Differentiating Superior and Inferior Vestibular Neuritis: Insights from an Integrated VEMP and vHIT Assessment

Vestibular neuritis (VN) is a peripheral vestibular disorder commonly associated with viral infections or vascular insults and may affect either the superior or inferior division of the vestibular nerve. Diagnosis is based on case history and clinical vestibular assessments, including cervical (cVEMP) and ocular (oVEMP) vestibular evoked myogenic potentials (VEMPs). The video head impulse test (vHIT) is a recent advancement that enables canal-specific assessment of the vestibulo-ocular reflex (VOR), aiding in identifying nerve involvement.

This study aimed to compare and correlate vestibular profiles of superior VN (SVN) and inferior VN (IVN) using vHIT-derived parameters (VOR gain and corrective saccades) and VEMPs, and to explore VEMP tuning shift characteristics in patients with VN.

A prospective case review was conducted using purposive sampling of patients diagnosed with VN.

Eighteen patients with VN (SVN: n = 10; IVN: n = 8) were evaluated through case history, pure-tone audiometry, cVEMP, oVEMP, and vHIT. SVN was defined by abnormal oVEMPs with preserved cVEMPs and IVN by reduced or absent cVEMPs with preserved oVEMPs.

No therapeutic intervention was administered; only diagnostic assessments were conducted.

VEMP responses at 500 and 1000 Hz were analyzed for tuning shifts. vHIT parameters included VOR gain and corrective saccades across semicircular canals. Mann-Whitney tests compared VOR gain, corrective saccades, and tuning shifts between groups. Spearman correlation assessed associations between VEMP and vHIT parameters.

No significant difference in VOR gain was found between SVN and IVN groups (p > 0.05). However, SVN patients exhibited significantly more corrective saccades in the lateral canal (p < 0.05). Tuning shifts were more frequent in IVN (50 percent), suggesting altered saccular frequency sensitivity. Significant correlations were found between saccadic metrics and VEMP amplitudes.

Combined analysis of vHIT and VEMP, particularly including corrective saccade and tuning shift parameters, enhances the diagnostic precision in differentiating SVN from IVN.

These findings support incorporating advanced vestibular tests, vHIT (VOR gain, corrective saccades), and VEMP (cVEMP, oVEMP) into routine clinical protocols to improve differential diagnosis, monitor vestibular integrity, and guide individualized management in patients with VN.