Clinical commentaryOutcomes of middle fossa craniotomy for the repair of superior semicircular canal dehiscence

- Autophony was the most common symptom at presentation, followed by tinnitus.
- Aural fullness and autophony were the most common symptoms to resolve after repair.
- A small number of patients developed disequilibrium, vertigo or aural fullness after repair.
- Number of patients with symptoms, except headache, were statistically different after repair.

Superior semicircular canal dehiscence (SSCD) is a rare defect of the arcuate eminence that causes an abnormal connection between the superior semicircular canal and middle cranial fossa. Patients often present with a variety of auditory and vestibular symptoms. Trigger avoidance is the initial strategy, but surgery may be necessary in debilitating cases. We retrospectively reviewed SSCD patients undergoing repair via a middle fossa craniotomy between March 2011 and September 2015. Forty-nine patients undergoing 58 surgeries were identified. Autophony was the most common symptom at presentation (n = 44; 90%). Mean follow-up was 10.9 months, with 100% of patients reporting resolution of at least one symptom. Aural fullness was the most commonly resolved symptom following surgical repair (n = 19/22; 86%). Hearing loss (n = 11/25; 44%) and tinnitus (n = 11/38; 29%) were the most common symptoms to persist following surgery. The most common symptom to develop after surgery was disequilibrium (n = 4/18; 22%). Upon comparing the overall pre-operative and post-operative groups, the number of patients with autophony (p < 0.0001), aural fullness (p = 0.0006), hearing loss (p = 0.0119), disequilibrium (p = 0.0002), sound- and pressure-induced vertigo (p < 0.0001), and tinnitus (p < 0.0001) were significantly different. Improved clinical outcomes were demonstrated in patients undergoing SSCD repair through a middle cranial fossa approach. The most common presenting symptom (autophony) was also most likely to resolve after surgery. Hearing loss is less amenable to surgical correction. Disequilibrium developed in a small number of patients after repair.