title: Preservation of vestibular function after scala vestibuli cochlear implantation.
abstract: A 58-year-old man, in whom the cochlear implant (CI) had been inserted into the left ear, had right middle-ear cancer. The CI was removed immediately before receiving subtotal removal of right temporal bone. Four months later, the CI was again inserted in his left cochlea. Because of obliterated scala tympani, the 22 active electrodes of the CI were placed into the scala vestibuli. After the surgery, the patient complained that he experienced rotary vertigo and "jumbling of vertical direction" of objects on walking. Using rotation test, we evaluated vestibular function of remaining left ear. Numerous horizontal nystagmus beats were induced during earth-vertical axis rotation, whereas vertical downbeat nystagmus was scarcely induced during off-vertical axis rotation. The horizontal vestibulo-ocular reflex (VOR) was almost normally induced by sinusoidal stimulation at 0.8Hz. These data suggest that the scala vestibuli insertion of CI would be not so invasive against the lateral semicircular canal.
authors.affiliation: Department of Otolaryngology, Sakura Medical Center, University of Toho, Chiba, Japan. misuzuki-tky@umin.ac.jp
authors.forename: Mitsuya
authors.initials: M
authors.lastname: Suzuki
authors.forename: Takio
authors.initials: T
authors.lastname: Goto
authors.forename: Akinori
authors.initials: A
authors.lastname: Kashio
authors.forename: Takuya
authors.initials: T
authors.lastname: Yasui
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Ken
authors.initials: K
authors.lastname: Ito
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yamasoba
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000601:surgery; D003051:Cochlea / Q000473:pathology; D019929:Cochlear Implantation / Q000379:methods; D020878:Device Removal; D004432:Ear, Middle; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011183:Postoperative Complications / Q000628:therapy; D011184:Postoperative Period; D012027:Reflex, Vestibulo-Ocular; D012092:Replantation; D054738:Scala Vestibuli / Q000601:surgery*; D012888:Skull Neoplasms / Q000473:pathology / Q000601:surgery; D013701:Temporal Bone / Q000473:pathology / Q000601:surgery; D013997:Time Factors; D014717:Vertigo / Q000209:etiology / Q000628:therapy; D014724:Vestibular Function Tests