Severe traumatic pneumocephalus in association with epistaxis: the "twin peaks" sign

Abstract

An 88-year-old woman suffered recurrent falls. After one such fall, she presented with epistaxis, confusion, and progressive conscious decline. Her GCS was E4V3M5 and a CT showed a right-sided cribriform plate fracture (Fig. 1, top right) and severe pneumocephalus involving the extradural, subdural, intraventricular, and posterior fossa compartments (Fig. 1). Tension pneumocephalus was excluded as she slowly improved clinically (E4V4M6) and radiologically; the amount of intracranial air gradually reduced on high-flow oxygen. Pneumocephalus is common after neurosurgical and sinus procedures, but also after traumatic base of skull fractures. The Mount Fuji sign refers to tension pneumocephalus, when a ball-valve mechanism leads to air being trapped intracranially, causing brain compression [1]. Pneumocephalus has also been reported after tamponade for epistaxis [2]. We postulated the following mechanism: the patient developed chronic subdural hematoma (CSDH) due to recurrent falls; she suffered a skull base fracture, which allowed the CSDH to leak through the nose. Hence her ‘epistaxis’ was probably a blood-stained CSF leak, which allowed the intracranial pressure to drop, encouraging air to enter the subarachnoid/subdural space, by means of a dehiscence in the skull base, creating a CSF fistula. Figure 2 shows brain reexpansion on follow-up neuroimaging at 10 weeks. In the Mount Fuji sign, the frontal lobes are collapsed by pneumocephalus in the convexity of each hemisphere. The significance of the "twin peaks" sign is two-fold: