BACKGROUND AND OBJECTIVES: Ginkgo biloba extract (GBE) enhances cell survival in various organs. GBE protects nerve cells in the central nervous system and is clinically applied in Parkinson's and Alzheimer's disease. GBE can protect ototoxicity caused by cisplantin and gentamycin through rescue of hair cells in Organ of Corti and is accepted as one of the therapeutic agents for sudden deafness and tinnitus. The experimental study on GBE for the inner ear is confined to the hair cells, not to the spiral ganglion neurons (SGNs) which is the stimulated part by the electrode of cochlear implant. The aim of this study is to elucidate the effect of GBE on the survival of SGNs after hair cell loss in rats. MATERIALS AND METHOD: Ten Sprague-Dawley rats aged 50 days (P50) were deafened with kanamycin sulfate. GBE (EGb 761) was injected into the right cochlea and artificial perilymph was injected into the left side. The number and size of SGNs were compared after immunohistochemical statin in both groups. The expression of pJun, which is well-known as a proapoptotic transcription factor in the cochlea, was also compared. RESULTS: The number of SGNs was significantly larger in the GBE group than the control. The expression of pJun activity was significantly decreased in GBE group than the control. The size of SGNs in both groups was similar. CONCLUSION: These results suggest that GBE can protect SGNs death by inhibiting the pJun-C-jun N-terminal kinase pathway. GBE might be a potential drug for the patients with total deafness before or after cochlear implantation surgery for better hearing results.
Aged ; Alzheimer Disease ; Animals ; Cell Survival ; Central Nervous System ; Cochlea ; Cochlear Implantation ; Cochlear Implants ; Deafness ; Ear, Inner ; Electrodes ; Gentamicins ; Ginkgo biloba ; Hair ; Hearing ; Hearing Loss, Sudden ; Humans ; Hydroxymethylglutaryl-CoA Reductase Inhibitors ; Kanamycin ; Neurons ; Organ of Corti ; Perilymph ; Phosphotransferases ; Rats ; Rats, Sprague-Dawley ; Spiral Ganglion ; Tinnitus ; Transcription Factors

BACKGROUND AND OBJECTIVES: Stapedial reflex (SR) threshold is of considerable diagnostic significance in the evaluation of audiological function, especially under sedation or general anesthesia since anesthetic drugs often act on neurotransmitters or neuromodulators. The aim of this study was to evaluate the changes in the SR threshold according to the depth of anesthesia. SUBJECTS AND METHOD: Sixty patients with normal hearing who were scheduled for operation under general anesthesia were included in this study. Anesthetic agent used was propofol and the depth of anesthesia was monitored by the bispectral index (BIS). SR was measured five times according to depth of anesthesia. RESULTS: Both ipsilateral and contralateral SR thresholds were increased according to the depth of anesthesia using propofol. In particular, ipsilateral SR showed no response at BIS 60 and contralateral SR at BIS 40. However, there were no significant differences between age groups and gender. CONCLUSION: Propofol significantly increased both ipsilateral and contralateral SR threshold according to depth of anesthesia. When it is necessary to measure SR under general anesthesia, we should consider the effect on SR threshold according to the depth of anesthesia.
Anesthesia ; Anesthesia, General ; Anesthetics ; Cellulose ; Hearing ; Humans ; Neurotransmitter Agents ; Propofol ; Reflex ; Reflex, Acoustic

BACKGROUND AND OBJECTIVES: A distortion product otoacoustic emission (DPOAE) is a non-invasive method which is commonly used to assess the hearing function of the cochlea and to reflect objective information of specific frequency in the cochlea. We hypothesize that after applying a broad band noise (BBN), the outer hair cell's function will change and cause reduction in the amplitude of DPOAEs and signal to noise ratio (SNR). SUBJECTS AND METHOD: We performed the examination on 40 subjects (80 ears) who have a normal hearing function. DPOAEs were recorded before and after BBN stimulation (intensity: 90 dB HL, duration: 10 minutes). RESULTS: After the BBN stimulation, the amplitude of DPOAEs and SNR were decreased at all frequencies. The amplitude of DPOAEs and SNR decreased 0.3-1.6 dB SPL, 0.6-1.5 dB SPL, respectively. Decreases in the amplitude had statistical significances after 3 and 6 minutes in 1 kHz, 3 and 6 minutes in 2 kHz, immediately after noise exposure, and after 3 and 6 minutes in 6 kHz. However, the SNR changes had statistical significance only after 3 minutes in 1 kHz. After the stimulation, pure tone threshold at 4 kHz increased 3.2+/-3.9 dB HL. After the BBN exposure, the amplitude of DPOAEs and SNR decreased at all frequencies and most of them recovered within 12 minutes. CONCLUSION: These results suggest that DPOAE could be a clinically useful method for the purpose of screening, managing and assessing the prognosis of acoustic trauma and noise induced sensorineural hearing loss.
Auditory Fatigue ; Cochlea ; Hair ; Hearing ; Hearing Loss, Noise-Induced ; Hearing Loss, Sensorineural ; Mass Screening ; Noise ; Prognosis ; Signal-To-Noise Ratio

BACKGROUND AND OBJECTIVES: Vestibular evoked myogenic potentials (VEMP) have become a good diagnostic tool to evaluate the integrity of the vestibulocollic reflex. To investigate the standard recording of VEMP response in normal hearing subjects, the authors studied the effects of test positions and different acoustic stimulations on the VEMP. SUBJECTS AND METHOD: We performed VEMP on both ears of thirty normal hearing volunteers. Three acoustic stimulations (clicks and 500 Hz and 1,000 Hz short tone bursts) and four test positions were presented alternately to evoke VEMP. The latencies of peak p13 and n23, p13n23 interpeak latency (IPL) and amplitude were measured by EMG equipment and compared by statistical program. We also made up questions for the compliance of the test positions. RESULTS: The effects of test positions p13 latency had no significant difference on all test positions except between test position 2 and 4, n23 latency and p13n23 IPL had shortest waveform on test position 2, p13n23 amplitude had the largest waveform in test position 4. Acoustic stimulations on all test positions were influenced that clicks had shorter waveform about 2-3 ms than STBs on p13 latency and n23 latency, STBs had larger waveform than clicks on p13n23 amplitude. And the compliance of the test positions exhibited highest comfort in test position 1. CONCLUSION: Test position 1 had higher VEMP response rates and compliance, 500 Hz STB had a largest p13n23 amplitude. Therefore we recommend that the ideal conditions were position 1 and 500 Hz STB for acoustic stimulations to evoke VEMP.
Acoustics* ; Compliance ; Ear ; Hearing ; Reflex ; Vestibular Evoked Myogenic Potentials* ; Volunteers

BACKGROUND AND OBJECTIVES: To determine the clinical application of otoacoustic emissions (OAE) in screening of cochlear function, author studied changes of OAE in Meniere's disease patients. MATERIALS AND METHODS: The author has measured several parameters of OAE with 34 meniere's patients and 15 normal persons. Pass rate, response amplitude, reproducibility were recorded at TEOAE. Amplitude of DP-gram were measured at 2 F2 frequencies-1000, 2000 Hz. The input/output functions of DPOAE were recorded at 2 F2 frequencies -1001, 2002 Hz (respectively DP-1000, DP-2000). Input/output function were determined based on 2 parameters- maximal level and Detection threshold of DPOAE. RESULTS: 1) TEOAE: Significant lower rate of positive finding was recorded at involved ears (55.8%, 19/34) than normal ears (100%, 30/30). 2) DP-gram: At frequency was 2000 Hz, amplitude of involved ears (n=28, 6.3+/-.5 dB/SPL) was significant smaller than normal ears (n=30, 6.3+/-.5 dB/SPL). 3) DP-input/output function: At maximum DP level of DP-2000, response of involved ears (n=11, 51.6+/-.9 dB/SPL) was significant larger than normal ears (n=22, 48.5+/-.0 dB/SPL). CONCLUSION: Parameters of OAE, such as pass rate of TEOAE, amplitude of DP-gram at 2000 Hz, and maximum DP level of DP-2000 was considered to good indicators for monitoring cochlear function of Meniere's disease. Furthermore, evaluation by changes in the TEOAE & DPOAE combined parameters, appeared to be very useful for detection of subtle change in cochlear function of Meniere's disease.
Ear ; Humans ; Mass Screening ; Meniere Disease*

BACKGROUND AND OBJECTIVES: To determine the clinical application of otoacoustic emissions (OAE) in screening of cochlear function, author studied changes of OAE in Meniere's disease patients. MATERIALS AND METHODS: The author has measured several parameters of OAE with 34 meniere's patients and 15 normal persons. Pass rate, response amplitude, reproducibility were recorded at TEOAE. Amplitude of DP-gram were measured at 2 F2 frequencies-1000, 2000 Hz. The input/output functions of DPOAE were recorded at 2 F2 frequencies -1001, 2002 Hz (respectively DP-1000, DP-2000). Input/output function were determined based on 2 parameters- maximal level and Detection threshold of DPOAE. RESULTS: 1) TEOAE: Significant lower rate of positive finding was recorded at involved ears (55.8%, 19/34) than normal ears (100%, 30/30). 2) DP-gram: At frequency was 2000 Hz, amplitude of involved ears (n=28, 6.3+/-.5 dB/SPL) was significant smaller than normal ears (n=30, 6.3+/-.5 dB/SPL). 3) DP-input/output function: At maximum DP level of DP-2000, response of involved ears (n=11, 51.6+/-.9 dB/SPL) was significant larger than normal ears (n=22, 48.5+/-.0 dB/SPL). CONCLUSION: Parameters of OAE, such as pass rate of TEOAE, amplitude of DP-gram at 2000 Hz, and maximum DP level of DP-2000 was considered to good indicators for monitoring cochlear function of Meniere's disease. Furthermore, evaluation by changes in the TEOAE & DPOAE combined parameters, appeared to be very useful for detection of subtle change in cochlear function of Meniere's disease.
Ear ; Humans ; Mass Screening ; Meniere Disease*

BACKGROUND AND OBJECTIVES: This study was designed to isolate bacteria and fungi from healthy ear canal in Koreans and compare with known pathogens. SUBJECTS AND METHOD: Specimens were collected from the external ear swab and cerumen of 45 healthy volunteers from February 2003 to May 2003. RESULTS: Forty-five subjects were cultured. In 8 subjects, we failed to obtain enough cerumen. Three canal and 11 cerumen showed no growth. Forty-two canal specimens yielded 72 microorganisms, of which 84.7% were gram positive bacteria. Twenty-six cerumen specimens yielded 43 microorganisms and 76.7% of them were gram positive. Staphylococci was 76.4% of canal bacteria and 74.4% of cerumen bacteria. In both canal and cerumen, the most commonly isolated microorganism was Staphylococcus capitis. Coryneform bacteria were 6.9% of bacteria in canal and were not isolated from cerumen. Two Aspergillus species and one Penicillium species were isolated from canal and cerumen. CONCLUSION: Coagulase-negative staphylococcus (CNS) were found to be the predominant microorganism and, in particular, Staphylococcus capitis was the most commonly isolated microorganism from the normal external auditory canal in Koreans.
Aspergillus ; Bacteria ; Cerumen ; Ear Canal* ; Ear* ; Ear, External ; Fungi ; Gram-Positive Bacteria ; Healthy Volunteers ; Penicillium ; Staphylococcus

BACKGROUND AND OBJECTIVES: Raman spectroscopy is a vibrational spectroscopic technique capable of providing details on the chemical composition, molecular structure and molecular interactions in cells and tissues. Its application of distinguishing normal and cancer tissue has been studied in a variety of sites, such as the cervix, lung, larynx and skin. The purpose was to explore spectral changes between normal and cancer tissue in the larynx using Raman spectroscopy to assess the feasibility of using Raman spectroscopy for the early diagnosis of laryngeal cancer. MATERIALS AND METHOD: Laryngeal tissue specimens (13 adjacent normal and 13 cancer tissues) were obtained from patients who underwent total laryngetomy or supracricoid laryngectomy with squamous cell carcinoma of the larynx. The specimens were stored -70 degrees C until use. These specimens were defrosted at room temperature. The Raman spectra from laryngeal tissue specimens could be obtained at 300 mW and 250 scan during 15 minutes of the signal acquisition time using FT-Raman spectroscopy (Bruker Co., Karsruhe, Germany). RESULTS: Raman spectra were different significantly between cancer and adjacent normal tissues of the larynx at 1446 cm-1, 1240 cm-1, 1335 cm-1, and 1655 cm-1 (p=0.007, 0.2, 0.2, 0.3, respectively). The difference of 1446 cm-1 means the change of CH2 bending mode in protein and lipid of malignant tissue. The change of 1335 cm-1 means a decrease in CH3CH2 to a wagging mode of collagen and polynucleotide chain of malignant tissue. The difference of 1240 and 1655 means a decrease in the alpha-helix conformation of collagen. CONCLUSION: This study demonstrates the differences of Raman units between laryngeal cancer and adjacent normal tissue using Raman spectroscopy. In future, Raman spectroscopy may become a useful tool of guided biopsy for accurate pathologic diagnosis and assessment of the adequacy of resection margins.
Biopsy ; Carcinoma, Squamous Cell ; Cervix Uteri ; Collagen ; Diagnosis ; Early Diagnosis ; Female ; Humans ; Laryngeal Neoplasms ; Laryngectomy ; Larynx* ; Lung ; Molecular Structure ; Skin ; Spectrum Analysis ; Spectrum Analysis, Raman*

BACKGROUND AND OBJECTIVES: This study was designed to evaluate relation between frequencies of noise and tinnitus in noise-induced hearing loss and to elucidate mechanism of tinnitus in noise-induced hearing loss. MATERIALS AND METHODS: Four factories were selected, of which noise frequencies were different except one factory. Preliminary screening hearing test with a pure tone audiometer on 1000 and 4000 Hz was done. And if the hearing threshold was over 40 dB, history taking, otological examination, tympanometry, pure tone audiometry on 500, 1000, 2000, 4000, 6000 Hz were done. Noise was measured in 125, 250, 500, 1000, 2000, 4000, 8000 Hz. Tinnitus was measured using 1000, 2000, 4000 Hz pure tone. RESULTS: 1) Hearing loss was most severe in the 4000, 6000 Hz range. 2) In A factory, noise was most intense on 4000 Hz, in B factory on 2000 Hz, and in C and D factory on 1000 Hz. 3) Forty-three workers (42.2%) of total 102 subjects complained tinnitus. And frequency of tinnitus was 4000 Hz in 71 ears (89.9%) among 79 ears with tinnius. CONCLUSION: Regardless of the frequency of noise, most workers complain of 4 kHz tinnitus. And it was in accord with frequency of most severe hearing loss in the noise-induced hearing loss.
Acoustic Impedance Tests ; Audiometry ; Ear ; Hearing ; Hearing Loss ; Hearing Loss, Noise-Induced* ; Hearing Tests ; Mass Screening ; Noise* ; Tinnitus*

BACKGROUND AND OBJECTIVES: The majority of tinnitus is classified not as objective, but as subjective tinnitus. The nature of tinnitus is different according to countries, cities, personal expression, but the objective assessment guideline for the diagnosis of subjective expression in tinnitus is not present in Korea. The aim of this study has been to compare subjective expressions with pitch in tinnitus and to find out whether we can predict tinnitus pitch by patient subjective expression. SUBJECTS AND METHOD: We reviewed the records of 633 patients (690 ears) with continuous tinnitus who performed questionnaires of tinnitus and audiologic study. In addition to standard audiometric tests, patients received tests for tinnitus pitch using pure tone stimuli and/ or narrow band noise. RESULTS: Among 50 onomatopoeia of tinnitus, [wi: ng] shows highest incidence (25.4%), followed by [s'oi: ](13.8%), [u: ng] (11.7%), [p'i: ](7.8%), and [tchi: ](5.4%). High pitches, especially 4 kHz (28.6%), 8 kHz (24.9%), were more frequently noted in tinnitus. With respect to the relationship between tinnitus pitch and onomatopoeia, [u: ng] shows highest incidence in low pitches, below 500 Hz, [wi: ng] in 1 kHz, and [s'oi: ] in 4 kHz, 8 kHz. In tinnitus pitch according to onomatopoeia, [wi: ng] had 4 kHz, 8 kHz, 1 kHz, [s'oi: ] had 4 kHz, 1 kHz, 8 kHz, [u: ng] had 125 Hz, 250 Hz, 500 Hz, [p'i: ] had 8 kHz, 4 kHz, 1 kHz, and [tchi: ] had 4 kHz, 8 kHz, more frequently in sequence. Dividing pitches into low, middle and high levels, [u: ng] had low pitches, [s'oi: ] had middle and high pitches, [p'i: ] and [tchi: ] had high pitches, but [wi: ng] was distributed evenly through low to high pitches. CONCLUSION: Our results suggest that there was apparent relationship between subjective expression and pitch in tinnitus.
Diagnosis ; Humans ; Incidence ; Korea ; Noise ; Pitch Perception ; Surveys and Questionnaires ; Tinnitus*