Background: video head impulse test (vHIT) is a useful tool in evaluation of vestibular. In the vHIT, the examiner who performs the head impulse test should master sufficient skills. A few studies have been conducted that explore whether the hand positions of the examiner affect the horizontal vHIT in healthy individuals and vestibular disorder patients. The purpose of this study is to identify the effects of hand positions (head and jaw) on the video head-impulse test (vHIT) in unilateral vestibular neuritis (UVN).Methods: Eighty-six healthy volunteers and sixty-seven patients with unilateral vestibular
neuritis (UVN) were recruited for this study. Different hand positions (head and jaw) were used in the vHIT of horizontal semicircular canals in healthy volunteers and UVN patients. All the obtained horizontal vHIT gains were analyzed.
Results: It was observed that when horizontal vHIT was performed with the head hand position, the number of head impulses that produced over high vestibulo-ocular reflex (VOR) gains was more than that with the jaw hand position (p < 0.01), irrespective of whether the test was performed in healthy volunteers or UVN patients. The gains obtained were lower when the jaw hand position was used than that obtained when the head hand position was used (p < 0.05). However, no significant difference existed in the mean head velocity between the two hand positions (p > 0.05). Using the head hand position has greater a chance to elicit in UVN patients normal horizontal vHIT gains with refixation saccades than using the jaw hand position (p = 0.04).
Conclusion: The jaw hand position can increase the accuracy of vHIT in determining the lesion side.