Cushing's reflex due to spontaneous pneumocephalus after forceful nose blowing: A case report.

Pneumocephalus is the presence of air in the brain parenchyma, ventricular cavities, or epidural, subdural, or subarachnoid spaces. Simple pneumocephalus is often asymptomatic; however tension pneumocephalus can present with the altered sensorium, cardiorespiratory arrest, and the Cushing's triad. The Cushing's triad (widened pulse pressure, bradycardia, and irregular respirations) is known to emergency medicine practitioners to be an ominous sign of increased intracranial pressure and indicates imminent brainstem herniation. Here we present a case of acute pneumocephalus from the patient blowing their nose. The patient was bradycardic, hypertensive, and tachypneic in triage. Her CT was notable for extensive pneumocephalus around the brainstem with a visible tract connecting the external auditory canal, through the internal auditory canal, to the infratentorial space with pressure on the brainstem. Upon further imaging, the patient had a defect in her left round window allowing for this air entry. The etiology of pneumocephalus is discussed as well as management strategies.