Available online at www.sciencedirect.com American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 350 – 355 www.elsevier.com/locate/amjoto Cochlear implantation in patients with bilateral cochlear trauma Gediz Murat Serin, MDa,⁎, Ufuk Derinsu, PhDb , Murat Sarı, MDa , Özgül Gergin, MDa , Ayça Çiprut, PhDb , Ferda Akdaş, PhD, Prof b , Çağlar Batman, MD, Prof a a Department of Otorhinolaryngology, Marmara University School of Medicine, Istanbul, Turkey b Department of Audiology, Marmara University School of Medicine, Istanbul, Turkey Received 13 January 2009 Abstract Purpose: Temporal bone fracture, which involves the otic capsule, can lead to complete loss of auditory and vestibular functions, whereas the patients without fractures may experience profound sensorineural hearing loss due to cochlear concussion. Cochlear implant is indicated in profound sensorineural hearing loss due to cochlear trauma but who still have an intact auditory nerve. Material and methods: This is a retrospective review study. We report 5 cases of postlingually deafened patients caused by cochlear trauma, who underwent cochlear implantation. Preoperative and postoperative hearing performance will be presented. These patients are cochlear implanted after the cochlear trauma in our department between 2001 and 2006. Results: All patients performed very well with their implants, obtained open-set speech understanding. They all became good telephone users after implantation. Their performance in speech understanding was comparable to standard postlingual adult patients implanted. Conclusion: Cochlear implantation is an effective aural rehabilitation in profound sensorineural hearing loss caused by temporal bone trauma. Preoperative temporal bone computed tomography, magnetic resonance imaging, and promontorium stimulation testing are necessary to make decision for the surgery and to determine the side to be implanted. Surgery could be challenging and complicated because of anatomical irregularity. Moreover, fibrosis and partial or total ossification within the cochlea must be expected. © 2010 Published by Elsevier Inc. 1. Introduction The cochlear implant is a surgically implanted device that bypasses a nonfunctional cochlea and stimulates the hearing nerves with patterns of electrical currents so that speech and other sounds can be experienced by profoundly deaf people. Sensorineural hearing loss (SNHL) due to bilateral temporal bone fractures (trauma) is a dramatic consequence for the injured patients. In patients with severe to profound SNHL due to cochlear trauma but who still have an intact auditory nerve, cochlear implant is indicated [1]. Because of posttraumatic ossification of the cochlea, implantation should be performed early and can be ⁎ Corresponding author. Marmara Üniversitesi Hastanesi KBB A.B. D, Tophanelioglu cad., No: 13-15, Altunizade, 34662 Istanbul, Turkey. Tel.: +90 216 5450047. E-mail address: gedizserin@yahoo.com (G.M. Serin). 0196-0709/$ – see front matter © 2010 Published by Elsevier Inc. doi:10.1016/j.amjoto.2009.04.008 recommended to the patient if bilateral deafness is diagnosed. And also, due to the trauma, surgery can be difficult because of the distorted anatomy. Treatment of SNHL may be various caused by additional damage of auditory nerve fibers and posttraumatic central lesions. In the case of auditory nerve damage and distorted anatomy, brain stem implants may offer new possibilities. We report 5 cases of postlingually deafened patients caused by cochlear trauma, who underwent cochlear implantation. Preoperative and postoperative hearing performance will be presented. 2. Materials and methods 2.1. Case 1 A 46-year-old male had a severe head injury in a car accident in May 2000. He was operated on 2 times because G.M. Serin et al. / American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 350–355 351 Fig. 3. Axial CT scan of the temporal bone, bilateral petrous bone transversetype fractures involving the vestibule, right side. Fig. 1. Axial CT scan of the temporal bone, right petrous bone fracture. of intracranial hemorrhage, and he had an intensive care unit (ICU) stay unconsciously for 3 months. After discharge from the ICU, he noticed bilateral hearing loss. Otoscopic examination was normal, and audiological examination revealed bilateral profound SNHL. Temporal bone computed tomographic (CT) scan showed a transverse-type fracture in the right petrous bone involving the vestibule (Fig. 1). Left temporal bone scan revealed fracture line on the squamous part of the temporal bone (Fig. 2). The promontory stimulation test demonstrated good dynamic range as shown by the test frequencies for both ears. A left cochlear implant was performed 14 months after the accident. Two separate fracture lines were noticed at the operation on the mastoid and squamous part of the temporal bone. A simple mastoidectomy, posterior tympanotomy, and round window Fig. 2. Axial CT scan of the temporal bone with the fracture line on the squamous part. approach were performed. Free blood was seen in the cochlea through the incision made on the round window membrane and the electrode array of Nucleus 24M (Cochlear Corporation, Inssbruck, Australia) applied with full insertion. Intraoperative electrical stapedius reflex threshold (ESRT) and neural response telemetry tests were positive. 2.2. Case 2 A 40-year-old male presented with sudden onset of complete bilateral hearing loss after being assaulted by others in prison with a wooden stick in 1995. Head trauma caused a skull base fracture and required a craniotomy at that time. After being discharged from the hospital, he complained bilateral hearing loss and vertigo. The patient's vertigo and postural instability gradually improved over the weeks, but his hearing loss remained unchanged. Audiological evaluation revealed bilateral profound SNHL. Otologic examination revealed retraction of both tympanic Fig. 4. Axial CT scan of the temporal bone, bilateral petrous bone transversetype fractures involving the vestibule, left side. 352 G.M. Serin et al. / American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 350–355 Fig. 7. Axial CT scan of the temporal bone, bilateral transverse-type temporal bone fracture passing through otic capsule. membranes. Temporal bone CT scan revealed normal. The promontory stimulation test demonstrated bilateral sufficient neural function. A right ear cochlear implant was performed. A simple mastoidectomy, posterior tympanotomy, and cochleostomy were performed, and all electrodes were inserted using a Medel Combi 40+ device (Med-El, Innsbruck, Austria). Intraoperative ESRT was obtained for all electrodes. discharged from the ICU and was referred to our department. Otologic examination revealed normal. His audiological evaluation showed bilateral profound SNHL; no response was obtained from speech reception thresholds. Temporal bone CT scan demonstrated bilateral petrous bone transverse-type fractures involving the vestibule (Figs. 3 and 4). Promontory stimulation test showed good dynamic range for both ears. After 11 months, right ear was implanted by using a Medel Pulsar device (Med-El, Innsbruck, Austria). A simple mastoidectomy, posterior tympanotomy, and standard cochleostomy were performed, with observation of free blood in the cochlea. Full insertion of the electrode array was noted. Intraoperative ESRT was positive. 2.3. Case 3 2.4. Case 4 A 44-year-old male presented to the emergency department after falling from the fourth floor in May 2004. He presented with bilateral hearing loss and vertigo after being A 12-year-old boy had a severe head injury in a car accident in September 2005. On physical examination, he had broken right arm and leg. Because of the brain concussion, he Fig. 6. Postoperative transorbitale radiograph. Fig. 8. Axial CT scan of the temporal bone, bilateral transverse-type temporal bone fracture passing through otic capsule. Fig. 5. Axial CT scan of the temporal bone, right petrous bone transversetype fracture involving the vestibule. 353 G.M. Serin et al. / American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 350–355 Table 2 Postoperative performance for closed-set final phoneme recognition test Patients Case 1 Case 2 Case 3 Case 4 Case 5 R Case 5 L Closed-set final phoneme 6 mo 1y 2y 3y 4y 5y 7y 88% 76% 92% 88% 24% 88% 92% 82% 100% 96% 12% 100% 100% 92% 100% 100% 4% 100% 100% 100% 100% 100% 100% 100% 100% A 45-year-old had blunt head injury in July 2003. He was admitted to a nearby hospital, and CT scans demonstrated skull base fracture sparing the temporal bones and brain contusion. One week after the trauma, when he recovered consciousness, he was aware of bilateral hearing loss. He was referred to our hospital 1 month after the trauma. His otologic examination revealed normal results, but his audiogram revealed bilateral profound SNHL (Fig. 6). He also complained about a momentary vertigo. The promontory stimulation test indicated appropriate neural function in both ears. On CT scans, bilateral transverse-type temporal bone fracture passing through otic capsule was noted (Figs. 7 and 8). Right cochlear implantation was carried in August 2004. Incus appeared to be dislocated; granulation tissue and bone chips were observed over the promontorium. Promontorium was appeared as flattened and displaced through facial canal. Oval and round window could not be identified. Cochleostomy was performed, and all electrodes of Medel Combi 40+ device cochlear implant were inserted. C-arm radiography, in the surgical room, confirmed good positioning with positive intraoperative telemetry. A mild facial paresis that responded to steroid therapy at the early postoperative period was noted. Control radiographs confirmed correct positioning. The patient used the cochlear implant for nearly 2 years with decreasing performance in time. With the increase of most comfortable loudness levels over time, the number of electrodes causing nonauditory sensation also observed. The speech perception tests demonstrated disappointing results. Because of limited benefit, reimplantation was planned. Subsequently, a second surgery was agreed to perform explantation and reimplantation. The implant was explanted from the right ear in February 2007. Cochleostomy window could not be exposed because of fibrous tissues and scarring. At that time, it was decided to perform implantation in the left ear, cochleostomy was performed, and a new Medel Pulsar device cochlear implant was implanted. Electrical stapedius reflex threshold was negative. Intraoperative telemetry indicated the insertion of 8 of 12 electrodes. All patients postoperative radiograph confirmed correct positioning. Programming and aural rehabilitation were performed 1 month later. Table 1 Postoperative performance for closed-set initial phoneme recognition test Table 3 Postoperative performance for open-set 3-syllabic word identification test Patients Closed-set initial phoneme Patients Open-set 3-syllabic 6 mo 1y 2y 3y 4y 5y 7y 6 mo 1y 2y 3y 4y 5y 7y Case 1 Case 2 Case 3 Case 4 Case 5 R Case 5 L 88% 88% 92% 84% 36% 84% 96% 92% 100% 100% 16% 96% 100% 100% 100% 100% 12% 100% 100% 100% 100% 100% 100% 100% 100% Case 1 Case 2 Case 3 Case 4 Case 5 R Case 5 L 100% 76% 92% 92% 20% 64% 100% 96% 100% 96% 8% 84% 100% 100% 100% 100% 4% 100% 100% 100% 100% 100% 100% 100% 100% Fig. 9. Preoperative hearing thresholds and the sound field hearing thresholds with the cochlear implant from 250 to 4000 Hz. Mean hearing thresholds are shown with O and X for right and left ear. Mean hearing thresholds with the cochlear implant in the sound field are marked with cochlear implantation. was admitted in the ICU for 20 days where he developed progressive hearing loss. Otoscopic ear examination was normal. His audiological examination revealed bilateral profound SNHL. Temporal bone CT scan showed a bilateral petrous bone transverse-type fracture involving the vestibule (Fig. 5). Right ear was implanted in March 2006 using a Medel Pulsar device in 6 months after the accident. A posterior tympanotomy and cochleostomy were performed. The electrode array was fully inserted. Although the intraoperative telemetry was normal, ESRT was not obtained. 2.5. Case 5 354 G.M. Serin et al. / American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 350–355 Table 5 Postoperative performance for open sentence test 2.6. Audiological data Auditory performance was measured using a battery of closed- and open-set speech tests. All tests were developed for Turkish language, by the audiology department of Marmara University Medical School (Istanbul, Turkey). The open-set test batteries included 3 syllabic words, phonetically balanced monosyllabic word recognition, and common phrase comprehension. For the closed-set testing, identification for the phonemes at the beginning and the end of monosyllabic word tests was administered. All tests were presented via live voice, at a distance of 1 m with 0° azimuth, and at 70 dB A in sound-treated test booth. During the tests, the patients were asked to set their speech processors' sensitivity to the most comfortable level. The data on cochlear implant patients were collected preoperatively and at 6 months, 1, 2, 3, 4, 5, and 7 years postoperatively. 3. Results There were 5 patients who had implants, and one of them required device explantation because of the device failure, and new device was implanted to the other ear. Median follow-up was 2.9 years. There were no minor and major complications. Two separate fracture lines were noticed at the operation on the mastoid and squamous part of the temporal bone in case 1. Case 5 had a distorted middle ear anatomy, fracture line over the cochlea, and partial ossification in the right ear and needed extensive drilling for cochleostomy. And in his left ear, partial ossification was observed. Free blood was seen in the cochlea in case 1 and 3. Fig. 9 shows the mean preoperative hearing thresholds for right and left ears and mean postoperative hearing thresholds in the free field with cochlear implant. All patients had profound SNHL before implantation, their hearing thresholds ranged from 30 to 45 dB hearing level, 250 to 8000 Hz after implantation. Preoperatively, none of the patients demonstrated open-set and closed-set speech understanding without lip-reading. No response was obtained for all the speech tests administered for all patients. Tables 1 to 5 show the closed-set and open-set speech test results obtained at 6 months, 1, 2, 3, 4, 5, and 7 years postoperatively. Table 6 shows a summary of implanted patients. Table 4 Postoperative performance for open-set monosyllabic word identification test Patients Open-set monosyllabic 6 mo 1y 2y 3y 4y 5y 7y Case Case Case Case Case Case 60% 24% 56% 64% 0% 52% 84% 48% 76% 76% 0% 72% 80% 56% 76% 88% 0% 88% 60% 84% 92% 76% 92% 80% 96% 1 2 3 4 5R 5L Patients Case 1 Case 2 Case 3 Case 4 Case 5 R Case 5 L Open sentence 6 mo 1y 2y 3y 4y 5y 7y 88% 92% 72% 76% 12% 68% 92% 96% 88% 84% 12% 80% 100% 100% 88% 100% 0% 100% 100% 92% 100% 100% 100% 100% 100% All patients performed very well with their implants and obtained open-set speech understanding. They all became good telephone users after implantation. Their performance in speech understanding was comparable to standard postlingual adult patients implanted. The speech test results in case 5 were presented for both ears; right ear results stand for the speech performance after the first implantation on the right ear, whereas left ear results are for the speech understanding after the second implantation on the left. With a new implant on the left ear, the speech perception in case 5 improved substantially. 4. Conclusion Cochlear implants have proven to be an effective means of auditory rehabilitation for both adults and children. Patients with post–lingual-onset hearing loss can expect to receive sound awareness, enhanced lip-reading, and substantial closed-set speech perception with a cochlear implant [2]. We reported 5 patients with post–lingual-onset hearing loss caused by skull trauma. Historically, temporal bone fractures have been classified as longitudinal, transverse, or mixed fractures based on the relationship of the fracture line to the long axis of the petrous pyramid. However, the descriptions correlate poorly with clinical findings. However, simply, distinguishing petrous from nonpetrous involvement demonstrate significant correlation with the occurrence of serious sequelae [3]. Not only the fracture line that involves the otic capsule can lead to complete loss of auditory and vestibular function, but the patients without fractures may experience profound SNHL due to cochlear concussion as well [4,5]. Implantation of trauma patients may be challenging because of some factors that may jeopardize the middle ear anatomy. Granulation tissue in the middle ear or mastoid cavity may prevent the recognition of middle ear structures. Cochlear ossification was reported after head injury with fracture of the labyrinth or even without any clear-cut fracture. One of our cases had a bilateral partial ossification. Because most of the traumatic patients experiencing ICU stay unconsciously, the diagnosis of hearing loss may be delayed [1,5]. Hemorrhage and free blood in the cochlear lumen had not been reported before, being present in our 2 patients, which could lead to fibrosis and ossification. These pathologies G.M. Serin et al. / American Journal of Otolaryngology–Head and Neck Medicine and Surgery 31 (2010) 350–355 355 Table 6 Summary of implanted patients Patient 1 Patient 2 Patient 3 Patient 4 Patient 5 Age Method of trauma Degree of fibrosis and ossification Time to cochlear implantation Cochlear implant No. of functioning electrodes 46 40 44 12 45 Car accident Assaulted Falling from the building Car accident Blunt head injury (window shutter) – – – – Bilateral partial ossification 14 mo Nucleus 24M Medel Combi 40+ Medel Pulsar Medel Pulsar Medel Combi 40+ Medel Pulsar 22 12 12 12 12 (nonauditory sensation over time) 8 may involve the basal turn or the entire cochlea, and the presence of bony derangement may complicate electrode insertion. Because fractures of otic capsule may lead to loss of spiral ganglion cells over time, early implantation after trauma would provide better overall performance [5-7]. Camilleri [6] reported 2 patients who experienced facial nerve stimulation after cochlear implantation because of temporal bone trauma and suggested that current leaks from the electrode through the low resistance of the fracture line may cause a higher than expected rate of unintended facial nerve stimulation. Simons [5] alluded in his report that structural abnormalities such as temporal bone trauma may have a high risk of developing meningitis after cochlear implantation. Our patients experienced neither facial stimulation nor meningitis during the follow-up period. Cochlear implantation is an effective aural rehabilitation in profound SNHL caused by temporal bone trauma. The results are similar to that of postlingual patients. All 5 of our patients have top performances, increasing in time. The diagnosis may be delayed because of other injuries and possible unconscious period, overshadowing the hearing loss. Preoperative temporal bone CT, magnetic resonance imaging, and promontorium stimulation testing are neces- 11 mo 6 mo 11 mo 3y sary to make decision for the surgery and to determine the side to be implanted. Surgery could be challenging and complicated because of anatomical irregularity. Moreover, fibrosis and partial or total ossification within the cochlea must be expected. References [1] Graeme C. Cochlear implants, fundamentals and applications. New York Inc: Springer-Verlag; 2003. [2] Moody-Antonio S, Takayanagi S, Masuda A, et al. Improved speech perception in adult congenitally deafened cochlear implant recipients. Otol Neurotol 2005;26:649-54. [3] Ishman SL, Friedland DR. Temporal bone fractures: traditional classification and clinical relevance. Laryngoscope 2004;114:1734-41. [4] Morgan WE, Coker NJ, Jenkins HA. Histopathology of temporal bone fractures: implications for cochlear implantation. Laryngoscope 1994;104:426-32. [5] Simons JP, Whitaker ME, Hirsch BE. Cochlear implantation in a patient with bilateral temporal bone fractures. Otolaryngol Head Neck Surg 2005;132:809-11. [6] Camilleri AE, Toner JG, Howarth KL, et al. Cochlear implantation following temporal bone fracture. J Laryngol Otol 1999;113:454-7. [7] Teoh SW, Pisoni DB, Miyamoto RT. Cochlear implantation in adults with prelingual deafness. Part II. Underlying constraints that affect audiological outcomes. Laryngoscope 2004;114:1714-9.