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.

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.

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.

Median Nerve Somatosensory Evoked Potentials in Patients with Chiari Malformation

Abnormal SEP reflects dysfunction of the medial lemniscus and posterior cervical cord. These structures are likely to be affected in Chiari malformation. Therefore, SEP abnormalities may provide valuable information in patients with CM. However, the consistency of SEP abnormality or normality with the damage is a matter of research. Knowing whether median nerve somatosensory evoked potential (SEP) is useful in revealing subclinical damage in patients with Chiari malformation is important in the treatment and follow-up plan of the disease. The aim of this study was to investigate the relationship between median nerve SEP values and the severity of cerebellar ectopia in patients with Chiari type 1 malformation. Median nerve SEP values were obtained from 30 healthy individuals and 146 individuals with Chiari malformation. The cerebellar ectopia degree and McRae line length were measured. SEP values were not significantly different between groups. The McRae line was found to be significantly shorter in the control group than in the Chiari malformation group (p = 0.031). There was no correlation between the degree of cerebellar ectopia and the length of the McRae line (r = 0.002, p = 0.979). Neither cerebellar ectopy degree nor McRae line length had a relationship with SEP values (r = -0.153, p = 0.066;r = -0.056, p = 0.500, respectively). There was no difference in cerebellar ectopy degree or SEP values between the groups with cerebellar ectopy with and without a syrinx (p = 0.899;p = 0.080, respectively). Likewise, McRae line length was not found to be related to the presence of a syrinx (p = 0.139). Median nerve SEP examination was not beneficial for diagnosing asymptomatic-oligosymptomatic Chiari malformation as a subclinical injury, whether accompanied by syringomyelia or not.

Retro-labyrinthine Lesion Site Detected by Galvanic Vestibular Stimulation Elicited Vestibular-evoked Myogenic Potentials in Patients with Auditory Neuropathy

Objective Auditory neuropathy(AN)is a unique pattern of hearing loss with preservation of hair cell function.The condition is characterized by the presence of otoacoustic emissions(OAE)or cochlear microphonic(CM)responses with severe abnormalities of the auditory brainstem response(ABR).The vestibular branches of the VIII cranial nerve and the structures innervated by it can also be affected.However,the precise lesion sites in the vestibular system are not well characterized in patients with AN.Methods The air-conducted sound(ACS)vestibular-evoked myogenic potentials(VEMPs)and galvanic vestibular stimuli(GVS)-VEMPs were examined in 14 patients with AN.Results On examination of VEMPs(n=14,28 ears),the absent rates of ACS-cervical VEMP(cVEMP),ACS-ocular VEMP(oVEMP),GVS-cVEMP,GVS-oVEMP and caloric test were 92.9%(26/28),85.7%(24/28),67.9%(19/28),53.6%(15/28),and 61.5%(8/13),respectively.Impaired functions of the saccule,inferior vestibular nerve,utricle,superior vestibular nerve,and horizontal semicircular canal were found in 25.0%(7/28),67.9%(19/28),32.1%(9/28),53.6%(15/28)and 61.5%(8/13)patients,respectively.On comparing the elicited VEMPs parameters of AN patients with those of normal controls,both ACS-VEMPs and GVS-VEMPs showed abnormal results in AN patients(such as,lower presence rates,elevated thresholds,prolonged latencies,and decreased amplitudes).Conclusion The study suggested that patients with AN often have concomitant vestibular disorders.Retro-labyrinthine lesions were more frequently observed in this study.GVS-VEMPs combined with ACS-VEMPs may help identify the lesion sites and facilitate detection of areas of vestibular dysfunction in these patients.

Identification of injury type using somatosensory and motor evoked potentials in a rat spinal cord injury model

The spinal cord is at risk of injury during spinal surgery.If intraoperative spinal co rd injury is identified early,irreve rsible impairment or loss of neurological function can be prevented.Different types of spinal cord injury result in damage to diffe rent spinal cord regions,which may cause diffe rent somatosensory and motor evoked potential signal res ponses.In this study,we examined electrophysiological and histopathological changes between contusion,distra ction,and dislocation spinal cord injuries in a rat model.We found that contusion led to the most severe dorsal white matter injury and caused considerable attenuation of both somatosensory and motor evoked potentials.Dislocation resulted in loss of myelinated axons in the lateral region of the injured spinal cord along the rostrocaudal axis.The amplitude of attenuation in motor evoked potential responses caused by dislocation was greater than that caused by contusion.After distraction injury,extracellular spaces were slightly but not significantly enlarged;somatosensory evoked potential res ponses slightly decreased and motor evoked potential responses were lost.Correlation analysis showed that histological and electrophysiological findings we re significantly correlated and related to injury type.Intraope rative monitoring of both somatosensory and motor evoked potentials has the potential to identify iatrogenic spinal cord injury type during surgery.

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.……

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

Monitoring somatosensory evoked potentials in spinal cord ischemia-reperfusion injury

It remains unclear whether spinal cord ischemia-reperfusion injury caused by ischemia and other non-mechanical factors can be monitored by somatosensory evoked potentials. Therefore, we monitored spinal cord ischemia-reperfusion injury in rabbits using somatosensory evoked potential detection technology. The results showed that the somatosensory evoked potential latency was significantly prolonged and the amplitude significantly reduced until it disappeared during the period of spinal cord ischemia. After reperfusion for 30-180 minutes, the amplitude and latency began to gradually recover; at 360 minutes of reperfusion, the latency showed no significant difference compared with the pre-ischemic value, while the somatosensory evoked potential amplitude in- creased, and severe hindlimb motor dysfunctions were detected. Experimental findings suggest that changes in somatosensory evoked potentia~ ~atency can reflect the degree of spinat cord ischemic injury, while the amplitude variations are indicators of the late spinal cord reperfusion injury, which provide evidence for the assessment of limb motor function and avoid iatrogenic spinal cord injury.

Effect of sodium tungstate on visual evoked potentials in diabetic rats

AIM： To evaluate the effect of sodium tungstate on visual evoked potentials（VEPs） in diabetic rats.· METHODS： Wistar rats were randomly divided into three groups as normal control, diabetic control and diabetic rats treated with sodium tungstate. Diabetes was induced by single intraperitoneal injection of streptozotocin（50 mg/kg）. Sodium tungstate [40 mg/（kg·d）]was administered for 12 wk and then VEPs were recorded.Additionally, thiobarbituric acid reactive substance（TBARS） levels were measured in brain tissues.·RESULTS： The latencies of P1, N1, P2, N2 and P3 waves were significantly prolonged in diabetic rats compared with control group. Diabetes mellitus caused an increase in the lipid peroxidation process that was accompanied by changes in VEPs. However, prolonged latencies of VEPs for all components returned to control levels in sodium tungstate-treated group. The treatment of sodium tungstate significantly decreased brain TBARS levels and depleted the prolonged latencies of VEP components compared with diabetic control group.· CONCLUSION： Sodium tungstate shows protective effects on visual pathway in diabetic rats, and it can be worthy of further study for potential use.

Changes of auditory evoked magnetic fields in patients after acute cerebral infarction using magnetoencephalography

Auditory evoked magnetic fields were recorded from 15 patients with acute cerebral infarction and 11 healthy volunteers using magnetoencephalography.The auditory stimuli of 2 kHz pure tone were binaurally presented with an interstimulus interval of 1 second.The intensity of stimuli was 90 dB and the stimulus duration was 8 ms.The results showed that the M100 was the prominent response, peaking approximately 100 ms after stimulus onset in all subjects.It originated from the area close to Heschl’s gyrus.In the patient group,the peak latency of M100 responses was significantly prolonged,and the mean strength of equivalent current dipole was significantly smaller in the affected hemisphere.The three-dimensional inter-hemispheric difference of the M100 positions was increased in the patient group.Our experimental findings suggested that impairment of cerebral function in patients with acute ischemic stroke can be detected using magnetoencephalography with the higher spatial resolution and temporal resolution.Magnetoencephalography could provide objective and sensitive indices to estimate auditory cortex function in patients with acute cerebral infarction.

Short-duration transient visual evoked potentials and color reflectivity discretization analysis in glaucoma patients and suspects

AIM： To evaluate the use of short-duration transient visual evoked potentials（VEP） and color reflectivity discretization analysis（CORDA） in glaucomatous eyes,eyes suspected of having glaucoma,and healthy eyes.METHODS： The study included 136 eyes from 136 subjects： 49 eyes with glaucoma,45 glaucoma suspect eyes,and 42 healthy eyes.Subjects underwent Humphrey visual field（VF） testing,VEP testing,as well as peripapillary retinal nerve fiber layer optical coherence tomography imaging studies with post-acquisition CORDA applied.Statistical analysis was performed using means and ranges,ANOVA,post-hoc comparisons using Turkey＇s adjustment,Fisher＇s Exact test,area under the curve,and Spearman correlation coefficients.RESULTS： Parameters from VEP and CORDA correlated significantly with VF mean deviation（MD）（P〈0.05）.In distinguishing glaucomatous eyes from controls,VEP demonstrated area under the curve（AUC） values of 0.64-0.75 for amplitude and 0.67-0.81 for latency.The CORDA HR1 parameter was highly discriminative for glaucomatous eyes vs controls（AUC=0.94）.CONCLUSION： Significant correlations are found between MD and parameters of short-duration transient VEP and CORDA,diagnostic modalities which warrant further consideration in identifying glaucoma characteristics.

Benefits of combination of electroencephalography, short latency somatosensory evoked potentials, and transcranial Doppler techniques for confirming brain death

Objective: Optimization of combining electroencephalography (EEG), short latency somatosensory evoked potentials (SLSEP) and transcranial Doppler (TCD) techniques to diagnose brain death. Methods: One hundred and eleven patients (69 males, 42 females) from the major hospitals of Zhejiang Province were examined with portable EEG, SLSEP and TCD devices. Re-examinations occurred ≤12 h later. Results: The first examination revealed that the combination of SLSEP and EEG led to more sensitive diagnoses than the combination of SLSEP and TCD. Re-examination confirmed this and also revealed that the combination of TCD and EEG was the most sensitive. Conclusion: The results show that using multiple techniques to diagnose brain death is superior to using single method, and that the combination of SLSEP and EEG is better than other combinations.

Changes in the latencies of visual-evoked potentials in people undergoing tennis training Dynamic comparison before and after 8 weeks training

BACKGROUND： Some previous studies have shown that exercise is an important factor that affects the latencies of visual-evoked potentials （VEPs）. OBJECTIVE： To investigate the effects of spending a period of time undergoing tennis training on the latencies of VEPs by comparing the latencies of VEPs before tennis training with those after 8 weeks of tennis training. DESIGN, TIME AND SETTING： The non-randomly concurrent controlled experiment was performed in the Department of Human Movement Sciences, Physical Education College, Shandong Normal University from April to June 2007. PARTICIPANTS： In total, 45 healthy volunteers from Shandong Normal University were selected as subjects, including 31 students majoring in physical education （11 males and 5 females participated in the tennis training plan for 8 weeks）, and 14 students from other subjects. Informed consent was obtained. According to whether they were majoring in physical education or not, and whether or not they took part in tennis training, the students were divided into 3 groups： a tennis group of physical education students （n = 16） a non-tennis group of physical education students （n =15） and a non-tennis group of non-physical education students （n = 14）. METHODS： The subjects in the tennis group took part in a regular tennis training plan of 2 hours a day and 3 days per week, for 8 weeks, while the subjects in two non-tennis groups were not in the tennis training plan The NDI-200 neural electricity tester （Shanghai Haishen Medical Electronic Instrument Co., Ltd.） was used to measure VEPs before and after the experiment in all three groups, and to compare the latencies of VEPs recorded before training with those recorded after training. MAIN OUTCOME MEASURES： Comparison of the changes in latencies of VEPs before and after 8 weeks of tennis training. RESULTS： All 45 subjects finished the test and datas from all were included in the statistical analysis. There were no significant differences among all the three groups before tennis training, but the female subjects in each group showed significantly shorter N75 latencies than male subjects of the same group （P 〈 0.05）. Comparing the latencies of VEPs after training with those recorded before training, the N75, P100 and N145 latencies were all found to be significantly shorter than before training in the tennis group （P 〈 0.05）, but the N75, P100 and N145 latencies were unaffected in the two non-tennis groups （P 〉 0.05）; some latencies were even significantly longer than the before-training values. CONCLUSION： Special tennis training for 8 weeks can make the subjects＇ VEP latencies significantly shorter. Thus, VEP latencies can change with tennis training.

INTRAOPERATIVE LOCALIZATION OF CORTICAL MOTOR EVOKED POTENTIALS IN CENTRAL SULCUS LESIONS

Objective To study direct cortical electrical stimulation technique for the recording of motor evoked potentials under general anesthesia in central sulcus lesions. Methods The largest N20-P25 response was recorded from postcentral gyrus by intraoperative monitoring of cortical motor evoked potentials in 10 patients with intracranial lesions near or in the central area. The muscles of upper extremity in all patients were activated by delivering stimulus to cortical areas continuously. Moving the cortical electrodes forward, the largest P20-N25 response, SEP phase reversal,was obtained as a motor center stimulus. In this site of cortex, a short train stimulation elicited reproducible muscle action potentials that could be observed from the oscilloscope without averaging.Results MEPs can be recorded, pre-and post-operatively, without motor deficits of upper limbs in all patients.Conclusion This technique seems to be preferable for intraoperative localization of motor evoked potentials in central sulcus lesions under total intravenous anesthesia.

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 event-related brain potentials for an early discrimination between normal and pathological brain aging

The brain as a system with gradually decreasing resources maximizes its chances by reorganizing neural networks to ensure efficient performance. Auditory event-related potentials were recorded in 28 healthy volunteers comprising 14 young and 14 elderly subjects in auditory discrimination motor task （low frequency tone - right hand movement and high frequency tone - left hand movement）. The amplitudes of the sensory event-related potential components （N1, P2） were more pronounced with increasing age for either tone and this effect for P2 amplitude was more pronounced in the frontal region. The latency relationship of N1 between the groups was tone-dependent, while that of P2 was tone-independent with a prominent delay in the elderly group over all brain regions. The amplitudes of the cognitive components （N2, P3） diminished with increasing age and the hemispheric asymmetry of N2 （but not for P3） reduced with increasing age. Prolonged N2 latency with increasing age was widespread for either tone while between-group difference in P3 latency was tone-dependent. High frequency tone stimulation and movement requirements lead to P3 delay in the elderly group. The amplitude difference of the sensory components between the age groups could be due to a general greater alertness, less expressed habituation, or decline in the ability to retreat attentional resources from the stimuli in the elderly group. With aging, a neural circuit reorganization of the brain activity affects the cognitive processes. The approach used in this study is useful for an early discrimination between normal and pathological brain aging for early treatment of cognitive alterations and dementia.

Determination of Median Nerve Somatosensory Evoked Potentials in 27 Patients with Hemiplegia

Summary: Twenty-seven in-patients with hemiplegia following brain injury were studied by using upper extremity median nerve somatosensory evoked patentials (SVEP), Brunnstrom assessment in hemiplegic hand and assessment of the patients' activities of daily lioing (ADL) (Barthel index). The upper extremity median nerve SEP on the affected and normal sides was determined. By using Kovindha standard, upper extremity median nerve SEP was graded in accordance with N20. The correlation between the differences of SEP N20 amplitude and the latencies on the both sides and the Barthel index scores was analyzed. A Spearman correlation analysis was made between the median nerve SEP N20 grades and Brunnstrom stages in hand or ADL on the affected side. The results showed that upper extremity median nerve SEP grades were positively correlated with those of the Brunnstrom stages in hand (r 1=0.6925, P 1<0.01). The correlation coefficient between SEP N20 grades and patients' ADL grades was r 2=0.5015, P 2<0 01. It was concluded that upper extremity median nerve SEP could be used as a sensitive electrophysiological predictor to clinically assess hemiplegic hand function. SEP N20 might play a role in predicting the ADL of the patients with hemiplegia to some extent, but could not be used as a sensitive predictor to directly observe and predict the ADL of the patients.