Hearing in Patients Operated Unilaterally for Otosclerosis. Self-assessment of Hearing and Audiometric Results

Transcription

1 Acta Otolaryngol (Stockh) 1999; 119: Hearing in Patients Operated Unilaterally for Otosclerosis. Self-assessment of Hearing and Audiometric Results LARS LUNDMAN 1, LENNART MENDEL 1, DAN BAGGER-SJO BA CK 1 and ULF ROSENHALL 2 From the Departments of 1 Otolaryngology and 2 Audiology, Karolinska Hospital, Stockholm, Sweden Lundman L, Mendel L, Bagger-Sjöbäck D, Rosenhall U. Hearing in patients operated unilaterally for otosclerosis. Self-assessment of hearing and audiometric results. Acta Otolaryngol (Stockh) 1999; 119: The objective of this study was to examine the outcome of unilateral stapes surgery in one patient group with bilateral hearing loss and one group with unilateral hearing loss. The patients own estimations of improvement in hearing ability and the occurrence of other ear-related symptoms were examined retrospectively and in a follow-up study. Ninety-five of 123 patients operated for otosclerosis in only one ear between 1987 and 1992 responded to a follow-up examination. Observed audiometric findings and changes thereof, along with the patients own estimations of their hearing handicap pre- and postoperatively, and the occurrence of other ear-related symptoms were studied. Despite good surgical results (closure of air bone gap within 2 db in 94%), 33% of the patients had severe hearing disabilities postoperatively, and many of these patients needed further amplification with a hearing aid. Mild dizziness occurred in 33% of the patients postoperatively and did not decrease over time. Discomfort in the operated ear due to strong sounds was reported in 2%. Change in sound quality occurred in 8% of the operated ears, but tended to disappear over time. From the results of this study it may be concluded that surgery in one ear only, leaving the other ear with poor hearing, is not an optimal hearing rehabilitation of patients with otosclerosis. It is important endevour to achieve bilateral hearing in order to give the patient good social hearing. Postoperative dizziness and unpleasant hearing quality do occur frequently, and the patients need to be informed about these problems preoperatively. Key words: complications, patient assessment, quality of life, sound distortion. INTRODUCTION Results after otosclerosis surgery are usually determined by measuring pure-tone threshold improvement or air bone gap (ABG) closure. Although these techniques provide hard data, they give limited information about the status of the patient s hearing. Improvement of air conduction threshold closure may not always be indicative of restored normal hearing function, since many of the qualitative aspects of hearing are not examined by this method. The aim of many papers reporting treatment results after otosclerosis surgery is often to demonstrate the advantage of one method over another, or to report the results of one or several surgeons (1 4). One of the reasons that routinely performed puretone audiometry is not a reliable way of measuring restored hearing function or results from stapes surgery is that otosclerosis affects not only the middle ear, but also the inner ear. While surgical procedures of the stapes may bypass the obstacle created by the ankylosed footplate, it is not known what effects this may have on the cochlea. Another important consideration is that stapes surgery does not affect the otosclerotic process. The disease progresses over time, possibly resulting in impaired bone conduction (BC) and deterioration in cochlear function in both operated and non-operated ears (5). This deterioration may explain why after stapes surgery, patients often state that although their hearing ability has improved considerably, the quality of sound is different. Furthermore, despite the hearing improvement, many patients complain of hearing problems in certain listening situations. The aim of the present study was to study the treatment results of stapes surgery as seen primarily from the patient s point of view. We studied both unilateral and bilateral disease patients. We assessed their preoperative hearing and to what extent surgery improved the quality of hearing. Follow-up time was a minimum of 3 years and a maximum of 8 years. During this period, stapedotomy was adopted as a surgical technique in our department. MATERIAL AND METHODS The study group consisted of 123 consecutive patients with otosclerosis, operated on one ear only between 1987 and 1992 at the Department of Otolaryngology, Karolinska Hospital, Stockholm. The patients were invited to participate in a follow-up study during the first 5% of None had undergone any further stapes surgery after 1992 until the time of the followup. Despite repeated attempts to contact them, 28 of these patients did not respond to the invitation, leaving 95 patients that completed the study. We selected patients operated on only one side because this surgical policy was predominant during the study period. Out of these 95 patients, 11 had had surgery previously in the other ear, 4 underwent revision surgery and 1 underwent primary and revision surgery during the study period. Mean age at surgery was 46 years 1999 Scandinavian University Press. ISSN

2 454 L. Lundman et al. Acta Otolaryngol (Stockh) 119 (range: years). All patients had clinical evidence of otosclerosis (i.e. progressive conductive hearing loss, impedance measurements indicating stapes fixation and preoperative findings of fixed stapes and otosclerosis plaques). The patients were operated either with partial stapedectomy (n=34) aiming to remove the posterior part of the footplate, or with stapedotomy (n=57) using a microdrill. A.6-mm teflon platinum wire piston was used in both the stapedectomy and stapedotomy groups and, if necessary, the oval window was sealed with fascia. Operating charts, preoperative pure-tone audiograms, including speech discrimination score, and corresponding audiograms obtained approximately 6 months postoperatively were collected. Audiometry was performed according to internationally accepted procedures. The patients were re-examined in the same way 3 8 years (mean: 5 years) after surgery. At that time, they filled in a questionnaire with assistance of an audiologist. The questionnaire included questions regarding the time of onset of the hearing difficulties as well as hearing disability before and after surgery. Furthermore, the patients own estimations of the hearing disability in three common situations, i.e. at home, at work and in social life were assessed before and after surgery. If the patients assessed their hearing difficulties as severe at work and/or in social life, they were classified as having severe social hearing disability. The patients were also asked whether they had had tinnitus, changes of sound quality or dizziness. The use of hearing aids was documented. Hearing results were described using the pure-tone average (PTA) for frequencies of.5, 1, 2 and 3 khz, as recommended by the Committee on Hearing and Equilibrium Guidlines (7), and using the speech discrimination score in quiet conditions. According to the audiometric findings, the patients were categorized into three different groups preoperatively and at follow-up: patients with normal hearing, unilateral hearing loss (UHL) or bilateral hearing loss (BHL). The definition of hearing loss was set to a PTA of air conduction (AC) of 2 db or worse. Preoperative ABG was calculated using the PTA for bone conduction (BC) obtained at follow-up (8). In a majority of the cases BC had not been measured during the early postoperative period. Statistical analyses were performed with the Mann-Whitney test and Fisher s exact test. RESULTS The preoperative hearing and hearing at time of follow-up in each patient are presented in Fig. 1. Descriptive statistics of PTA of AC, PTA of BC, ABG and discrimination score are shown in Table I. In the 4 revised ears, the preoperative PTA of AC was 61 db. Improvement of hearing ( 25 db PTA of AC at follow-up) was achieved in 3 of these ears. In one ear the hearing was unchanged at followup. In the group of 23 patients that did not respond to the invitation, audiograms 6 months postoperatively were analysed. These audiograms showed similar re- Fig. 1. Hearing in both ears preoperatively and at time of follow-up. The PTA of AC in the operated ear is plotted with the non-operated ear in 95 patients operated on one side only.

3 Acta Otolaryngol (Stockh) 119 Hearing in otosclerosis surgery patients 455 Table I. Descripti e statistics of PTA of AC, PTA of BC, ABG and discrimination score Operated ear Non-operated ear Before surgery At follow-up Before surgery At follow-up Pure tone average (PTA) Mean PTA of AC (db, SD) 57, 1 26, 14 32, 15 36, 17 Mean PTA of BC (db, SD) 22, 8 19, 1 17, 7 19, 9 PTA of AC 2 db (%) PTA of AC 21 3 db (%) PTA of AC 31 4 db (%) 2 15 PTA of AC 4 db (%) Air bone gap (ABG) Mean ABG (db, SD) 34, 8 8, 7 16, 13 17, 13 ABG 1 db (%) ABG 11 2 db (%) 3 ABG 21 3 db (%) ABG 31 db (%) Discrimination score 95% 62% 78% 82% (n=71) 82% Change of PTA of AC (%) Worsening by 21 3 db 3 Worsening by11 2 db 14 None ( 1 db) 5 81 Improvement by 11 2 db 9 2 Improvement by 21 3 db 29 Improvement by 31 Change of PTA of BC (%) 57 Worsening by 21 3 db 1 Worsening by11 2 db 1 7 None ( 1 db) Improvement by 11 2 db 22 1 Improvement by 21 3 db 2 Improvement by 31 sults as for the study group, except in 1 patient, who became deaf in the operated ear 3 months postoperatively. UHL and BHL were present before surgery in 25% (n=24) and 75% (n=71), respectively. A detailed description of the reported severity of the hearing disability preoperatively and at follow-up, in relation UHL and BHL, is presented in Fig. 2. When analysing the 95 patients at the time of follow-up, it was found among the 49 patients with BHL after surgery, 51% (n=25) still had severe social hearing disability, and 8 of these had severe problems at home. The patients with BHL and severe social hearing disability had significantly worse mean PTAs of AC in the better ear (34 db, p.1) and the worse ear (51 db, p.1), as compared to the patients with BHL and no or mild hearing disability at follow-up (24 and 38 db, respectively). Patients with UHL at follow-up had significantly less frequency (2%) of severe social hearing disability than did patients with BHL (5%) at follow-up (p.1). When comparing audiometric findings in patients with severe social hearing disability and patients with mild or no social hearing disability in the follow-up UHL group, the mean PTA of AC in the worse ear was 3 db poorer in patients with severe social hearing disability. The difference was not statistically significant. Of the 11 patients with previous surgery in the other ear, 9 reported BHL before surgery. Seven patients still had BHL at follow-up. Only 2 of these 11 patients had severe social hearing disability at follow-up. Despite this, the preoperative mean PTA of AC in both operated and non-operated ears was worse than in the group of patients not operated previously in the other ear (operated: 63 db vs 57 db, p.5, non-operated: 4 db vs 35 db, n.s.). The mean PTA of AC in the operated ears, and the mean PTA of AC in the non-operated ear at follow-up, did not differ significantly from the rest of the study group. In only 8% (2/24) of the patients with UHL prior to surgery was the operated ear judged as the better ear at follow-up. By contrast, in 75% (53/71) of the patients with BHL preoperatively, the operated ear was judged as the better ear after surgery.

4 456 L. Lundman et al. Acta Otolaryngol (Stockh) 119 Hearing improvement and the need for hearing aid amplification postoperatively are presented in Table II. Hearing aids were used by 2 patients with UHL and 17 with BHL at follow-up. In those 19 patients requiring hearing aids postoperatively, the mean PTA of AC in the better ear was 17 db (36 db vs 19 db) worse than in the patients not requiring a hearing aid (p.1). Among the patients with severe social hearing disability at follow-up, 38% required hearing aids, as compared to 1% of the rest of the patients. Patient assessment of other symptoms pre- and postoperatively is presented in Table II. Tinnitus was found in equal frequencies pre- and postoperatively. No relation between surgery and occurrence of tinnitus was found. Twenty percent of the patients complained about dizziness preoperatively and 34% experienced dizziness after surgery (Table II). In 19 of these, the dizziness increased over time, in 3 it tended to decrease and in the remainder it was unchanged. In no patient was the dizziness incapacitating. Eighty percent of the patients reported that the sound in the operated ear had a different quality during the early postoperative period (Table II). A Table II. Self-assessment of hearing and other symptoms postoperati ely in 95 patients operated unilaterally for otosclerosis Symptoms Tinnitus Before surgery 6 Remaining after surgery 48 Not before surgery 4 New after surgery 16 In the operated ear at follow-up 22 In the non-operated ear at follow-up 27 In both ears at follow-up 15 Dizziness Before surgery 2 Directly after surgery 34 Remaining at follow-up 31 Sound-distortion/hyperacusis Immediate after surgery 8 Persistent at follow-up 2 Hearing (self-assessment) Improvement 6 months after surgery 82 Decline in the operated ear after 6 months 31 Decline in the non-operated ear 46 Hearing aid after surgery metallic character and hyperacusis were the major complaints. In 2% hyperacusis and distortion were still present at follow-up. % Fig. 2. Hearing disability (HD), at work or in social life as well as at home, preoperatively and at follow-up in relation to unilateral hearing loss (UHL) or bilateral hearing loss (BHL). NH=no hearing loss. Each box contains the number of patients. DISCUSSION The main objective of this study was to investigate the patients own assessments of hearing gain and the degree of hearing disability pre- and postoperatively. In order to for patients to be comparable, we chose to compare those patients in whom no additional ear surgery had been performed after If favourable audiometry-based criteria are specified for success, the hearing results from stapes surgery may be improved artificially (8). It is therefore important to include a totally different measure of the hearing results, and the questionnaire utilized in this study fulfils this criterion. In the present study it is intriguing to notice that self-assessments give a much more complex and less embellished picture than is gained from audiometry. In this study the hearing results obtained after stapes surgery correspond well to previously reported results in the literature (1, 2, 4, 6). It is well known from earlier reports and also clear in this study that revision surgery succeeds less frequently (9). Regardless of whether they had UHL or BHL preoperatively, most patients noticed profound social hearing disability. At home, however, patients with BHL preoperatively had a much higher frequency of severe hearing disability than did those with UHL. In

5 Acta Otolaryngol (Stockh) 119 the present study, a hearing loss 4 db in one ear, even with the other ear normal, appears to be a strong predictor for hearing problems in social situations. In otosclerosis, UHL 4 db can be regarded as sufficient social hearing only in a quiet environment. As seen in Fig. 2, hearing ability at work or in social life for the patients in the preoperative BHL group improved to the same degree as in the preoperative UHL group. However, if a patient goes from BHL to UHL due to surgery, self-assessed severe hearing disability will be significantly less than it would if the patient remained in the BHL group after surgery. The degree of audiometrically measured hearing loss in both operated and non-operated ears was also related to self-assessed hearing after surgery. Despite poorer preoperative hearing, the 11 patients previously operated in the other ear tended to have better self-assessed hearing at follow-up than did patients not operated previously. Most patients noticed hearing gain during the early postoperative period, but as many as 33% of the patients subsequently noted some decline of hearing on the operated side, and 5% noted a decline in the non-operated ear thereafter. This decline can be attributed to progress of otosclerosis in the non-operated ear and, in elderly patients, also to progress of presbyacusis. Despite acceptable surgical results in 95% (closure of ABG within 2 db) of patients, only 64% had satisfactory social hearing (normal or mild hearing disability at work or in social life) at follow-up. When stapes surgery has been performed on a patient with unilateral otosclerosis, there is a high probability that the patient will enjoy good long-term social hearing if the other ear is stable. However, almost 33% of the patients with UHL preoperatively had progressed to BHL at follow-up, and 5% of these had severe social hearing disability. After patients with otosclerosis have undergone surgery, the risk of retaining severe social hearing disability is high. In this study, almost 33% of patients with both UHL and BHL preoperatively retained their severe social hearing handicap. These long-term problems have previously been addressed in the literature (6, 1 14). In a recent follow-up study by Ramsay et al. (6), 21% of the operated patients had considerable or moderate limitations on daily life (page 25, table 2). However, that study consisted of several patients operated on both ears. In this study, 66% of the patients experienced tinnitus to various degrees both preoperatively and at follow-up. Other investigators have reported a similar or lower incidence (6, 14, 15). In some patients the tinnitus disappeared after surgery, but in more than Hearing in otosclerosis surgery patients % of the patients with no tinnitus preoperatively, this symptom was present after surgery. This study indicates that in most patients, the presence of tinnitus in otosclerosis is not related to surgery. It is more likely related to the progress of otosclerosis. Dizziness was present in 33% of the cases postoperatively. We are, however, uncertain about the quality and severity of the dizziness, since an in-depth analysis of this problem was not performed. However, no patient was incapacitated by the dizziness. Sound distortion and hyperacusis were common complaints in the immediate postoperative period. Twenty percent of the patients still experienced this phenomenon in their operated ears at follow-up. In the study by Ramsay et al., loud noise intolerance occurred in 35% of the operated ears (6). Sound distortion and hyperacusis are not major problems after otosclerosis surgery, but patients must be informed that it might occur, and that it may even be permanent after surgery. This study clearly shows the importance of considering the hearing in both ears in all patients slated for otosclerosis surgery. Surgical hearing restoration in one ear only in patients with bilateral otosclerosis is frequently insufficient to achieve acceptable social hearing. These patients should be offered additional surgery in the other ear if needed. The patients must be informed about what degree of functional improvement may be anticipated from closure of the ABG, as well as the long-term prognosis. The patients also need to be informed about the risks of distorted sound quality, tinnitus and dizziness. ACKNOWLEDGMENTS The authors thank Ms. Gull-Britt Westin for skilful performance of the audiometric measurements, interviews and plotting the data. REFERENCES 1. Browning GG, Gatehouse S, Swan IRC. The Glasgow benefit plot: a new method for reporting benefits from middle ear surgery. Laryngoscope 1991; 11: Cremers CWR, Beusen JMH, Huygen PLM. 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6 458 L. Lundman et al. Acta Otolaryngol (Stockh) Ramsay H, Kärkkäinen J, Palva T. Success in surgery for otosclerosis: hearing improvement and other indicators. Am J Otolaryngol 1997; : Committee on Hearing and Equilibrium Guidelines for Evaluation of Results of Treatment of Conductive Hearing Loss. Otolaryngol Head Neck Surg 1995; 113: Berliner KI, Doyle KJ, Goldenberg RA. Reporting operative hearing results in stapes surgery: does choice of outcome measure make a difference? Am J Otolaryngol 1996; 17: Silverstein H, Bendet E, Rosenberg S, et al. Revision stapes surgery with and without laser: a comparison. Laryngoscope 1994; 14: Eriksson-Mangold M, Erlandsson SI, Jansson G. The subjective meaning of illness in severe otosclerosis: a descriptive study in three steps based on focus group interviews and written questionnaire. Scand Audiol 1996; 25(Suppl 43): Smythe GDL, Pattersson CC. Results of middle ear reconstruction. Do patients and surgeons agree? Am J Otol 1985; 6: Smyth GDL, Hassard TH. Hearing aids post-stapedectomy: incidence and timing. Laryngoscope 1986; 96: Doyle PJ, Spafford P. Stapes surgery: subjective and objective results revisited. J Otolaryngol 1993; 22: Doyle PJ, Woodham J. Results of stapes surgery subjective and objective. J Otolaryngol 198; 9: Ginsberg IA, Hoffman SR, Stinziano GD. White TP. Stapedectomy in-depth analysis of 245 cases. Laryngoscope 1978; 88: Submitted July 3, 1998; accepted January 28, 1999 Address for correspondence: Lars Lundman, M.D. Department of Otolaryngology Karolinska Hospital SE Stockholm Sweden Fax: LLN@ent.ks.se