Otology & Neurotology 35:1065Y1069 Ó 2014, Otology & Neurotology, Inc.
Tinnitus Modulation by Stapedectomy *C. Y. Joseph Chang and †Steven W. Cheung *Department of Otorhinolaryngology Y Head and Neck Surgery, University of Texas, Houston Medical School and Texas Ear Center, Houston, Texas; and ÞDepartment of Otolaryngology Y Head and Neck Surgery, University of California, San Francisco, California, U.S.A.
Objective: To assess change in tinnitus severity after stapedectomy using the validated Tinnitus Functional Index (TFI) at 1 and 6 months in 2 cohorts of subjects with otosclerosis with different preoperative (TFIpre) distress levels. Study Design: Prospective within-subjects repeated measures. Materials and Methods: Twenty-six subjects completed the study between January 2012 and April 2013. Demographic information, preoperative and postoperative audiometric data at 1 month, and TFI scores measured preoperatively within 1 month of stapedectomy and postoperatively at 1 and 6 months were captured and analyzed. Results: Stapedectomy has its largest effect on tinnitus severity reduction within the first month of surgery. Cohort A (TFIpre 9 15, n = 16) $TFI mean and median values were È20 for the intervals preoperatively to 1 month and preoperatively to 6 months (p values
G 0.01) and dropped to È0 for the interval between 1 and 6 months postoperatively. Cohort B (TFIpre G 15, n = 10) $TFI mean and median values were È0 for all time intervals (all pairwise comparison p values 9 0.05). Conclusion: Stapedectomy in patients with otosclerosis with more than a small problem with tinnitus (TFIpre 9 15) will reduce severity by at least 1 clinical category in È85% of cases within 6 months of surgery. The majority of patients will experience stable tinnitus suppression within the first postoperative month. In patients with no tinnitus or less than a small problem with tinnitus (TFIpre G 15), stapedectomy carries a 10% risk of transient worsening of tinnitus at 1 month, which resolves by the sixth postoperative month. Key Words: OtosclerosisVOutcomeVRepeated measureVStapedectomyVTinnitusVTinnitus Functional Index. Otol Neurotol 35:1065Y1069, 2014.
Tinnitus is an abnormal sound sensation that some patients with hearing loss experience. Patients with otosclerosis may experience variable degrees of tinnitus associated with their hearing loss. Gristwood et al. (1) reported that 65% of patients with hearing loss due to otosclerosis have tinnitus based on a review of 1,014 consecutive cases of clinical otosclerosis. Previous studies have indicated that tinnitus does decrease when hearing improves after stapedectomy. However, previous studies in general have neither delineated the time frame of tinnitus improvement nor quantified the improvement using a validated tinnitus instrument in a prospective fashion. This prospective study was performed to collect data on tinnitus using a validated tinnitus severity instrument over time so that the clinician can inform patients with preoperative bothersome tinnitus as well as notify patients with no or nonbothersome tinnitus
what to expect after stapedectomy. This information could also provide a temporal roadmap to study tinnitus plasticity electrophysiologically or by functional brain imaging for future research.
MATERIALS AND METHODS Study Design A prospective within-subjects repeated-measures study design with a single surgeon performing all stapedectomy procedures was carried out to assess the longitudinal effects of stapedectomy on tinnitus severity. Subjects were recruited from an Otology and Neurotology subspecialty referral practice between January 2012 and April 2013. Demographic information was entered into a deidentified database. Preoperative and postoperative audiometric data at 1 month (single exception: a postoperative audiogram was performed at the 6-mo visit) were extracted. The Tinnitus Functional Index (TFI) (2), a validated self-administered questionnaire with excellent internal consistency (Cronbach > = 0.97), excellent testYretest reliability (0.78), and effect sizes generally larger than the Tinnitus Handicap Inventory (3) and Visual Analog Scale (VAS), was used as the primary clinical outcome measure to assess severity at 3 time points: preoperatively, within 1 month of stapedectomy, and postoperatively at 1 and 6 months.
Address correspondence and reprint requests to C. Y. Joseph Chang, M.D., Texas Ear Center, 7900 Fannin, Suite 1800, Houston, TX 77054, U.S.A.; E-mail: [email protected] This study was financially supported by departmental funds and was partially supported by the Coleman Memorial Fund and Hearing Research, Inc. The authors disclose no conflicts of interest.
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Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
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C. Y. J. CHANG AND S. W. CHEUNG audiometric indices. Parametric unpaired and Bonferronicorrected paired t tests were used to perform comparisons of continuous numerical data. Nonparametric Wilcoxon signed-rank test was used to perform comparisons of interval data.
RESULTS
FIG. 1.
Subject accrual flow diagram.
Stapedectomy Technique The surgical intervention consisted of a partial (1/3 to 2/3) stapedectomy with placement of a titanium bucket prosthesis over a soft tissue graft performed under general anesthesia. All patients were administered 8 to 12 mg of dexamethasone intravenously for nausea prophylaxis as well as intravenous antibiotic. The presence of otosclerosis was confirmed by visual inspection. Patients were evaluated in the office 1 month after surgery with examination and audiogram.
Data Analysis This study was approved by the local institutional review board, the Committee for the Protection of Human Subjects at the University of Texas Y Houston Health Science Center (HSCMS-11-0550). Enrolled subjects were separated into 2 groups based on preoperative (TFIpre) tinnitus distress levels. Cohort A had TFIpre 9 15, indicating that tinnitus severity was more than a small problem. Cohort B had TFIpre G 15, indicating that tinnitus severity was less than a small problem. Partitioning the data set in this manner mitigated the floor effect on tinnitus modulation imposed by those subjects with no or a minor problem with tinnitus preoperatively because any intervention is not expected to improve tinnitus severity in subjects who do not have tinnitus or are minimally bothered by it. A consolidated analysis of Cohorts A and B together would have skewed results. Clinical category shifts in tinnitus severity related to stapedectomy were determined in a conservative manner. A change in the TFI score by 13 was accepted as the qualifying criterion to evaluate for a clinically significant shift (2). The number of category shifts in tinnitus severity was determined by calculating $TFI/13 and rounding down to the whole number, meaning a TFI change of 13 to 25 indicated a categorical shift of 1 level and 26 to 35 indicated a categorical shift of 2 levels. A negative $TFI signified improvement in tinnitus severity. Descriptive statistics (mean, standard deviation, minimum, and maximum) were used to characterize subject age and preoperative and postoperative audiometric air conduction (AC), bone conduction (BC), and air-bone gap (ABG) values. In accordance with the 1995 American Academy of Otolaryngology Committee on Hearing and Equilibrium guidelines (4) for the evaluation of results of treatment of conductive hearing, the thresholds at 0.5, 1, 2, and 3 kHz were averaged to compute
Demographic Characteristics There were 31 subjects who enrolled in the study (Fig. 1). After completion of postoperative audiometric evaluation and the TFI at the 1-month time point, 5 subjects dropped out. One subject developed a middle ear effusion that confounded results, and 4 subjects declined to complete the final TFI survey at the postoperative 6-month mark. The net number of study subjects was 26, distributed between Cohorts A (TFIpre 9 15; n = 16) and B (TFIpre G 15; n = 10). One subject in Cohort A had her audiometric evaluation at the 6-month time point. Those data were used for the 1-month time point. Save for sex distribution, the 2 cohorts (Table 1) were nearly identical (all p values 9 0.05). The preoperative and postoperative mean BC values were È28 and È18 dB, indicating overclosure due to the Carhart notch phenomenon. The preoperative and postoperative mean AC values were È52 and È21 dB. The preoperative and postoperative mean ABG values were È25 dB È4 dB. In both cohorts, the postoperative ABG was closed to within 10 dB in 90% or more of subjects. TFI Score Changes Tinnitus Functional Index raw scores for individual subjects in both cohorts across all 3 time points are shown
TABLE 1.
Cohort demographic characteristics
Male/female Age (yr) Mean (SD) Range Preoperative BC (dB) Mean (SD) Range Postoperative BC (dB) Mean (SD) Range Preoperative AC (dB) Mean (SD) Range Postoperative AC (dB) Mean (SD) Range Preoperative ABG (dB) Mean (SD) Range Postoperative ABG (dB) Mean (SD) Range e10 dB (%) e20 dB (%)
Cohort A (TFIpre 9 15)
Cohort B (TFIpre G 15)
3:13
4:6
46.7 (10.9) 27 to 66
48.2 (12.0) 32 to 64
27.6 (10.9) 16.3 to 53.8
28.3 (12.6) 13.3 to 57.5
17.3 (13.3) 1.3 to 50.0
18.0 (7.0) 7.5 to 30.0
52.7 (12.2) 35.0 to 86.3
54.3 (14.2) 36.3 to 78.8
20.8 (14.3) 3.8 to 52.5
21.9 (9.8) 10.0 to 41.3
25.1 (6.7) 13.8 to 35.0
25.9 (8.2) 13.8 to 37.5
3.5 (3.3) 0.0 to 13.8 94 100
3.9 (6.1) j2.5 to 20.0 90 100
SD indicates standard deviation; TFI, Tinnitus Functional Index.
Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
TINNITUS MODULATION BY STAPEDECTOMY
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È20 for the intervals preoperatively to 1 month and preoperatively to 6 months (p values G 0.01) and drops to È0 for the interval between 1 and 6 months postoperatively. Cohort B $TFI mean and median values are È0 for all time intervals, indicating no significant change in tinnitus severity (all pairwise comparison p values 9 0.05). Taken together, in patients with troublesome tinnitus preoperatively, stapedectomy has its largest effect on tinnitus severity reduction within the first month of surgery. The $TFI preoperatively to 1 month postoperatively versus $TFI 1 month to 6 months postoperatively show a significant difference (Bonferroni-corrected p G 0.01). The $TFI preoperatively to 6 months postoperatively versus $TFI 1 month to 6 months postoperatively show a significant difference (Bonferroni-corrected p G 0.01). The $TFI preoperatively to 1 month postoperatively versus $TFI preoperatively to 6 months postoperatively show no significant difference (Bonferroni-corrected p 9 0.05). The effect of preoperative hearing loss pattern (unilateral versus bilateral) on tinnitus severity improvement after stapedectomy is analyzed. Unilateral hearing loss is defined as the better ear with an average threshold of 25 dB or less for any 3 adjacent frequencies (air or bone). Using this definition, Cohort A has 7 subjects with unilateral
FIG. 2.
Tinnitus Functional Index raw scores.
in Figure 2. Cohort A illustrates that the majority (10/16) of subjects have the largest drops in TFI score in the interval between stapedectomy and 1 month postoperatively. There is a general flattening of TFI scores in the interval between 1 and 6 months postoperatively. Cohort A TFI mean (SD) descriptive statistics are as follows: TFI pre = 39.1 (17.5), TFI1month = 17.8 (18.3), TFI 6month = 15.8 (15.5). Cohort B illustrates the floor effect inherent in measuring intervention-related change in a group of subjects not troubled by tinnitus. There is a mixture of increase, decrease, and no change in TFI scores in the interval between stapedectomy and 1 month postoperatively. Thereafter, the pattern of change is similar, but the magnitude of change is smaller in the interval between 1 and 6 months postoperatively. Cohort B TFI mean (SD) descriptive statistics are as follows: TFIpre = 6.5 (5.9), TFI1month = 8.6 (8.5), TFI6month = 4.5 (5.9). Tinnitus severity score improvement, computed as a decrement in TFI scores, for Cohorts A and B is shown in Figure 3 using Tukey box plots. Tinnitus Functional Index improvement scores are plotted for the following intervals: preoperatively to 1 month, preoperatively to 6 months, and 1 month to 6 months. This analytic approach displays the timing of the largest tinnitus modulation effect after stapedectomy. Cohort A $TFI mean and median values are
FIG. 3. Tinnitus severity improvement at 3 postoperative intervals: star indicates p G 0.01; NS, p 9 0.05. Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1068 TABLE 2.
C. Y. J. CHANG AND S. W. CHEUNG Tinnitus Functional Index severity categories (adapted from Meikel et al. [2])
TFI score
Tinnitus severity description
G10 10Y20 30Y40 40Y60 60Y90
Not a problem Small problem Moderate problem Big problem Very big problem
TFI indicates Tinnitus Functional Index.
hearing loss and 9 subjects with bilateral hearing loss. This analysis is not applied to Cohort B principally because subjects with no tinnitus or tinnitus is less than a small problem impose a floor effect on tinnitus modulation, thereby confounding results. After stapedectomy, Cohort A (unilateral loss) $TFI mean and median values are 21.1 and 18.4 (preoperatively to 1 mo), 24.1 and 22.4 (preoperatively to 6 mo), and 2.9 and 0 (1 to 6 mo). For Cohort A (bilateral loss), $TFI mean and median values are 21.5 and 20.0 (preoperatively to 1 mo), 22.7 and 26.8 (preoperatively to 6 mo), and 1.2 and j1.6 (1 mo to 6 mo). Subjects with unilateral and bilateral hearing loss show no difference in tinnitus severity reduction after stapedectomy (all pairwise comparison p values 9 0.05). Tinnitus Modulation Category descriptions of clinical tinnitus severity are shown in Table 2 as adapted from Meikle et al. (2). Clinical category changes over time after stapedectomy are shown in Table 3. In Cohort A, significant improvements in tinnitus severity, manifested by shifts of 1 or 2 categories, are realized by 1 month (12/16, p G 0.01) and carry through to 6 months (14/16, p G 0.01) postoperatively. There is no statistically significant change in clinical severity between 1 and 6 months postoperatively (p 9 0.05). In Cohort B, there is no statistically significant change in tinnitus severity after stapedectomy at all intervals (all p values 9 0.05). DISCUSSION Clinical outcomes of stapes surgery have largely focused on hearing outcomes including closure of the ABG. In general, the various surgical techniques and prostheses TABLE 3.
used yield good ABG outcomes, with a high percentage of subjects experiencing ABG closure to within 10 dB. There are fewer studies that have evaluated the effect of stapedectomy on tinnitus, but they all show a reduction in tinnitus. The following studies prospectively evaluated patients with tinnitus who underwent stapedectomy. Ayache et al. (5) evaluated 62 patients (65 ears) and determined that 74% of patients had tinnitus preoperatively, with severely disabling tinnitus in 24.6% of patients based on a descriptive evaluation. Postoperatively, tinnitus ceased in 55.9% of patients, decreased in 32.4% of patients, remained the same in 8.8% of patients, and increased in 2.9% of patients at 6 months after surgery. Sobrinho et al. (6) presented a study of 48 patients and found 39.6% reported severe disabling tinnitus (7Y10 on the VAS). Of these patients, 91% reported improvement at 4 to 10 months after surgery. A telephone follow-up of 25 of these patients over 14 to 48 months revealed a stable level of tinnitus. Lima et al. (7) evaluated 23 consecutive patients with tinnitus due to otosclerosis who had undergone stapedotomy based on the VAS. They found that 95.7% of the patients achieved improvement or complete resolution of their tinnitus after stapedotomy. The following studies retrospectively evaluated patients with tinnitus who underwent stapedectomy. Sakai et al. (8) sent a tinnitus questionnaire to 22 Japanese patients who had undergone stapedectomy or stapedotomy and noted that tinnitus improved in 68% of patients, remained unchanged in 27% of patients, and worsened in 5% of patients. Gersdorff et al. (9) reported on 50 patients with tinnitus, and based on a descriptive evaluation after surgery, tinnitus resolved in 64% of patients, improved in 16% of patients, remained unchanged in 14% of patients, and worsened in 6% of patients. Szymacski et al. (10) reported on 149 patients who had tinnitus associated with otosclerosis and who were questioned about their tinnitus 1 to 19 years after surgery. Of these, 73% of patients reported that their tinnitus had ceased after surgery, 17% of patients reported that it had improved, and 10% of patients reported that it was unchanged. Sparano et al. (11) evaluated 40 patients using the standardized KlockhoffLindblom (K/L) classification system and found that 85% of patients had improved K/L tinnitus grades after stapedectomy, 12.5% of patients had no change, and 2.5%
Tinnitus modulation at 3 postoperative intervals
Tinnitus modulation after stapedectomy
Cohort A (TFIpre 9 15) Cohort B (TFIpre G 15)
Time interval (mo)
Better by 2 categories
Better by 1 category
No change
Worse by 1 category
Wilcoxon signed-rank test, p
Pre to 1 Pre to 6 1 to 6 Pre to 1 Pre to 6 1 to 6
2 2 0 0 0 0
10 12 3 0 0 1
3 2 12 9 10 9
1 0 1 1 0 0
G0.01 G0.01 90.05 90.05 90.05 90.05
One category change in TFI occurs with a TFI score change of 13. TFI indicates Tinnitus Functional Index. Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
TINNITUS MODULATION BY STAPEDECTOMY of patients had a worse K/L grade postoperatively. Both the preoperative and postoperative data were collected after the surgery. To our knowledge, there is no previous study on tinnitus severity outcomes after stapes surgery using a validated survey instrument in a prospective within-subjects repeatedmeasures design. In this study, Cohorts A and B had very similar pretreatment characteristics regarding age, BC and AC thresholds, as well as similar posttreatment BC and AC thresholds and closure of the ABG to within 10 dB in 94% (Cohort A) and 90% (Cohort B) of subjects. In patients with tinnitus, the likelihood that the auditory phantom will be localized to the poorer ear is correlated with the magnitude of interaural asymmetry. When the average of 2 or more adjoining frequencies has an interaural difference greater than 15 dB, the predictive value that tinnitus will be localized to the poorer ear is 76% (12). As the magnitude of interaural difference grows, so does that the likelihood tinnitus will be lateralized to the poorer ear. This is germane to both cohorts in this study, where the preoperative and postoperative mean ABG values were È25 and È4 dB. Any residual tinnitus would be expected to be nonlocalizing. However, this hypothesis is unproven and could be the topic of a future investigation. The findings of the current study have practical implications. Patients with preoperative bothersome tinnitus can expect substantial reduction within 1 month of stapedectomy. Six months after stapedectomy, È85% of these patients will experience at least 1 or 2 categories of tinnitus severity improvement. Patients with no or minor preoperative tinnitus have a 10% risk of temporary worsening at 1 month after stapedectomy. However, by 6 months, any worsening of tinnitus is expected to resolve. The overall 85% of patients with tinnitus improvement found in our study are in general agreement with previous studies that did not use a validated tinnitus instrument but used measurements such as the VAS or a descriptive severity of tinnitus. In addition, the stability of tinnitus outcomes between 1 and 6 months after surgery was also observed by Sobrinho et al. (6), and the general lack of tinnitus worsening in patients with low or no tinnitus was observed by Ayache et al. (5). These findings should be helpful to the clinician for patient counseling before stapes surgery. Time series continuous TFI and categorical clinical data on tinnitus modulation are important for researchers designing longitudinal electrophysiological and neuroimaging plasticity studies. An initial postsurgical assessment at 1 month would capture the majority of treatment-related changes. A final assessment at 6 months would likely document stable, postsurgical brain states. Because this is a pilot prospective study with relatively small sample sizes for both cohorts, the results have 2 important of limitations. First, while a within-subjects is more powerful than a between-subjects study design to
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detect differences in small cohorts, preoperative baseline tinnitus severity assessment with a single TFI administration could conceivably be susceptible to severity fluctuations that would alter results. A more rigorous study in the future could implement baseline TFI measures at the time of initial consultation and at least 1 month thereafter, just before stapedectomy, to confirm testYretest validity. Second, study results are based on small cohorts treated at a single site by a single surgeon. Broad generalization of results would require a more comprehensive study with larger cohorts treated at multiple sites and by at least several surgeons. CONCLUSION Stapes surgery in patients with otosclerosis with more than a small problem with tinnitus (TFI pre 9 15) improves severity by at least 1 clinical category in È85% of cases. The majority of patients will experience stable tinnitus suppression benefit within the first month after surgery. In patients with no tinnitus or less than a small problem with tinnitus (TFI pre G 15), stapedectomy may cause tinnitus to worsen in 10% of cases, but the worsening of tinnitus resolves by the sixth postoperative month. REFERENCES 1. Gristwood RE, Venables WN. Otosclerosis and chronic tinnitus. Ann Otol Rhinol Laryngol 2003;112:398Y403. 2. Meikle MB, Henry JA, Griest SE, et al. The Tinnitus Functional Index: development of a new clinical measure for chronic, intrusive tinnitus. Ear Hear 2012;33:153Y76. 3. Newman CW, Sandridge SA, Jacobson GP. Psychometric adequacy of the Tinnitus Handicap Inventory (THI) for evaluating treatment outcome. J Am Acad Audiol 1998;9:153Y60. 4. Committee on Hearing and Equilibrium Guidelines for the evaluation of results of treatment of conductive hearing loss. American Academy of Otolaryngology Y Head and Neck Surgery Foundation, Inc. Otolaryngol Head Neck Surg 1995;113:186Y7. 5. Ayache D, Earally F, Elbaz P. Characteristics and postoperative course of tinnitus in otosclerosis. Otol Neurotol 2003;24:48Y51. 6. Sobrinho PG, Oliveira CA, Venosa AR. Long-term follow-up of tinnitus in patients with otosclerosis after stapes surgery. Int Tinnitus J 2004;10:197Y201. 7. Lima Ada S, Sanchez TG, Marcondes R, et al. The effect of stapedotomy on tinnitus in patients with otospongiosis. Ear Nose Throat J 2005;84:412Y4. 8. Sakai M, Sato M, Iida M, Ogata T, Ishida K. The effect on tinnitus of stapes surgery for otosclerosis. Rev Laryngol Otol Rhinol (Bord) 1995;116:27Y30. 9. Gersdorff M, Nouwen J, Gilain C, et al. Tinnitus and otosclerosis. Eur Arch Otorhinolaryngol 2000; 257:314Y6. 10. Szymacski M, Goaabek W, Mills R. Effect of stapedectomy on subjective tinnitus. J Laryngol Otol 2003;117:261Y4. 11. Sparano A, Leonetti JP, Marzo S, et al. Effects of stapedectomy on tinnitus in patients with otosclerosis. Int Tinnitus J 2004;10:73Y7. 12. Tsai BS, Sweetow RW, Cheung SW. Audiometric asymmetry and tinnitus laterality. Laryngoscope 2012;122:1148Y53.
Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Tinnitus Modulation by Stapedectomy *C. Y. Joseph Chang and †Steven W. Cheung *Department of Otorhinolaryngology Y Head and Neck Surgery, University of Texas, Houston Medical School and Texas Ear Center, Houston, Texas; and ÞDepartment of Otolaryngology Y Head and Neck Surgery, University of California, San Francisco, California, U.S.A.
Objective: To assess change in tinnitus severity after stapedectomy using the validated Tinnitus Functional Index (TFI) at 1 and 6 months in 2 cohorts of subjects with otosclerosis with different preoperative (TFIpre) distress levels. Study Design: Prospective within-subjects repeated measures. Materials and Methods: Twenty-six subjects completed the study between January 2012 and April 2013. Demographic information, preoperative and postoperative audiometric data at 1 month, and TFI scores measured preoperatively within 1 month of stapedectomy and postoperatively at 1 and 6 months were captured and analyzed. Results: Stapedectomy has its largest effect on tinnitus severity reduction within the first month of surgery. Cohort A (TFIpre 9 15, n = 16) $TFI mean and median values were È20 for the intervals preoperatively to 1 month and preoperatively to 6 months (p values
G 0.01) and dropped to È0 for the interval between 1 and 6 months postoperatively. Cohort B (TFIpre G 15, n = 10) $TFI mean and median values were È0 for all time intervals (all pairwise comparison p values 9 0.05). Conclusion: Stapedectomy in patients with otosclerosis with more than a small problem with tinnitus (TFIpre 9 15) will reduce severity by at least 1 clinical category in È85% of cases within 6 months of surgery. The majority of patients will experience stable tinnitus suppression within the first postoperative month. In patients with no tinnitus or less than a small problem with tinnitus (TFIpre G 15), stapedectomy carries a 10% risk of transient worsening of tinnitus at 1 month, which resolves by the sixth postoperative month. Key Words: OtosclerosisVOutcomeVRepeated measureVStapedectomyVTinnitusVTinnitus Functional Index. Otol Neurotol 35:1065Y1069, 2014.
Tinnitus is an abnormal sound sensation that some patients with hearing loss experience. Patients with otosclerosis may experience variable degrees of tinnitus associated with their hearing loss. Gristwood et al. (1) reported that 65% of patients with hearing loss due to otosclerosis have tinnitus based on a review of 1,014 consecutive cases of clinical otosclerosis. Previous studies have indicated that tinnitus does decrease when hearing improves after stapedectomy. However, previous studies in general have neither delineated the time frame of tinnitus improvement nor quantified the improvement using a validated tinnitus instrument in a prospective fashion. This prospective study was performed to collect data on tinnitus using a validated tinnitus severity instrument over time so that the clinician can inform patients with preoperative bothersome tinnitus as well as notify patients with no or nonbothersome tinnitus
what to expect after stapedectomy. This information could also provide a temporal roadmap to study tinnitus plasticity electrophysiologically or by functional brain imaging for future research.
MATERIALS AND METHODS Study Design A prospective within-subjects repeated-measures study design with a single surgeon performing all stapedectomy procedures was carried out to assess the longitudinal effects of stapedectomy on tinnitus severity. Subjects were recruited from an Otology and Neurotology subspecialty referral practice between January 2012 and April 2013. Demographic information was entered into a deidentified database. Preoperative and postoperative audiometric data at 1 month (single exception: a postoperative audiogram was performed at the 6-mo visit) were extracted. The Tinnitus Functional Index (TFI) (2), a validated self-administered questionnaire with excellent internal consistency (Cronbach > = 0.97), excellent testYretest reliability (0.78), and effect sizes generally larger than the Tinnitus Handicap Inventory (3) and Visual Analog Scale (VAS), was used as the primary clinical outcome measure to assess severity at 3 time points: preoperatively, within 1 month of stapedectomy, and postoperatively at 1 and 6 months.
Address correspondence and reprint requests to C. Y. Joseph Chang, M.D., Texas Ear Center, 7900 Fannin, Suite 1800, Houston, TX 77054, U.S.A.; E-mail: [email protected] This study was financially supported by departmental funds and was partially supported by the Coleman Memorial Fund and Hearing Research, Inc. The authors disclose no conflicts of interest.
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Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1066
C. Y. J. CHANG AND S. W. CHEUNG audiometric indices. Parametric unpaired and Bonferronicorrected paired t tests were used to perform comparisons of continuous numerical data. Nonparametric Wilcoxon signed-rank test was used to perform comparisons of interval data.
RESULTS
FIG. 1.
Subject accrual flow diagram.
Stapedectomy Technique The surgical intervention consisted of a partial (1/3 to 2/3) stapedectomy with placement of a titanium bucket prosthesis over a soft tissue graft performed under general anesthesia. All patients were administered 8 to 12 mg of dexamethasone intravenously for nausea prophylaxis as well as intravenous antibiotic. The presence of otosclerosis was confirmed by visual inspection. Patients were evaluated in the office 1 month after surgery with examination and audiogram.
Data Analysis This study was approved by the local institutional review board, the Committee for the Protection of Human Subjects at the University of Texas Y Houston Health Science Center (HSCMS-11-0550). Enrolled subjects were separated into 2 groups based on preoperative (TFIpre) tinnitus distress levels. Cohort A had TFIpre 9 15, indicating that tinnitus severity was more than a small problem. Cohort B had TFIpre G 15, indicating that tinnitus severity was less than a small problem. Partitioning the data set in this manner mitigated the floor effect on tinnitus modulation imposed by those subjects with no or a minor problem with tinnitus preoperatively because any intervention is not expected to improve tinnitus severity in subjects who do not have tinnitus or are minimally bothered by it. A consolidated analysis of Cohorts A and B together would have skewed results. Clinical category shifts in tinnitus severity related to stapedectomy were determined in a conservative manner. A change in the TFI score by 13 was accepted as the qualifying criterion to evaluate for a clinically significant shift (2). The number of category shifts in tinnitus severity was determined by calculating $TFI/13 and rounding down to the whole number, meaning a TFI change of 13 to 25 indicated a categorical shift of 1 level and 26 to 35 indicated a categorical shift of 2 levels. A negative $TFI signified improvement in tinnitus severity. Descriptive statistics (mean, standard deviation, minimum, and maximum) were used to characterize subject age and preoperative and postoperative audiometric air conduction (AC), bone conduction (BC), and air-bone gap (ABG) values. In accordance with the 1995 American Academy of Otolaryngology Committee on Hearing and Equilibrium guidelines (4) for the evaluation of results of treatment of conductive hearing, the thresholds at 0.5, 1, 2, and 3 kHz were averaged to compute
Demographic Characteristics There were 31 subjects who enrolled in the study (Fig. 1). After completion of postoperative audiometric evaluation and the TFI at the 1-month time point, 5 subjects dropped out. One subject developed a middle ear effusion that confounded results, and 4 subjects declined to complete the final TFI survey at the postoperative 6-month mark. The net number of study subjects was 26, distributed between Cohorts A (TFIpre 9 15; n = 16) and B (TFIpre G 15; n = 10). One subject in Cohort A had her audiometric evaluation at the 6-month time point. Those data were used for the 1-month time point. Save for sex distribution, the 2 cohorts (Table 1) were nearly identical (all p values 9 0.05). The preoperative and postoperative mean BC values were È28 and È18 dB, indicating overclosure due to the Carhart notch phenomenon. The preoperative and postoperative mean AC values were È52 and È21 dB. The preoperative and postoperative mean ABG values were È25 dB È4 dB. In both cohorts, the postoperative ABG was closed to within 10 dB in 90% or more of subjects. TFI Score Changes Tinnitus Functional Index raw scores for individual subjects in both cohorts across all 3 time points are shown
TABLE 1.
Cohort demographic characteristics
Male/female Age (yr) Mean (SD) Range Preoperative BC (dB) Mean (SD) Range Postoperative BC (dB) Mean (SD) Range Preoperative AC (dB) Mean (SD) Range Postoperative AC (dB) Mean (SD) Range Preoperative ABG (dB) Mean (SD) Range Postoperative ABG (dB) Mean (SD) Range e10 dB (%) e20 dB (%)
Cohort A (TFIpre 9 15)
Cohort B (TFIpre G 15)
3:13
4:6
46.7 (10.9) 27 to 66
48.2 (12.0) 32 to 64
27.6 (10.9) 16.3 to 53.8
28.3 (12.6) 13.3 to 57.5
17.3 (13.3) 1.3 to 50.0
18.0 (7.0) 7.5 to 30.0
52.7 (12.2) 35.0 to 86.3
54.3 (14.2) 36.3 to 78.8
20.8 (14.3) 3.8 to 52.5
21.9 (9.8) 10.0 to 41.3
25.1 (6.7) 13.8 to 35.0
25.9 (8.2) 13.8 to 37.5
3.5 (3.3) 0.0 to 13.8 94 100
3.9 (6.1) j2.5 to 20.0 90 100
SD indicates standard deviation; TFI, Tinnitus Functional Index.
Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
TINNITUS MODULATION BY STAPEDECTOMY
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È20 for the intervals preoperatively to 1 month and preoperatively to 6 months (p values G 0.01) and drops to È0 for the interval between 1 and 6 months postoperatively. Cohort B $TFI mean and median values are È0 for all time intervals, indicating no significant change in tinnitus severity (all pairwise comparison p values 9 0.05). Taken together, in patients with troublesome tinnitus preoperatively, stapedectomy has its largest effect on tinnitus severity reduction within the first month of surgery. The $TFI preoperatively to 1 month postoperatively versus $TFI 1 month to 6 months postoperatively show a significant difference (Bonferroni-corrected p G 0.01). The $TFI preoperatively to 6 months postoperatively versus $TFI 1 month to 6 months postoperatively show a significant difference (Bonferroni-corrected p G 0.01). The $TFI preoperatively to 1 month postoperatively versus $TFI preoperatively to 6 months postoperatively show no significant difference (Bonferroni-corrected p 9 0.05). The effect of preoperative hearing loss pattern (unilateral versus bilateral) on tinnitus severity improvement after stapedectomy is analyzed. Unilateral hearing loss is defined as the better ear with an average threshold of 25 dB or less for any 3 adjacent frequencies (air or bone). Using this definition, Cohort A has 7 subjects with unilateral
FIG. 2.
Tinnitus Functional Index raw scores.
in Figure 2. Cohort A illustrates that the majority (10/16) of subjects have the largest drops in TFI score in the interval between stapedectomy and 1 month postoperatively. There is a general flattening of TFI scores in the interval between 1 and 6 months postoperatively. Cohort A TFI mean (SD) descriptive statistics are as follows: TFI pre = 39.1 (17.5), TFI1month = 17.8 (18.3), TFI 6month = 15.8 (15.5). Cohort B illustrates the floor effect inherent in measuring intervention-related change in a group of subjects not troubled by tinnitus. There is a mixture of increase, decrease, and no change in TFI scores in the interval between stapedectomy and 1 month postoperatively. Thereafter, the pattern of change is similar, but the magnitude of change is smaller in the interval between 1 and 6 months postoperatively. Cohort B TFI mean (SD) descriptive statistics are as follows: TFIpre = 6.5 (5.9), TFI1month = 8.6 (8.5), TFI6month = 4.5 (5.9). Tinnitus severity score improvement, computed as a decrement in TFI scores, for Cohorts A and B is shown in Figure 3 using Tukey box plots. Tinnitus Functional Index improvement scores are plotted for the following intervals: preoperatively to 1 month, preoperatively to 6 months, and 1 month to 6 months. This analytic approach displays the timing of the largest tinnitus modulation effect after stapedectomy. Cohort A $TFI mean and median values are
FIG. 3. Tinnitus severity improvement at 3 postoperative intervals: star indicates p G 0.01; NS, p 9 0.05. Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
1068 TABLE 2.
C. Y. J. CHANG AND S. W. CHEUNG Tinnitus Functional Index severity categories (adapted from Meikel et al. [2])
TFI score
Tinnitus severity description
G10 10Y20 30Y40 40Y60 60Y90
Not a problem Small problem Moderate problem Big problem Very big problem
TFI indicates Tinnitus Functional Index.
hearing loss and 9 subjects with bilateral hearing loss. This analysis is not applied to Cohort B principally because subjects with no tinnitus or tinnitus is less than a small problem impose a floor effect on tinnitus modulation, thereby confounding results. After stapedectomy, Cohort A (unilateral loss) $TFI mean and median values are 21.1 and 18.4 (preoperatively to 1 mo), 24.1 and 22.4 (preoperatively to 6 mo), and 2.9 and 0 (1 to 6 mo). For Cohort A (bilateral loss), $TFI mean and median values are 21.5 and 20.0 (preoperatively to 1 mo), 22.7 and 26.8 (preoperatively to 6 mo), and 1.2 and j1.6 (1 mo to 6 mo). Subjects with unilateral and bilateral hearing loss show no difference in tinnitus severity reduction after stapedectomy (all pairwise comparison p values 9 0.05). Tinnitus Modulation Category descriptions of clinical tinnitus severity are shown in Table 2 as adapted from Meikle et al. (2). Clinical category changes over time after stapedectomy are shown in Table 3. In Cohort A, significant improvements in tinnitus severity, manifested by shifts of 1 or 2 categories, are realized by 1 month (12/16, p G 0.01) and carry through to 6 months (14/16, p G 0.01) postoperatively. There is no statistically significant change in clinical severity between 1 and 6 months postoperatively (p 9 0.05). In Cohort B, there is no statistically significant change in tinnitus severity after stapedectomy at all intervals (all p values 9 0.05). DISCUSSION Clinical outcomes of stapes surgery have largely focused on hearing outcomes including closure of the ABG. In general, the various surgical techniques and prostheses TABLE 3.
used yield good ABG outcomes, with a high percentage of subjects experiencing ABG closure to within 10 dB. There are fewer studies that have evaluated the effect of stapedectomy on tinnitus, but they all show a reduction in tinnitus. The following studies prospectively evaluated patients with tinnitus who underwent stapedectomy. Ayache et al. (5) evaluated 62 patients (65 ears) and determined that 74% of patients had tinnitus preoperatively, with severely disabling tinnitus in 24.6% of patients based on a descriptive evaluation. Postoperatively, tinnitus ceased in 55.9% of patients, decreased in 32.4% of patients, remained the same in 8.8% of patients, and increased in 2.9% of patients at 6 months after surgery. Sobrinho et al. (6) presented a study of 48 patients and found 39.6% reported severe disabling tinnitus (7Y10 on the VAS). Of these patients, 91% reported improvement at 4 to 10 months after surgery. A telephone follow-up of 25 of these patients over 14 to 48 months revealed a stable level of tinnitus. Lima et al. (7) evaluated 23 consecutive patients with tinnitus due to otosclerosis who had undergone stapedotomy based on the VAS. They found that 95.7% of the patients achieved improvement or complete resolution of their tinnitus after stapedotomy. The following studies retrospectively evaluated patients with tinnitus who underwent stapedectomy. Sakai et al. (8) sent a tinnitus questionnaire to 22 Japanese patients who had undergone stapedectomy or stapedotomy and noted that tinnitus improved in 68% of patients, remained unchanged in 27% of patients, and worsened in 5% of patients. Gersdorff et al. (9) reported on 50 patients with tinnitus, and based on a descriptive evaluation after surgery, tinnitus resolved in 64% of patients, improved in 16% of patients, remained unchanged in 14% of patients, and worsened in 6% of patients. Szymacski et al. (10) reported on 149 patients who had tinnitus associated with otosclerosis and who were questioned about their tinnitus 1 to 19 years after surgery. Of these, 73% of patients reported that their tinnitus had ceased after surgery, 17% of patients reported that it had improved, and 10% of patients reported that it was unchanged. Sparano et al. (11) evaluated 40 patients using the standardized KlockhoffLindblom (K/L) classification system and found that 85% of patients had improved K/L tinnitus grades after stapedectomy, 12.5% of patients had no change, and 2.5%
Tinnitus modulation at 3 postoperative intervals
Tinnitus modulation after stapedectomy
Cohort A (TFIpre 9 15) Cohort B (TFIpre G 15)
Time interval (mo)
Better by 2 categories
Better by 1 category
No change
Worse by 1 category
Wilcoxon signed-rank test, p
Pre to 1 Pre to 6 1 to 6 Pre to 1 Pre to 6 1 to 6
2 2 0 0 0 0
10 12 3 0 0 1
3 2 12 9 10 9
1 0 1 1 0 0
G0.01 G0.01 90.05 90.05 90.05 90.05
One category change in TFI occurs with a TFI score change of 13. TFI indicates Tinnitus Functional Index. Otology & Neurotology, Vol. 35, No. 6, 2014
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TINNITUS MODULATION BY STAPEDECTOMY of patients had a worse K/L grade postoperatively. Both the preoperative and postoperative data were collected after the surgery. To our knowledge, there is no previous study on tinnitus severity outcomes after stapes surgery using a validated survey instrument in a prospective within-subjects repeatedmeasures design. In this study, Cohorts A and B had very similar pretreatment characteristics regarding age, BC and AC thresholds, as well as similar posttreatment BC and AC thresholds and closure of the ABG to within 10 dB in 94% (Cohort A) and 90% (Cohort B) of subjects. In patients with tinnitus, the likelihood that the auditory phantom will be localized to the poorer ear is correlated with the magnitude of interaural asymmetry. When the average of 2 or more adjoining frequencies has an interaural difference greater than 15 dB, the predictive value that tinnitus will be localized to the poorer ear is 76% (12). As the magnitude of interaural difference grows, so does that the likelihood tinnitus will be lateralized to the poorer ear. This is germane to both cohorts in this study, where the preoperative and postoperative mean ABG values were È25 and È4 dB. Any residual tinnitus would be expected to be nonlocalizing. However, this hypothesis is unproven and could be the topic of a future investigation. The findings of the current study have practical implications. Patients with preoperative bothersome tinnitus can expect substantial reduction within 1 month of stapedectomy. Six months after stapedectomy, È85% of these patients will experience at least 1 or 2 categories of tinnitus severity improvement. Patients with no or minor preoperative tinnitus have a 10% risk of temporary worsening at 1 month after stapedectomy. However, by 6 months, any worsening of tinnitus is expected to resolve. The overall 85% of patients with tinnitus improvement found in our study are in general agreement with previous studies that did not use a validated tinnitus instrument but used measurements such as the VAS or a descriptive severity of tinnitus. In addition, the stability of tinnitus outcomes between 1 and 6 months after surgery was also observed by Sobrinho et al. (6), and the general lack of tinnitus worsening in patients with low or no tinnitus was observed by Ayache et al. (5). These findings should be helpful to the clinician for patient counseling before stapes surgery. Time series continuous TFI and categorical clinical data on tinnitus modulation are important for researchers designing longitudinal electrophysiological and neuroimaging plasticity studies. An initial postsurgical assessment at 1 month would capture the majority of treatment-related changes. A final assessment at 6 months would likely document stable, postsurgical brain states. Because this is a pilot prospective study with relatively small sample sizes for both cohorts, the results have 2 important of limitations. First, while a within-subjects is more powerful than a between-subjects study design to
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detect differences in small cohorts, preoperative baseline tinnitus severity assessment with a single TFI administration could conceivably be susceptible to severity fluctuations that would alter results. A more rigorous study in the future could implement baseline TFI measures at the time of initial consultation and at least 1 month thereafter, just before stapedectomy, to confirm testYretest validity. Second, study results are based on small cohorts treated at a single site by a single surgeon. Broad generalization of results would require a more comprehensive study with larger cohorts treated at multiple sites and by at least several surgeons. CONCLUSION Stapes surgery in patients with otosclerosis with more than a small problem with tinnitus (TFI pre 9 15) improves severity by at least 1 clinical category in È85% of cases. The majority of patients will experience stable tinnitus suppression benefit within the first month after surgery. In patients with no tinnitus or less than a small problem with tinnitus (TFI pre G 15), stapedectomy may cause tinnitus to worsen in 10% of cases, but the worsening of tinnitus resolves by the sixth postoperative month. REFERENCES 1. Gristwood RE, Venables WN. Otosclerosis and chronic tinnitus. Ann Otol Rhinol Laryngol 2003;112:398Y403. 2. Meikle MB, Henry JA, Griest SE, et al. The Tinnitus Functional Index: development of a new clinical measure for chronic, intrusive tinnitus. Ear Hear 2012;33:153Y76. 3. Newman CW, Sandridge SA, Jacobson GP. Psychometric adequacy of the Tinnitus Handicap Inventory (THI) for evaluating treatment outcome. J Am Acad Audiol 1998;9:153Y60. 4. Committee on Hearing and Equilibrium Guidelines for the evaluation of results of treatment of conductive hearing loss. American Academy of Otolaryngology Y Head and Neck Surgery Foundation, Inc. Otolaryngol Head Neck Surg 1995;113:186Y7. 5. Ayache D, Earally F, Elbaz P. Characteristics and postoperative course of tinnitus in otosclerosis. Otol Neurotol 2003;24:48Y51. 6. Sobrinho PG, Oliveira CA, Venosa AR. Long-term follow-up of tinnitus in patients with otosclerosis after stapes surgery. Int Tinnitus J 2004;10:197Y201. 7. Lima Ada S, Sanchez TG, Marcondes R, et al. The effect of stapedotomy on tinnitus in patients with otospongiosis. Ear Nose Throat J 2005;84:412Y4. 8. Sakai M, Sato M, Iida M, Ogata T, Ishida K. The effect on tinnitus of stapes surgery for otosclerosis. Rev Laryngol Otol Rhinol (Bord) 1995;116:27Y30. 9. Gersdorff M, Nouwen J, Gilain C, et al. Tinnitus and otosclerosis. Eur Arch Otorhinolaryngol 2000; 257:314Y6. 10. Szymacski M, Goaabek W, Mills R. Effect of stapedectomy on subjective tinnitus. J Laryngol Otol 2003;117:261Y4. 11. Sparano A, Leonetti JP, Marzo S, et al. Effects of stapedectomy on tinnitus in patients with otosclerosis. Int Tinnitus J 2004;10:73Y7. 12. Tsai BS, Sweetow RW, Cheung SW. Audiometric asymmetry and tinnitus laterality. Laryngoscope 2012;122:1148Y53.
Otology & Neurotology, Vol. 35, No. 6, 2014
Copyright © 2014 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
