Video Head Impulse Test (vHIT) Findings in Patients With Superior Semicircular Canal Dehiscence: A Case-Control Study.

OBJECTIVE To explore the usefulness of the responses of video head impulse testing (vHIT) in assessing symptomatic patients with superior semicircular canal dehiscence (SSCD). METHODS This was a prospective case-control study performed in a tertiary skull base referral Centre in the UK. It included all patients ¬diagnosed with SSCD from January 2015 to January 2019 and compared to a control group of age and gender-matched unaffected indi¬viduals. The main outcome of the study was semicircular canal vestibule-ocular reflex (VOR) gains during vHIT assessment and link to patients' symptoms. RESULTS A total of 28 patients were diagnosed with SSCD during the study period and completed the vHIT assessment. Reduced VOR gains ( .05). CONCLUSION SSCD can affect the vestibular responses from all 3 semicircular canals; not necessarily the superior one. Similar responses were found in a control group of normal subjects. Although the use of vHIT in the assessment of SSCD is not diagnosis-specific, it can still help with identifying the impact of surgery on all canals prior to any intervention in order to avoid bilateral vestibular failure.