상반고리관피열증후군에서 중두개와 접근법의 치료결과

Treatment Result of Middle Fossa Approach in Superior Canal Dehiscence Syndrome

Introduction : Superior semicircular canal dehiscence (SSCD) syndromes are characterized by tinnitus, noise- and pressure- induced vertigo, and autophony. Surgical repair of the dehiscence is the principal treatment for the patients suffering disabling symptoms. In this study, we evaluated the surgical outcome of SSCD repair via middle fossa approach (MFA). Materials and Methods : 5 patients who underwent SSCD repair via MFA were recruited. Median age of patients was 42 years (37-45) and median follow-up duration after surgery was 39.5 months (12.8-97.2). Clinical symptoms (autophony, aural fullness, hearing loss, imbalance, sound, pressure induced vertigo, and tinnitus), audiometry, vestibular evoked myogenic potential (VEMP), and electrocochleography (ECoG) were evaluated before and after surgery. Results : Sensorineural hearing loss was developed after surgery in 1 patient. In the remaining 4 patients, there were air-bone gap at lower frequency range due to lowered bone conduction threshold below 0dB, which were normalized after surgery. VEMP threshold was significantly improved after surgery (preoperative: 49 dB, postoperative: 79 dB, p=0.04). SP/AP ratio of ECoG was also improved after surgery, but it could not reach statistical significance due to small number (preoperative: 0.58, postoperative: 0.26, p=0.068). Conclusion : Most of subjective symptoms were relieved after SSCD repair via MFA. Hypersensitive bone conduction threshold, air-bone gap, VEMP threshold and SP/AP ratio of ECoG were normalized after successful repair of SCD.