Impact of auditory stimulation nursing protocol on auditory response in cerebrovascular stroke patients

Objectives:The objective of the study was to explore the impact of auditory stimulation protocol on auditory response in cerebrovascular stroke(CVS)patients.Materials and Methods:A pre-posttest nonequivalent control group quasi-experimental study was conducted at Al Mainal Hospital at Al Kars Einy Hospital,Cairo University,among 60 CVS patients,and the sample was randomly assigned through a coin to allocate subjects to study or control group(30 for each group).Auditory stimulation techniques were applied three times per week for the study group for two consecutive weeks.Patients in the control group received only routine hospital care during the study period.The Glasgow Coma Scale(GCS)score for assessing the neurological function and level of arousal and the auditory subscale score of Western Neuro Sensory Stimulation Profile(WNSSP)for assessing auditory response were recorded and compared between the two groups before and after the intervention.Results:There were statistically significant differences between the study group and the control group regarding third reading of GCS score(11.5±0.3 vs.10.6±0.9,t=4.676,P=0.000).The scores of all auditory subscales of WNSSP in the study groups increased after implementing the auditory stimulation protocol(P<0.05).Conclusion:Utilizing the auditory stimulation protocol by nurse proves to be an effective method for enhancing hearing responses in individuals with CVS.

The characterization of auditory brainstem response(ABR) waveforms: A study in tree shrews(Tupaia belangeri)

To characterize the patterns of ABR waves in tree shrews, we must understand the hearing sensitivity and auditory function of healthy adult tree shrews. Fifteen tree shrews(30 ears) were stimulated with clicks and tone-pips at 11 different frequencies from 1 to 60 kHz. The ABR waves were recorded and analyzed. The ABR consisted of five to seven positive waves in the first 10 ms after a click stimulus, and the average hearing threshold of component III was 27.86 ± 3.78 dB SPL. Wave III was the largest and most clear. The ABR threshold was related to the tone-pip sitmulus by a "U" shaped curve. The sensitive frequency was approximately 8 kHz in tree shrews. The latencies systematically decreased with increasing stimulus frequencies. The ABR amplitudes of wave III increased as the sound pressure level increased. All of these results provide an empirical basis for future studies of hearing diseases in tree shrews.

Auditory brainstem functioning in individuals with misophonia

Purpose:Misophonia is not investigated much from an audiological perspective.Our study aims to examine the processing of the auditory retro-cochlear pathways in individuals with misophonia.Methods:A cross-sectional study was conducted among university students who had misophonia.The revised Amsterdam Misophonia Scale was used to determine the severity of misophonia.Participants were divided into mild and moderate-severe misophonia and compared with the healthy control group.Auditory Brainstem Response testing was recorded from all the individuals with misophonia.The absolute latency,amplitude,inter-peak latency difference,and inter-rate latency difference were compared between the groups.Results:One-way ANOVA result showed no significant difference in all the parameters of auditory brainstem response between the groups.These results are suggestive of normal brainstem processing in individuals with misophonia.Conclusions:The study concludes that the auditory pathway up to brainstem areas is intact in individuals with misophonia.Further studies are essential on a larger population for generalizing the results.

The Auditory Brainstem and Middle Latency Responses in Healthy Mice

The auditory brainstern responses(ABR)and middle latency responses(MLR)were recorded in 24 normal mice with a 7S11A processor,and the normalparameters of ABR and MLR obtained.The results showed that the ABR of mice werecomposed of 6 waves,waves Ⅰ to Ⅵ.The mean threshold was 35.12±8.03 dB ,whichwas significantly different from the 22.63 dB of ABR found in guinea pigs.Thelatency of ABR waves Ⅰ to Ⅵizn the mice was found to be 1.30±8.03 ms ;2.02±0.24ms ;2.90±0.27 ms ;3.80±0.24 ms ;4.87±0.42 ms and 5.83±0.40 ms respectively.Nosex or strain differences were found.The MLR waveform of the mice were similar tothose of human and the latency was found to be P0 3.94±1.76 ms;P8.38±1.57ms;Na 14.98±2.54 ms;Pa 24.56±3.15 ms rcspectively.It is suggested that mice can beused for hearing research.Since the Na and Pa waves of MLR were unstable under anes-thesia,testing conditions for determining MLR in mice need further study.

AUDITORY BRAINSTEM RESPONSES IN SENILE PRESBYCUSIS PATIENTS OVER 90 YEARS

Objective To analyze the characteristics of auditory brainstem response (ABR) in presbycusis patients el-der than 90 years. Methods Fourteen presbycusis patients elder than 90 years (presbycusis group, 91.1.4 ± 1.3 years, 26 ears) and 9 normal-hearing young adults (control group, 22.7 ± 1.2 years, 18 ears) participated in the study. Alternative click-evoked ABRs were recorded in both groups. The peak latency (PL) of peak I,Ⅲ, and V, and the inter-peak latency (IPI) of I-Ⅲ,Ⅲ-V, and I-V were compared between groups. Results In elder presbycusis patients, the occurrence rate of peak I andⅢwere both 76.9%, and that of peak V was 84.6%. In presbycusis group, the peak latencies of I, Ⅲ, V were significantly longer than that of control group (P<0.001). There was no significant difference between groups in the IPI of peak I-IⅢ (P=0.298, peakⅢ-V (P=0.254) and peak I-V (P=0.364). Conclusions Auditory brainstem responses in presbycusis pa-tients elder than 90 years showed worse wave differentiation.

Effects of glutamate on distortion-product otoacoustic emissions and auditory brainstem responses in guinea pigs

Objectives To investigate changes in evoked potentials and structure of the guinea pig cochleae during whole cochlear perfusion with glutamate. Methods CM, CAP, DPOAE, and ABR were recorded as indicators of cochlear functions during whole cochlear perfusion. The morphology of the cochlea was studied via transmission electron microscopy. Results There were no significant changes in DPOAE amplitude before and after glutamate perfusion. CM I/O function remained nonlinear during perfusion. ABR latencies were delayed following glutamate perfusion. The average CAP threshold was elevated 35 dB SPL following glutamate perfusion.. The OHCs appeared normal, but the IHCs and afferent dendrites showed cytoplasmic blebs after glutamate perfusion. Conclusions While being a primary amino acid neurotransmitter at the synapses between hair cells and spiral ganglion neurons, excessive glutamate is neurotoxic and can destroy IHCs and spiral ganglion neurons. The technique used in this study can also be used to build an animal model of auditory neuropathy.

Analysis of Time and Frequency Domain of Auditory Brainstem Response in Normal Guinea Pigs

The auditory brainstem response (ABR) was measured for 90 cars of norml gui-nea pigs,from which the mean latency,amplitude and recognition of waves were obtain-ded.The waves were classified into six types,with wave Ⅲ as the main wave which ac-counted for 77.1% of all the waves.The frequency domain of each type was analysed bymeans of digital filtering and auto-regressive (AR)estimation.The main frequency com-position of ABR in the guinea pigs was restricted within 1600 Hz,in which there werethree peaks at AR spectrum,the mean value of the peaks being 107.33 Hz,566.67 Hzand 1076 Hz respectively.The AR spectrograms of all types waves were very similar toeach other.

Analysis of the variability of auditory brainstem response components through linear regression

The analysis of the Auditory Brainstem Response (ABR) is of fundamental importance to the investigation of the auditory system behavior, though its interpretation has a subjective nature because of the manual process employed in its study and the clinical experience required for its analysis. When analyzing the ABR, clinicians are often interested in the identification of ABR signal components referred to as Jewett waves. In particular, the detection and study of the time when these waves occur (i.e., the wave latency) is a practical tool for the diagnosis of disorders affecting the auditory system. In this context, the aim of this research is to compare ABR manual/visual analysis provided by different examiners. Methods: The ABR data were collected from 10 normal-hearing subjects (5 men and 5 women, from 20 to 52 years). A total of 160 data samples were analyzed and a pair- wise comparison between four distinct examiners was executed. We carried out a statistical study aiming to identify significant differences between assessments provided by the examiners. For this, we used Linear Regression in conjunction with Bootstrap, as a method for evaluating the relation between the responses given by the examiners. Results: The analysis suggests agreement among examiners however reveals differences between assessments of the variability of the waves. We quantified the magnitude of the obtained wave latency differences and 18% of the investigated waves presented substantial differences (large and moderate) and of these 3.79% were considered not acceptable for the clinical practice. Conclusions: Our results characterize the variability of the manual analysis of ABR data and the necessity of establishing unified standards and protocols for the analysis of these data. These results may also contribute to the validation and development of automatic systems that are employed in the early diagnosis of hearing loss.

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 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.

THE EFFECTS OF SALICYLATE ON AUDITORY EVOKED POTENTIAL AMPLITWDE FROM THE AUDITORY CORTEX AND AUDITORY BRAINSTEM

Tinnitus has often been studied using salicylate in animal models as they are capable of inducing tempo-rary hearing loss and tinnitus. Studies have recently observed enhancement of auditory evoked responses of the auditory cortex (AC) post salicylate treatment which is also shown to be related to tinnitus like behavior in rats. The aim of this study was to observe if enhancements of the AC post salicylate treatment are also present at structures in the brainstem. Four male Sprague Dawley rats with AC implanted electrodes were tested for both AC and auditory brainstem response (ABR) recordings pre and post 250 mg/kg intraperitone-al injections of salicylate. The responses were recorded as the peak to trough amplitudes of P1-N1 (AC), ABR wave V, and ABR waveⅡ. AC responses resulted in statistically significant enhancement of ampli-tude at 2 hours post salicylate with 90 dB stimuli tone bursts of 4, 8, 12, and 20 kHz. Wave V of ABR re-sponses at 90 dB resulted in a statistically significant reduction of amplitude 2 hours post salicylate and a mean decrease of amplitude of 31%for 16 kHz. WaveⅡamplitudes at 2 hours post treatment were signifi-cantly reduced for 4, 12, and 20 kHz stimuli at 90 dB SPL. Our results suggest that the enhancement chang-es of the AC related to salicylate induced tinnitus are generated superior to the level of the inferior colliculus and may originate in the AC.

40 Hz Auditory Steady State Response to Linguistic Features of Stimuli during Auditory Hallucinations

The auditory steady state response （ASSR） may reflect activity from different regions of the brain, depending on the modulation frequency used. In general, responses induced by low rates （_〈40 Hz） emanate mostly from central structures of the brain, and responses from high rates （〉80 Hz） emanate mostly from the peripheral auditory nerve or brainstem structures. Besides, it was reported that the gamma band ASSR （30-90 Hz） played an important role in working memory, speech understanding and recognition. This paper investigated the 40 Hz ASSR evoked by modulated speech and reversed speech. The speech was Chinese phrase voice, and the noise-like reversed speech was obtained by temporally reversing the speech. Both auditory stimuli were modulated with a frequency of 40 Hz. Ten healthy subjects and 5 patients with hallucination symptom participated in the experiment. Results showed re- duction in left auditory cortex response when healthy subjects listened to the reversed speech compared with the speech. In contrast, when the patients who experienced auditory hallucinations listened to the reversed speech, the auditory cortex of left hemispheric responded more actively. The ASSR results were consistent with the behavior results of patients. Therefore, the gamma band ASSR is expected to be helpful for rapid and objective diagnosis of hallucination in clinic.

Context Dependent Auditory Thresholds Determined by Brainstem Audiometry and Prepulse Inhibition in Mongolian Gerbils

Information on hearing thresholds is not always reliable as differences in these thresholds have been described even for the same species. This may partially be due to different methods used by different labs. A frequently used approach to obtain an estimate of hearing threshold is the electrophysiological recording of auditory brainstem responses (ABR). They are usually recorded under deep anesthesia and represent the auditory evoked far-field potentials at various levels in the central auditory pathway. Alternatively, several behavioral approaches are employed. These commonly use operant or classical conditioning to determine hearing thresholds. A potential disadvantage of these methods is that any sound conditioning may in principle alter auditory perception and therefore auditory thresholds. To exclude this type of methodological bias a prepulse inhibition (PPI) paradigm can be used where an audiogram can be determined without any kind of pre-training. Here we compare the threshold estimates obtained by two different ABR and PPI measurements where stimuli are presented in different contexts, either randomly or non-randomly, to test for a possible effect of auditory sensitization. In addition we test the effect of a frequency specific acoustic trauma on the audiograms obtained with both methods. In general we find behaviorally determined audiograms to be significantly lower in absolute thresh- old compared to ABR measurements. Furthermore non-randomized presentation context of the stimuli generally results in audiograms with 10 to 15 dB lower thresholds than pseudo-randomized presentation. Finally, the amount of threshold loss induced by acoustic trauma is similar for all methods tested.

Awake craniotomy for auditory brainstem implant in patients with neurofibromatosis type 2:Four case reports

BACKGROUND The auditory brainstem implant(ABI)is a significant treatment to restore hearing sensations for neurofibromatosis type 2(NF2)patients.However,there is no ideal method in assisting the placement of ABIs.In this case series,intraoperative cochlear nucleus mapping was performed in awake craniotomy to help guide the placement of the electrode array.CASE SUMMARY We applied the asleep-awake-asleep technique for awake craniotomy and hearing test via the retrosigmoid approach for acoustic neuroma resections and ABIs,using mechanical ventilation with a laryngeal mask during the asleep phases,utilizing a ropivacaine-based regional anesthesia,and sevoflurane combined with propofol/remifentanil as the sedative/analgesic agents in four NF2 patients.ABI electrode arrays were placed in the awake phase with successful intraoperative hearing tests in three patients.There was one uncooperative patient whose awake hearing test needed to be aborted.In all cases,tumor resection and ABI were performed safely.Satisfactory electrode effectiveness was achieved in awake ABI placement.CONCLUSION This case series suggests that awake craniotomy with an intraoperative hearing test for ABI placement is safe and well tolerated.Awake craniotomy is beneficial for improving the accuracy of ABI electrode placement and meanwhile reduces non-auditory side effects.

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.

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.

Auditory steady-state evoked response in diagnosing and evaluating hearing in infants

BACKGROUND: Auditory steady-state evoked response (ASSR) is one of the new objective electrophysiological methods to test hearing in infants. It can provide a reliable and complete audiogram with specific frequency to help the hearing diagnosis and rehabilitation of hearing and languaging following auditory screening. OBJECTIVE: To compare the response threshold of ASSR with auditory threshold of visual reinforcement audiometry (VRA) in infants failed in the hearing screening for investigating their hearing loss. DESIGN: A comparative observation. SETTINGS: Maternal and child health care hospitals of Guangdong province, Shunde city, Nanhai city and Huadu district. PARTICIPANTS: Totally 321 infants of 0-3 years undergoing ASSR test were selected from the Hearing Center of Guangdong Maternal and Child Health Care Hospital from January 2002 to December 2004. Informed consents were obtained from their guardians. There were 193 cases (60.2%) of 0-6 months, 31 cases (9.7%) of 7-12 months, 17 cases (5.3%) of 13-18 months, 14 cases (4.4%) of 19-24 months, 33 cases of 25-30 months, and 33 cases (10.2%) of 31-36 months. METHODS: ① The 321 infants failed in the hearing screening were tested under sleeping status, the ranges of response threshold distribution in ASSR of different frequencies were analyzed in each age group. ② The infants above 2 years old were also tested with VRA, and their response thresholds were compared between VRA and ASSR. ③ Evaluative standards: The response threshold was < 30 dB for normal hearing, 31-50 dB for mild hearing loss, 51-70 dB for moderate hearing loss, 71-90 dB for severe hearing loss, and > 91 dB for extremely severe hearing loss. MAIN OUTCOME MEASURES: ① ASSR results of the infants failed in the screening; ② Proportion of cases of each response threshold in each age group; ③ Comparison of ASSR response thresholds and VRA auditory thresholds in the infants of 2-3 years old. RESULTS: ①The response threshold was < 30 dB in 47.4% of the 321 infants failed in the initial hearing screening and secondary screening after 42 days. ② Severe to extremely severe hearing loss was detected in only 16 cases (8.3%) of the 193 infants of 0-6 months, in 9 cases (27.3%) of the 33 infants of 25-30 months, and 13 cases (39.4%) of the 33 infants of 31-36 months. Of the 193 infants of 0-6 months old who failed in the initial screening and the second screening after 42 days, the ASSR auditory threshold was < 30 dB in 97 cases (50.26%), 31-50 dB in 63 cases (32.6%), 51-70 dB in 17 cases (8.8%), 71-90 dB in 7 cases (3.6%), and > 91 dB in 9 cases (4.7%). ③ Among the 321 infants failed in the screening, the auditory threshold in the 6 age groups was < 30 dB in 47.4%, 31-50 dB in 27.1%, 51-70 dB in 8.4%, 71-90 dB in 6.2%, and > 91 dB in 10.9%. ④ The difference between ASSR response threshold and VRA auditory thresholds was 6-18 dB in the normal hearing group, mild and moderate hearing loss groups, and there was high correlation between them. The difference of ASSR and VRA thresholds was less than 5 dB between extremely severe and severe hearing loss groups, 5-13 dB between extremely severe and moderate-to-severe hearing loss groups (P < 0.05), and there was no significant differences between severe and moderate-to-severe hearing loss groups (P > 0.05). CONCLUSION: ① The hearing was normal in about half of the infants, although they failed in the primary screening and secondary screening. ② The proportion of the severity of hearing loss was increased along with aging. ③ Mild and moderate hearing losses are dominant in infants. ④ ASSR is reliable to evaluate the hearing of infants.

Reproducibility of Test-Retest Cortical Evoked Responses in Patients with Focal Epilepsy

This exploratory study examined the short-term reliability of cortical auditory evoked responses recorded from patients undergoing whole-head scalp elec-troencephalography (EEG) monitoring to assess their candidacy for surgical treatment of intractable focal seizures. Participants were 26 patients with either left-sided (N = 13) or right-sided focal epilepsy admitted to the hospital for continuous scalp EEG monitoring for possible epilepsy surgery planning. Cortical auditory evoked responses were recorded over multiple days from scalp EEG electrodes using tones presented binaurally in a passive oddball paradigm. Test-retest intervals were 1 - 6 days (mean 2 days). Test-retest reproducibility of the auditory N1 response was assessed by paired t-test (latency) and cross-correlation analysis (amplitude and latency). Within-patient comparisons of test-retest auditory N1 peak latencies revealed no significant differences. The cross-correlation coefficient indicated high test-retest reproducibility of the N1 waveform (rcc = 0.88). Seizure lateralization was not associated with asymmetries in N1 latencies or amplitudes. An N1 amplitude asymmetry (right > left) in patients with focal seizures originating from the left hemisphere was initially observed, but disappeared when patients with prior resections were excluded, suggesting that reduced left hemisphere tissue volume may account for the smaller N1 amplitudes. Test-retest reliability of cortical auditory evoked responses was unexpectedly high in patients with focal epilepsy regardless of seizure lateralization or localization. These findings challenge the view that neural responses are intrinsically unstable (unreliable) in patients with seizures.

受试者测试状态对卡尔曼加权平均ABR测试残余噪声的影响

目的探讨采用卡尔曼加权平均(Kalman-weighted averaging,KWA)的听性脑干反应(ABR)测试中,受试者不同测试状态对残余噪声及ABR波V振幅的影响。方法选取21例(42耳)18~34岁听力正常成年人,分别在安静诊室内三种不同的状态下(安静平卧、坐位、写字)使用卡尔曼加权平均的新型ABR系统(vivosonic integrity system)进行ABR测试,同时使用传统ABR测试系统(interacoustics,IA)在隔声屏蔽室内进行ABR测试,记录各状态下受试者ABR反应的残余噪声水平和波V幅值并进行比较。结果①传统ABR和卡尔曼加权平均ABR三种不同测试状态(平卧、坐位、写字)下波V振幅没有显著差异(P>0.05);②卡尔曼加权平均ABR安静平卧和坐位两种状态下的残余噪声水平较传统ABR低,但无统计学差异(P>0.05);卡尔曼加权平均ABR在写字状态下的残余噪声水平显著高于其他三种状态(P<0.05);③写字状态下卡尔曼加权平均ABR的残余噪声、波V振幅在左右耳之间没有显著差异(P>0.05)。结论与传统ABR相比,卡尔曼加权平均ABR在写字状态下的残余噪声显著升高,但安静平卧和坐位状态下的残余噪声水平与传统ABR无显著差异,受试者的不同测试状态对残余噪声水平有一定影响。