Relationship between Video Head Impulse Gain and Severity of Dizziness in Patients with Vestibular Neuritis / 대한이비인후과학회지

ABSTRACT

BACKGROUND AND OBJECTIVES: We evaluated the correlation between video head impulse test (vHIT) and dizziness handicap inventory (DHI), which is commonly used to quantify severity of dizziness in vestibular neuritis (VN). SUBJECTS AND METHOD: Twenty VN patients undergoing vHIT either at the acute or follow-up stages of treatment were assessed by DHI questionnaire. Gain and gain asymmetry (GA) were correlated with DHI scores and abnormal vHIT rates were compared according to the severity of dizziness (mild ≤30; moderate-to-severe ≥32). RESULTS: vHIT gains significantly increased from the acute to follow-up stages (from 0.45±0.18 to 0.70±0.25), whereas GA and DHI scores decreased (GA, from 0.36±0.15 to 0.22±0.18; DHI scores, from 35±26 to 23±23). Although vHIT gains or GA showed no correlation with DHI scores at the acute stage, vHIT gains showed significant correlation with DHI scores at the follow-up (R-sq=0.32, p=0.01) stage. vHIT gains and GA did not differ according to the severity of dizziness during the acute stage; however, vHIT gains (0.78±0.25) of patients with mild dizziness were significantly higher than those (0.51±0.14) with moderate-to-severe dizziness at the follow-up stage. During the follow-up, all patients with moderate-to-severe dizziness showed abnormal vHIT gain, but 43% of patients with mild dizziness showed abnormal vHIT gain, showing a significant difference (p<0.05). CONCLUSION: Reduced vHIT gain was significantly correlated with high degrees of dizziness at the follow-up, but not at the acute stage, suggesting that high-frequency canal dysfunction is contributed in part by the subjective dizziness at the follow-up. Our findings suggest that vHIT might give an indirect evidence for implementing vestibular rehabilitation for enhancing impaired vestibular function and relieving subjective dizziness.