Relation Between Horizontal Saccade Test and Anti-Compensatory Saccade in the Suppression Head Impulse Test Paradigm

Abstract

Background and ObjectivesThere is limited study reported on the relationship between horizontal saccades and anti-compensatory saccades (ACS) in the suppression head impulse paradigm (SHIMP). We investigated the relationship between horizontal saccades and ACS in SHIMP in individuals with normal vestibular function and determined the correlation between the associated factors. Subjects and Method Medical records of 79 patients with normal vestibular function and brain magnetic resonance images were retrospectively reviewed. Results ACS and horizontal saccades results were strongly correlated with velocity (R= 0.345, p<0.001) and latency (R=0.547, p<0.001). The latency of ACS was significantly shorter (p<0.001) than that of horizontal saccades. The velocity of ACS was negatively correlated with the latencies of ACS (R=-0.318, p<0.001) and horizontal saccades (R=-0.322, p<0.001). Bilateral ACS latency (R=0.384 and 0.471 in right and left, p<0.001 in both side) and left side ACS velocity (R=-0.263, p=0.019) were significantly affected by age. Conclusion ACS in the SHIMP was strongly correlated with horizontal saccades. However, the latency of ACS was shorter than that of horizontal saccades. Therefore, patient age and results of the horizontal saccades tests should be considered while interpreting the ACS velocity, which reflects vestibulo-ocular reflex function in patients with vestibulopathy.