Abstract
Objectives
An acute interruption of the blood supply to the inner ear is one of the most likely causative factors for sudden deafness (SD). Reactive oxygen species (ROS) have been suggested to be important mediators of the tissue injury during cochlear ischemia and reperfusion. Radix astragali (RA) is natural antioxidant. The aim of this study was to investigate the efficacy of RA in patients with SD.
Patients and methods
We compared the hearing gains from hearing impairment in 46 ears treated with RA with 46 ears treated with non-RA. RA was given intravenously daily for 10 days. There were no significant differences in clinical or audiological data between RA and non-RA groups.
Results
The hearing gain at 250, 500, 1000, 2000, and 4000 Hz in RA group was much higher than that of non-RA group correspondingly ( P < .01). Also, the hearing gain at PTA (pure-tone average of 250, 500, 1000, 2000, and 4000 Hz) in RA group was significantly higher than that of non-RA group ( P < .01).
Conclusion
The recovery of hearing was significantly better after treatment of RA than non-treatment of RA. RA can be valuable concurrent therapy for patients with SD.
1
Introduction
Sudden deafness (SD) is considered to be an otologic emergency with no known specific cause. Viral infection, autoimmunity, vascular pathologies, and trauma have been suggested for theoretical causes . Among these potential pathogenic factors, an acute interruption of the blood supply to the inner ear is one of the most likely causative factors , and thus a number of regimens aiming to improve inner ear circulation and oxygen supply have been employed as therapy, including vasodilators, anticoagulants, plasma expanders, carbogen, stellate ganglion block, and hyperbaric oxygen (HBO). Reactive oxygen species (ROS) have been suggested to be important mediators of the tissue injury during cochlear ischemia and reperfusion , and antioxidants are candidates to alleviate the ischemia-reperfusion injury of the cochlea . Also, ROS take an important part in cochlear pathological injury induced by autoimmunity, viral infection, and trauma .
Radix Astragali (RA) is a kind of traditional Chinese herb, which is widely used in treating ROS-mediated injury in various organs through its anti-oxidant properties . RA has been used for treatment of deafness for hundreds of years in Chinese Medicine history. From these, we have speculated RA has the potential effects for treatment of SD. From 2005, RA has been a part of the routine treatment of SD in our department. In this study we investigate the effect of RA therapy on the recovery from SD.
2
Materials and methods
2.1
Patients and evaluation
The study material consisted of two patient groups: RA group and non-RA group. All patients of SD adopted in this study were treated in the Department of Otolaryngology, Guangzhou General Hospital of Guangzhou Military Command from September 1998 to August 2011. All patients met the following inclusion criteria: (1) sudden onset of sensorineural hearing loss; (2) unknown cause of hearing loss; (3) nonfluctuating hearing loss; (4) A hearing loss of 30 dB or greater in at least 3 contiguous frequencies formed the audiometric inclusion criterion. (5) time from the onset of hearing loss to the start of treatment ≤5 days. The patients underwent standard otolaryngologic and otoneurologic examination after admittance to the hospital. All patients were evaluated with an audiometric test battery consisting of pure tone audiometry, tympanometry, and auditory brainstem evoked responses. The severity of hearing loss was assessed by using the average hearing level at frequencies of 250, 500, 1000, 2000, and 4000 Hz, as measured at the first visit. If a patient did not respond to the maximum level of sound generated by the audiometer, 5 dB was added to the maximum level to determine a threshold value. Unless the patient refused, magnetic resonance imaging (MRI) of the internal auditory canal/cerebellopontine angle was performed during or after treatment, and acoustic tumors and brainstem lesions were thus ruled out. The patients were observed at the hospital ward and treated with RA or non-RA. The study was approved by the Ethics Committee of Guangzhou General Hospital of Guangzhou Military Command.
2.2
Patient groups
2.2.1
RA group
RA group consisted of 46 patients (46 ears) treated with RA during a period from May, 2005 to August, 2011. RA (Chengdu Diao Pharmaceutical Company, Sichuan, China; was approved by Chinese Drug Administration, approved Number:2001ZFB0171.) was administrated intravenously at the dosage of 0.5 ml/kg/d for 10 continuous days. 10 ml injection of RA contains 20 g of crude medication astragalus membranaceus.
2.2.2
Non-RA group
For each RA treated patient a best matching non-RA control was selected. The control group of 46 patients (46 ears) was selected from the total of 221 patients with SD treated with non-RA from September, 1998 to May, 2004. The adopted criteria were: (1) the same gender; (2) very near age (within 3 years old); (3) almost equal delay of time from the onset of hearing loss to the start of treatment (limit of 12 hours); (4) the same feature of tinnitus; (5) the same characteristic of vertigo; and (6) similar amount and audiogram configuration of the initial hearing impairment (pure-tone average of 250, 500, 1000, 2000, and 4000 Hz (PTA), maximal hearing loss (max HL) with a difference ≤5 dB). The matching was carried out without any information of the patients’ outcome.
2.3
Measurements of hearing
The first hearing measurement was done as soon as possible after arrival at our department and before any treatment. A qualified audiometric technician measured the pure-tone thresholds in a sound proof chamber using a clinical audiometer (GSI 61 clinical audiometer) calibrated by national sound center every year. Then tympanometry and auditory brainstem evoked responses were detected. The follow-up audiograms were taken at the end of the therapy (on day 10) and the last measurement in 12 weeks if some degree of damage was present on day 10. The hearing level at 12 weeks after the initiation of treatment was considered to be fixed. Pure-tone audiograms were compared using the averaged hearing loss in dB at 250, 500, 1000, 2000, and 4000 Hz (PTA). Absolute hearing gain was defined as the difference in hearing thresholds in decibels before and after the treatment.
2.4
Treatment
All patients were strictly instructed to not smoke or drink caffeinated beverages during the 10 days of hospitalization. Mental fatigue was suggested to be avoided, doing slightly sports were encouraged simultaneously. Both RA group and non-RA group were treated with dexamethasone intravenously at the dosage of 0.2 mg/kg/d for 10 successive days, and hyperbaric oxygen therapy daily. Compound vitamin B was administrated 2 tablets three times a day. Salvia injection which is a vasodilator was also administrated. RA group received the same basic treatment as non-RA group, with the addition of RA therapy.
2.5
Statistics
Data values are expressed as means ± SEM. Statistical differences of ratios and means were analyzed using the x 2 test and t test, respectively. Differences were considered to be significant when P was < .05.
2
Materials and methods
2.1
Patients and evaluation
The study material consisted of two patient groups: RA group and non-RA group. All patients of SD adopted in this study were treated in the Department of Otolaryngology, Guangzhou General Hospital of Guangzhou Military Command from September 1998 to August 2011. All patients met the following inclusion criteria: (1) sudden onset of sensorineural hearing loss; (2) unknown cause of hearing loss; (3) nonfluctuating hearing loss; (4) A hearing loss of 30 dB or greater in at least 3 contiguous frequencies formed the audiometric inclusion criterion. (5) time from the onset of hearing loss to the start of treatment ≤5 days. The patients underwent standard otolaryngologic and otoneurologic examination after admittance to the hospital. All patients were evaluated with an audiometric test battery consisting of pure tone audiometry, tympanometry, and auditory brainstem evoked responses. The severity of hearing loss was assessed by using the average hearing level at frequencies of 250, 500, 1000, 2000, and 4000 Hz, as measured at the first visit. If a patient did not respond to the maximum level of sound generated by the audiometer, 5 dB was added to the maximum level to determine a threshold value. Unless the patient refused, magnetic resonance imaging (MRI) of the internal auditory canal/cerebellopontine angle was performed during or after treatment, and acoustic tumors and brainstem lesions were thus ruled out. The patients were observed at the hospital ward and treated with RA or non-RA. The study was approved by the Ethics Committee of Guangzhou General Hospital of Guangzhou Military Command.
2.2
Patient groups
2.2.1
RA group
RA group consisted of 46 patients (46 ears) treated with RA during a period from May, 2005 to August, 2011. RA (Chengdu Diao Pharmaceutical Company, Sichuan, China; was approved by Chinese Drug Administration, approved Number:2001ZFB0171.) was administrated intravenously at the dosage of 0.5 ml/kg/d for 10 continuous days. 10 ml injection of RA contains 20 g of crude medication astragalus membranaceus.
2.2.2
Non-RA group
For each RA treated patient a best matching non-RA control was selected. The control group of 46 patients (46 ears) was selected from the total of 221 patients with SD treated with non-RA from September, 1998 to May, 2004. The adopted criteria were: (1) the same gender; (2) very near age (within 3 years old); (3) almost equal delay of time from the onset of hearing loss to the start of treatment (limit of 12 hours); (4) the same feature of tinnitus; (5) the same characteristic of vertigo; and (6) similar amount and audiogram configuration of the initial hearing impairment (pure-tone average of 250, 500, 1000, 2000, and 4000 Hz (PTA), maximal hearing loss (max HL) with a difference ≤5 dB). The matching was carried out without any information of the patients’ outcome.
2.3
Measurements of hearing
The first hearing measurement was done as soon as possible after arrival at our department and before any treatment. A qualified audiometric technician measured the pure-tone thresholds in a sound proof chamber using a clinical audiometer (GSI 61 clinical audiometer) calibrated by national sound center every year. Then tympanometry and auditory brainstem evoked responses were detected. The follow-up audiograms were taken at the end of the therapy (on day 10) and the last measurement in 12 weeks if some degree of damage was present on day 10. The hearing level at 12 weeks after the initiation of treatment was considered to be fixed. Pure-tone audiograms were compared using the averaged hearing loss in dB at 250, 500, 1000, 2000, and 4000 Hz (PTA). Absolute hearing gain was defined as the difference in hearing thresholds in decibels before and after the treatment.
2.4
Treatment
All patients were strictly instructed to not smoke or drink caffeinated beverages during the 10 days of hospitalization. Mental fatigue was suggested to be avoided, doing slightly sports were encouraged simultaneously. Both RA group and non-RA group were treated with dexamethasone intravenously at the dosage of 0.2 mg/kg/d for 10 successive days, and hyperbaric oxygen therapy daily. Compound vitamin B was administrated 2 tablets three times a day. Salvia injection which is a vasodilator was also administrated. RA group received the same basic treatment as non-RA group, with the addition of RA therapy.
2.5
Statistics
Data values are expressed as means ± SEM. Statistical differences of ratios and means were analyzed using the x 2 test and t test, respectively. Differences were considered to be significant when P was < .05.
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