Decision-Making in Meningoencephalic Herniation in the temporal bone: A report of 95 cases

Meningoencephalic herniation (MEH) of the temporal bone is a rare but potentially life-threatening condition that may lead to meningitis, encephalitis, cerebral abscess, or epilepsy. Its incidence appears to be increasing, particularly in spontaneous cases, which are frequently multifocal and associated with obesity and benign intracranial hypertension.

A retrospective review was performed of 88 patients (95 cases) surgically treated for MEH at a tertiary referral center between January 2000 and February 2023. Inclusion criteria were intraoperatively confirmed MEH and a minimum follow-up of six months. Data collected included demographics, aetiology, surgical approach, symptoms, otoscopic findings, body mass index (BMI), imaging, complications, recurrences, and audiometric outcomes.

The cohort comprised 35 females and 53 males, aged 22-78 years (mean 54.5). Seven patients had bilateral MEH. Aetiology was idiopathic in 46 patients, post-surgical in 29, cholesteatomatous in 10, and traumatic in 3. Surgical approaches included middle cranial fossa (57 patients), transmastoid (21), and subtotal petrosectomy (17). Hearing loss was the most common symptom (22 patients), followed by ear fullness (18), otorrhea (17), and meningitis (16). Life-threatening manifestations occurred in 34.5% of cases. Complications were reported in 11 patients, all transient or medically managed. Mean BMI was 30 (range 21-44); all patients with BMI > 34.99 had idiopathic MEH. Multiple hernias were strongly associated with idiopathic origin. No recurrences were observed.

Surgical repair is indicated in all confirmed cases of meningoencephalic herniation to prevent intracranial complications. The selection of approach is guided by hearing status, location, and aetiology. The middle cranial fossa approach is preferred in most spontaneous or multifocal cases, whereas subtotal petrosectomy is reserved for non-serviceable hearing or poor general condition. The transmastoid approach is suitable for isolated defects in the tegmen antri. Autologous grafts remain the gold standard for reconstruction.

The rising incidence of spontaneous MEH highlights the need for tailored surgical strategies. We present one of the largest surgical series of MEH to date and confirm that a tailored surgical strategy is essential for achieving successful outcomes. Our data support an algorithm based on hearing status and aetiology to optimize outcomes while minimizing complications.