Long-Term Effect of Acupuncture for Treatment of Tinnitus: A Randomized,Patient- and Assessor-Blind,Sham-Acupuncture-Controlled,Pilot Trial

Abstract

Objective:

The aim of this study was to investigate the long-term effect of acupuncture for treatment of tinnitus.

Study design:

This study is a randomized, patient- and assessor-blind, sham-acupuncture-controlled, pilot trial.

Subjects:

Participants were adults (18–60 years old) with chronic (≥6 months), unilateral tinnitus, and without moderate or severe hearing loss.

Interventions:

Thirty-three (33) participants were randomized to one of two treatment groups: real acupuncture and sham-acupuncture (nonmeridian; no specific response, de qi). Participants received 10 sessions of acupuncture treatment (twice a week for 5 weeks), and usual patient care education.

Outcome measures:

The subjective outcome was the score of Tinnitus Handicap Inventory (THI) and Visual Analogue Scale (VAS) from baseline to 3 months after. Pure Tone Average (PTA) and Speech Discrimination (SD) from baseline to 3 months after were assessed as objective outcomes.

Results:

A significant interaction between time and group in VAS (p=0.017) was evident, but not in THI, PTA, and SD scores. THI showed significant improvement at the end of treatment and 3 months after, compared to baseline, in real acupuncture (p=0.004). In SD, a significant long-term effect of real acupuncture was observed until 3 months after (p=0.011). However, the effect of real acupuncture in PTA was not maintained until 3 months after the end of treatment. No significant difference in the sham-acupuncture treatment group was evident. No statistical difference in any outcome was observed between real and sham acupuncture. Only in the mean percent change of VAS, real acupuncture showed statistical significance, compared with sham-acupuncture from baseline to 3 months after (p=0.019).

Conclusions:

Through evaluation of subjective (THI and VAS) and objective outcomes (PTA and SD), this study demonstrates the long-term effect of real acupuncture.

Introduction

T innitus is defined as the conscious perception of a noise, which originates in the ear or the nervous system.¹ The pathophysiology of this disease is complex and not well understood; therefore, treatment remains a challenge. Although a number of drugs have been applied and pharmacologic treatment can improve the emotional and psychologic reaction to tinnitus,^2,3 there is no drug that can be considered efficacious for long-term relief from tinnitus.^4,5

Acupuncture has been used widely in East Asia, and its frequent indication includes neurological conditions.⁶ Acupuncture treatment can improve the symptoms of tinnitus by stimulation of the auditory activation of endogenous opioid mechanisms and neuropeptides that stimulate specific brain structures.⁷ Several studies have evaluated the effect of acupuncture on tinnitus. Some studies have reported positive effects^8,9; however, others have reported on the ineffectiveness of acupuncture on tinnitus.^10
–12

In a previous study, it was determined that acupuncture treatment by stimulation of the cervical region and around the ear was effective in refractory sudden sensorineural hearing loss of more than 3 weeks after a failure of conventional treatment.¹³ According to this result, it was hypothesized that acupuncture treatment around the cervical region and ear might also be effective for tinnitus.

Thus, in the present study, for evaluation of the long-term effect of acupuncture for treatment of tinnitus by stimulation of the major meridian points around the cervical region and ear, a randomized, patient- and assessor-blind, sham-acupuncture-controlled, pilot trial of acupuncture treatment was conducted on unilateral and chronic (>6 months) tinnitus without moderate or severe hearing loss.

Materials and Methods

Ethical approval

The study was conducted in accordance with the ethical standards of the Helsinki Declaration. The Institutional Review Board of the Kyung Hee Medical Center approved the study protocol (IRB approval number KOMC MIRB 2009-08).

Participants and eligibility

The study was carried out from March 2010 to March 2011 at the Kyung Hee Oriental Medical Hospital. Participants were recruited through the website and bulletin boards of the hospital. Interested participants were screened by the study coordinator by telephone before the enrollment visit. Participants were included or excluded according to the following eligibility criteria, as shown in Table 1. During the trial, no concomitant tinnitus treatments were permitted. All participants provided written informed consent prior to participation in the study.

Table 1.

Inclusion and Exclusion Criteria

Inclusion criteria

18–60 years of age

Occurrence of tinnitus for ≥6 months

Unilateral tinnitus

Exclusion criteria

History of acupuncture treatment for tinnitus within recent 3 months

Abnormal blood test results (hemoglobin ≤10 g/dL, platelets ≤100,000/mm, aspartate transaminase, alanine transaminase ≥40 IU/L

History of heart disease

Intake of aspirin within recent 3 months

Pregnant or breast-feeding

Chronic otitis media

Moderate or severe hearing loss (mean of 0.5, 1, and 2 KHz audiogram >50 dB)

Study design

This study was a randomized, patient- and assessor-blind, sham-acupuncture-controlled, pilot trial with 33 participants. Participants were randomly allocated to one of two groups according to the table of random sampling numbers. The random allocation table sequence was software-generated (Excel, Microsoft Office 2007), and was hidden from the assessor, except for the acupuncture practitioner. The statistician who generated the random sequence also had no contact with the assessor. The experimental group was treated with real acupuncture (stimulating selected meridian points) and the control group was treated with sham-acupuncture (stimulating false-meridian points). Patients were blinded to the identity of their treatment group. After randomization, 10 sessions of acupuncture treatment were performed twice a week for 5 weeks. To evaluate the short-term and long-term effect of acupuncture treatment, outcome measurements were performed before treatment (Baseline), after the 10th acupuncture treatment (End of treatment), and 3 months later, after the last acupuncture treatment (3 months after) (Fig. 1). Before treatment, all participants were interviewed to assess and evaluate their condition by the same oriental medical doctor.

FIG. 1.

Diagrammatic representation of the time flow for the study of the group treated for tinnitus with acupuncture and the control group. THI, Tinnitus Handicap Inventory; VAS, Visual Analogue Scale; PTA, Pure Tone Average; SD, Speech Discrimination.

Real acupuncture/sham-acupuncture

Acupuncture treatment was performed by one oriental medical doctor who has completed a 6-year full-time practicum course of traditional medicine, where acupuncture is one of the major modalities, with clinical and research experience in the field of acupuncture on tinnitus for more than 3 years. Disposable stainless-steel acupuncture needles (0.25×40 mm, Dong Bang Acupuncture, Korea) were used in both groups.

The experimental group was treated in real meridian-points, which were selected by a previous study.¹³ First, cervical meridian points (unilateral GV-14, GV-15, GV-16, GV-20, GB-21 and bilateral GB-12, GB-20) were stimulated with subjects in the prone position. Needles were inserted manually intramuscularly to a depth of 10±2 mm at each meridian point, and retention time was 10 minutes. De qi response was searched for when stimulating points were located in extremities. After 10 minutes, with subjects in the supine position, meridian points around the ear (TE-21, TE-22, SI-19, GB-2, TE-17, GB-7, GV-20, EX-HN3 and bilateral BL-2, LI-20) were stimulated, and the same techniques and retention time were used.

The control group was treated by sham-acupuncture. False meridian points, unilateral 6 points around the ear (1.5 cm anterior to the TE-21, SI-19 and GB-2, 5 cm above from TE-20, 3 cm below from GB-12 and the middle of the sternocleidomastoid muscle) and bilateral points below 5 cm of ST-36 and above 3 cm of TE-5 were selected. No specific needle stimulation techniques were used. Needles were inserted to a depth of within 3 mm at each point, and no specific response, such as de qi, was obtained. Retention time was also 10 minutes.

Subjects in both groups underwent the same infrared light treatment to promote blood circulation around the ear during acupuncture treatment, and the usual patient care education such as a regular life including diet and sleeping hours, stress management, and exercise, was provided during every session.

Outcome measurement

Outcome measurement was divided into two types: subjective and objective outcomes.

Subjective outcomes were Tinnitus Handicap Inventory (THI) score and Visual Analogue Scale (VAS). The Korean adaptation of THI (translation of English THI) was used in this trial. This Korean version of THI was verified for its reliability and validity.¹⁴ THI is a 25-item self-administered questionnaire that measures tinnitus severity. Each item can receive a score of 0, 2, or 4 points, resulting in a total possible score of 100 (0 points=“no,” 2 points=“sometimes,” 4 points=“yes”). The range of VAS was 0–10 (0=no tinnitus, 10=the worst tinnitus ever). The participants were informed of their prior VAS scores at the time of the next measurement. However, prior THI scores were kept secret from participants during this experiment.

Objective outcomes were Pure Tone Average (PTA) and Speech discrimination (SD) (GSI 61; Grason-Stadler, Inc., USA). PTA was evaluated according to the average of three frequencies (0.5, 1, and 2 KHz).

Statistical analysis

Analyses were performed using SPSS version 17.0 for Windows, and based on an intention-to-treat analysis that considered all randomized participants with at least one measurable outcome value during the study. Missing data were analyzed using the last observation carried forward. Data are presented as mean±standard deviation (SD). The Generalized Estimating Equation was used for examination of a significant main effect and interaction between time and group. The Mann-Whitney U-test was used for examination of significant difference within groups and between groups at baseline, end of treatment, and 3 months after. All differences were considered significant at p<0.05.

Results

Patients

Forty-three (43) participants were recruited and 33 were enrolled who remained after screening tests. Ten (10) participants who did not meet the inclusion criteria were excluded. Of 33 participants, 23 completed the treatment sessions (real acupuncture: 13, sham-acupuncture: 10). Nine (9) participants had dropped out because of private reasons. One participant in sham-acupuncture refused to visit the hospital again because she felt a lack of efficacy. Three (3) months after, 14 participants visited the medical center again for evaluation of the change of THI, VAS, PTA, and SD (real acupuncture: 9, sham-acupuncture: 5), and 9 participants who did not visit the medical center answered the THI questionnaire and VAS score was determined by telephone (real acupuncture: 5, sham-acupuncture: 5) (Fig. 2).

FIG. 2.

Flow chart of the clinical study.

Demographic and baseline characteristics of the patients are shown in Table 2. There was no difference between two groups with regard to any demographic or baseline characteristics.

Table 2.

Demographic and Baseline Characteristics of the Patients

Characteristic	Acupuncture (N=17)	Sham-acupuncture (N=16)	p-Value ^a
Mean age (y)	47.29±10.33	49.63±9.49	0.493
Sex
Male (n, %)	13 (76.5)	8 (50.0)	0.120
Female (n, %)	4 (23.5)	8 (50.0)
Blood pressure (mm Hg)
Systolic	117.53±11.34	121.75±13.94	0.505
Diastolic	75.53±8.95	76.38±5.12	0.551
Duration of tinnitus (months)	37.41±21.58	45.75±19.70	0.150
Exposure of loud noise (n, %)	3 (17.6)	3 (18.8)	0.936
Lack of sleep or insomnia (n, %)	5 (29.4)	5 (31.3)	0.910
THI	45.65±25.61	39.75±22.31	0.516
VAS	6.76±1.75	6.69±1.92	0.796
PTA	24.33±15.26	27.50±13.96	0.367
SD	89.29±10.58	92.38±9.63	0.336

Values are mean±standard deviation.

Statistical significance was set at p<0.05 using the Mann-Whitney U-test.

THI, Tinnitus Handicap Inventory; VAS, Visual Analogue Scale; PTA, Pure Tone Average; SD, Speech Discrimination.

Interaction between time and group

A significant interaction between time and group in VAS (p=0.017) was evident, but not in THI (p=0.259), PTA (p=0.539), and SD (p=0.749). When analyzing THI, PTA, and SD scores in which no significant interaction between time and group was evident, statistically significant differences were observed according to time (p=0.002 [THI], p=0.007 (PTA), p=0.031(SD)], but not according to group [p=0.861 (THI), p=0.471 (PTA), p=0.442 [SD]) (Fig. 3).

FIG. 3.

Main effect and interaction between group and time in Tinnitus Handicap Inventory (THI), Visual Analogue Scale (VAS), Pure Tone Average (PTA), and Speech Discrimination (SD).

Changes of subjective and objective outcomes

THI showed significant improvement at the end of treatment and 3 months after, compared with baseline, in the real acupuncture group (p=0.004), but not in the sham acupuncture group (p=0.387). In VAS, significant differences were apparent at the end of treatment and 3 months after, compared with baseline, in the real and sham acupuncture groups (p=0.000, 0.039). PTA showed significant improvement at the end of treatment, compared with baseline, in the acupuncture treatment group (p=0.023), but not in the sham acupuncture group (p=0.276). SD showed significant improvement at the end of treatment and 3 months after, compared with baseline, in the acupuncture treatment group (p=0.011), but not in the sham acupuncture group (p=0.391) (Fig. 4).

FIG. 4.

Comparisons of Tinnitus Handicap Inventory (THI), Pure Tone Average (PTA), and Speech Discrimination (SD) scores at baseline, the end of acupuncture, and 3 months after within groups. *Statistical significance was set at p<0.05 using the Mann-Whitney U-test. VAS; Visual Analogue Scale.

There was no statistical difference between real and sham-acupuncture in any outcomes. However, the mean percent change of VAS from baseline to 3 months after in real acupuncture was significantly higher than in sham-acupuncture (Table 3).

Table 3.

Mean Percent Change of THI and VAS from Baseline to the End of the Study and from Baseline to 3 Months After

		Real acupuncture (%)	Sham-acupuncture (%)	p-Value
THI	From baseline to the end of treatment	24.20±29.86	0.31±49.93	0.059
	From the end of treatment to 3 months after	8.25±18.93	−12.18±65.56	0.292
	From baseline to 3 months after	24.36±27.51	−1.78±56.66	0.168
VAS	From baseline to the end of treatment	25.27±20.86	11.72±20.28	0.053
	From the end of treatment to 3 months after	6.18±13.73	−3.21±14.70	0.132
	From baseline to 3 months after	29.35±23.41	10.58±16.20	0.019^a

Values are mean±standard deviation.

Statistical significance was set at p<0.05 using the Mann-Whitney U-test.

THI, Tinnitus Handicap Inventory; VAS, Visual Analogue Scale.

Discussion

Tinnitus is a disease that is difficult to relieve by conventional therapy; therefore, many attempts have been made to find the solution in alternative therapies.¹⁵ Among these alternative therapies, acupuncture was suggested as one of the solutions for tinnitus, and several studies of the effect of acupuncture treatment on tinnitus have been conducted; however, the results fell short of expectations.^15,16

It is difficult to confirm whether acupuncture treatment has a significant effect on tinnitus, as compared with the placebo group. Most studies have reported no significant difference between acupuncture treatment and the placebo group.^10
–12,16 Only a few studies have reported on a significant effect of acupuncture for treatment of tinnitus; however, even these significant effects were immediate relief.^17,18

This study focused on the long-term effectiveness of acupuncture. THI and VAS were measured as subjective outcomes. The participants were informed of their previous VAS score at the time of the next evaluation. However, THI scores were kept secret from participants throughout this trial because the aim was to know whether knowledge of previous results would have an effect on the next results.

In this trial, no statistical difference in any outcome was observed between real and sham-acupuncture. However, THI showed significant improvement at the end of treatment, compared with baseline, in real acupuncture, and the effect was maintained throughout the 3-month follow-up period, but not in sham-acupuncture. In VAS, both real and sham-acupuncture showed significant improvement from baseline to 3 months after; however, different from THI, which showed no interaction between group and time, a significant interaction between group and time was apparent in VAS.

Results of the mean percent change of THI and VAS were interesting because only VAS real acupuncture showed statistical significance, compared with sham acupuncture, from baseline to 3 months later. From this result, it was inferred that 3 months is a long time to participants; therefore, they have a tendency to forget their tinnitus condition at baseline; knowledge of previous results would help them to remember and aid them in selection of a slightly more accurate score.

PTA and SD showed significant improvement at the end of treatment in real acupuncture, and the improvement was maintained until 3 months after in SD. Because participants with moderate or severe hearing loss were excluded according to their hearing level, which could have an influence on severity of tinnitus,¹⁹ it is difficult to confirm whether acupuncture would be effective for SD or not.

There were several limitations to this study. First, the sample size of this trial was small. Thoroughly confirming the effect of acupuncture on tinnitus was difficult. This study was a pilot study; afterward, the main study will have to continue in order to recruit a significantly sufficient number of participants. Second, the false-meridian points were stimulated as a sham-acupuncture; according to Kim,²⁰ sham-acupuncture by pricking the nonmeridian points without manipulation was inadequate as a placebo because it could have physiologic effects, such as diffuse noxious inhibitory controls on patients. However, it was not possible to select another sham-acupuncture, because Lee et al.²¹ reported on whether placebo acupuncture was meaningful or not in most Koreans who have a common experience of acupuncture treatment. A new approach to placebo acupuncture must be developed for accurate administration of acupuncture treatment in clinical trials. Third, this study had a patient- and assessor-blind design; therefore, there was no attempt to determine whether the blindness was a success or not at the end of study. Later, in the main study, evaluation of blindness will need to be performed.

In this study, the effect of acupuncture on tinnitus was evaluated not only at the end of treatment, but also 3 months after, and a significant improvement was observed in real acupuncture in pre- and post-treatment and 3 months later. The authors believe that this study would be helpful in providing clinicians with information on the effect of acupuncture on tinnitus and maintenance of the effect. In the future, through recruitment of more participants and development of a placebo acupuncture model, study of the effect of acupuncture on tinnitus study must be continued.

Conclusions

This study demonstrates the long-term effects of real acupuncture through evaluation of subjective (THI and VAS) and objective (PTA and SD) outcomes. However, no difference in any outcome was observed between real and sham-acupuncture.

Footnotes

Disclosure Statement

No competing financial interests exist.

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