Objective: To present the clinical characteristics of secondary BPPV after surgical drilling of the temporal bone.
Study design: Retrospective study.
Setting: Tertiary referral academic medical center.
Patients: Ten patients who developed BPPV after surgical procedure of temporal bone drilling were identified from 965 subjects who underwent surgical drilling of the temporal bone at Seoul National University Bundang Hospital. The localization and lateralization of BPPV were based on positional test using video eye movement recording system and videonystagmography.
Main outcome measures: Onset of BPPV after surgery, distributions of involved semicircular canals, response to particle repositioning maneuver and factors that may influence the development of secondary BPPV after surgical drilling of the temporal bone.
Results: Onset of positional vertigo was mostly within 3 days except 1 case (sixth postoperative day). Postoperative BPPV was usually in the contralateral ear in 9 cases (90%), which occurred predominantly on the contralateral horizontal canal in 8 patients (80%). Positional vertigo was resolved after repositioning maneuvers in every case. None of them showed aggravation of bone conduction threshold.
Conclusion: The incidence of BPPV after surgical drilling of the temporal bone was around 1%, and the horizontal semicircular canal of the contralateral ear was predominantly involved. Head position during surgery (head restriction to contralateral ear down) as well as limitation of head movement due to compressive mastoid bandage after surgery seems to be responsible for such predominance.