Video head impulse test in labyrinthine fistula due to middle ear cholesteatoma

OBJECTIVES: To assess and monitor lateral semicircular canal (LSC) function over time in patients affected by chronic otitis media with cholestea- toma (CHO) complicated by fistula of LSC (LSC-F) before and after surgery using video Head Impulse Test (vHIT). MATERIALS and METHODS: Eight patients aged 18-67 years affected by CHO with imaging-ascertained LSC-F were included in this preliminary prospective study. The following protocol has been applied: oto-microscopic diagnosis with patient’s history; computed tomography scan of the temporal bone; surgery with concomitant resurfacing of LSF-F; audiological and vestibular evaluation before surgery (T0) and at 30 days (T1), 6 months (T2), and 1 year after surgery (T3). vHIT was used to assess vestibulo-ocular reflex (VOR) in LSC. RESULTS: None of the patients showed deterioration of bone conduction hearing levels during the different time of evaluation. Three patients showed a reduced VOR gain and catch-up saccades at T0, with VOR gain normalization at T2. This finding remained stable at the 1-year follow-up. The VOR gain in the nonaffected side generally experienced an increase, paralleled by the normalization on the affected side, with statistically significant correlation. The subjects with normal vHIT before surgery did not show any variation following surgery. CONCLUSION: vHIT allows the assessment of LSC function in case of fistula. The adopted surgical fistula repair did not induce deterioration of the auditory or LSC function, but indeed, it could prevent worsening and help promoting recovery to the normal function. KEYWORDS: Lateral semicircular canal, cholesteatoma, video Head Impulse Test, vestibulo-ocular reflex, labyrinthine fistula