Roberts et al.: Cochlear Implant Outcomes in Older Adults

Transcription

1 The Laryngoscope VC 2013 The American Laryngological, Rhinological and Otological Society, Inc. Differential Cochlear Implant Outcomes in Older Adults Daniel S. Roberts, MD, PhD; Harrison W. Lin, MD; Barbara S. Herrmann, PhD; Daniel J. Lee, MD Objectives/Hypothesis: The goals of this study were to analyze whether cochlear implant (CI) users over 65 years of age have different surgical and audiological outcomes when compared to younger adult CI users and to identify reasons for these possible differences. Study Design: Retrospective single-institution study. Methods: Records of 113 postlingually deafened adults with unilateral cochlear implants were reviewed. Preoperative and postoperative speech perception scores, and medical and epidemiological data were recorded and analyzed. Results: Speech perception ability was significantly poorer in CI users over 65 years of age compared to younger adult patients (P ¼.012). Patients over the age of 80 years accounted for these findings (P ¼.017). Older patients were less likely to have a family history of hearing deficits. A history of noise exposure and idiopathic cause of hearing loss did not correlate with audiological outcomes. A family history of hearing loss was associated with a trend toward better speech recognition (P ¼.062). Older patients did not experience more vestibular symptoms or other complications compared to younger patients. Conclusions: Patients over the age of 80 years had lower speech perception scores than other adult CI recipients but did not have higher rates of dizziness or vertigo after surgery. A family history of hearing loss was associated with a trend toward better speech recognition, possibly representing a new prognostic variable. These findings provide important information that will aid clinicians in counseling older CI candidates. Key Words: Cochlear Implant outcomes, elderly, octogenarians. Level of Evidence: 2b. Laryngoscope, 123: , 2013 INTRODUCTION Older adults constitute a rapidly growing demographic group in the United States. The number of adults over the age of 65 years is expected to double between the years 2000 and 2030, with 72 million Americans representing 20% of the population by The demand for cochlear implant (CI) surgery among older adults with severe to profound hearing loss will likely increase accordingly. Advanced age is not considered a contraindication to CI candidacy. Several studies have shown that older adults do benefit from CI, with improvements both in hearing abilities and quality of life. 2 5 However, current studies are conflicting as to whether elderly patients have similar audiological and surgical outcomes as compared to younger adult patients. Recent data suggest From the Department of Otolaryngology (D.S.R., H.W.L., D.J.L.) and Department of Audiology (B.S.H.), Massachusetts Eye and Ear Infirmary, Boston, Massachusetts; and Department of Otology and Laryngology (D.S.R., H.W.L., B.S.H., D.J.L.), Harvard Medical School, Boston, Massachusetts, U.S.A. Editor s Note: This Manuscript was accepted for publication July 25, Presented at the Triological Society 115th Annual Meeting at COSM, San Diego, California, U.S.A., April 20 21, All research was conducted at the Massachusetts Eye and Ear Infirmary, Boston, Massachusetts. Support for this research was from the Massachusetts Eye and Ear Department of Otolaryngology fund for resident research. The authors have no other funding, financial relationships, or conflicts of interest to disclose. Send correspondence to Daniel J. Lee, MD, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, 243 Charles Street, Boston, MA daniel_lee@meei.harvard.edu DOI: /lary that elderly patients benefit from cochlear implantation but have lower mean speech recognition scores compared to adult patients under the age of 65 years. 6 These two patient groups were matched for pre-implant speech perception abilities and duration of deafness preoperatively. These data are in contrast to other reports showing similar audiological outcomes between younger and older adult CI users. 3 5 Finally, a study from 2011 suggests that duration of deafness rather than age may account for performance differences between younger adult CI users and those older than 70 years. 7 To resolve these conflicting findings in the literature, we performed a retrospective review of postlingually deafened adults with unilateral cochlear implants implanted at our institution to study the influence of advanced age. We stratified our cohort to determine whether a subgroup of CI users over 65 years of age might demonstrate lower word intelligibility scores (consonant-nucleus-consonant [CNC]) compared to younger adult patients. We also analyzed the effects of duration of hearing loss, history of noise exposure, and family history of hearing loss on CI performance. MATERIALS AND METHODS This retrospective study was approved by the Human Studies Committee of the Massachusetts Eye and Ear Infirmary ( X, PI: Daniel J. Lee, MD). Subjects We performed a retrospective review of the medical and audiologic records of CI patients at our institution over the period from 2006 to Patients were included in our analysis if they were 1) postlingually deafened, 2) 18 years of age or

2 TABLE I. Patient Demographics. Group 65 Years <65 Years P Value No Average age, yr Female 30 (44.7%) 21 (45.6%) Audiological follow-up (mo) Duration of hearing loss (mo) Noise exposure 15 (22.4%) 6 (13.0%).231 Family history of hearing 18 (26.9%) 22 (47.8%).028* loss Idiopathic etiology 31 (46.2%) 14 (30.4%).118 Right ear implanted 30 (43.3%) 27 (60.8%).181 History of neurological 3 (4.5%) 4 (8.7%).440 disease Device/electrode AB HiRes 90K/HiFocus 18 (26.9%) 10 (21.7%).650 Helix AB HiRes 90K/HiFocus 1j 29 (43.3%) 21 (45.6%).849 Cochlear Freedom/Contour 4 (3.5%) 7 (6.2%).112 Nucleus CI512/Contour Advance 11 (16.4%) 13 (28.3%).162 Average age, audiological follow-up, and duration of hearing loss are 6 standard error of mean. History of neurological disease was defined as a history of a central nervous system malignancy, stroke, head injury, or degenerative neurological disorder. *Statistically different groups determined by v 2 analysis/fisher exact test or t test. AB ¼ Advanced Bionics. older, 3) underwent a single cochlear implant, and 4) had follow-up audiologic data after at least 5 months of CI use. Results represent the outcomes of 10 surgeons performing a postauricular mastoidectomy and posterior tympanotomy with scala tympani insertion. Insertion occurred through a cochleostomy anterior and inferior to the round window. Demographic and medical data included age, sex, timing of audiological follow-up, duration of hearing loss, noise exposure history, family history of hearing loss, cause of hearing loss, history of neurological disease, device and electrode type, and the presence of dizziness and vertigo postoperatively. Audiologic data recorded included CNC scores before and after implantation. between age groups. Univariate analysis was performed using an unpaired t-test. A P value of.05 determined significance. In addition, the differences in mean CNC scores for each of the medical and epidemiologic factors was also tested. v 2 analysis and Fisher exact test were used to test for any differences in categorical data including the frequency of postoperative complications. Analysis of variance and Bonferroni post-test was utilized to determine differences between CNC performance based on decade of life. RESULTS We analyzed our audiologic database and identified 156 CI recipients who fulfilled criteria for initial inclusion in our study. Of these 156 patients, 113 had complete audiologic and medical data for review. These 113 patients were divided into two primary groups: 1) under 65 years of age (n ¼ 46) and 2) those 65 years of age or older (n ¼ 67) (Table I). We also subdivided our cohort of adult CI users according to decade of age. Table I shows the mean patient demographic data for our two primary age groups. The major difference observed between these two groups was incidence of family history of hearing loss (65 years, 26.9% vs. <65 years, 47.8%; P ¼.028). Although the older patient group was more likely to report an unknown cause and a longer duration of their hearing loss, these trends were not statistically significant (P ¼.118, P ¼.068). Total audiological follow-up time, sex, noise exposure, history of neurological disease, side of implantation, and device type were not different between groups. There were no differences seen in either postoperative vestibular symptoms or surgical complications between these two primary age groups (Table II). The results of pre- and postoperative speech perception testing are shown in Figure 1. Preoperative CNCs were statistically equivalent between groups, and speech perception improved in both cohorts (<65 years, P ¼ 9.23 E-22, 65 years, P ¼ 6.33 E-22). In contrast, mean postoperative CNC scores were higher among younger adult CI users (<65 years) compared to older adults (65 years) (63.21% standard error of mean [SEM] vs % SEM; P ¼.0124, respectively) (Fig. 1). When we stratified our cohort by decade of life, word intelligibility differed only between octogenarians Speech Testing Speech testing was done during the standard clinical evaluations for CI candidates and for monitoring performance after surgery in the Department of Audiology, Massachusetts Eye and Ear Infirmary. Preoperatively, the CNC test was performed using headphones (TDH-49, Telephonic Corp., Farmingdale, NY) at a level that was predicted to produce the maximum speech perception score. 8 Postoperatively, CNC testing was done in the sound field with the patient using the CI alone and facing the speaker (0 azimuth) using a presentation level of 65 db HL. If the patient had better hearing in the contralateral ear or wore a hearing aid in that ear, the contralateral ear was plugged or the hearing aid turned off during the testing. The maximal CNC score obtained after at least 5 months of implant experience was used. Data Analysis Multivariate regression analysis was performed using STATA software to analyze differences in mean CNC score TABLE II. Surgical Complications. Group 65 Years <65 Years P Value No Postoperative 10 (14.9%) 8 (17.3%) 1.00 dizziness/vertigo Implant failure 1 1 Perilymphatic fistula 1 0 Infection (device removed) 0 1 Wound complication 2 0 Delayed facial nerve paresis 2 0 Permanent facial nerve injury 0 0 Postoperative delirium 1 0 Total 17 (25.3%) 10 (21.7%).822 Statistically different groups determined by v 2 analysis/fisher exact test or t test. 1953

3 Fig. 1. Cochlear implant outcomes in patients over 65 years. There were 113 patients identified with complete audiologic and medical data for analysis; 67 patients were over 65 years and 46 were below 65 years of age. Consonant-nucleus-consonant (CNC) testing was performed before and after implantation. Mean preoperative (Pre-op) and postoperative (Post-op) CNC are shown (significantly different as determined by a t test). Values are reported as mean scores 6 standard error of mean (SEM). P ¼ 9.23 E-22. **P ¼ 6.33 E-22. ***P ¼ regarding this topic are inconsistent. Several reports show no difference in CI outcomes in patients over 65 years of age compared with younger adults, 3 5 whereas another study demonstrated lower word intelligibility in older CI users. 6 Our data are consistent with these recent observations by Friedland et al., but what has not been shown previously is that patients over the age of 80 years account for lower performance among CI users over 65 years of age. Differences in age-related auditory central processing is often cited for inferior speech perception among older CI users. 6,9 Such changes could occur as the result neurological disease or through reductions in age-related neuroplasticity. We found no difference in the prevalence of neurologic disease among our patient groups, suggesting that this factor does not account for age- related differences in speech outcomes. An alternative explanation could be changes in central auditory processing and other adult CI users (P ¼.017). Octogenarians had poorer speech recognition compared to patients 60 to 69 years of age (43.0% SEM vs. 64.0% SEM; P ¼.019) (Fig. 2B). Patients in the 20s to 30s age category trended toward a difference when compared to octogenarians (P ¼.090). Variables that may impact speech recognition scores were also studied (Table III). Patients who reported a family history of hearing loss trended toward higher CNC scores compared to those patients who did not (63.19% SEM vs % SEM; P ¼.062, respectively) (Table III). These patients were more likely to be below the age of 65 years (Table I). A longer period of hearing loss trended toward poorer speech recognition (P ¼.114). The side of implantation had no impact on preoperative CNC scores (right, 6.6% SEM vs. left, 6.0% SEM; P ¼.74) or postoperative CNC scores (right, 54.3% SEM vs. left, 53.7% SEM; P ¼.88). Noise exposure history or idiopathic etiology of hearing loss was not associated with better CI performance (Table III). Overall, complication rates were equivalent (Table II). Interestingly, older patients were equally as likely to experience vertigo/disequilibrium when compared to younger patients (Table II) (14.9% vs. 17.3%; P ¼ 1.00). DISCUSSION In this study we examined the association between older age and other demographic factors with performance following unilateral CI surgery in postlingually deafened adults. Consistent with previous studies, we found that elderly patients with severe to profound hearing loss improved their speech recognition abilities with the CI. However, our findings indicated that as a group, older patients had poorer speech recognition outcomes compared to younger adult patients. Previous data 1954 Fig. 2. Cochlear implant outcomes by age. (A) Postoperative consonant-nucleus-consonant (CNC) scores are shown by age at implantation. Outcomes of octogenarians are highlighted by shading. (B) Implant outcomes were segregated by decades. Patients in their 20s to 30s (n ¼ 7), 40s (n ¼ 19), 50s (n ¼ 14), 60s (n ¼ 26), 70s (n ¼ 25), and 80s (n ¼ 22) were compared. Preoperative (Pre-op) and postoperative (Post-op) values were calculated (significantly different as determined by analysis of variance and Bonferroni post-test). Values are reported as mean scores 6 standard error of mean (SEM). *P ¼.019. #P ¼.09.

4 TABLE III. Analysis of Factors Contributing to Postoperative CNC Scores. CNC Score P Value Yes No Coefficient Univariate Multivariate Age > 65 years *.041* Noise exposure Family history of hearing loss *.062 Etiology idiopathic Duration hearing loss (mo) Data are average 6 standard error of mean. *Statistically different groups determined by multivariate analysis or t test. CNC ¼ consonant-nucleus-consonant. with age. Some electrophysiologic studies suggest that temporal processing, or the ability of the auditory system to follow changes in stimulus timing may become poorer with age. 10,11 Although evidence in this area is conflicting and difficult to isolate from other confounding factors, differences in central processing is a likely candidate, at least in part, for impaired speech perception in older CI implant recipients. An important question is how these outcomes relate to quality of life. In a similar study comparing the results of cochlear implant recipients over the age of 70 years to those of younger recipients, both audiologic and quality of life outcomes were measured. 2 Despite lower speech perception abilities in the older CI user group, improvements in quality of life were found to be similar between groups. These findings suggest that the similar quality of life benefits for both the younger and older adult CI user groups 12 may arise from the individual improvement in auditory communication rather than the absolute mean outcomes between groups. Previous studies indicate that adult CI outcomes are associated with the duration of deafness, residual hearing before implantation, auditory verbal therapy, and postlingual versus prelingual deafness We found that our two groups of patients differed in the prevalence of family history of hearing loss. In addition, a family history of hearing loss was associated with a trend toward improved postimplantation speech perception when examining our entire patient cohort (Table III). Family history of hearing loss was more common among younger implant patients, possibly contributing to improved outcomes. This interesting finding has not been reported previously and may have value as a prognostic variable; it merits further study with a larger number of patients. Noise exposure history, side of implantation, and duration of hearing loss were investigated as predictors of postimplantation speech perception. To our knowledge, the role of noise exposure has not been studied. A history of noise exposure appears to be unrelated to implant outcomes. A recent report suggests that the side of implantation may have a role in postoperative speech perception, with those implanted on the right performing better than those implanted on the left. 7 In our cohort, older patients trended toward a preference for left-sided implantation; however, speech perception was not influenced by the side of implantation in our study. Finally, duration of deafness has been shown to be a predictor of audiological outcomes. 7,18,19 Our data demonstrate that the length of self-reported hearing loss has no association with audiometric outcomes, highlighting the importance of deafness rather than duration of hearing loss as a predictor. Surgical complications are a consideration when counseling older adults for CI surgery. Previous studies raise the concern for exacerbations of previous comorbid conditions in elderly patient undergoing CI surgery such as urinary retention and acute delirium. 8,20 These authors also report that the most common postoperative complaint among elderly CI recipients is temporary dizziness or vertigo. 8 We investigated whether older patients in our study disproportionately experienced these symptoms. In our entire cohort, the rate of vestibular symptoms postimplantation was similar to previous reports. 21,22 To our surprise, we also found that older patient group was not more likely to experience dizziness compared to the younger CI group. Although differential rates of vertigo/dizziness are described between pediatric and adult patients, with adult patients experiencing more vertigo/dizziness when compared to children, 21 our findings suggest that postimplantation dizziness is not more frequently experienced by elderly adults, and such patients can therefore be counseled accordingly. Several limitations of our study are acknowledged. Because this is a retrospective study, there is the risk of bias from this type of evaluation. Also, this type of analysis prevents the utilization of strict clinical definitions to define variables such as family history, the amount of noise exposure, or recording the specific length of deafness, as these data were not available in our records. We did not use established hearing, dizziness, or quality-oflife surveys in the assessment of outcomes, and a prospective study at our institution with a larger number of patients will incorporate such instruments. Finally, these data represent a single institution s experience with cochlear implantation. CONCLUSION Although elderly implant patients are more likely to have poorer speech perception when compared to 1955

5 younger adult recipients, they still demonstrate significant hearing gains following CI surgery. Our results furthermore suggest that better speech perception may be associated with a family history of hearing loss. Importantly, we show that although vertigo/disequilibrium is a common finding among all cochlear implant recipients, older patients are at no greater risk of experiencing these symptoms. These observations provide useful guidance for clinicians counseling older patients considering cochlear implantation surgery. Acknowledgments The authors thank Dr. Joseph B. Nadol for his thoughtful comments and his review of this manuscript. The authors also thank the Massachusetts General Hospital Biostatics Center for assistance with statistical analysis and Dr. Ahmad R. Sedaghat for his perspective on this important topic. BIBLIOGRAPHY 1. He W, Sengupta M, Velkoff VA, DeBarros KA. 65 in the United States. Washington, DC: US Census Bureau; Available at: gov/prod/2006pubs/p Accessed November 1, Vermeire K, Brokx JP, Wuyts FL, Cochet E, Hofkens A, Van de Heyning PH. Quality-of-life benefit from cochlear implantation in the elderly. Otol Neurotol 2005;26: Djalilian HR, King TA, Smith SL, et al. Cochlear implantation in the elderly: results and quality-of-life assessment. Ann Otol Rhinol Laryngol 2002;111: Labadie RF, Carrasco VN, Gilmer CH, et al. Cochlear implant performance in senior citizens. Otolaryngol Head Neck Surg 2000;123: Pasanisi E, Bacciu A, Vincenti V, et al. Speech recognition in elderly cochlear implant recipients. Clin Otolaryngol 2003;28: Friedland DR, Runge-Samuelson C, Baig H, et al. Case-control analysis of cochlear implant performance in elderly patients. Arch Otolaryngol Head Neck Surg 2010;136: Budenz CL, Cosetti MK, Coelho DH, et al. The effects of cochlear implantation on speech perception in older adults. J Am Geriatr Soc 2011;59: Halpin C. The tuning curve in clinical audiology. Am J Aud 2002;11: Eshraghi AA, Rodriguez M, Balkany TJ, et al. Cochlear implant surgery in patients more than seventy-nine years old. Laryngoscope 2009;119: Tremblay KL, Piskosz M, Souza P. Effects of age and age-related hearing loss on the neural representation of speech cues. Clin Neurophysiol 2003;114: Boettcher FA. Presbyacusis and the auditory brainstem response. J Speech Lang Hear Res 2002;45: Haensel J, Ilgner J, Chen Y-S, Thuermer C, et al. Speech perception in elderly patients following cochlear implantation. Acta Otolaryngol 2005; 125: Gantz BJ, Woodworth GG, Knutson JF, et al. Multivariate predictors of audiological success with multichannel cochlear implants. Ann Otol Rhinol Laryngol 1993;102: Blamey P, Arndt P, Bergeron F, et al. Factors affecting auditory performance of postlinguistically deaf adults using cochlear implants. Audiol Neurootol 1996;1: van Dijk JE, van Olphen AF, Langereis MC, Mens LH, Brokx JP, Smoorenburg GF. Predictors of cochlear implant performance. Audiology 1999; 38: Leung J, Wang NY, Yeagle JD, et al. Predictive models for cochlear implantation in elderly candidates. Arch Otolaryngol Head Neck Surg 2005;131: Bodmer D, Shipp DB, Ostroff JM, et al. A comparison of postcochlear implantation speech scores in an adult population. Laryngoscope 2007;117: Rubinstein JT, Parkinson WS, Tyler RS, et al. Residual speech recognition and cochlear implant performance: effects of implantation criteria. Am J Otol 1999;20: Friedland DR, Venick HS, Niparko JK. Choice of ear for cochlear implantation: the effect of history and residual hearing on predicted postoperative performance. Otol Neurotol 2003;24: Carlson ML, Breen JT, Gifford RH, et al. Cochlear implantation in the octogenarian and nonagenarian. Otol Neurotol 2010;31: Hansen S, Anthonsen K, Stangerup SE, et al. Unexpected findings and surgical complications in 505 consecutive cochlear implantations: a proposal for reporting consensus. Acta Otolaryngol 2010;130: Krause E, Louza JP, Wechtenbruch J, et al. Incidence and quality of vertigo symptoms after cochlear implantation. Laryngol Otol 2009;123: