Penetrating injury to the maxilla and skull base resulting in the mount fuji sign of tension pneumocephalus and ipsilateral vision loss

Pneumocephalus is defined as the presence of intracranial air seen most commonly secondary to a traumatic head injury. Tension pneumocephalus is often termed in radiology as the Mount Fuji sign due to a perceived similarity with the iconic mountain peak in Japan. We present the case of a 62-year-old gentleman who presented to the emergency department following a penetrating injury to the right maxilla and skull base which resulted in acute-onset ipsilateral vision loss due to direct traumatic injury to the optic nerve by the fractured bone fragments encountered in the optic canal.