碩士 / 國立高雄師範大學 / 聽力學與語言治療研究所 / 103 / Background:
Noise-induced tinnitus is continuous, nonpulsating, and persistent in nature. Tinnitus is a manifestation of the spontaneous depolarization of the auditory fibers, which creates noise without an external auditory stimulus. Zinc is present in the cochlea, especially the stria vascularis, in the form of Cu/Zn superoxide dismutase and trace elements, and zinc deficiency could cause tinnitus and hearing loss. We investigated the role of zinc supplementation in the treatment of tinnitus with noise-induced hearing loss (NIHL).
Materials and methods:
The study sample comprised 20 patients (mean age, 48.5 ± 11.3 years) with long-standing tinnitus and a typical NIHL audiogram. Another 20 patients without tinnitus made up the control group. A full medical history assessment was performed, and each underwent an otoscopic examination, a basic audiologic evaluation, distortion product otoacoustic emissions (DPOAE) testing, and tinnitus match testing. Zinc levels in serum were also measured. Tinnitus matching and subjective judgments regarding the severity of tinnitus were subsequently assessed using the Tinnitus Handicap Inventory (THI). After 2 months of treatment with zinc at 40 mg daily, all tests were repeated. Hearing thresholds, DPOAE results, tinnitus match test results, and serum zinc levels before and after each measure were analyzed and compared between the two groups. Pretreatment and post-treatment scores based on the THI were also analyzed. The paired t-test, Pearson’s correlation coefficient, and simple linear regression analysis were used for statistical analyses, and all data were analyzed using SPSS v.20 for descriptive statistics.
Results:
No significant differences were noted in pretreatment zinc levels between the two groups. However, a significant difference was found between pretreatment and post-treatment within the zinc group (73.6 ± 11.6 vs. 84.5 ± 12.5 µg/dL, respectively). The level increased to a lesser degree in older people after zinc supplementation. There were no statistically significant differences in hearing thresholds, speech reception thresholds, or DPOAE results before and after treatment. The pretreatment and post-treatment tinnitus pitch match rates were 5973.7 ± 1965.8 and 6052.6 ± 2026.2 Hz, respectively, without a statistically significant difference. A significant correlation was found between pretreatment and post-treatment tinnitus intensity (9.74 ± 10.2 vs. 5.6 ± 6.4 dB SL, p < .05), indicating a clinical improvement. The correlation between pretreatment and post-treatment THI-total scores was significant (38.3 ± 18.9 vs. 30.0 ± 18.6, p< .05). The most significant improvement was seen in the catastrophic category (p < .01).
Conclusion:
Subjective tinnitus loudness and THI scores significantly improved after oral zinc supplementation in patients with tinnitus-associated NIHL. However, no improvement in objective hearing parameters occurred. A larger sample is needed to confirm the results of this study.
Identifer | oai:union.ndltd.org:TW/103NKNU5748002 |
Date | January 2015 |
Creators | Leng-Hsuan Tseng, 曾楞瑄 |
Contributors | Chung-Feng Hwang, 黃仲鋒 教授 |
Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
Language | zh-TW |
Detected Language | English |
Type | 學位論文 ; thesis |
Format | 66 |
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