Comparing the Suppression Head Impulse Paradigm and the Head Impulse Paradigm in Vestibular Neuritis.

OBJECTIVE: To compare the results of suppression head impulse paradigm (SHIMP) and head impulse paradigm (HIMP) in acute vestibular neuritis (AVN). STUDY DESIGN: Retrospective study. SETTING: Tertiary otology clinic. PATIENTS AND INTERVENTIONS: We tested 21 patients with AVN with the HIMP, SHIMP, and caloric tests, and we analyzed the relationships between the tests' results. MAIN OUTCOME MEASURES: For this study, we adopted vestibulo-ocular reflex (VOR) gains in the SHIMP and HIMP, peak saccade velocity (PSV) of SHIMP which is another indicator of residual vestibular function, and canal paresis of caloric test. RESULTS: VOR gains showed significant correlation (R = 0.926, p < 0.001) between the SHIMP and HIMP, but VOR gains were slightly lower in the SHIMP than in the HIMP (mean difference 0.07 ±â€Š0.09, p < 0.001). The difference between the HIMP and SHIMP gains was slightly larger on the affected side (0.10 ±â€Š0.09) than on the healthy side (0.03 ±â€Š0.09). The PSV of SHIMP had significant correlation with HIMP gain and canal paresis. Sixteen of 21 patients showed 100% ipsilesional caloric canal paresis, and eight (50%) of them showed no anti-compensatory saccade (direction toward head rotation) in the SHIMP. However, they showed not extremely low VOR gain but variable VOR gain. CONCLUSION: The new parameters of SHIMP might be used as complement for evaluating vestibular function in AVN. However, the clinical impact of the saccades of SHIMP in AVN has not been revealed clearly yet. This question should be investigated in further studies.