Characteristics of brainstem auditory evoked potentials of students studying folk dance

BACKGROUND： Previous experiments have demonstrated that brainstem auditory evoked potential is affected by exercise, exercise duration, and frequency. OBJECTIVE： Comparing the brainstem auditory evoked potential of students studying folk dance to students studying other subjects. DESIGN： Observational contrast study. SETTING： Physical Education College, Shandong Normal University PARTICIPANTS： Fifty-five female students were enrolled at Shandong Normal University between September and December in 2005, including 21 students that studied folk dance and 34 students that studied other subjects. The age of the folk dance students averaged （19 ± 1） years and dance training length was （6.0 ± 1.5） years. The students that studied other subjects had never taken part in dance training or other physical training, and their age averaged （22 ± 1） years, body height averaged （162 ± 5） cm, body mass averaged （51 ± 6） kg. All subjects had no prior ear disease or history of other neurological disorders. All students provided informed consent for the experimental project. METHODS： The neural electricity tester, NDI-200 （Shanghai Poseidon Medical Electronic Instrument Factory） was used to examine and record Brainstem Auditory Evoked Potential values of the subjects during silence, as well as to transversally analyze the Brainstem Auditory Evoked Potential values. The electrode positions were cleaned and degreased with soapy water, followed by ethanol. The selected bipolar electrodes were situated on the head： recording electrodes were placed at the Baihui acupoint, and the reference electrode was placed at the mastoid of the measured ear, with grounding electrodes in the center of the forehead. Brainstem Auditory Evoked Potential values were elicited by monaural stimulation of a ＂click＂ though an earphone; the other ear was sheltered by the white noise. The click intensity was 102 db, the stimulation frequency was 30 Hz, the bandpass filters were 1 000-3 000 Hz, the sensitivity was 5 ta V, and a total of 2 000 sweeps were averaged. Waveform identification and analysis： various components of the Brainstem Auditory Evoked Potential values were identified, and the peak latencies and peak-peak values were analyzed. MAIN OUTCOME MEASURES： Latency of Ⅰ , Ⅱ, Ⅲ, Ⅳ, Ⅴ and Peak-Peak Value of Ⅰ, Ⅲ, Ⅴwere measured. RESULTS： Fifty-five subjects were enrolled in the final analysis, without any loss. Compared to the students who studied other subjects ① Ⅰ -Ⅴ peak latencies （PL）： Ⅳ PL of the right ear of the folk dance students was obviously longer （P 〈 0.05）; ② Ⅰ, Ⅲ, V peak-peak values：Ⅰ peak-peak values of the right ear were obviously higher （P 〈 0.05）. CONCUSION： ① PL of the right ear of the folk dance students was obviously longer, which indicates that dancing results in a stronger sensibility to auditory stimuli. ②. Peak-peak values were obviously higher, which indicates that long-term exercise enhances the music senses and synchrony of auditory nerve impulses.

Effect of Qiangli Dingxuan Tablet on Cerebral Hemodynamics and Brainstem Auditory Evoked Potentials in Vertigo Patients with Posterior Circulation Ischemia

OBJECTIVE: To observe the effect of Qiangli Dingxuan Tablet on cerebral hemodynamics and brainstem auditory evoked potentials in vertigo patients with posterior circulation ischemia. METHODS: A total of 120 vertigo patients with posterior circulation ischemia were randomly divided into observation group and control group. 60 patients in the control group were treated with conventional western medicine. 60 patients in the observation group were treated with Qiangli Dingxuan Tablet on the basis of the control group. After 2 weeks of treatment, the improvement of vertigo(dizziness handicap inventory(DHI), dizziness handicap inventory(DHI)), the hemodynamic index(Basilar artery blood flow velocity(BA), left vertebroarterial artery(LVA), and the average blood flow velocity of right vertebroarterial artery(RVA)) and the changes in brain stem auditory evoked potential(BAEP) of two groups were observed. And statistical analysis was conducted for the clinical efficacy and adverse reactions during treatment of two groups. RESULTS: The total effective rate of the observation group was significantly higher than that of the control group(P < 0.05). The DHI and DARS scores of the two groups were significantly lower than those before treatment(P < 0.05), and the degree of reduction was more obvious in the observation group(P < 0.05). The levels of BA, LVA and RVA in the two groups were significantly higher than those before treatment(P < 0.05), and the levels of BA, LVA and RVA in the observation group were significantly higher than those in the control group(P < 0.05). The indexes of BAEP latency I, II, III and indexes of BAEP peak latency I-III, III-V, IV were obviously lower than those before treatment(P < 0.05). Besides, the decrease of BAEP index in the observation group was significantly lower than that in the control group(P < 0.05). No adverse reactions occurred during the treatment of the two groups. CONCLUSION: Qiangli Dingxuan Tablet is able to significantly improve the cerebral hemodynamics and brainstem auditory evoked potentials of patients with PCIV, and quickly relieve vertigo. It is safe and reliable and worthy of clinical application.

Brainstem auditory evoked potentials in patients with delayed encephalopathy after acute carbon monoxide poisoning

Objective:To evaluate the changes of brainstem auditory evoked potential (BAEP) in patients with delayed encephalopathy after acute carbon monoxide poisoning. Methods: BAEPs were performed in 32 controls and 40 patients. Wave Ⅰ , Ⅱ , Ⅲ ,Ⅳ, Ⅴ latencies and Ⅰ-Ⅲ , Ⅲ-Ⅴ , Ⅰ-Ⅴ interpeak latencies were measured, respectively. Results: Abnormalities of BAEPs in 13 patients (13/40, 32 ％). Among the13 abnormal BAEPs, 3 displayed prolongation of latency to waves in one side, no potential in another side; 5 displayed a similar abnormality which was bilateral prolongation of latency to waves ;and another 5 displayed unilateral latency delay. Compared wave Ⅰ , Ⅱ , Ⅲ , Ⅳ, Ⅴ latencies and Ⅰ-Ⅲ , Ⅲ-Ⅴ , Ⅰ-Ⅴ interpeak latencies in the patients and the controls, there were no significant differences (P＞0.05). Conclusion: BAEPs can be used for evaluating the diagnostic and prognostic values in the cases of delayed encephalopathy after acute carbon monoxide poisoning.

Characteristics of brainstem auditory evoked potential of neonates with mild or moderate hyperbilirubinemia

BACKGROUND： Brainstem auditory evoked potential （BAEP） has been widely used to evaluate the functional integrity and development of injured auditory system and brain, especially to objectively evaluate the function of auditory system and brain stem of very young babies, such as neonates and sick babies. OBJECTIVE： To observe the changes of BAEP of neonates with hyperbilirubinemia, and to investigate the relationship of bilirubin concentration and BAEP. DESIGN： An observation experiment. SETTING： Department of Pediatrics, the 309 Clinical Division, General Hospital of Chinese PLA. PARTICIPANTS： Fifty-eight neonates with mild or moderate hyperbilirubinemia exhibiting jaundice within 24 hours after born, who received the treatment in the Department of Pediatrics, the 309 Clinical Division, General Hospital of Chinese PLA between January 2004 and May 2007, were recruited in this study. The involved neonates, 31 boys and 27 girls, had gestational age of 37 to 46 weeks. They had no history of birth asphyxia, and were scored 8 to 10 points when born. Written informed consents of examination and treatment were obtained from the guardians of the neonates. This study was approved by the Hospital Ethics Committee. According to serum total bilirubin value, the neonates were assigned into 3 groups： low-concentration bilirubin group （n =16）, moderate-concentration bilirubin group （n =27） and high-concentration bilirubin group （n =15）. According to mean daily bilirubin increase, the subjects were sub-assigned into bilirubin rapid increase group （n =39） and bilirubin slow increase group （n = 19）. METHODS： After admission, all the neonates received drug treatment. Meanwhile, their 116 ears were examined with a myoelectricity evoked potential equipment （KEYPOINT） in latency, wave duration, amplitude and wave shape differentiation of each wave of BAEP. BAEP abnormal type was observed and abnormal rate of BAEP was calculated. MAIN OUTCOME MEASURES： ①Abnormal rate and abnormal type of BAEP. ② Latency of waves Ⅰ , Ⅲ and Ⅴ, and wave duration of waves Ⅰ to Ⅲ,Ⅲ to Ⅴ, and Ⅰ to Ⅴ. RESULTS： Fifty-eight neonates with mild or moderate hyperbilirubinemia were involved in the final analysis. ①Abnormal type and abnormal rate of BAEP of neonates with hyperbilirubinemia： Among the 116 ears, unilateral or bilateral waves Ⅰ, Ⅲ,Ⅴ still existed. The latency of waves Ⅰ, Ⅲ and Ⅴ was ＋2.5 s longer than the normal level in 8, 4 and 15 ears, respectively. The wave duration of waves Ⅰ to Ⅲ and waves Ⅲ to Ⅴ was ＋2.5 s longer than the normal level in 6 and 14 ears, respectively. The wave duration of waves Ⅲ to Ⅴ was longer than that of ipsilateral waves Ⅰ to Ⅲ in 24 ears. The latency difference of wave Ⅴ between two ears was larger than 0.4 ms in 31 neonates with hyperbilirubinemia; The amplitude of wave Ⅴ to that of ipsilateral wave 1 was lower than 0.5 in 29 neonates. Totally 52 ears were abnormal, and the abnormal rate was 44.8%. One to two months later, 98% abnormal neonates with hyperbilirubinemia recovered. The abnormal rate in the low-, moderate-, and high-concentration bilirubin groups was 37.5%, 44.4% and 53.3%, respectively. ② Comparison of latency and wave duration of each wave of BAEP： Latency of waves Ⅰ, Ⅲ and Ⅴ, and wave duration of waves Ⅰ to III and Ⅲ to Ⅴ were gradually prolonged in low-, moderate-, and high-concentration bilirubin groups, but significant difference did not exist between two groups （P 〉 0.05）. ③ There were no significant differences in latency of waves Ⅰ, Ⅲand Ⅴ, and wave duration of waves Ⅰ to Ⅲ, Ⅲto Ⅴ and Ⅰ to Ⅴ between bilirubin rapid increase group and bilirubin slow increase group （P 〉 0.05）. CONCLUSION： Auditory acuity and brainstem of neonates with mild or moderate hyperbilirubinemia are damaged to some extent. High-concentration bilirubin causes BAEP abnormality easily. Bilirubin increase and its concentration change are not consistent with nervous lesion degree.

Electroencephalogram and brainstem auditory evoked potential in 539 patients with central coordination disorder

BACKGROUND： Electroencephalogram （EEG） and brainstem auditory evoked potential （BAEP） are objective non-invasive means of measuring brain electrophysiology. OBJECTIVE： To analyze the value of EEG and BAEP in early diagnosis, treatment and prognostic evaluation of central coordination disorder. DESIGN, TIME AND SETTING： This case analysis study was performed at the Rehabilitation Center of Hunan Children＇s Hospital from January 2002 to January 2006. PARTICIPANTS： A total of 593 patients with severe central coordination disorder, comprising 455 boys and 138 girls, aged 1-6 months were enrolled for this study. METHODS： EEG was monitored using electroencephalography. BAEP was recorded using a Keypoint electromyogram device. Intelligence was tested by professionals using the Gesell scale. MAIN OUTCOME MEASURES： （1） The rate of abnormal EEG and BAEP, （2） correlation of abnormalities of EEG and BAEP with associated injuries, （3） correlation of abnormalities of EEG and BAEP with high risk factors. RESULTS： The rate of abnormal EEG was 68.6% （407/593 patients）, and was increased in patients who also had mental retardation （P 〈 0.05）. The rate of abnormal BAEP was 21.4% （127/593 patients）. These 127 patients included 67 patients （52.8%） with peripheral auditory damage and 60 patients （47.2%） with central and mixed auditory damage. The rate of abnormal BAEP was significantly increased in patients who also had mental retardation （P 〈 0.01 ）. Logistic regression analysis showed that asphyxia （P 〈 0.05）, jaundice, preterm delivery, low birth weight and the umbilical cord around the neck were closely correlated with abnormal EEG in patients with central coordination disorder, lntracranial hemorrhage, jaundice （P 〈 0.05）, low birth weight and intrauterine infection （P 〈 0.05） were closely correlated with abnormal BAEP in patients with central coordination disorder. CONCLUSION： Central coordination disorder is often associated with abnormal EEG and BAEP. The rate of EEG or BAEP abnormality is positively associated with the size of the brain injury. Asphyxia is a high risk factor for abnormal EEG in central coordination disorder. Jaundice and intrauterine infection are high risk factors for abnormal BAEP in central coordination disorder.

Enhanced auditory evoked potentials in musicians:A review of recent findings

Auditory evoked potentials serve as an objective mode for assessment to check the functioning of the auditory system and neuroplasticity.Literature has reported enhanced electrophysiological responses in musicians, which shows neuroplasticity in musicians. Various databases including Pub Med, Google, Google Scholar and Medline were searched for references related to auditory evoked potentials in musicians from 1994 till date. Different auditory evoked potentials in musicians have been summarized in the present article. The findings of various studies may support as evidences for music-induced neuroplasticity which can be used for the treatment of various clinical disorders. The search results showed enhanced auditory evoked potentials in musicians compared to non-musicians from brainstem to cortical levels. Also, the present review showed enhanced attentive and pre-attentive skills in musicians compared to non-musicians.

The effect of lead on brainstem auditory evoked potentials in children

To determine whether lead affects brainstem auditory evoked potentials (BAEPs) in low-to-moderate lead exposed children Methods BAEPs were recorded from 114 asymptomatic children aged 1-6 years Average values were calculated for peak latency (PL) and amplitude (Amp) Whole blood lead (PbB) levels were assessed by graphite furnace atomic absorption spectroscopy Based on their PbB levels, subjects were divided into low lead (PbB<100 μg/L) and high lead subgroups (PbB ≥100 μg/L) Results The PbB levels of the 114 subjects ranged from 32 0 to 380 0 μg/L in a positively skewed distribution The median of PbB levels was 90 0 μg/L while the arithmetic average was 88 0 μg/L Of the subjects, 43 0% (49/114) had levels equal to or greater than 100 μg/L Bilateral PLs Ⅰ, Ⅴ, and Ⅲ of the left ear in the high lead subgroup were significantly longer than those in the low lead subgroup (P<0 05) A positive correlation was found between PbB levels and bilateral PLs Ⅰ, Ⅴ and Ⅲ of the left ear (P<0 05), after controlling for age and gender as confounding factors A significant and positive correlation between PbB levels and PL Ⅰ of the left ear, even when PbB levels were lower than 100 μg/L, in the low subgroup (r=0 295, P=0 019) was also found Conclusions Lead poisoning in children younger than 6 years old is a very serious problem to which close attention should be paid The indications that lead prolongs partial PLs may imply that lead, even at PbB levels lower than 100 μg/L, impairs both the peripheral and the central portions of the auditory system BAEPs may be a sensitive detector of subclinical lead exposure effects on the nervous system in children

Effect of Noise on the Function of Auditory Brainstem Center

The amplitudes and latencies of auditory brainstem evoked response(ABR)were recorded at both high(50/s)and low(10/s)click rates as sound stimuli before andafter the guinea pigs were exposed to variant intensity noise.The maximum amplitude ofwave V increased significantly,but those of wave Ⅰ,Ⅲ,and Ⅳ decreased significantly afterexposure to 110 dB noise for 20 or 30 min.The wave Ⅴ latency recorded at 50/s clickrate was shorter in every group after exposure.The changes of wave V latency recordedat 10/s click rate were complex,it was shorter after exposure to 95 dB or 105 dB for 10min;no change was found after exposure to 110 dB for 10 min,but it was longer initiallyand then became shorter after exposure to 110 dB noise for 30 min.The difference valueof wave V latency from 10/s to 50/s was negatively correlated with the noise intensityand exposure time.The more intense noise stimuli and the longer time,the less the differ-ence value became.The results indicate that the auditory bralnstem center was affectedby intense noise,and it is helpful to use difference value of wave V latency to analysis thefunction of brainstem center after exposure to noise.

Effect of Acupuncture on the Auditory Evoked Brain Stem Potential in Parkinson's Disease

Under the auditory evoked brain stem potential (ABP) examination, the latent period of V wave and the intermittent periods of III-V peak and I-V peak were significantly shortened in Parkinson's disease patients of the treatment group (N=29) after acupuncture treatment. The difference of cumulative scores in Webster's scale was also decreased in correlation analysis. The increase of dopamine in the brain and the excitability of the dopamine neurons may contribute to the therapeutic effects, in TCM terms, of subduing the pathogenic wind and tranquilizing the mind.……

Impacts of acupuncture on brainstem evoked potentials in patients with primary depression

Objective To observe the impacts of acupuncture on brainstem evoked potentials in the patients with primary depression. Methods Forty cases of primary depression were treated by acupuncture at Baihui （百会 GV 20）, Yinatng （印堂 GV 29）, DazhuT （大椎 GV 14）, bilateral Shenmen （神门 HT 7）, bilateral Taichong （太冲 LR 3）, bilateral Neiguan （内关 PC 6） and SanyTnjiao （三阴交 SP 6）. The needles were retained for 30 min. Acupuncture treatment was given once every two days, three treatments a week. The brainstem auditory evoked potential （BAEP） and visual evoked potential （VEP） were observed in 6 weeks of treatment. The change in Hamilton depression scale （HAMD） score was observed before and after treatment in the depression group. Results After treatment, VEP wave latency was shortened significantly in patients of depression （P〈0.05）, BAEPIII wave latency was shortened significantly （P〈0.05）. The score of HAMD was decreased apparently in the depression group （P〈0.05）. Conclusions The stressability of visual and auditory stimuli in the central nervous system was decreased in the patients of depression. Acupuncture shortens remarkably the brainstem evoked potentials latency in the patients of depression and achieves the effective results in the treatment of primary depression.

RELATIONS OF INTRACRANIAL PRESSURE, CREATINE KINASE AND BRAINSTEM AUDITORY EVOKED POTENTIAL IN PATIENTS WITH TRAUMATIC BRAIN EDEMA

We studied the relations of intracranial pressure (ICP),creatine kinase (CK) and bralnstem auditory evoked potential (BAEP) in 44 patients with traumatic brain edema who were admitted to our hospital from June 1990 to February 1991. There were 30 males and 14 females, with age range from 9 to 67 years. The results showed that the abnormal BAEP could reflect the severity of cerebral edema in acute head injury and was related to ICP and serum CK levels. When ICP>30 mmHg (4kPa), the abnormality of BAEP was more obvious than that of the control group (P<0.05); the serum CK levels were also elevated markedly. In patients with ICP over and below 4kPa, the rate of abnormal BAEP was 38.46% and 77.78% respectively (P<0.05). The serum CK level in the normal group or in the group with moderate abnormality of BAEP was significantly different from that in the group with severe abnormality or lack of BAEP (274.8± 98.24 U/L vs 705.3± 364.27 U/L; P<0.001). After treatment, the ICP returned to normal, and the BAEP norm

Combined monitoring of evoked potentials during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms

Background Neurophysiologic monitoring during surgery is to prevent permanent neurological injury resulting from surgical manipulation. To improve the accuracy and sensitivity of intraoperative neuromonitoring, combined monitoring of transcranial electrical stimulation motor evoked potentials （TES-MEPs）, somatosensory evoked potentials （SSEPs） and brainstem auditory evoked potentials （BAEPs） was attempted in microsurgery for lesions adjacent to the brainstem and intracranial aneurysms. Methods Monitoring of combined TES-MEPs with SSEPs was attempted in 68 consecutive patients with lesions adjacent to the brainstem as well as intracranial aneurysms. Among them, 31 patients （31 operations, 28 of posterior cranial fossa tumors, 3 of posterior circulation aneurysms） were also subjected to monitoring of BAEPs. The correlation of monitoring results and clinical outcome was studied prospectively. Results Combined monitoring of evoked potentials （EPs） was done in 64 （94.1%） of the 68 patients. MEPs monitoring was impossible for 4 patients （5.9%）. No complication was observed during the combined monitoring in all the patients. In 45 （66.2%） of the 68 patients, EPs were stable, and they were neurologically intact. Motor dysfunction was detected by MEPs in 8 patients, SSEPs in 5, and BAEPs in 4, respectively. Conclusions A close relationship exists between postoperative motor function and the results of TES-MEPs monitoring TES-MEPs are superior to SSEPs and BAEPs in detecting motor dysfunction, but combined EPs serve as a safe, effective and invasive method for intraoperative monitoring of the function of the motor nervous system. Monitoring of combined EPs during microsurgery for lesions adjacent to the brainstem and intracranial aneurysms may detect potentially hazardous maneuvers and improve the safety of subsequent procedures.

Otoacoustic Emissions and Evoked Potentials in Infants after Breast-Feeding Jaundice——Hearing Dysfunction in Breast-Feeding Jaundice

We study hearing in a group of infants with Breast-feeding jaundice (BFJ) by means of Transient-evoked otoacoustic emissions (T-EOE) and Brainstem auditory evoked potentials (BAEP) searching for relationship between bilirubin serum levels and auditory dysfunction. Eleven infants born at-term with BFJ were selected for the study. We studied also 11 control age- and gender matched healthy at-term infants without signs of jaundice. T-EOAE studies were performed between 5-7 days after birth, and 3 months later. BAEP studies were performed once. BFJ group infants exhibited lower amplitudes in T-EOE than infants in the control group. These differences disappear at the 3-month evaluation. In BAEP, we observed a significant latency delay of waves I and V in Breast-feeding jaundice group infants. All infants in both groups demonstrated reproducible wave V response at 30 decibels. No significant correlation values were observed between bilirubin serum levels and T-EOE and BAEP variables. Our data suggest that BFJ can result in transient peripheral and central auditory dysfunction. Dysfunction is reversible after treatment of infants with BFJ.

Intraoperative Auditory Evoked Potential Monitoring for Anaesthesia Depth and Utilization of Inhaled Isoflurane

Background: Hypnosis monitoring has been shown to reduce the incidence of awareness. A-line ARX-IndexTM (AAI) derived from auditory evoked potentials (AEP) represents as a numerical variable depth of anaesthesia. Objectives: To study the efficacy of AEP as an indicator of anaesthetic depth and monitor intraoperative awareness in neurosurgical patients by using the AAI scale. Design: Prospective cohort study is used. Setting: The study is in Neurosurgical centre of Tertiary care hospital. Participants: Neurosurgical patients requiring general anaesthesia with duration of surgery between 90 - 150 minutes were enrolled for the study. Intervention: Patients in Group 1 (control) were monitored by conventional methods. Patients in Group 2 (study) underwent intraoperative monitoring by using the AEP monitor. Primary outcome: To study the efficacy of AEP monitoring and AAI index for monitoring the depth of anaesthesia and reducing the incidence of awareness. Results: There was no significant difference in the intraoperative haemodynamic responses measured between the two study groups (p > 0.5). There was no significant difference in the identification of intraoperative awareness by using conventional parameters between the two groups (p > 0.5). There was also a significantly faster time to recovery for patients in Group 2 (p < 0.05). Conclusion: Hypnosis monitoring using AEP monitor/AAI in neurosurgical patients under general anaesthesia did not show any significant difference in haemodynamic response and intraoperative awareness but had significant lower consumption of volatile anaesthetic with cost sparing effect and a faster recovery time as compared to conventional monitoring.

Clinical Study on Effect of Electro-acupuncture Combined with Different Anesthetics on Auditory-evoked Potential Index

To observe the effect of electro-acupuncture （EA） on auto regressive with exogenous input model （ARX-model） auditory evoked index （AAI） in patients anesthetized with different anesthetics. Methods： Forty-eight adult patients undergoing scheduled surgical operation were enrolled and divided into two groups （24 in each group） according to the anesthetics applied, Group A was anesthetized with propofol sedation and Group B with Isoflurane-epidural anesthesia. Group A was subdivided into three groups of low, middle and high concentration of target effect-site of 1.0 μg/ml, 1.5 μg/ml and 2.0 μg/ml through target controlled infusion （TCI） and Group B into 3 subgroups of minimum alveolar effective concentration of isoflurane （0.4 MAC, 0.6 MAC and 0.8 MAC for B1, B2 and B3 subgroups） respectively, with 8 patients in every subgroup. EA on acupoints of Hegu （LI4） and Neiguan （P6） was applied on all the patients during anesthesia, and the change of AAI at various time points was recorded. Results： In the three subgroups of Group A, levels of AAI were significantly elevated in the first few minutes after EA, and significantly lowered 20 min after EA in subgroup A2. While in the subgroups of Group B, except the elevating in Group B11 - 2 rain after EA, levels of AAI remained unchanged at other time points. Conclusion： Pain response could be reflected by AAI during EA. EA could enhance the sedative effect of propofol in middle concentration, but its effect on isoflurane epidural anesthesia is insignificant.

AN EXPERIMENTAL STUDY OF ELECTROACUPUNCTURE ON AUDITORY IMPAIRMENT CAUSED BY KANAMYCIN IN GUINEA PIGS

Frequency following response(FFR)and auditory brain stem evoked potential response(ABR)were used to determine the auditory acuity in evaluating the effect of electro-acupuncture treatment of kanamycin-induced auditory impairment in guinea pigs.Thesuccinate dehydrogenase(SDH)activity and morphological changes of the inner earreceptors were examined under the light and scanning electron microscope in cochlearspread preparations.The results showed that 1)electro-acupuncture was effective but nosignificant differences were found among the stimulating wave forms;2)Tinggong(SI19),Yifeng(SJ 17),Shenshu(UB 23),Sanyinjiao(Sp 6),Zhubin(K 9)and Waiguan(SJ 5)are all effective acupoints,especially the combination of Tinggong(SI 19),Sanyinjiao(Sp6)and Zhubin(K 9)acupoints;3)improvement in the cochlear function and excitabilityof the cortical and lower auditory center and increase of the mitochondrial SDH activityand energy supply in hair cells might contribute to the mechanism of the treatment.

Sensory evoked potentials in patients with affective disorders accompanying suicidal behavior

OBJECTIVE: To investigate the variations of sensory evoked potentials (SEPs) in patients with affective disorders accompanying suicidal behavior. METHODS: 39 depressive patients, 22 manic patients and 33 normal controls were included in the study. Visual, auditory and somatosensory evoked potentials (VEP, AEP & SSEP) were recorded from every subject using a Nicolet Spirit Instrument. RESULTS: Both the depressive and manic groups presented prolonged latencies and decreased amplitudes of major components of SEPs as compared to that of normal controls. Depressive patients with suicidal behavior had decreased P(3) amplitude of VEP (P

Effect of noise on the auditory center

Adult guinea pigs with normal Preyer’s reflexes were used in this experiment and were di-vided into 3 groups according to the intensity of noise and exposure time.Auditory brainstemevoked response was recorded before and after exposure to noise.Clicks were presented monaurallyat a rate of high (50Hz) as well as low (10Hz).The superior olive and inferior colliculus were ob-served under an electron microscope after the guinea pigs were exposured to 110dB noise for30min.The average shift of wave Ⅳ amplitude-intensity function curve was more than that ofwave Ⅰ after exposure to intensive noise.The difference value of wave \ latency from low(10Hz) to high (50Hz) stimulus click rate decreased and was negatively correlated with the exposuretime.Ⅰ-Ⅴ,Ⅲ-Ⅴ and Ⅳ-Ⅴ interpeak latencies were shorter after exposure to noise.Themitochondria and neurilemma swelling were found in the superior olive and inferior colliculus afterexposure,Some mechanisms of the changes of auditory center were discussed in this paper.

Formal Auditory Training with Individuals after Traumatic Brain Injury

Purpose: Establishing the effects of a formal auditory training program on individuals, after a traumatic brain injury by means of behavioral and electrophysiological tests. Study Design: Longitudinal study. Setting: Study conducted at the electrophysiology clinic of the Federal University of S&#227;o Paulo. Patients: Nine individuals with normal hearing, 20 to 37 years old, who were exposed to severe traumatic brain injury (score of 3 - 8 on the Glasgow Coma Scale upon hospital admission), 6 - 24 months earlier (11 months on average) and had imaging tests showing diffuse axonal injury with or without associated focal lesion. Intervention(s): subjected to a formal auditory training program in an acoustic booth involving eight 45-minute sessions aiming at training the auditory temporal order judgment (frequency and duration of sounds), auditory closure, and figure-ground separation skills for verbal and nonverbal sounds in monotic and dichotic listening tasks. The sessions and activities, in each session, were organized in increasing order of complexity to challenge the auditory system. In order to establish the efficacy of the auditory training, all participants were subjected to behavioral and electrophysiological assessments of the auditory processing, before and after the formal auditory training. Results: On the electrophysiological assessment, the absolute latencies of waves III and V, and of interpeak interval I-V decreased after the auditory training. However, the P300 did not exhibit a significant difference in either the latency or the amplitude parameters. Regarding the behavioral assessment of the auditory processing, it was verified that adequacy of the auditory figure-ground skills for verbal sounds, and the temporal order judging skills. Conclusions: individuals with diffuse axonal injury following a severe traumatic brain injury exhibited an improvement of central auditory processing after formal auditory training, as manifested on electrophysiological and behavioral assessments.

Dysfunction of the peripheral and central auditory pathway in patients with type 1 diabetes mellitus

Although auditory alterations are not a typical symptom of diabetes mellitus (DM), they can occur in patients with type 1 DM. The findings of previous studies are controversial, because the frequency and degree of hearing loss varies, and quite often alterations are still subclinical. The typical test used to detect and manage hearing loss is the audiogram, but this test alone is only capable of detecting alterations due to injury of the inner hair cells and/or alterations in the central auditory pathway. However, auditory alterations resulting from a dysfunction that is still subclinical are only able to be detected through electrophysiological auditory tests, such as the otoacoustic emissions (OAE) and the auditory brainstem response (ABR) tests. Thus, the purpose of this paper is to review the studies that utilize the OAE and ABR tests, and to verify if the dysfunction is cochlear and/or neural in patients with type 1 DM. The findings of this review demonstrate that patients with type 1 DM can have auditory alterations stemming from a central cochlear origin. Following this finding, early diagnosis is very important in order to implement preventative treatments and initiate therapy.