Petrous Apex Cephaloceles: Radiology Features and Surgical Management of a Rare Entity

Abstract

Objective:To characterize the radiologic findings of petrous apex cephalocele (PAC) in a patient cohort, and report the surgical management for three symptomatic PAC patients and cerebrospinal fluid (CSF) leak via the middle cranial fossa approach.Study Design:Retrospective case series.Setting:Academic center.Patients:Thirty-five patients with PAC were identified by review of the imaging archive between 2008 and 2019 (29 females; mean, 55 yrs; range, 4–86 yrs). All patients underwent magnetic resonance imaging of the skull base and/or computed tomography examination.Intervention(s):Surgical repair of PAC.Main Outcome Measure(s):Radiologic features of PAC.Results:Radiological features of PAC: 25.7% bilateral; partial or expanded empty sella in 82.9%; arachnoid pits in 14.2%; and enlarged CSF space of optic nerve sheath in 20.0%. Coexisting pathology included temporal, sphenoid, and bilateral jugular foramen meningocele; as well as cribriform, middle crania fossa, and right temporal defect. Three case studies describing the surgical course of spontaneous CSF leak secondary to PAC were managed with the middle cranial fossa approach.Conclusions:PAC is an exceedingly unusual cause for CSF leak in the adult and pediatric population. A middle fossa approach may be used to treat CSF leak as a result of PAC. Typically, CSF otorrhea originates from an encephalocele that extends via a bony defect in the tegmen tympani or tegmen mastoideum. However, on occasion the source of the CSF otorrhea is not via the tegmen, instead defects in the middle fossa floor, medial to the ridge for the gasserian ganglion (tubercle of Princeteau), need to be considered.

Incidental Petrous Apex Cephalocele Presenting With Transient Global Amnesia: A Case Report and Rapid Literature Review

“…Indeed, Mulcahy et al presented a case where the PAC could be involved in the seizure initiation process, mainly due to its close association with the deep temporal lobe structures [ 27 ]. In addition, the mass effect caused by the PAC could compromise, probably temporarily, the blood supply to the adjacent temporal lobe structures [ 30 , 36 ]. According to Ropper et al, both the epileptiform activity and the temporal lobe hypoperfusion theories have been implicated in the pathogenesis of TGA [ 1 ].…”

“…Notably, CSF leaks were frequently associated with meningitis [ 17 , 18 , 27 - 30 ]. The bibliography identified several heterogeneous clinical manifestations, such as cranial nerve palsies, hearing loss, and bilateral papilledema [ 17 - 19 , 22 , 30 - 40 ].…”

A Rare Case of Asymptomatic Bilateral Naso-Orbital Meningoencephalocele

“…Подобные патологии редки: частота их встречаемости, по данным литературы, составляет в среднем 4 случая на 10 тыс. больных [2][3][4][5][6][7][8][9][10][11][12]. Согласно другим источникам менингоцеле и МЭЦ встречается значительно реже, с частотой 1 случай на 12,5 тыс.…”

“…МЭЦ -преимущественно единичное образование, множественные МЭЦ у одного пациента встречаются крайне редко [11,12,[22][23][24][25][26][27]. Известен один случай с тремя идиопатическими МЭЦ у одного больного [27].…”

“…Известен один случай с тремя идиопатическими МЭЦ у одного больного [27]. Все описанные случаи идиопатических двусторонних МЭЦ относятся к базальным, а не фронтоэтмоидальным [11,12,[22][23][24][25]. Клинические проявления МЭЦ крайне разнообразны ввиду различной локализации и размеров.…”