What is the prevalence of new-onset benign paroxysmal positional vertigo (BPPV) before and after superior canal dehiscence (SCD) repair?
Bottom Line: New-onset BPPV occurs commonly after SCD repair, but the exact etiology remains unknown. Based on the high percentage of BPPV cases following SCD surgery, a preoperative discussion about postoperative BPPV is warranted.
Explore this issue:September 2016
Background: SCD is a bony defect of the superior semicircular canal (SSC). In some patients, SCD-related symptoms are severe and require surgical repair, resulting in symptom resolution in a high percentage of patients. Disequilibrium may arise, persist, or even worsen during the postoperative period, however. One potential explanation is BPPV onset, believed to be caused by dislodged otoliths that migrate to the semicircular canals, resulting in acute episodic vertigo. To date, the association between SCD repair and BPPV onset has not been described in detail.
Study design: Retrospective chart review at a tertiary care center of 180 patients with a diagnosis of SCD syndrome (SCDS) between January 2002 and May 2015.
Setting: Massachusetts Eye and Ear Infirmary, Boston, Massachusetts.
Synopsis: Eighty-four patients underwent either middle fossa craniotomy or transmastoid surgery for SCDS (surgical group), while the remaining 96 did not (control group). Median follow-up times were 21.2 months for the surgical group and 13.9 months for controls. Demographic features of the surgical and control groups were not significantly different. In surgical subjects, 23.8% had documented BPPV following SCD repair; of these, 19 were ipsilateral to the side of SCD repair, and one had nonlateralizing symptoms and exam findings. Only 6.2% of control subjects had BPPV. There was no statistical significance for BPPV associations with the type of surgical repair or type of repair material. The majority of subjects (58%) experienced BPPV symptoms within the first three months following repair. There was a median and mean of 83 days and 207 days, respectively, to BPPV onset following surgery. All subjects with BPPV presented with symptoms of episodic positional vertigo and demonstrated geotropic rotatory nystagmus in the posterior canal plane on Dix-Hallpike testing. Limitations include limited chart data, a potential for sample bias, lack of statistical corrections for multiple comparisons, and shorter follow-up length for control patients.
Citation: Barber SR, Cheng YS, Owok M, et al. Benign paroxysmal positional vertigo commonly occurs following repair of superior canal dehiscence. Laryngoscope. 2016;126:2092-2097.