Neurophysiological, histological, and behavioral characterization of animal models of distraction spinal cord injury: a systematic review

Distraction spinal cord injury is caused by some degree of distraction or longitudinal tension on the spinal cord and commonly occurs in patients who undergo corrective operation for severe spinal deformity.With the increased degree and duration of distraction,spinal cord injuries become more serious in terms of their neurophysiology,histology,and behavior.Very few studies have been published on the specific characteristics of distraction spinal cord injury.In this study,we systematically review 22 related studies involving animal models of distraction spinal cord injury,focusing particularly on the neurophysiological,histological,and behavioral characteristics of this disease.In addition,we summarize the mechanisms underlying primary and secondary injuries caused by distraction spinal cord injury and clarify the effects of different degrees and durations of distraction on the primary injuries associated with spinal cord injury.We provide new concepts for the establishment of a model of distraction spinal cord injury and related basic research,and provide reference guidelines for the clinical diagnosis and treatment of this disease.

Intraoperative neurophysiological monitoring in spinal surgery

Recently, many surgeons have been using intraoperative neurophysiological monitoring(IOM) in spinal surgery to reduce the incidence of postoperative neurological complications, including level of the spinal cord, cauda equina and nerve root. Several established technologies are available and combined motor and somatosensory evoked potentials are considered mandatory for practical and successful IOM. Spinal cord evoked potentials are elicited compound potentials recorded over the spinal cord. Electrical stimulation is provoked on the dorsal spinal cord from an epidural electrode. Somatosensory evoked potentials assess the functional integrity of sensory pathways from the peripheral nerve through the dorsal column and to the sensory cortex. For identification of the physiological midline, the dorsal column mapping technique can be used. It is helpful for reducing the postoperative morbidity associated with dorsal column dysfunction when distortion of the normal spinal cord anatomy caused by an intramedullary cord lesion results in confusion in localizing the midline for the myelotomy. Motor evoked potentials(MEPs) consist of spinal, neurogenic and muscle MEPs. MEPs allow selective and specific assessment of the functional integrity of descending motor pathways, from the motor cortex to peripheral muscles. Spinal surgeons should understand the concept of the monitoring techniques and interpret monitoring records adequately to use IOM for the decision making during the surgery for safe surgery and a favorable surgical outcome.

Progress in Intraoperative Neurophysiological Monitoring for the Surgical Treatment of Thoracic Spinal Stenosis

Thoracic spinal stenosis (TSS) is a group of clinical syndromes caused by thoracic spinal cord compression, which always results in severe clinical complications. The incidence of TSS is relatively low compared with lumbar spinal stenosis, while the incidence of spinal cord injury during thoracic decompression is relatively high. The reported incidence of neurological deficits after thoracic decompression reached 13.9%.Intraoperative neurophysiological monitoring (IONM) can timely provide information regarding the function status of the spinal cord, and help surgeons with appropriate performance during operation. This article illustrates the theoretical basis of applying IONM in thoracic decompression surgery, and elaborates on the relationship between signal changes in IONM and postoperative neurological function recovery of the spinal cord. It also introduces updated information in multimodality IONM, the factors influencing evoked potentials,and remedial measures to improve the prognosis.

Cell-based therapies for neural replacement strategies in stroke-related neurodegeneration： neurophysiological insights into stem progenitor cell neurogenesis within a host environment

The restricted neurogenesis limits the brain ability to overcome neuronal cell death following ischemic lesion：Failure of the damaged brain to regenerate following cerebral ischemia results in functional deficits those are most often irreversible and can further deteriorate,causing mortality and severe disability,progressive memory loss and cognitive impairments,known as dementia.

Applying Graph Theory and Mathematical-Computational Modelling to Study a Neurophysiological Circuit

The aim of the present study is to contribute to the knowledge about the functioning of the neuronal circuits. We built a mathematical-computational model using graph theory for a complex neurophysiological circuit consisting of a reverberating neuronal circuit and a parallel neuronal circuit, which could be coupled. Implementing our model in C++ and applying neurophysiological values found in the literature, we studied the discharge pattern of the reverberant circuit and the parallel circuit separately for the same input signal pattern, examining the influence of the refractory period and the synaptic delay on the respective output signal patterns. Then, the same study was performed for the complete circuit, in which the two circuits were coupled, and the parallel circuit could then influence the functioning of the reverberant. The results showed that the refractory period played an important role in forming the pattern of the output spectrum of a reverberating circuit. The inhibitory action of the parallel circuit was able to regulate the reverberation frequency, suggesting that parallel circuits may be involved in the control of reverberation circuits related to motive activities underlying precision tasks and perhaps underlying neural work processes and immediate memories.

High-Performance Liquid Chromatograph (HPLC) Equipped with a Neurophysiological Detector (NPD) as a Tool for Studying Olfactory System Intoxication by the Organophosphate (OP) Pesticide Diazinon and the Influence of OP Pesticides on Reproduction

A neurophysiological detector (NPD) is a hybridization of olfactory system neurons of the fish crucian carp, Carassius carassius L., with a computerized electronic device connected to a high-performance liquid chromatograph (HPLC). This system makes it possible to measure neurophysiological activities in the olfactory system of C. carassius L. after exposure of this fish to alarm pheromones. The construction of the system was presented for the first time at the 3rd International Symposium on Separation in Bio Sciences SBS 2003 in I. Brondz, et al., The Fish Olfactory System Used as an In-Line HPLC Neurophysiologic Detector NPD, 3rd Int. Symposium on Separation in Bio Sciences SBS 2003: A 100 Years of Chromatography, 13-18 May, Moscow, Russia, 2003, Abstract O- 27, p. 95. A complete paper was published in I. Brondz, et al., Neurophysiologic Detector (NPD)—A Selective and Sensitive Tool in High-Performance Liquid Chromatography, Chromatography B: Biomedical Sciences and Applications, Vol. 800, No. 1-2, 2004, pp. 41-47, and the hybridization of living cells with an electronic device has been discussed (I. Brondz, et al., International Scientific-Technical Conference Sensors Electronics and Microsystems Technology (SEMST-1), 1-5 June, (Odessa), Ukraine, 2004, Plenum Lecture, Abstract p. 17;I. Brondz, et al., The European Chemoreception Research Organization ECRO 2004 Congress, 12-15 September, (Dijon), France, 2004, Abstract P-3;and I. Brondz, et al., Biosensors as Electronic Compounds for Detector in the High-Performance Liquid Chromatography (HPLC), Electronic Components and Systems, Vol. 3, No. 103, 2006, pp. 25-27). In the present study, an HPLC equipped with an NPD was used to assess the influence of organophosphate (OP) pesticides on olfactory sensory nerves and the modification of nerve signals from the olfactory organ. The results show that exposure of the olfactory system to OP pesticides can lead to disruption of normal reflexes and to significant suppression of individual sexual activity and, as a result, to the suppression of a population.

Review: Practical Use of a Neurophysiological Detector and the Protocol for High-Performance Liquid Chromatography

The main aim for discovery and development of the neurophysiological detector was detection of the production’ seats and criminal use of poisons in warfare. Phosphor-organic (PO) substances with acetylcholinesterase-blocking effects are prohibited in warfare by international law (Geneva Protocol. https://www.un.org/disarmament/wmd/bio/1925-geneva-protocol/). Monitoring PO analogs with acetylcholinesterase-blocking effects and their degradation products in water and soil can provide clues to unlawful production sites and the possible use of POs in warfare. Attempts to analyze POs by derivatization have had a low ability to detect them. A neurophysiological detector (NPD)-high-performance liquid chromatography (HPLC) system was developed for specific detection with high detection ability. The first official presentation of our NPD was at the 3rd International Symposium on Separation in BioSciences SBS 2003: A 100 Years of Chromatography, May 13-18, 2003, in Moscow, Russia. The NPD in connection to HPLC was developed 14 years before the presentation at the SBS in 2003. Initially, NPD combined with an HPLC system was developed for intelligence services and only for use in monitoring and espionage against the unlawful production of neuroparalytic agents, as explained in this article. NPD combined with an HPLC system was developed in Umeå, Sweden, in 1987-89;the protocol was further developed in Statens Plantevern Institutt, Ås, Norway, in 1990-92. NPD may have great utility during the current period of active warfare in Europe. The initial challenge was detecting unlawful production and use of PO compounds and their metabolites that can potentially block acetylcholinesterase. The sensor in NPD can detect and monitor substances such as tabun, soman, and modern PO poisons used in military applications. This article describes the history of the development of NPD and its aim as a sensitive sensor in detecting PO substances with acetylcholinesterase-blocking effects.

Evolution and Role of Intraoperative Neurophysiological Monitoring in Intramedullary Spinal Cord Surgery: A 2-Year Series from Saudi Arabia

Introduction: Despite recent advances in neuroimaging and microsurgical techniques, surgical resection of spinal cord tumours remains a challenge. However, the evolution with advances and refinement of neurophysiological equipment and methodologies, intra-operative neurophysiolo- gical monitoring (IONM) is now regarded as an essential adjunct to the surgical management of intramedullary spinal cord tumours. This study aims to report our preliminary experience with IONM and emphasise its effective role of achieving maximum tumour resection and minimising neurological injury. Methods: This is a retrospective study performed at our institution between July 2012 and August 2013. It included a cohort of 6 consecutive patients presented with intramedullary spinal cord tumours. Their mean age was 26 years (range, 4 months - 37 years), all were males, and the mean follow up was 11.6 months. Results: We combined the use of somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) in spinal cord surgery. SSEPs are monitored during the incision of the dorsal midline of the spinal cord and this was used in two of our patients and MEPs were used as an essential monitoring during the tumour resection. In addition, we used free-running electromyography (EMG) and muscle MEPs (mMEPs) during tumour resection. Four of our patients (two with ependymoma, one with ganglioglioma, and one with pilocytic astrocytoma) had complete tumour resection and two patients (pilocytic and diffuse astrocytoma) had IONM changes during surgery and had partial tumour resection. At 6-month follow up all our patients had made a good recovery with no new neurological sequelae. Conclusion: This small series and literature review is presented to add and improve the understanding of IONM in intramedullary spinal cord procedures and to reinforce the importance of IONM in optimising tumour resection and neurological outcome. Our series confirm that without D-wave monitoring, free-running EMG and MEP monitoring during tumour resection remain an important adjunct. We also draw attention to the fact that changes in the free-running EMG occur before any changes in the MEPs are noted.

Mechanism of Neurophysiological Treatment of Amblyopia Using Functional Magnetic Resonance Imaging

Purpose: To research the mechanism of neurophysiological treatment of amblyopia by observing the visual cortex activation under rotating grating stimulus with functional magnetic resonance imaging (MRI), and identify the components of the activation. Methods: Nine healthy volunteers were examined using gradient-recalled echo and echo-planar imaging (GRE-EPI) pulse sequence performed at the 1.5 Tesla MRI scanner. In the block designing, rotating grating, stationary grating and luminance were plotted as task states, stationary grating, luminance and darkness as control states, respectively. The tasks of stimuli included 6 steps. Imaging processing and statistical analysis were carried out off-line using statistical parametric mapping (SPM99) software in single-subject. Results: Some individual areas of visual cortex were activated by various stimuli information supplied by rotating grating. The strong activation in the middle of occipital lobe related to the stimuli of luminance, bilateral activation of Brodmann’s 19th area related to visual motion perception, and the mild activation in the middle of occipital lobe related to form perception. Conclusion: The plotting of control state is important in bock design. The effective visual information of rotating grating includes components of luminance, visual motion perception and form perception. Functional MRI has potential as a tool for studying the physiological mechanism of visual cortex.

Surgical strategies for peripheral nerve schwannoma based on the intraoperative neurophysiological monitoring

Objective:To present our classification for peripheral nerve schwannomas as well as explore the surgical strategies and operative management of peripheral nerve schwannomas based on the intraoperative neurophysiological monitoring(INM)technique and to decrease the risk of postoperative neurological deficits in the management of these schwannomas.Materials and methods:A retrospective study was conducted on 92 cases of peripheral nerve microsurgery performed,using the INM technique.We also made the classification for peripheral nerve schwannomas into two types according to operative findings and proceeded corresponding surgical strategies.Results:All tumors were removed completely under microscopy and INM.Three patients developed residual neurological deficits at final follow-up.There were different results about temporary(18/92,19.6%)and permanent(3/92,3.3%)neurological deficits.The incidence of temporary and permanent neurological deficits in type II group was significantly higher than that in type I group(p<0.01).The incidence of permanent neurological deficits in larger size tumors was significantly higher than that of smaller size(p<0.01).Conclusions:We made the classification for peripheral nerve schwannomas according to operative findings based on INM that is helpful to our surgical strategies.Intracapsular enucleation was the preferred strategy with satisfactory results and low risk of nerve injury.The size and location of tumors seem to be related to the risk of fascicular injury.

Clinical characteristics,neurophysiological grade and outcome of patients with carpal tunnel syndrome A retrospective study

BACKGROUND： Carpal tunnel syndrome （CTS） is diagnosed mainly according to clinical symptoms, physical sign and neurodiagnostic laboratory examination. The therapeutic effect of conservative management and surgical operation in treating CTS need to be further observed and evaluated. OBJECTIVE： To analyze the clinical characteristics, neurophysiological grade and outcome in patients with CTS. DESIGN： Retrospective case-analysis. SETTING： Department of Neurology, First Affiliated Hospital, Medical College, Xi＇an Jiaotong University. PARTICIPANTS： Totally 161 patients with suspected CTS from National Neuroscience Institute of Singapore referred to the Neurodiagnostic Laboratory for the confirmatory testing between January and September 2002. The involved patients, 137 male and 24 female, were aged 21 - 85 years. METHODS： ①The condition of diabetes mellitus complicated by abnormal thyroid function was observed.② The effect on predominant hand, and paraesthesia were observed. ③Neuroelectrophysiological studies were performed and the results were graded into mild, moderate and severe CTS according to the American Association of Electrodiagnostic Medicine （AAEM） criteria.④ Conservative management and surgical intervention were followed up 3 months later, and symptoms and physical sign basically disappeared, and function was basically recovered, which indicated that disease condition improved. MAIN OUTCOME MEASURES： ①Condition of CTS complicated by metabolic disease; ②Effects on predominant hand and paraesthesia; ③Electrophysiological grading; ④Prognosis. RESULTS： Totally 161 patients participated in the final analysis. ①Condition of CTS complicated by metabolic disease： Among 161 patients, 17.4% （28/161） were documented to have diabetes mellitus and 7（4.3%） had hypothyroidism. ②Effects on predominant hand and paraesthesia： Dominant hand involvement was present in 134 patients （83.2%） and more than 75% had onset of symptoms in the dominant hand. Sensory symptoms like numbness and paresthesias were the predominant symptoms, accounting for 89.1% （134/161）, this discomfort was felt in all 5 digits of the hand in 47.6%, and lateral three and half digits in 21.4%. The noctural symptoms were present in 30.4% （49/161） patients. ③Electrophysiological typing： The most frequent abnormality was that of the prolonged mid-palm median and ulnar latency difference in 146（54.7%） hands; 103（38.6%） hands had prolonged median motor distal latency. Absent response from thenar muscle was present in 35 （13.1%） hands. Nerve conduction study showed bilateral CTS in 105 （65.2%） patients and unilateral CTS in 56 （34.8%） patients. Sixteen patients with bilateral CTS had symptoms in one hand only. Overall, 36.8% had mild, 49.2 % had moderate and 13.9 % had severe CTS, with median duration of symptoms of 6, 9 and 14 months, respectively. ④Delay in diagnosis： 37（22.9%） patients delayed in diagnosis from 1-4 months, 16（43.2%） were misdiagnosed as cervical spondylosis; 6（16.2%） were ignored due to their condition by busy work; 15（40.5%） were unware of their symptoms. ⑤Prognosis： Follow up data was available for only 72.7% （117/161） patients. Conservative management was conducted in 73.5% （86/117）. Clinical symptoms were resolved or improved in 65.1% （56/86） patients with 17 mild CTS, 29 moderate CTS, and 10 severe CTS. 26.5% （31/117） patients underwent surgery for CTS release, and clinical symptoms were improved in 12（38.7%） with moderate CTS and 2 （6.5%） with severe CTS at 3 months of follow up. CONCLUSION： ①Sensory symptoms in CTS are more in severe and common in dominant hand. ②Conservative management showed resolution or improvement for mild and moderate CTS. Surgical intervention shows either resolution or improvement in clinical symptoms in moderate CTS. ③The common reasons for delay in diagnosis were due to misdiagnosis as cervical spondylosis and lack of awareness of the condition.④Assessment on severity of CTS by electrophysiological grade is of important significance for determining therapeutic mean.

Mechanism of Action of Low Dose Preparations from <i>Coffea arabica</i>, <i>Gelsemium</i>and <i>Veratrum</i>Based on <i>in Vivo</i>and <i>in Vitro</i>Neurophysiological Findings

Low dose remedies are widely administered in medicine. We used Tele-Stereo-EEG and the hippocampal slice preparation to measure physiological effects of orally given Coffea D6 (40 mg/kg), Gelsemium D4 (10 mg/kg) and Veratrum D6 (30 mg/kg) in rats. Adult rats were implanted with electrodes positioned stereotactically into four brain regions. Changes in field potentials were transmitted wirelessly. After frequency analysis data from 6 - 8 animals were averaged. For in vitro testing, preparations were superfused directly on hippocampal slices. Stimulation of Schaffer Collaterals by single stimuli (SS) or theta burst stimulation (TBS) resulted in stable population spike amplitudes. All three low dose preparations produced decreases of spectral power. Statistically significant changes were observed in delta, theta and alpha2 spectral power. In the hippocampal slice preparation Coffea facilitated signal transfer presumably by enhancing glutamate AMPA receptor transmission. Gelsemium showed a similar effect, but only after single shock stimulation. Opposite to this, attenuation of the electric pathway was recognized after theta burst stimulation due to AMPA receptor and glutamate metabotropic II receptor mediated transmission. Veratrum was able to attenuate glutamatergic due to receptor-mediated signalling sensitive to AMPA and NMDA. The results strongly speak in favour of the existence of biologically active molecules in these low dose preparations.

Opposite Neurophysiological Findings Induced by Sideritis scardica and Sideritis euboa Extract in the Rat

Psychophysiological effects of Sideritis herba extracts depend on biologically active ingredients, which might be different for several botanical types of this plant. The present investigation aimed at the characterization of extracts from Sideritis scardica and Sideritis euboa in vivo and in vitro. Construction of electropharmacograms on the base of recording of electrical field potentials from four different brain regions was used to compare the possible pharmacological effects to a database of reference drugs with known clinical indications. Whereas Sideritis scardica produced decreases of spectral power in line with stimulatory frequency patterns as observed in the presence of Ginkgo biloba extract, administration of Sideritis euboa produced opposite effects. Electrical stimulation of the Schaffer Collaterals was used to elicit a pyramidal cell response called population spike in vitro. The amplitude of this spike was determined in the presence of single as well as theta burst stimuli. Direct exposure of brain matter to Sideritis scardica extract led to concentration dependent increases of the population spike amplitude under both stimulation patterns in the range from 12.5 to 100 mg/L. On the opposite, extract from Sideritis euboa did not change the electric response up to 50 mg/L. Higher concentrations of this extract attenuated the signal amplitude. A 1:1 blend of both gave intermediate results. The in vitro results are in line with the in vivo EEG recordings, where both extracts induced opposite changes of the electric power with respect to electric frequency patterns. The results from both models suggest a stimulatory and/or memory-enhancing action for the extract from Sideritis scardica but not for Sideritis euboa extract, where a more tranquillizing effect like that observed in the presence of Humulus cone extract may be expected.

<i>In Vitro</i>Hippocampal Electrophysiology and <i>in Vivo</i>Quantitative EEG Revealed Robust Neurophysiological Effects of the Antivertigo-Agent Vertigoheel^&#174;in a Rat Study

Vertigo is a common symptom with impact on daily life. Vertigoheel&#174;(VH-04) has demonstrated to be effective for Vertigo in former studies. This paper aims to investigate the mode of action of the medicinal product VH-04 in the rat brain. In an in vitro study neurophysiological recording from hippocampal slices from adult male Sprague Dawley&#174;rats was performed in order to substantiate a possible direct effect on the brain of VH-04 in different concentrations. In an in vivo cross-over study with 11 Fischer 344&#174;?rats, a neurophysiological method was applied to systemically analyse VH-04’s activity in the rat brain. This method combines quantitative assessments of telemetrically transmitted field potentials after drug treatment with subsequent discriminant analysis to classify the compound. The database used for the analysis of classification contained numerous chemicals and medicinal products of different dosages, all tested in the same paradigm, which is continuous wireless monitoring of the EEG of freely moving rats before and after drug intake. Following single stimuli on the Schaffer collaterals in the presence of VH-04 in different concentrations, in vitro responses of pyramidal cells increased depending on the VH-04 concentration (0.25 - 4 ml/L). Results were statistically significant for concentrations above 2.5 ml/L. Long-term potentiation was only marginally affected. Out of several specific glutamate receptor antagonists the effect of VH-04 was only antagonized by AMPA and kainic acid receptor-mediated signalling. Their enhancement indicates better information processing in the hippocampus, a brain structure primarily involved in memory processes. The in vivo characterisation of VH-04-induced changes in EEG-signatures of four brain areas (the frontal cortex (FC), the hippocampus (HC), the striatum (ST) and the reticular formation (RF)) revealed a dose-dependent attenuation of delta, theta, alpha 2 and beta 1 waves. The subsequent discriminant function analysis classified the VH-04 EEG-signature into a subset of cognition-enhancing medicinal products.

The role of intraoperative neurophysiological monitoring in intramedullary spinal cord tumor surgery

Intramedullary tumors are a class of central nervous system tumors with an incidence of 2 to 4%.As they are located very deep and frequently cause postoperative neurological complications,surgical resection is difficult.In recent years,many surgeons have performed electrophysiological monitoring to effectively reduce the occurrence of post-operative neurological complications.Modern electrophysiological monitoring technology has advanced considerably,leading to the development of many monitoring methods,such as SSEPs,MEPs,DCM,and EMG,to monitor intramedullary tumors.However,electrophysiological monitoring in tumor resection is still being studied.In this article,we discussed the different monitoring methods and their role in monitoring intramedullary tumors by reviewing previous studies.Intratumorally tumors need to be monitored for a summary of the condition of the patient.Only by using various monitoring methods flexibly and through clear communication between surgeons and neurophysiological experts can good decisions be made during surgery and positive surgical results be achieved.

Stretching boundaries in neurophysiological monitoring

The most prevalent among nervous system tumors significantly jeopardize patient health.For nerve integrity preservation after tumor removal,continuous intraoperative neurophysiological monitoring(CINM)is indispensable during microsurgery.The paper highlights the articles about the development of a system that employs soft and stretchable organic electronic materials for CINM.This innovative system harnesses soft and stretchable organic electronic materials and deploys conductive polymer electrodes with low impedance and modulus.These electrodes facilitate uninterrupted near-field action potential recording during surgery,resulting in enhanced signal-to-noise ratios and reduced invasiveness.Additionally,the system's multiplexing capabilities enable precise nerve localization,even in the absence of anatomical landmarks.

Stepping up after spinal cord injury:negotiating an obstacle during walking

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate obstacles.After spinal cord injury,stepping over an obstacle becomes challenging.Stepping over an obstacle requires sensorimotor transformations in several structures of the brain,including the parietal cortex,premotor cortex,and motor cortex.Sensory information and planning are transformed into motor commands,which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory,coordinate the limbs,and maintain balance.After spinal cord injury,bidirectional communication between the brain and spinal cord is disrupted and animals,including humans,fail to voluntarily modify limb trajectory to step over an obstacle.Therefore,in this review,we discuss the neuromechanical control of stepping over an obstacle,why it fails after spinal cord injury,and how it recovers to a certain extent.

The application of intraoperative neurophysiological monitoring in selective dorsal neurotomy for primary premature ejaculation:a prospective single-center study

Selective dorsal neurotomy(SDN)is a surgical treatment for primary premature ejaculation(PE),but there is still no standard surgical procedure for selecting the branches of the dorsal penile nerves to be removed.We performed this study to explore the value of intraoperative neurophysiological monitoring(IONM)of the penile sensory-evoked potential(PSEP)for standard surgical procedures in SDN.One hundred and twenty primary PE patients undergoing SDN were selected as the PE group and 120 non-PE patients were selected as the normal group.The PSEP was monitored and compared between the two groups under both natural and general anesthesia(GA)states.In addition,patients in the PE group were randomly divided into the IONM group and the non-IONM group.During SDN surgery,PSEP parameters of the IONM group were recorded and analyzed.The differences in PE-related outcome measurements between the perioperative period and 3 months'postoperation were compared for the PE patients,and the differences in effectiveness and complications between the IONM group and the non-IONM group were compared.The results showed that the average latency of the PSEP in the PE group was shorter than that in the normal group under both natural and GA states(P<0.001).Three months after surgery,the significant effective rates in the IONM and non-IONM groups were 63.6%and 34.0%,respectively(P<0.01),and the difference in complications between the two groups was significant(P<0.05).IONM might be useful in improving the short-term therapeutic effectiveness and reducing the complications of SDN.

Possible Cortical Spreading Depression Recorded Intraoperatively Following a Generalized Seizure: Illustrative Case

Background: We present a compelling case fitting the phenomenon of cortical spreading depression detected by intraoperative neurophysiological monitoring (IONM) following an intraoperative seizure during a craniotomy for revascularization. Cortical spreading depression (CSD, also called cortical spreading depolarization) is a pathophysiological phenomenon whereby a wave of depolarization is thought to propagate across the cerebral cortex, creating a brief period of relative neuronal inactivity. The relationship between CSD and seizures is unclear, although some literature has made a correlation between seizures and a cortical environment conducive to CSD. Methods: Intraoperative somatosensory evoked potentials (SSEPs) and electroencephalography (EEG) were monitored continuously during the craniotomy procedure utilizing standard montages. Electrophysiological data from pre-ictal, ictal, and post-ictal periods were recorded. Results: During the procedure, intraoperative EEG captured a generalized seizure followed by a stepwise decrease in somatosensory evoked potential cortical amplitudes, compelling for the phenomenon of CSD. The subsequent partial recovery of neuronal function was also captured electrophysiologically. Discussion: While CSD is considered controversial in some aspects, intraoperative neurophysiological monitoring allowed for the unique analysis of a case demonstrating a CSD-like phenomenon. To our knowledge, this is the first published example of this phenomenon in which intraoperative neurophysiological monitoring captured a seizure, along with a stepwise subsequent reduction in SSEP cortical amplitudes not explained by other variables.

Anesthetic considerations for patients with acute cervical spinal cord injury

Anesthesiologists work to prevent or minimize secondary injury of the nervous system and improve the outcome of medical procedures.To this end,anesthesiologists must have a thorough understanding of pathophysiology and optimize their skills and equipment to make an anesthesia plan.Anesthesiologists should conduct careful physical examinations of patients and consider neuroprotection at preoperative interviews,consider cervical spinal cord movement and compression during airway management,and suggest awake fiberoptic bronchoscope intubation for stable patients and direct laryngoscopy with manual in-line immobilization in emergency situations.During induction,anesthesiologists should avoid hypotension and depolarizing muscle relaxants.Mean artery pressure should be maintained within 85–90 mmHg（1 mmHg = 0.133 kPa; vasoactive drug selection and fluid management）.Normal arterial carbon dioxide pressure and normal blood glucose levels should be maintained.Intraoperative neurophysiological monitoring is a useful option.Anesthesiologists should be attentive to postoperative respiratory insufficiency（carefully considering postoperative extubation）,thrombus,and infection.In conclusion,anesthesiologists should carefully plan the treatment of patients with acute cervical spinal cord injuries to protect the nervous system and improve patient outcome.