title: Vestibular effects of lidocaine intratympanic injection in rats.
abstract: When lidocaine is locally delivered into the inner ear, it rapidly paralyzes the peripheral vestibular afferent neurons and induces unilateral vestibular loss. The goals of this study were to explore the possibility of developing intratympanic injection (IT) of lidocaine as a modality for treating acute vertigo. To evaluate the minimum concentration required, latent time, action duration, and possibility of lidocaine IT readministration to the vestibular system, we compared the development of horizontal nystagmus after IT of 2, 4, 6, 8, and 10% lidocaine solutions in rats. To identify the induction of vestibular compensation, c-Fos-like protein expression was observed in the vestibular nucleus. Results of our investigation showed that lidocaine IT concentrations greater than 4% induced vestibular hyporeflexia in the injected ear. In order to induce hyporeflexia 4 and 6% lidocaine solutions could also be repeatedly injected. Regardless of concentration, effects of the lidocaine IT dissipated gradually over time. Our findings could be used to develop novel methods for symptom control in vestibular disorder patients.
authors: Department of Otolaryngology-Head and Neck Surgery, Kosin University College of Medicine, Busan, South Korea.
authors: H H
authors: HH
authors: Lee
authors: Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, South Korea.
authors: M J
authors: MJ
authors: Kim
authors: Department of Otolaryngology-Head and Neck Surgery, Kosin University College of Medicine, Busan, South Korea.
authors: Y K
authors: YK
authors: Jo
authors: Department of Otolaryngology-Head and Neck Surgery, Kosin University College of Medicine, Busan, South Korea.
authors: J Y
authors: JY
authors: Kim
authors: Department of Otolaryngology-Head and Neck Surgery, Gachon University of Medicine and Science, Graduate School of Medicine, Incheon, South Korea hangckr@gmail.com.
authors: G C
authors: GC
authors: Han
mesh_terms: D000779:Anesthetics, Local / Q000008:administration & dosage* / Q000009:adverse effects; D000818:Animals; D005260:Female; D007267:Injections; D008012:Lidocaine / Q000008:administration & dosage* / Q000009:adverse effects; D009759:Nystagmus, Pathologic / Q000139:chemically induced*; D017207:Rats, Sprague-Dawley; D014432:Tympanic Membrane; D014717:Vertigo / Q000188:drug therapy; D014722:Vestibule, Labyrinth / Q000187:drug effects*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine
keywords: Vertigo; concentration; lidocaine; nystagmus