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case_images: Pure tone audiometry at age 7 and age 16 with right sloping mild-to-moderate sensorineural hearing loss without any progression.
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case_images: The child born of nonconsanguineous parents who failed hearing screening was diagnosed with a mild-to-moderate sensorineural hearing loss (SNHL) with normal middle ear (Figure 1).
case_images: Video head impulse test at age 16 showing saccades in the lateral and posterior semicircular canals with normal VOR gain in the lateral but reduced VOR gain in the posterior semicircular canal (arrow). VOR -vestibulo-ocular reflex.
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case_images: Subsequent vestibular function tests indicated unsteadiness on the vestibulospinal test battery, and the video head impulse test (vHIT) showed the presence of saccades on the lateral/posterior semicircular canals with normal/reduced vestibulo-ocular reflex (VOR) gains on the lateral semicircular and posterior canals, respectively (Figure 2).
case_images: Suppression Head Impulse test at age 16 showing asymmetry between the right and the left side and normal peak saccadic velocities.
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case_images: Suppression Head Impulse test (SHIMP) demonstrated a 52% asymmetry (L < R, Figure 3).
case_images: Cervical evoked myogenic potential test at age 16 showing absent responses on the left and a reduced amplitude on the right with 100% asymmetry when compared to the left. cVemp - cervical vestibular evoked myogenic potential.
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case_images: Cervical vestibular evoked myogenic potential (cVEMP) test revealed a 100% asymmetry with an absent response on the left and a grossly reduced amplitude of 0.5 microvolts on the right (Figure 4).
case_images: Axial (A) and coronal (B) computed tomography scan images of the petrous temporal bone demonstrate bilateral hypoplastic posterior semicircular canals (arrow). Selected maximum intensity projection reconstructions of the Magnetic Resonance Imaging(C and D) demonstrate a small and dysplastic left posterior semicircular canal (curved arrow). Similar appearances were noted on the right. Normal superior (dashed arrow) and lateral (dotted arrow) semicircular canals are shown.
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case_images: A high-resolution computed tomography and magnetic resonance imaging (MRI) scan showed bilateral posterior semicircular canal dysplasia (Figure 5A-5D).