a case of delayed tension pneumocephalus, occurring approximately 16 weeks after bifrontal craniectomy for a self-inflicted gunshot wound. Following a month of rhinorrhea, postnasal drip, and cough, the patient presented with a sensation of expansion in the area of the right forehead. As tension pneumocephalus is an emergency that can be fatal, this patient was treated expediently and avoided severe neurological deficits. The case recounted here is important as a demonstrative example that tension pneumocephalus does not always follow a defined course immediately after trauma or neurosurgery but rather can develop insidiously without obvious signs.

When Mount Fuji Can Erupt after Seven Days: A Case Report of Delayed Posttraumatic Tension Pneumocephalus with Literature Review

“…8 The two theories regarding the etiology of TPC are Dandy theory of ball valve mechanism and Horowitz theory. 9,10 Dandy theory states that unidirectional flow of air through a defect and trapping of air within the cavity causes TPC. Horowitz explains that TPC is due to negative pressure within the cavity as a result of excessive loss of CSF (inverted soda bottle effect).…”

Delayed Posttraumatic Tension Pneumocephalus: A Rare Case Report and Review of the Literature

“…Intracranial postoperative infection had been reported previously in one case involving a gunshot victim approximately 16 weeks after the first craniotomy [6]. It was postulated to be caused by gas-producing organism based on the clinical scenario of the case.…”

“…Intracranial air may accumulate at any site, that is, at epidural, subdural, subarachnoid, ventricular, or intracerebral sites. Interestingly, if it collects at the subdural site and extends downward to the interhemispheric fissure, it shows a unique appearance on CAT scan referred to radiologically as "Mount Fuji sign" [6,11,12] (Figure 3).…”

“…This will eventually lead to the appearance of significant neurological deficit if not treated promptly. By contrast, simple PNC is usually asymptomatic and requires no intervention [4][5][6].…”

Tension pneumocephalus – A rare complication of cerebrospinal fluid leak

“…Pneumocephalus is a common benign finding following craniotomies and is managed conservatively [1]. However, tension pneumocephalus (TP), defined by the accumulation of intracranial air producing mass effect under tension resulting in neurologic deterioration, is a neurosurgical emergency requiring prompt decompression in order to prevent rapid deterioration, herniation, and death [2], [3]. Although rare and reported to occur in only 0.1%–0.2% of all craniotomies, it is important to recognize and treat TP, as the management of benign postoperative pneumocephalus and TP differ greatly [2].…”