Masseter Vestibular evoked myogenic potentials: A new tool to assess the vestibulomasseteric reflex pathway

Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also reviews the contemporary researches involving the clinical applications of the mVEMP. Conclusions: Masseter VEMP is an evolving yet clinically promising neuro-otology test tool that has recently gained more research interest and is considered an additional tool to diagnose various vestibular disorders. Masseter VEMP assesses the functional integrity of the acoustic-masseteric and vestibulo-masseteric reflex pathways. The mVEMP could be used as a complementary test to evaluate the same peripheral generator as the cervical VEMP but a different central pathway i.e., vestibulo-trigeminal pathway. Various research studies that have experimented on parameters such as the effect of different electrode montages(zygomatic vs mandibular configurations), stimulation rates, filter settings and stimuli used to evoke mVEMP have been discussed in this article that could assist in the optimization of a comprehensive clinical protocol. The latency and the amplitude of mVEMP waveforms serve as significant parameters in differentiating normals from those of the clinical populations. Along with the cVEMPs and oVEMPs, mVEMP might help diagnose brainstem lesions in REM Sleep behaviour disorders, Multiple Sclerosis and Parkinson's disease. However, further studies are required to probe in this area of research.

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.

Odors Best at Evoking Emotionally Charged Memories

西方富国的科研人员进行了一些在我们看来多少有些“荒诞”的实验。本文就是一例。但是,细读之下,你不仅为其认真的实验态度所感动,而且,也会觉得“荒诞”之中也有不少“正经”因素。说不准,一项“荒诞”的实验引发了震惊世界的科研成果!本文的标题理解起来不易,弄懂了标题,文章的中心思想也就在其中了。Odors Best at Evoking Emotionally Charged Memories可以完整地表达为:Odors are best at evoking memories which are emotionally charged.可译:气味最能激活与情感相连的记忆。本文的首句和标题呼应,值得玩味。

婴儿分泌性中耳炎的听力学结果分析

目的 探讨226、1 000 Hz鼓室声导抗测试和气-骨导听性脑干反应(ABR)以及畸变产物耳声发射(DPOAE)在诊断低月龄婴儿分泌性中耳炎(OME)中的作用。方法 回顾性分析年龄为1~6个月的119例(192耳)中耳积液患儿(异常组)和66例(132耳)正常婴儿(正常组)的226、1 000 Hz鼓室声导抗测试和气-骨导ABR,以及DPOAE检测结果。结果 (1)OME婴儿,1 000 Hz鼓室声导抗异常图形(As型、B型、C型)有189耳(98.44%),226 Hz鼓室声导抗异常图形(As型、B型、C型)有135耳(70.31%);(2)OME婴儿ABR波Ⅰ潜伏期延长179耳(93.23%),ABR波Ⅴ反应阈中度异常69耳(35.94%)、轻度异常97耳(50.52%)、阈值正常26耳(13.54%),骨导ABR阈值正常164耳(85.42%),阈值轻度异常28耳(14.58%),气-骨导ABR阈值差值变大162耳(84.37%);(3)OME婴儿DPOAE未引出151耳(78.65%)。结论 1 000 Hz声导抗异常、气-骨导ABR阈值差变大、ABR波I潜伏期延长和气导ABR阈值异常对低月龄婴儿中耳积液的诊断有重要参考价值,226 Hz声导抗对部分低月龄婴儿中耳积液的诊断不能提供准确信息。

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.

Binaural masking level difference for pure tone signals

The binaural masking level difference(BMLD)is a psychoacoustic method to determine binaural interaction and central auditory processes.The BMLD is the difference in hearing thresholds in homophasic and antiphasic conditions.The duration,phase and frequency of the stimuli can affect the BMLD.The main aim of the study is to evaluate the BMLD for stimuli of different durations and frequencies which could also be used in future electrophysiological studies.To this end we developed a GUI to present different frequency signals of variable duration and determine the BMLD.Three different durations and five different frequencies are explored.The results of the study confirm that the hearing threshold for the antiphasic condition is lower than the hearing threshold for the homophasic condition and that differences are significant for signals of 18ms and 48ms duration.Future objective binaural processing studies will be based on 18ms and 48ms stimuli with the same frequencies as used in the current study.

A Method of SSVEP Signal Identification Based on Improved eCAA

Brain-computer interfaces(BCI)based on steady-state visual evoked potentials(SSVEP)have attracted great interest because of their higher signal-to-noise ratio,less training,and faster information transfer.However,the existing signal recognition methods for SSVEP do not fully pay attention to the important role of signal phase characteristics in the recognition process.Therefore,an improved method based on extended Canonical Correlation Analysis(eCCA)is proposed.The phase parameters are added from the stimulus paradigm encoded by joint frequency phase modulation to the reference signal constructed from the training data of the subjects to achieve phase constraints on eCCA,thereby improving the recognition performance of the eCCA method for SSVEP signals,and transmit the collected signals to the robotic arm system to achieve control of the robotic arm.In order to verify the effectiveness and advantages of the proposed method,this paper evaluated the method using SSVEP signals from 35 subjects.The research shows that the proposed algorithm improves the average recognition rate of SSVEP signals to 82.76%,and the information transmission rate to 116.18 bits/min,which is superior to TRCA and traditional eCAA-based methods in terms of information transmission speed and accuracy,and has better stability.

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.

Efficient Authentication System Using Wavelet Embeddings of Otoacoustic Emission Signals

Biometrics,which has become integrated with our daily lives,could fall prey to falsification attacks,leading to security concerns.In our paper,we use Transient Evoked Otoacoustic Emissions(TEOAE)that are generated by the human cochlea in response to an external sound stimulus,as a biometric modality.TEOAE are robust to falsification attacks,as the uniqueness of an individual’s inner ear cannot be impersonated.In this study,we use both the raw 1D TEOAE signals,as well as the 2D time-frequency representation of the signal using Continuous Wavelet Transform(CWT).We use 1D and 2D Convolutional Neural Networks(CNN)for the former and latter,respectively,to derive the feature maps.The corresponding lower-dimensional feature maps are obtained using principal component analysis,which is then used as features to build classifiers using machine learning techniques for the task of person identification.T-SNE plots of these feature maps show that they discriminate well among the subjects.Among the various architectures explored,we achieve a best-performing accuracy of 98.95%and 100%using the feature maps of the 1D-CNN and 2D-CNN,respectively,with the latter performance being an improvement over all the earlier works.This performance makes the TEOAE based person identification systems deployable in real-world situations,along with the added advantage of robustness to falsification attacks.

Correlation study between the changes of motor evoked potential and the improvement of spinal canal volume in minimally invasive transforaminal lumbar interbody fusion

Objective:To analyze the correlation between the amplitude changes of motor evoked potential(MEP),the 3D volume changes of spinal canal measuring by postoperative CT and the improvement rate of clinical symptoms after the spinal canal decompression in minimally invasive transforaminal lumbar interbody fusion(MIS-TLIF),and to explore the predictive value of the changes of both MEP amplitude and spinal canal volume in the assessment of long-term clinical prognosis in MIS-TLIF.Methods:A retrospective study of 68 patients with L4/5 spinal stenosis treated with MIS-TLIF was performed.The changes of both intraoperative MEP amplitude and 3D spinal canal volume during the spinal canal decompression,as well as the visual analogue scale(VAS)and Oswestry dysfunction index(ODI)scores in the long-term follow-up were all recorded.Results:The values of intraoperative MEP amplitude was 159.04%higher in 68 patients with MIS-TLIF after spinal canal decompression(P<0.01).The 3 postoperative 3D spinal canal volume(4.89±1.27)cm increased by 31.22%in comparison 3 with preoperative date(3.78±1.08)cm(P<0.01).The VAS and ODI scores were improved to 78.55%and 80.60%,respectively at the last follow-up(P<0.01).The improvement rate of MEP amplitude on the decompression side was positively correlated with the improvement rate of postoperative spinal canal volume(r=0.272,P=0.025).The improvement rate of postoperative spinal canal volume was positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.656,r=0.490,P<0.01).Moreover,the improvement rate of MEP amplitude on the decompression side was also positively correlated with the improvement rate of VAS and ODI at the last follow-up(r=0.322 and 0.235,respectively,P<0.05).Conclusion:The increase of MEP amplitude after spinal canal decompression in patients with lumbar spinal stenosis treated by MIS-TLIF was closely correlated with both of the increase of spinal canal volume and the improvement of clinical symptoms.Therefore,MEP amplitude monitoring was not only the one of the important monitoring methods for predicting the prognosis of MIS-TLIF but also the reliably predictive value in the long-term clinical prognosis in MIS-TLIF.

Acute spinal subdural haematoma complicating a posterior spinal instrumented fusion for congenital scoliosis:A case report

BACKGROUND Acute spinal subdural haematoma(ASSH)is a rare and potentially devastating condition with a variable prognosis.Previously described subdural haematomas were thought to have occurred spontaneously or be related to major or minor iatrogenic or traumatic injuries caused by surgery,spinal puncture or epidural anaesthesia.Other contributing pathologies have been described,such as intradural tumours or spinal arteriovenous malformations.ASSH has also been associated with anticoagulation therapy,haemostatic abnormalities and risk factors such as pregnancy.To the best of our knowledge,this case study described the first reported occurrence of an ASSH during spinal surgery in a paediatric patient.The patient was not known to have any coagulopathies,and no obvious vascular lesions were documented.The surgical procedure did not directly involve the dura mater,and no evident intraoperative dural tears were found.CASE SUMMARY We reported and discussed a case of ASSH complicating a posterior spinal instrumented fusion during surgery for paediatric congenital scoliosis.This condition has not been previously described.We made recommendations for facing such an occurrence,explored its aetiology in the context of malformation and discussed the benefits of neuromonitoring during scoliosis correction and the management protocol.We conducted a PubMed literature review for cases of paediatric ASSH and other closely related disorders.We reviewed recommendations regarding neuromonitoring and treatment management in such cases.CONCLUSION ASSH is a rare complication of posterior spinal instrumented fusion.Published cases are more often associated with anticoagulation therapy or coagulopathy.Neuromonitoring is strongly recommended to detect and assess neurological status,thus enabling rapid diagnosis and treatment and facilitating early spinal decompression and a return to a normal neurological status.

神经电生理监测在脊柱外科的应用现状

在脊柱外科的手术中,神经并发症是临床医师不可回避的问题。各种神经电生理监测技术的引入及成熟,可明显降低包括脊髓、马尾及神经根损害的发生率。由于每种神经电生理监测技术都有一定的适用范围,而脊柱外科手术要求对脊髓及神经根的完整功能进行有效的监测,笔者将着重介绍脊柱外科常用的神经电生理监测技术及术中多模式神经电生理监测的应用现状。

电诱发听性脑干反应在人工耳蜗植入中的应用进展

电诱发听性脑干反应（electrically evoked audito-ry brainstem responses,EABR）是以听觉诱发电位（AEP）为基础,当用电刺激听神经末梢后,前10ms内产生的可在头颅表面记录到的一组短潜伏期电位。

听力正常成人CE-Chirp声与click声听性脑干反应特征比较

听性脑干反应（ABR）在神经科及耳科已被广泛应用,评估客观听力及判断病变部位。常用刺激声信号有短声（click）、短音（tone pip）和短纯音（tone burst）等,其中最常用为click声。近年来,CE-Chirp音已逐渐被用于临床。本研究通过对听力正常成人同时行click ABR及CE-Chirp ABR检查,将两者进行比较,探讨听力正常成人CE-Chirp ABR特点,为成人客观听力检测提供参考。

听觉中潜伏期诱发电位与人工耳蜗植入

人工耳蜗植入后听力及言语能力恢复与中枢听皮质功能密切相关,听觉中潜伏期诱发电位可反映中枢初级听觉皮层的功能状态。本文综述了听觉中潜伏期诱发电位的起源,声刺激和电刺激,测试方法,影响因素以及临床意义,并讨论其与人工耳蜗植入的相关关系。

脑干听觉诱发电位在耳科的临床应用(附125例分析)

本文报告了125例耳科及神经内科病人应用脑干听觉诱发电位的检查结果,通过临床与神经电生理检查的对照分析,讨论了该检查法在耳科临床的使用价值和适应证。

听觉诱发中潜伏期反应研究进展

听觉诱发中潜伏期反应（middle latency response,MLR）是较早发现的听觉诱发电位（auditory evoked potential,AEP）成分,常用于中枢听觉通路的功能评估。通过研究MLR的主要成分,可以了解MLR的参数、形态、起源、作用和应用范围,进一步探讨其与听觉通路生理变化的关系,并可以检测中枢神经病变和功能改变。

术中直接电刺激在脊髓栓系综合征手术中的应用

脊髓栓系综合征（tethered cord syndrome,TCS）为各种因素导致脊髓圆锥受到牵拉而引起的神经功能障碍症候群[1]。近年来术中应用显微外科和体感诱发电位（somatosensory evoked potential,SEP）、运动诱发电位（motor evoked potential,MEP）等技术显著提高了患者预后,

正常发育儿童言语声诱发ABR的复测一致性

听性脑干反应（ABR）是通过远场记录的方式反映听觉脑干核团对声信号反应同步性的一种测试方法。短声（click）诱发的ABR技术已非常成熟,其峰潜伏期在成人和儿童个体中的复测一致性非常好,在临床上已被广泛应用于客观听阈和听神经通路同步性检测。言语、音乐等复杂声信号也可用于诱发ABR,近年来,言语声诱发听性脑干反应（the speech-evoked ABR,言语声诱发ABR）得到了越来越广泛的应用。