Superior Semicircular Canal Dehiscence in Idiopathic Intracranial Hypertension: Preliminary Report

Abstract

Idiopathic intracranial hypertension (IIH), is a challenging condition with raised intracranial pressure without any identifiable cause. It's incidence increases due to it's close association with obesity. This pathology has strong relation with tegmental dehiscence and spontaneous cerebrospinal fluid (CSF) leaks. There are reports of tegmental dehiscence, spontaneous CSF leaks ocurring with SSCD. Superior semicircular canal dehiscence is also associated with obesity in the literature. The aim of this study is to determine the incidence of SSCD in IIH patients, to evaluate the audiovestibular findings in IIH patients with SSCD, and to discuss the possible pathogenetic mechanisms causing this co-occurence. Material and Methods: Twenty five consecutive patients diagnosed with IIH in the neurology department between 2016-2018 were evaluated. Ten patients fulfilling the necessary criteria and accepting to participate in this study, were enrolled in the study group. Audiometry, tympanometry, vestibular evoked myogenic potentials (VEMP) tests and high resolution computed tomography (HRCT) imagings were performed. The control group was constituded of 20 age and sex matched patients attended to our clinic with various other complaints, and to whom HRCT was conducted between 2016 and 2018. Results: Among the study group 1 (10%) patient with IIH had SSCD. Two (20%) patients had thinning in the bony canal. None of the patients in the control group had neither radiographic SSCD, nor bony thinning. Patient with SSCD had pathological signs in VEMP. Conclusion: According to our results, though not statistically significant, the incidence of SSCD seems higher in IIH. The incidence of bony thinning also seems more frequent in IIH. However further studies with wide patient series are essential.