Diagnosis and operative repair strategy of an underlying tegmen defect presenting with spontaneous otogenic pneumocephalus after Valsalva maneuver

Abstract

Background: The tegmen tympani and mastoideum are insidious locations of bony dehiscence. Large defects may result in encephalocele, cerebrospinal fluid leak, recurrent meningitis, and intracranial abscess. A rare complication is spontaneous otogenic pneumocephalus (SOP). Herein, we describe the clinical course and operative repair strategy of a case of SOP presenting uniquely with anomic aphasia managed by middle cranial fossa (MCF) approach with inlay AlloDerm. The proposed mechanisms behind the SOP development and rationale for the selected operative approach is subsequently discussed. Case description: A 68-year-old woman presented with a two-week history of intermittent headaches and word-finding difficulty after attempting to auto-equalize her middle ear pressure by Valsalva maneuver during an airplane flight. CT and MRI demonstrated a left temporal intraparenchymal pneumatocele with dehiscence in the tegmen tympani and mastoideum. A multi-layered MCF approach craniotomy using inlay AlloDerm was performed to repair the defect. Conclusions: Although rare, SOP is a diagnosis to consider in patients that develop otologic symptoms with focal neurological deficits in the context of ambient air pressure changes or a history of Valsalva maneuver. The patient developed this pathology likely due to congenitally thin bone, ectopic arachnoid granulations, obesity-related elevated intracranial pressure, and an underlying encephalocele that established a one-way valve during Valsalva maneuver. The MCF approach with inlay AlloDerm is an effective strategy for large and multiple defect repair.

Keywords

• Pneumocephalus
• Tegmen tympani
• Tegmen defect
• Encephalocele
• Valsalva maneuver
• Middle cranial fossa approach