Labyrinth Dysfunction 8 Months After Cochlear Implantation: A Case Report *John-Martin Hempel, †Lorenz Jäger, *Uwe Baumann, *Eike Krause, and *Gerd Rasp *Ear Nose and Throat Clinic and the †Institute of Clinical Radiology, Ludwig Maximilians University, Munich, Germany Objective: Investigate whether the cochleostomy is a possible port of entry for pneumolabyrinth and a resulting vertigo in patients provided with a cochlear implant. Study Design: Retrospective case review. Setting: Ludwig-Maximilians University of Munich, Hospital Grosshadern. Patient: 62-year-old patient who underwent implantation of a HiFocus II cochlear implant with positioner from Advanced Bionics (CLARION). Eight months postoperatively, the patient reported rotatory vertigo and right-side tinnitus after he had blown his nose harder than usual during an episode of rhinitis. Interventions: Preoperative and postoperative testing of both the petrosal bone with a CT scan and of balance function. Main Outcome Measure: Air inclusion in the labyrinth. Results: In contrast to the preoperative high resolution com- puted tomography (CT) scan, air inclusion was seen in the labyrinth during the episode of vertigo. At the same time, bal- ance function tests with Frenzel glasses revealed both sponta- neous and provoked horizontal nystagmus to the right side. At follow-up 8 weeks later, the level of vertigo had significantly decreased. Twelve months later, the control CT showed the cochlear implant positioned correctly and no visible air in the labyrinth. Conclusion: It is known that placement of the HiFocus II with Positioner from CLARION requires a relatively large cochleo- stomy of 1.5 mm. Moreover, in the connective tissue seal be- tween the electrode and the positioner, the latter reaches into the tympanic cavity, and this is possibly the weak point. Further investigation will be needed to determine whether the large cochleostomy with the HiFocus II with positioner increases the predisposition to labyrinth dysfunction. Key Words: Cochlea implantation—Labyrinth dysfunction—Vertigo. Otol Neurotol 25:727–729, 2004. Patients frequently complain of disturbances of bal- ance after cochlear implantation. According to the litera- ture, the incidence is between 0% and 60% (1–5). Kubo et al. (3) has classified disturbances of balance according to when they appear after surgery. The first group com- prises patients who have disturbed balance immediately after surgery. Symptoms usually disappear within 1 month. Characteristically, the vertigo is of short duration and is provoked by head movement. The second group of patients has persistent disturbances of balance lasting for more than 6 months after the surgical procedure. The final group contains patients who develop symptoms of vertigo at least 1 month after surgery, so-called “delayed vertigo” (3). According to Kubo et al. (3), the vertigo in these patients is usually idiopathic and is longer lasting. Delayed vertigo occurred in 15 of 94 cases reported by Kubo et al. (3). The likely etiology was meningitis in one of 15 cases and ototoxicity in two of 15 cases. The eti- ology was unknown in 12 patients (3). Fina et al. (5) just published data from a retrospective analysis of patients receiving a cochlear implantation. They also differenti- ated between early and late onset (>24 hours after im- plantation) of the dizziness and reported, in the type of early onset, recovering within 3 days (four of 29 pa- tients). They discussed labyrinthitis as a possible cause. Most of the patients (25 of 29) reported a late onset of vertigo (median time, 74 days) (5). Risk factors of vertigo after cochlea implantation include: 1. Preimplantation vestibular symptoms, especially Ménière’s disease (5); 2. Age at implantation greater than 59 years old (5); and 3. Age at onset of hearing loss greater than 26 years old (5). Other possible causes of vertigo after cochlear implan- tation include: 1. Perilymph fistula caused by the cochleostomy; 2. Direct trauma resulting from positioning of the electrode in the labyrinth; and 3. Conduction of electrical potentials originating in the cochlear implant into the balance organ (6). CASE REPORT A 62-year-old patient underwent implantation of a HiFocus II cochlear implant with positioner from Ad- vanced Bionics (CLARION; Rixheim, France) in the right ear at the age of 61 years because of severe bilateral inner ear deafness. The patient was one of six in whom we used the HiFocus II cochlear implant. The total num- ber of cochlear implantation is on average 30 a year, surgery being performed by the same surgeon. The deafness was of early childhood onset, assumed to be the result of asphyxia during birth. There were no other risk factors for early childhood-acquired or heredi- tary deafness. There was no history or evidence on clini- Address correspondence and reprint requests to J. M. Hempel, M.D., Klinik für Hals-, Nasen- und Ohrenheilkunde, der Ludwig- Maximilians-Universität München, Marchioninistrasse 15, 81377 München, Germany; Email: John-Martin.Hempel@med.uni-muenchen.de Otology & Neurotology 25:727–729 © 2004, Otology & Neurotology, Inc. 727