Management of temporal bone meningo-encephalocoele

Abstract

Meningo-encephalocoele of the temporal bone, also known as fungus cerebri, is a rare occurrence in clinical practice. We present a series of 13 patients with chronic otitis media who suffered brain herniation into the mastoid cavity. We also discuss the presentation and management of brain herniation with or without cerebrospinal fluid leak.Study design: Retrospective. Methods: Among 963 cases undergoing revision mastoid surgery, 13 patients suffered brain herniation. These cases were identified and analysed.Results: All 13 patients' initial diagnosis was chronic suppurative otitis media with cholesteatoma, and all had undergone previous mastoid surgery resulting in a defect in the tegmen and weakening of the dura mater. The revision procedures performed included 10 (76.9 per cent) modified radical mastoidectomies without ossicular chain reconstruction and one (7.6 per cent) modified radical mastoidectomy with ossicular chain reconstruction; two (15.3 per cent) patients required a blind sac closure. Brain herniation and/or cerebrospinal fluid leak were repaired by a transmastoid + minicraniotomy procedure.Conclusions: Injury to the tegmen and dura should be avoided during surgery for chronic middle-ear disease. Cerebrospinal fluid leaks, if encountered, should be managed in the same surgical session. The transmastoid approach is helpful in repairing defects smaller than 1 cm in diameter, whereas the combined transmastoid-minicraniotomy approach provides good access when closing defects larger than 1 cm in diameter and also enables auto-calvarial grafting.

Transtemporal management of temporal bone encephaloceles and CSF leaks: Review of 56 consecutive patients

“…These have been described in the literature since the beginning of the twentieth century [2]. Previous authors have classified encephaloceles according to their anatomic site of origin [3].…”

“…Temporal bone encephaloceles in the adult patient can remain undetected or present with clear otorrhea, conductive hearing loss, chronic otitis media, middle ear effusion, seizures, meningitis, epidural abscesses or brain abscesses [2,3,7,8].…”

“…While many agree that chronic otitis media, cholesteatoma, and iatrogenic injury can be potential causes of temporal bone encephaloceles [2,4,6,8], there has been disagreement with regard to the etiology of spontaneous or idiopathic temporal bone encephaloceles [1,7,9,10].…”

Meningoencephalocele of the temporal bone: Pictorial essay on transmastoid extradural-intracranial repair

“…High-resolution MRI may serve as an adjunct [18,[26][27][28] Unlike in CSF rhinorrhea, invasive dye tests using intrathecal fluorescein or radionuclide cisternography are not required in most cases.…”

Tegmen Tympani Defect and Brain Herniation Secondary to Mastoid Surgery: Case Presentation

“…Although it mostly depends on congenital skull base defects, trauma, infection, and tumours, idiopathic and iatrogenic cases are also encountered [1–4]. They are usually observed in patients who underwent mastoid cavity surgery due to chronic otitis media with or without cholesteatoma [5, 6].…”