Figure 3. Video head impulse test of a patient with UVL using SHIMP compared to conventional HIMP.

Typical patient with UVL showing reversed saccadic patterns during HIMP compared to SHIMP to the healthy and affected side. (A, affected) With standard HIMP, the patient elicits stereotyped covert saccades during head impulses to the affected side. (B, affected) With SHIMP, the patient elicits only small negative saccades after impulses to the affected side. Note that compared to HIMP (A, affected), SHIMP (B, affected) clears the eye velocity traces from covert saccades during head impulses to the affected side, thus facilitating gain calculation. Head impulses to the healthy side produce only small negative saccades during HIMP (A, healthy), but large negative saccades during SHIMP (B, healthy). Vestibulo-ocular reflex gain values to the healthy side are slightly lower during SHIMP compared to HIMP, but very similar to the affected right side. Head velocity = green traces; inverted slow phase eye velocity = blue traces; saccades = red traces; HIMP = conventional head impulse paradigm; SHIMP = suppression head impulse paradigm; UVL = unilateral vestibular loss.