Video-head impulse test in superior canal dehiscence

Area of Science:

• Neuroscience
• Otolaryngology
• Vestibular System Diagnostics

Background:

• Superior Canal Dehiscence (SCD) is traditionally diagnosed using Vestibular Evoked Myogenic Potentials (VEMPs) and Computed Tomography (CT).
• The diagnostic criteria for SCD often rely on specific findings from these established methods.

Purpose of the Study:

• To evaluate the effectiveness and diagnostic utility of the video Head Impulse Test (vHIT) in identifying Superior Canal Dehiscence (SCD).
• To explore the incidence of isolated superior canal dysfunction using vHIT in a broader neurotological patient population.

Main Methods:

• Retrospective review of data from 11 ears across 8 patients diagnosed with SCD.
• Correlation of vHIT results with VEMPs, CT, and MRI findings.
• Audit of 300 vHIT tests from patients with various neurotological complaints to assess isolated superior canal function.

Main Results:

• 82% of patients (9 ears) with SCD exhibited abnormal vHIT findings.
• Abnormalities in vHIT were isolated to the superior semicircular canal, characterized by reduced gain and catch-up saccades.
• An audit revealed instances of isolated abnormal superior canal function in routine vHIT testing.

Conclusions:

• While CT and VEMPs are crucial for SCD diagnosis, isolated superior canal vHIT abnormalities are highly suggestive of the condition.
• Patients presenting with isolated superior canal vHIT abnormalities warrant further investigation for Superior Canal Dehiscence.