[Analysis of the constitutive characteristics of positive video head impulse test in unilateral vestibular lesions].

Objective:To explore the characteristics of the video head impulse test（vHIT） in different peripheral vestibular diseases and the diagnostic value of vHIT for vertigo. Methods:A retrospective analysis was conducted on the medical records of patients with positive vHIT results from the vestibular function testing room of Fudan University Eye, Ear, Nose and Throat Hospital from January to December 2024. The vHIT parameters were comprehensively analyzed in patients diagnosed with different vertigo etiologies, including Acute Unilateral Vestibulopathy, Menière's disease, sudden sensorineural hearing loss with vertigo, vestibular schwannoma （VS） and Ramsay-Hunt syndrome. Diagnoses were confirmed by integrating medical history, physical examination, and imaging findings. Results:A total of 169 patients with unilateral positive vHIT results were included in the study. There were significant differences in the proportion of semicircular canal injury among different vestibular lesions （χ²=23.928, P=0.002）. Significant differences in the types of saccades were also observed in patients with unilateral vestibular disease at different compensation stages （χ²=27.623, P<0.001）. However, no significant differences were found regarding the specific semicircular canals affected, the characteristics of vHIT saccades, the gain values of the affected canals, or the asymmetry ratio of canal gain among patients with different sizes of VS（P>0.05）. Conclusion:The characteristics of positive vHIT results are closely associated with the specific type of peripheral vestibular disorder and the patient's stage of compensation. Detailed analysis of vHIT results across different vestibular diseases can enhance our understanding of the underlying pathological mechanisms of vestibular injury and provide a valuable reference for clinical diagnosis.