Superior Semicircular Canal Dehiscence Syndrome Following Head Trauma: A Multi-institutional Review

Objective To evaluate patients who become symptomatic from superior semicircular canal dehiscence (SSCD) following head trauma. Study Design Case series assessing patients presenting with SSCD after a trauma. Methods A case series was completed assessing patients presenting with SSCD after trauma. Data from three academic medical centers were evaluated, including the following: imaging, videonystagmography (VNG)/vestibular evoked myogenic potential (VEMP) testing, audiometric assessment, and surgical repair. Outcome measures included the following: 1) Description of audio-vestibular symptoms, 2) mean pre- and post-operative pure tone average (PTA), word recognition score (WRS), and air bone gap (ABG). Results A total of 14 patients were included; 86% were male. Approximately 43% were found to have bilateral SSCD on imaging, with 57% of patients pursuing surgical management. The most common presenting symptoms included pulsatile tinnitus (93%), autophony (79%), and hearing loss (64%). Approximately 36% of patients underwent VNG/VEMP testing, with 83.3% of those demonstrating abnormal results. The mean audiometric findings on the symptomatic side included an air-conduction PTA of 38.0 dB, bone-conduction PTA of 24.3 dB, WRS of 81%, and ABG of 17.9 dB. Among patients who underwent surgery (57%), there was no significant change in the air-conduction PTA, bone-conduction PTA, or WRS (P > .05). However, there was an improvement in the ABG (preoperative = 22.8 dB versus postoperative = 9.7 dB; P = .005). Conclusion Head trauma may be a potentiating event for SSCD syndrome. This study advances the hypothesis that these patients likely have underlying radiographic SSCD prior to their trauma, and a traumatic event increases in intra-vestibular or intracranial pressures, unmasking SSCD syndrome. Level of Evidence IV Laryngoscope, 2021