Zi-Chen Chen1,2,3,4, Yu-Zhong Zhang1,2,3,4, Huan-di Zhao1, Xinyu Wei1, Toshihisa Murofushi5, Juan Hu1, Ying Cheng1, Fei-Yun Chen1, Xin-da Xu6, Min Xu7, Qing Zhang8,9,10,11. 1. Department of Otorhinolaryngology, Head, and Neck Surgery, Second Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, 710000, China. 2. Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200082, China. 3. Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, 200082, China. 4. Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, 200082, China. 5. Department of Otolaryngology, Teikyo University School of Medicine Mizonokuchi Hospital, Kawasaki, 213-0001, Japan. 6. Department of Otorhinolaryngology, Affiliated Ophthalmology and Otolaryngology Hospital of Fudan University, Shanghai, 200082, China. 7. Department of Otorhinolaryngology, Head, and Neck Surgery, Second Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, 710000, China. ent551205@163.com. 8. Department of Otorhinolaryngology, Head, and Neck Surgery, Second Affiliated Hospital of Xi'an Jiaotong University School of Medicine, Xi'an, 710000, China. zhqent@163.com. 9. Department of Otorhinolaryngology-Head and Neck Surgery, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, 200082, China. zhqent@163.com. 10. Shanghai Jiaotong University School of Medicine Ear Institute, Shanghai, 200082, China. zhqent@163.com. 11. Shanghai Key Laboratory of Translational Medicine on Ear and Nose Diseases, Shanghai, 200082, China. zhqent@163.com.
Abstract
OBJECTIVE: Auditory neuropathy (AN) is a unique pattern of hearing loss with preservation of hair cell function. The condition is characterized by the presence of otoacoustic emissions (OAE) or cochlear microphonic (CM) responses with severe abnormalities of the auditory brainstem response (ABR). The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected. However, the precise lesion sites in the vestibular system are not well characterized in patients with AN. METHODS: The air-conducted sound (ACS) vestibular-evoked myogenic potentials (VEMPs) and galvanic vestibular stimuli (GVS)-VEMPs were examined in 14 patients with AN. RESULTS: On examination of VEMPs (n=14, 28 ears), the absent rates of ACS-cervical VEMP (cVEMP), ACS-ocular VEMP (oVEMP), GVS-cVEMP, GVS-oVEMP and caloric test were 92.9% (26/28), 85.7% (24/28), 67.9% (19/28), 53.6% (15/28), and 61.5% (8/13), respectively. Impaired functions of the saccule, inferior vestibular nerve, utricle, superior vestibular nerve, and horizontal semicircular canal were found in 25.0% (7/28), 67.9% (19/28), 32.1% (9/28), 53.6% (15/28) and 61.5% (8/13) patients, respectively. On comparing the elicited VEMPs parameters of AN patients with those of normal controls, both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients (such as, lower presence rates, elevated thresholds, prolonged latencies, and decreased amplitudes). CONCLUSION: The study suggested that patients with AN often have concomitant vestibular disorders. Retro-labyrinthine lesions were more frequently observed in this study. GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.
OBJECTIVE: Auditory neuropathy (AN) is a unique pattern of hearing loss with preservation of hair cell function. The condition is characterized by the presence of otoacoustic emissions (OAE) or cochlear microphonic (CM) responses with severe abnormalities of the auditory brainstem response (ABR). The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected. However, the precise lesion sites in the vestibular system are not well characterized in patients with AN. METHODS: The air-conducted sound (ACS) vestibular-evoked myogenic potentials (VEMPs) and galvanic vestibular stimuli (GVS)-VEMPs were examined in 14 patients with AN. RESULTS: On examination of VEMPs (n=14, 28 ears), the absent rates of ACS-cervical VEMP (cVEMP), ACS-ocular VEMP (oVEMP), GVS-cVEMP, GVS-oVEMP and caloric test were 92.9% (26/28), 85.7% (24/28), 67.9% (19/28), 53.6% (15/28), and 61.5% (8/13), respectively. Impaired functions of the saccule, inferior vestibular nerve, utricle, superior vestibular nerve, and horizontal semicircular canal were found in 25.0% (7/28), 67.9% (19/28), 32.1% (9/28), 53.6% (15/28) and 61.5% (8/13) patients, respectively. On comparing the elicited VEMPs parameters of AN patients with those of normal controls, both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients (such as, lower presence rates, elevated thresholds, prolonged latencies, and decreased amplitudes). CONCLUSION: The study suggested that patients with AN often have concomitant vestibular disorders. Retro-labyrinthine lesions were more frequently observed in this study. GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.