A rare case of spontaneous otogenic pneumocephalus with pictorial illustration of temporal evolution

Pneumocephalus is commonly seen on imaging in the setting of craniofacial trauma, skull base tumours, intracranial infection and after neurological intervention. Spontaneous pneumocephalus in the absence of these conditions is exceedingly rare, with only approximately 30 cases reported in the literature to date. Spontaneous otogenic pneumocephalus (SOP) is believed to occur as a result of anomalous commu-nication between the intracranial space and a hyper-pneumatised temporal bone, with either positive extra-to-intracranial pressure or negative intracranial pressure gradient. These anomalous communicat-ing channels may only become clinically apparent when triggered by episodes of acute increase in middle ear pressure during coughing, sneezing, Valsalva manoeuvre or significant change in atmospheric pres -sure. Patients may exhibit a wide range of neurological symptoms and the aim of treatment is to reduce the risk of complications such as infection and intracranial hypertension. Both conservative and neuro-surgical approaches have been described. We report a case of SOP in which the patient was conserva-tively managed, and spontaneous resolution of pneumocephalus was documented on serial computed tomography (CT) scans. This unique case clearly demonstrates the natural history and temporal evolution of SOP without surgical intervention. This knowledge may potentially obviate the need for surgery, thus reducing morbidity and mortality in patients who are poor surgical candidates. (c) 2021 Elsevier Ltd. All rights reserved.