Superior semicircular canal dehiscence (SSCD) is a condition in which the bony ceiling of the superior semicircular canal thins and/or disappears, creating a fistula between the semicircular canal and the cranial cavity. Patients with this condition present with cochleovestibular symptoms such as autophony, tinnitus, dizziness, hyperacusis, etc. The present study was done to further characterize the nature of repairs done at UCLA by looking at postoperative MRIs. The second part of the study involved identification of potential predictors of fluid signal loss and postoperative outcomes and symptomatology related to signal loss.
This study was a retrospective study that identified 137 SSCD repairs between 6/6/2013 and 3/8/2018. Pre and postoperative MRIs were examined for each case, identifying loss or preservation of the fluid signal on the anterior semicircular canal. After this, patient demographics, surgical notes, and pre/postoperative consult notes were reviewed to identify potential predictors or outcomes of fluid signal loss.
The total sample found 39 patients with a loss of fluid signal, 66 to have preservation of fluid signal, with the remaining 32 excluded because of lack of MRI or inability to confirm fluid signal preoperatively. The rates of pre and postoperative symptoms were compared between these groups, and a significant (p < .05) relationship was found between preservation/loss of signal and prior history of ear anomaly (p = .015), preoperative disequilibrium or imbalance (p = .044), postoperative dizziness (p = 0.024), changes in dizziness experienced after surgery (p = .015), and changes in headache (p = .009) experienced after surgery. A weaker but still significant (p < .10) relationship was found between preservation/loss of signal and postoperative autophony (p = .07) and postoperative aural fullness (p = 0 .090).
This study showed that most SSCD repairs performed at UCLA preserve the semicircular canal, categorizing the repairs as resurfacing repairs. We also demonstrated promising relationships between loss/preservation of fluid signal postoperatively and specific preoperative and postoperative symptomatology of SSCD patients. A larger study size is required to perform regression analyses to establish the specific nature of these relationships.