Publication:

Role of video head impulse test to indentify the site of lesion in patients with vestibular neuronitis

Background Vestibular neuronitis is one of the common causes of peripheral vertigo. Mostly the diagnosis of this entity is on clinical grounds. With the advent of video head impulse test (VHIT), assessment of function of all the semicircular canals has been possible based on principle of vestibulo-ocular reflex (VOR). The rationale of our study was to identify the affected branch of vestibular nerve in cases with clinical suspicion of vestibular neuronitis by measuring VOR gain and saccades using VHIT.

Methods This was a retrospective study carried out in the Department of ENT, Head & Neck Surgery of Institute of Medicine, Kathmandu, Nepal. Record files of patients who attended OPD between October 2017 to October 2018 with the clinical diagnosis of peripheral vestibular neuronitis were assessed. A total of 13 cases were included in the study. VHIT records of the cases were assessed for VOR gain and saccades. Normal contralateral canals were taken as control. Paired t-test was used to compare the statistical significance of gain asymmetry and presence of saccades between the affected side and normal side.

Results Of 13 cases, 11 had isolated involvement of lateral semicircular canal and 2 cases had isolated involvement of posterior semicircular canal. Average gain was 0.68 in both groups. Presence of overt and covert saccades was seen in all the affected canals.

Conclusions VHIT, in cases with vestibular neuronitis, is a good test not only to confirm the diagnosis but also to identify the division of vestibular nerve involved.