27例孤独症儿童的脑干听觉诱发电位检测结果临床分析

目的：探讨孤独症患儿脑干听觉诱发电位（BAEP）的临床特征,为临床工作指导提供参考依据.方法：将研究对象分为：孤独症组（AD）27例和对照组（NG）30例.研究对象给予脑干听觉诱发电位测试.结果：27例患儿中,BAEP正常11例（40.7％）,异常16例（59.2％）,主要表现为波幅改变、波潜伏期、峰间期延长、波形分化不良或听阈值增高.结论：孤独症患儿听力基本正常,但存在BAEP异常,提示脑干听觉传导通路异常,可能是造成其认知与语言发育障碍的原因之一.     

Brainstem Auditory Evoked Potential (BAEPs) in Cluster Headache (CH): New Aspects for a Central Theory

SYNOPSIS
16 patients suffering from cluster headache (CH) were studied by recording brainstem auditory evoked potentials(BAEPs). Some subjects underwent examination in a pain-free period, some others during an acute attack, andothers during treatment with lithium.All the data were compared with the BAEPs records of 16 normal control subjects. CH patients showed anasymmetrical interaural pattern, both in the basal condition and in a pain period, greater than the asymmetryoccurring in normal subjects.These specific neurophysiological findings may be evidence for suggesting a central pathogenesis of CH.     

Lateralization, connectivity and plasticity in the human central auditory system

Although it is known that responses in the auditory cortex are evoked predominantly contralateral to the side of stimulation, the lateralization of responses at lower levels in the human central auditory system has hardly been studied. Furthermore, little is known on the functional interactions between the involved processing centers. In this study, functional MRI was performed using sound stimuli of varying left and right intensities. In normal hearing subjects, contralateral activation was consistently detected in the temporal lobe, thalamus and midbrain. Connectivity analyses showed that auditory information crosses to the contralateral side in the lower brainstem followed by ipsilateral signal conduction towards the auditory cortex, similar to the flow of auditory signals in other mammals. In unilaterally deaf subjects, activation was more symmetrical for the cortices but remained contralateral in the midbrain and thalamus. Input connection strengths were different only at cortical levels, and there was no evidence for plastic reorganization at subcortical levels.     

Brain lesion diagnosis by recording cochlear and brainstem responses to sound stimuli

A technique has been developed for the recording of the cochlear action potential (electrocochleography) and the brainstem evoked responses to click stimuli by means of earlobe and scalp electrodes with an average response computer. This technique has already proved its usefulness in diagnosis of hearing loss. Since the brainstem responses are generated in the successive brainstem auditory nuclei and since the auditory nuclei and pathways constitute a relatively large volume of brainstem tissue, there is reason to believe that this same technique can also contribute to the diagnosis of brain stem lesions and their localization. When these recordings were made in patients with clinical signs of brain stem involvement, one (or more) of the usual response waves was smaller in amplitude, prolonged in latency, or completely absent. Recording of the cochlear and brainstem evoked potentials thus seems to be a new, simple and rapid tool for the diagnosis of brainstem lesions.     

Brain death and evoked potentials in pediatric patients

OBJECTIVE: To define the evoked potential responses (auditory and somatosensory) obtained from pediatric brain-dead patients. DESIGN: Prospective study over an 8-yr period (1988-1996). SETTING: A 14-bed pediatric intensive care unit in a multidisciplinary regional referral center (teaching hospital). PATIENTS: Fifty-one pediatric patients with clinically established brain death. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Auditory brainstem and somatosensory evoked potentials were performed with a mean evolution time of 24 hrs after clinical brain death. The first brainstem auditory evoked potential recording was compatible with the diagnosis in 45 patients (90%): 27 patients (53%) did not respond, wave I was patent in 16 (7 bilateral, 6 from the left side, and 3 from the right side), and 2 patients evoked waves I and II in one or both ears. Gross anomalies were found in the remaining six patients. Sixteen patients were tested for somatosensory evoked potentials. N13 identifiable wave (62.5% of the patients) or a flat record were the obtained findings. Electric silence was noted initially on the electroencephalogram (EEG) in only 14 of 29 patients. Later flattening was observed in seven patients. Missing brainstem evoked response was noted earlier than cortical electric silence (range, 12-144 hrs). Any central wave could be pointed out in the evoked potentials of patients with an isoelectric EEG. CONCLUSIONS: Evoked potential is useful in confirming the diagnosis of brain death in infants and in children as well as in adults. The test can be performed at bedside without interfering with patient care, and results are similar to those obtained in adult patients. Flattening of the EEG requires more time than achieving compatible evoked-potential responses.     

Role of multimodal evoked potentials in evaluations of persistent vegetative state of nontraumatic origin

Persistent vegetative state (PVS) is a kind of release from coma, manifesting by absence of any signs of cognitive activity. Progress in reanimatology leads to an increase in the number of patients with PVS, thus creating a new medical and social problem. Study of atraumatic PVS acquires special importance because of a drastic increase in its incidence, necessitating definition of criteria of this state formation and its prognostic signs. Multimodal evoked potentials (MEP) now play an important role in diagnosis and prediction of PVS. The impact of acoustic stem (ASEP), visual (VEP), somatosensory (SSEP), and cognitive (CEP) evoked potentials is analyzed and early diagnostic and prognostic neurophysiological criteria are defined. Results of dynamic examinations of 23 patients (9 men and 14 women) aged 10-67 years with atraumatic PVS are presented. According to neurophysiological data, PVS in the majority of patients is characterized by absence of cognitive responses to a significant stimulus (wave P300) during examinations of CEP and of cortical response during examination of SSEP. VEP and long latent acoustic evoked potentials are as rule intact in atraumatic PVS. According to ASEP, stem functions were intact or slightly changed in the examined patients with PVS. Prognostically unfavorable and relatively favorable signs in the time course of MEP are defined.     

Detection and localization of occult lesions with brainstem auditory responses

Seven vertex-positive potentials--the brainstem auditory response--can be recorded from the human scalp within 10 milliseconds of an appropriate acoustic stimulus. The first of these potentials is generated in the acoustic nerve, the third in the pons, and the fifth in the midbrain. Measurement of the relative latencies and amplitudes of these potentials allowed detection of subclinical lesions in 37 (53 percent) of 70 patients with suspected multiple sclerosis who had no signs or symptoms of brainstem involvement by the disease. Abnormalities in the brainstem auditory response provided the first evidence of the pressence of multiple lesions in 14 (35 percent) of 40 patients with suspected multiple sclerosis who had clinical evidence of only a single spinal or cerebral lesion. Response abnormalities also suggested the presence of tumors of the posterior fossa in three patients with nonspecific symptoms and normal neurologic examinations, the test indicated the need for contrast studies, which then led to the correct diagnosis of infratentorial neoplasm.     

Electroencephalographic and evoked potential monitoring in the hyperbaric environment

The purpose of this study was to investigate brain bioelectrical activity during hyperbaric oxygenation by continuous and simultaneous monitoring of electroenccphalographic and bimodal (auditory, somatosensory) evoked potentials. Multivariable recordings (electroencephalogram, brainstem auditory evoked potentials, early somatosensory evoked potentials, heart rate, heart rate variability, and transcutaneous partial pressure of oxygen) were measured with a new technique in 12 healthy male volunteers 26 to 52 years old (mean ± SD, 35.9 ± 9.5 years). Recordings were obtained while the subjects breathed (1) air at normal atmospheric pressure, (2) 100% oxygen at normal atmospheric pressure, (3) air at 2 atm (10 meters sea water [msw]), and (4) 100% oxygen at 2 atm (10 msw). Spontaneous brain electrical activity, somatosensory evoked potentials, and heart rate variability were not significantly affected during hyperbaric oxygénation, whereas the heart rate showed a significant decrease (pairedt test,P < 0.05). Alterations in brainstem auditory evoked potentials were seen under hyperbaric conditions and did not reach statistical significance (increase of the I-V interpeak latency by pairedt test;P < 0.2). All subjects showed insignificant increases in dominant alpha frequency and decreases in delta frequency under hyperbaric situations.     

Fetal MEG evoked response latency from beamformer with random field theory

Analysis of fetal magnetoencephalographic brain recordings is restricted by low signal to noise ratio (SNR) and non-stationarity of the sources. Beamformer techniques have been applied to improve SNR of fetal evoked responses. However, until now the effect of non-stationarity was not taken into account in detail, because the detection of evoked responses is in most cases determined by averaging a large number of trials. We applied a windowing technique to improve the stationarity of the data by using short time segments recorded during a flash-evoked study. In addition, we implemented a random field theory approach for more stringent control of false-positives in the statistical parametric map of the search volume for the beamformer. The search volume was based on detailed individual fetal/maternal biometrics from ultrasound scans and fetal heart localization. Average power over a sliding window within the averaged evoked response against a randomized average background power was used as the test z-statistic. The significance threshold was set at 10% over all members of a contiguous cluster of voxels. There was at least one significant response for 62% of fetal and 95% of newborn recordings with gestational age (GA) between 28 and 45 weeks from 29 subjects. We found that the latency was either substantially unchanged or decreased with increasing GA for most subjects, with a nominal rate of about − 11 ms/week. These findings support the anticipated neurophysiological development, provide validation for the beamformer model search as a methodology, and may lead to a clinical test for fetal cognitive development.     

Responses of Human Auditory Association Cortex to the Omission of an Expected Acoustic Event

Unexpected auditory events initiate a complex set of event-related potentials (ERPs) that vary in their latency and anatomical localization. Such “mismatch” responses include active responses to the omission of an expected event or the omission of elements in expected stimulus composites. Here we describe intracranial recordings of middle-latency ERPs elicited by the omission of an auditory event. We first presented a sequence of tones at regular temporal intervals and the tone was omitted 20% of the time. In a second condition, we presented a sequence of tone pairs and the second tone of the pair was omitted 20% of the time. These two conditions are complementary in that the single tone conformed to the expectancy in one condition, but violated the expectancy in the other. All patients demonstrated localized cortical responses to missing tones that were topographically similar to the responses evoked by actual tones. Responses to both actual and omitted tones were observed bilaterally in the vicinity of the temporal–parietal junction, where we also obtained midlatency ERPs to a variety of other auditory stimuli. Responses that appeared to be selective for the nonoccurrence of expected tones were also observed in a number of subjects. We interpret these effects in terms of processes associated with the comparison of sensory inputs to the contents of a short-term auditory memory. Such a system could automatically detect deviant auditory events, and provide input to higher-level, task-dependent cognitive processes.     

Evaluation of the central nervous function in resuscitated comatose patients by multilevel evoked potentials.

Multilevel evoked potentials were examined in 17 patients who became comatose after cardiac arrest and resuscitation. In 4 patients, the P1 through N3 components of the somatosensory evoked cerebral potential (SECP) were present altogether within 100 ms after the ischemic insults. They all subsequently regained consciousness, though three of them developed intelligence and motor disturbances to some extent. In 11 patients who regained consciousness, or remained in a vegetative state, the evoked potentials which reflect brainstem functions, such as the auditory evoked brainstem potential, the R1 wave of the orbicularis oculi reflex and the slow positive wave of the somatosensory evoked brainstem potential, were recognized. The somatosensory evoked spinal potential and spinal monosynaptic reflex showed normal appearances in the state of vegetation and even after the determination of brain death. The measures of SECP could be useful in predicting restoration of consciousness.     

乳果糖治疗亚临床肝性脑病不同疗程的疗效观察

目的　观察乳果糖对亚临床肝性脑病 (SHE)不同疗程的疗效。方法　经数字连接试验 (NCT)和脑干听觉诱发电位 (BAEPs)诊断的SHE患者 86例 ,随机分为对照A组 2 2例 ,治疗B组 2 1例、C组 2 2例、D组 2 1例 ;对照组予常规护肝治疗 ,治疗组在对照组治疗的基础上予以乳果糖口服治疗 ,疗程分别为 4周、8周、12周 ,治疗前后每 2周予血氨、NCT和BAEPs检测。结果　疗程结束治疗组与对照组比较 ,血氨水平改善明显 (P <0 .0 1) ,BAEPs异常率降低 (P <0 .0 1) ,各组转为肝性脑病 (HE)的例数分别为A组 5例、B组 4例、C组 3例和D组 1例 ,C、D组转为HE的病例数明显少于A组 (P <0 .0 1) ;B组、C组停用乳果糖后出现了血氨上升 ,BAEPs异常率增加 ,转为HE的病例数明显多于D组。结论　乳果糖是治疗SHE的有效药物 ,长期治疗能够降低血氨 ,改善NCT ,降低HE的患病率     

互动式针刺法对卒中后假性延髓麻痹吞咽困难的疗效

目的:观察互动式针刺法治疗脑卒中后假性延髓麻痹吞咽障碍的临床疗效.方法:脑卒中后假性延髓麻痹所致吞咽障碍患者90例,随机分为对照组30例、普针组30例、治疗组30例.各组患者均给予脑卒中常规处理、吞咽功能训练,普针组患者另给予常规针刺治疗,治疗组取额中线、廉泉、夹廉泉加用互动式针刺法.分别于治疗前、治疗3周和6周后,采用洼田饮水试验评价患者吞咽功能,观察脑干听觉诱发电位(BAEP)的变化.结果:与治疗前相比,三组患者治疗后吞咽功能有所改善,能有效缩短BAEP各波潜伏期和峰间潜伏期(P＜0.05),且随治疗时间的延长,疗效更加显著(P＜0.01).结论:互动式针刺法可能通过促进大脑皮质功能及脑干的吞咽反射恢复而发挥其治疗脑卒中后假性延髓麻痹吞咽障碍的作用.     

Binaural specialisation in human auditory cortex: an fMRI investigation of interaural correlation sensitivity

A listener's sensitivity to the interaural correlation (IAC) of sound plays an important role in several phenomena in binaural hearing. Although IAC has been examined humans, little is known about the neural basis of sensitivity to IAC in humans. The present study employed functional magnetic resonance imaging to measure blood oxygen level-dependent (BOLD) activity in auditory brainstem and cortical structures in human listeners during presentation of band-pass noise stimuli between which IAC was varied systematically. The stimuli evoked significant bilateral activation in the inferior colliculus, medial geniculate body, and auditory cortex. There was a significant positive relationship between BOLD activity and IAC which was confined to a distinct subregion of primary auditory cortex located bilaterally at the lateral extent of Heschl's gyrus. Comparison with published anatomical data indicated that this area may also be cytoarchitecturally distinct. Larger differences in activation were found between levels of IAC near unity than between levels near zero. This response pattern is qualitatively compatible with previous measures of psychophysical and neurophysiological sensitivity to IAC. extensively in neurophysiological studies in animals and in psychophysical studies in     

Traumatic brain injuries in adults: from coma to wakefulness. Neurophysiological data]

OBJECTIVE: To analyse relevant literature and to express an expert point of view concerning the interest of electroencephalography and evoked potentials recordings in the evaluation of severe head trauma in adults in the context of a consensus conference.MATERIAL AND METHODS: Scientific databases have been checked on the Internet using key-words.The summaries of 340 papers have checked out. Consequently 94 papers have been thoroughly analysed. Fifty-nine of them are cited in the text of this paper.RESULTS: Electroencephalography (EEG) and evoked potentials (Eps) evaluate the functional status of the brain. They augment the clinical examination. They are non invasive and easy to perform at patient's bedside. The EEG evaluate globally the functional status of the brain but it is very sensitive to sedative and anaesthetic drugs. It can disclose subclinical or electroclinical epileptic seizures. When reactivity to sensory stimulations can be elicited, this can be considered a prognostic indicator for a good outcome. Evoked potentials are less influenced by sedative drugs. There are several types of evoked potentials, each one with a different localizing value. Brainstem auditory evoked potentials (or short-latency Eps) evaluate the auditory nerve and brainstem. When normal they have no specificity. When abnormal they are an indicator of a poor or bad outcome. Somatosensory and auditory middle-latency Eps evaluate the primary cortex. In coma due to traumatic brain injury the presence of primary cortex components is an indicator of a good outcome and its absence is an indicator of a poor outcome at least when there is no focal brain lesion as to have the primary cortex component to be absent. Event-related potentials evaluate associative brain areas. When they are present in a comatose patient they favor the idea that some cognitive processes are active and they have a high positive predictive value for a return to consciousness. The electrophysiological evaluation can help to identify atypical situations and pathologies close to coma, disclose nonconvulsive seizures and localize certain complications or dysfunctions in atypical cases.     

Attenuated infrared neuron stimulation response in cochlea of deaf animals may associate with the degeneration of spiral ganglion neurons

Hypothesis: We hypothesize that degenerated spiral ganglion neurons (SGNs) in guinea pigs reduces auditory brainstem responses evoked by pulsed infrared stimulation. Background: Pulsed infrared laser excitation can directly evoke physiological responses in neuronal and other excitable cells in vivo and in vitro. Laser pulses could benefit patients with cochlear implants to stimulate the auditory system. Methods: Pulsed infrared lasers were used to study evoked optical auditory brainstem responses (oABRs) in normal hearing and deafened animals. Aslo, the morphology and anatomy of SGNs in normal hearing and deafened guinea pigs were compared. Results: By recording oABRs evoked by varying infrared laser pulse durations, it is suggested that degeneration of SGNs in deafened guinea pigs was associated with an elevated oABR threshold and with lower amplitudes. Moreover, oABR threshold decreased while amplitudes increased in both normal hearing and deafened animals as the pulse duration prolonged. Electron microscopy revealed that SGNs in deafened guinea pigs had swollen and vacuolar mitochondria, as well as demyelinated soma and axons. Conclusion: Infrared laser pulses can stimulate SGNs to evoke oABRs in guinea pigs. Deafened guinea pigs have elevated thresholds and smaller amplitude responses, likely a result of degenerated SGNs. Short pulse durations are more suitable to evoke responses in both normal hearing and deafened animals.OCIS codes: (140.0140) Lasers and laser optics, (140.3538) Lasers, pulsed, (170.5380) Physiology, (170.4940) Otolaryngology     

Intraoperative monitoring of sensory evoked potentials may be neither a proven nor an indicated technique

Excluding specific neurosurgical indications for cortical localization or peripheral nerve surgery, the use of sensory evoked potentials as a monitor in the operating room should be controversial at this time. Whether appropriate or not, legal and medical forces have largely established the use of somatosensory evoked potential monitoring as a standard during procedures that threaten the integrity of the spinal cord. The author believes that such monitoring should not replace the use of a wake-up test during these procedures because of the recognized possible occurrence of false negative results (i.e., normal evoked potentials despite abnormal spinal cord function). Another apparent established practice is monitoring of brainstem auditory evoked potentials to recognize the onset of disturbance in the auditory system. It has not been established that other recommended evoked potential monitoring practices, such as somatosensory evoked potential monitoring for such purposes as recognizing cerebral ischemia, or brainstem auditory evoked potential monitoring for recognizing untoward medullary stimulation, are as good as or better for these purposes than currently recognized and simpler monitors.     

体感音乐疗法治疗颅脑外伤的初步研究

目的：探讨体感音乐疗法对颅脑外伤患者的作用。方法：31例中、重度颅脑外伤患者随机分为音乐组16例和对照组15例,均接受药物及综合康复治疗。音乐组并增加体感音乐疗法,将音乐耳机置于双耳,昏迷患者倾听以维瓦尔第的《四季之春》经演绎和古典变奏曲为主;清醒患者倾听莫扎特的《D大调双纳琴吹奏曲》为主治疗。治疗前后检测2组脑电图（EEG）、脑干诱发电位（BAEP）的变化及应用格拉斯哥结局量表（GOS）评定患者治疗后的临床康复效果。结果：治疗1个月后,EEG显示2组脑皮层活动恢复明显优于治疗前,音乐组优于对照组（P〈0.05）;BAFP显示2组与治疗前差异无统计学意义;GOS评定音乐组中轻度患者例数明显多于对照组。结论：体感音乐疗法可促进颅脑外伤患者多个系统的恢复,在一定程度上改善患者的预后,提高患者的生存质量。     

多发性硬化患者的视觉、脑干听觉诱发电位测定及其意义

目的；探讨视觉诱发电位（VEP）、脑干听觉诱发电位（BAEP）对多发性硬化（MS）的诊断意义。方法：对20例临床诊断为MS的患者进行VEP、BAEP检测，并与对照组进行比较分析。结果：MS患者VEP、BAEP的异常率分别为70％和55％。VEP、BAEP异常者中，各有72％和63％的患者，临床有相应的症状；各有28％和37％的患者临床无相应症状。结论：VEP、BAEP检测对MS的诊断有重要意义。     

多模式脑诱发电位对早期帕金森病的诊断价值

目的探讨多模式脑诱发电位对早期未治疗帕金森病（Parkinson’s disease,PD）的诊断价值。方法未经治疗的早期PD患者33例（PD组）和同期体检健康者31例（对照组）,2组分别进行视觉诱发电位、脑干听觉诱发电位、短潜伏期躯体感觉诱发电位和瞬目反射的综合测试,并进行2组间比较。结果PD组视觉诱发电位的P100潜伏期、脑干听觉诱发电位的V波潜伏期及Ⅲ-V波峰间潜伏期、I～V波峰间潜伏期和瞬目反射的R2波及R2’波潜伏期均较对照组明显延长,差异有统计学意义（P〈0．01）;2组短潜伏期躯体感觉诱发电位各波潜伏期差异均无统计学意义（P〉0．05）。结论PD早期存在视觉传导通路和脑干传导通路损害,对PD患者进行多模式脑诱发电位检测有助于疾病早期诊断。