Idiopathic Intracranial Hypertension is Associated with Recurrent CSF Leak and Reoperation for Spontaneous Temporal Encephalocele

Abstract

Objective: Spontaneous temporal encephaloceles (STEs) are increasingly recognized as sequelae of idiopathic intracranial hypertension (IIH), which in turn may further complicate their management. We endeavored to review the University of Pennsylvania institutional experience on operative management of STEs, with a focus on factors which may influence surgical outcomes, particularly IIH. Design: Retrospective chart review over 9 years from 2013 – 2022. Setting: Single-center, two-hospital, tertiary care, academic setting. Participants: Patients undergoing middle cranial fossa (MCF, 43.9%), transmastoid (TM, 44.9%) or combined (11.2%) approaches for repair of STEs during the study period (n=107). Main Outcome Measures: Post-operative complication rates, recurrence and diagnosis of IIH. Results: The majority of patients were female (64.5%), with a mean BMI of 37 kg/m2 and mean age of 57 years. Twelve patients (9%) represented re-operations after failed primary repairs. Fourteen percent of patients undergoing primary surgical repair of STE were diagnosed with IIH, compared to 42% of patients undergoing re-operations (p = 0.015). In addition, there was a significant difference in the average BMI of patients undergoing primary (36.4 kg/m2) versus revision surgery (40.9 kg/m2, p=0.04). Half of those undergoing re-operation were placed on post-operative acetazolamide compared to 11% of patients undergoing primary operations. No patient experienced recurrent leak after re-operation. Conclusion: Based on our institutional experience, elevated BMI and the presence of IIH are significant predictors of re-operation for STE. In our experience, acetazolamide is a common adjunct management strategy in addition to re-operation for patients with recurrent CSF leak in the setting of STE.