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.

A New Technique for Attention Management and Somatosensory Processing in Hypnotherapy: Mental Access/Somatosensory Access (MASSA)

The author introduces a new hypnotherapeutic technique termed “Mental Access/Somatosensory Access” (MASSA). MASSA is designed to utilize an external somatosensory stimulus in the context of hypnotherapy, based on a Bottom-Up/Top-Down Paradigm, which complements and mutually reinforces hypnotic inductions by using imbedded suggestions. The intervention’s algorithm includes a combination of real-time stimulation through one of the following somatosensory modalities: sensorimotor activation of the palms, visual, auditory, vibration, thermal, olfaction or oropharyngeal. These modalities are accompanied by guided hypnotic dissociation and suggestions. Somatosensory stimulation amplifies patients’ engagement in the procedure, focusing their attention on a stimulus and on the hypnotic experience during the intervention. A stream of closed questions with imbedded suggestions, presented by the therapist, is designed using suggestive presuppositions, termed by the author “The Create and Verify Principle” (CVP). This principle facilitates effective pacing and helps transform patients’ sensory and mental experiences. Imbedded suggestions followed by real-time stimulation, maintain a focus on the somatosensory content, boost the hypnotic experience, and gradually combine awareness of the somatosensory stimulation experience (Bottom-Up regulation) with memory, imagination, emotions and meanings, for mental access of resources and adaptive coping (Top-Down regulation). In the first part of this article, the author briefly introduces the neurophysiological mechanism behind the suggestive, somatosensory, attention-management intervention and provides an example of a basic algorithm of the MASSA technique. The second part includes clinical samples with scripts of successfully treated patients, who experienced tension headache, psychogenic balance disorder, tinnitus. .

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.

FUNCTIONAL MAPPING OF THE HUMAN BRAIN DURING ACUPUNCTURE WITH MAGNETIC RESONANCE IMAGINGSOMATOSENSORY CORTEX ACTIVATION

Hegu (LI 4) is one of the most frequently used and most important analgesic points in Chinese acupuncture. It is particularly effective for treating disorders of the head and face. According to the meridian theory in Traditional Chinese Medicine (TCM), the Large Intestine Meridian to which it belongs originates in the hand and terminates in the face. This theory is based, however, more on thousands of years of clinical experience rather than on scientific evidence. In our study of acupuncture effects on normal human volunteers with the non-invasive BOLD (blood oxygenation level dependant)technique for FMRI (functional magnetic resonance imaging), we demonstrated widespread effects in the brain during acupuncture at Hegu and Zusanli (ST 36). A finding of special interest was observed in the primary somatosensory cortes (SI) during Hegu acupuncture. In additlon to activation of the area representing the hand in response to the sensory impulses arising from the site of stimulation, activation also occurred in the face representation in all 3 subjects brains studied by coronal brain sections. In one of these subjects activation in the face representation was even stronger than that in the hand representation. Areas representing the neck, trunk and other parts of the upper extremity also exhibited increase in signal intensity, subject to individual variability. As compared with Hegu, such effects were either absent or much weaker with acupuncture at Zusanli (ST 36) or with other forms of sensory stimulation to the hand. Functional mapping of the brain with MRI has provided the first direct evidence in support of the important role of Hegu acupuncture in TCM.

In vivo neuronal and astrocytic activation in somatosensory cortex by acupuncture stimuli

Acupuncture is a medical treatment that has been widely pra cticed in China for over 3000 years,yet the neural mechanisms of acupuncture are not fully understood.We hypothesized that neurons and astrocytes act independently and synergistically under acupuncture stimulation.To investigate this,we used two-photon in vivo calcium reco rding to observe the effects of acupuncture stimulation at ST36(Zusanli)in mice.Acupuncture stimulation in peripheral acupoints potentiated calcium signals of pyramidal neurons and astrocytes in the somatosensory cortex and resulted in late-onset calcium transients in astrocytes.Chemogenetic inhibition of neurons augmented the astrocytic activity.These findings suggest that acupuncture activates neuronal and astrocytic activity in the somatosensory co rtex and provide evidence for the involvement of both neurons and astrocytes in acupuncture treatment.

Application of the Somatosensory Interaction Technology Combined with Virtual Reality Technology on Upper Limbs Function in Cerebrovascular Disease Patients

Objective: To explore the effects of the somatosensory interaction technology combined with virtual reality technology on upper limbs function and activities of daily living (ADL) in cerebrovascular disease patients. Methods: Form January, 2019 to December, 2019, 80 cerebrovascular disease patients were recruited, and had been divided into control group (n = 40) and observation group (n = 40), randomly. The control groups received conventional rehabilitation treatment, for 40 minutes per day, while observation group received conventional rehabilitation treatment, for 20 minutes per day, and virtual reality technology treatment, 20 minutes per day, 5 days a week for 4 weeks. Wolf Motor Function Test (WMFT), Fugl-Meyer Assessment-Upper Extremities (FMA-UE) and modified Barthel index (MBI) were used to assess the motor function of the upper limbs and ADL before and after treatment. Results: Before treatment, the scores of WMFT, FMA-UE and MBI were no significant difference between two groups (P > 0.05). The scores improved in both groups after treatment (P < 0.01), and were higher in the observation group than in the control group (P < 0.05). Conclusion: The somatosensory interaction technology combined with virtual reality technology could facilitate to improve the upper limbs function and ADL in cerebrovascular disease patients.

Cortical evoked potential changes in a rat model of acute ischemic stroke Detection of somatosensory evoked potential and motor evoked potential

BACKGROUND: Studies have shown that latency changes of some elements in a somatosensory evoked potential (SEP) and motor evoked potential (MEP) can reflect electrical activity of cerebral cortical neurons and conduction of white matter nerve fibers. However, there is a paucity of information regarding the dynamic observation of SEP and MEP following cerebral ischemic injury. OBJECTIVE: To explore SEP and MEP changes following acute ischemic stroke, and investigate the role of evoked potentials in monitoring brain function in stroke. DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Chongqing Key Laboratory of Neurology, Affiliated Hospital of Chongqing Medical University from September 2007 to August 2008. MATERIALS: Hydrogen blood flow detector was purchased from Soochow University Medical Instrument Co., China, and Power lab system was purchased from AD Instruments, Inc., USA. METHODS: A total of 36 healthy, adult, male, Sprague Dawley rats were randomly assigned to four groups (n = 9), including three ischemia groups (12, 24 and 72 hours of ischemia) and a sham-surgery group. The rat model of acute ischemic stroke was established by middle cerebral artery occlusion (MCAO) in the left hemisphere. MAIN OUTCOME MEASURES: SEP and MEP of the left limbs were detected, and cerebral blood flow was measured by the hydrogen cleaning method. RESULTS: The latency of positive wave 1 (P1), negative wave 1 (N1) and positive wave 2 (P2) waves in SEP, and latency of negative wave 1, 2 (N1, N2) waves in MEP were significantly prolonged with increasing ischemic duration following MCAO (P < 0.01), but cerebral blood flow was significantly decreased (P < 0.05, or P < 0.01). CONLUSION: Ischemic stroke prolongs the latency of SEP waves (P1, N1, P2) and MEP waves (N1, N2), and cerebral cortical evoked potential may correlate with cerebral blood flow changes. This indicates that SEP and MEP can be used to evaluate brain function following acute ischemic stroke.

Effects of ligustrazine on somatosensory evoked potential in normal rabbits and rabbits with cerebral ischemia-reperfusion injury

BACKGROUND: Somatosensory evoked potential (SEP) has become a method with higher sensitivity and specificity than electroencephalogram in detecting the brain function and the region, range and degree of ischemia. However, the effects of ligustrazine on SEP is still not clear. OBJECTIVE: To study the protective effects of ligustrazini injection on cerebral ischemiareperfusion injury. DESIGN: Auto-control study, random grouping. SETTING: Qilu Hospital of Shandong University. MATERIALS: The experiment was completed in the Cerebral Functional Room of Qilu Hospital Affiliated to Shandong University from March 2002 to June 2004. A totally of 24 healthy Harbin rabbits were randomly divided into blank control group (n=8), model control group (n=8) and ligustrazine treatment group (n=8). Hydrochloric ligustrazine injection, 40 mg/2 mL each ampoule, was provided by the Third Pharmaceutical Factory of Beijing (certification: 93035236273). The main component was hydrochloric ligustrazine and the chemical name was 2, 3, 5, 6-tetramethyl pyrazine hydrochloride. METHODS: ① Modeling method: The bilateral common carotid artery ligation was adopted to make the model. ② Index of cerebral functional lesion evaluated with SEP during ischemia-reperfusion: DISA 2000C neuromyoeletrometer provided by Dantec Electronics Ltd, Denmark was used to detect SEP. ③ Interventional process: Blank control group: The latencies and amplitudes of SEP were measured before injection with 1.5 mg/kg ligustrazine and at the points of 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after injection. Ligustrazine treatment group: Rabbits were injected with 1.5 mg/kg ligustrazine, and those of model control group were injected the same volume of saline. Thirty minutes later, the bilateral common carotid artery of the rabbits all had been ligated for 30 minutes, and then reperfused for 120 minutes. The latencies and amplitudes of SEP were measured before injection, before ligation, at the points of 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes and 30 minutes after ligation, and at the points of 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 60 minutes, 90 minutes and 120 minutes after reperfusion. ④ Evaluating criteria: Normal values of P-wave latencies and amplitudes were (19.34±3.18) ms and (4.55±1.43) μV. Average value before injection in blank control group and average values before injection, after injection and before ligation in ischemia-reperfusion group were regarded as control criteria to evaluate changes of Pwave latencies and amplitudes after experiment. MAIN OUTCOME MEASURES: P-wave latencies and amplitudes of SEP in the three groups. RESULTS: A total of 24 rabbits were involved in the final analysis without any loss. ① Blank control group: The P-wave latencies delayed markedly at each time point after injection. Compared with that before injection, there was a significant difference (P < 0.05-0.01). The P-wave amplitudes did not fluctuate noticeably all the time after injection, but significantly decreased when compared with those before injection (P < 0.05-0.01). ② Ischemia-reperfusion group: The P-wave latencies delayed and amplitudes decreased in the rabbits with cerebral ischemiareperfusion at all points of time during cerebral ischemia-reperfusion, and there was significant difference when compared with the levels before ischemia (P < 0.05). When ligustrazine was injected, the latencies and amplitudes changed less, and as compared with the levels before ischemia, the difference was not significant (P > 0.05). CONCLUSION: ① Ligustrazine can inhibit P-wave latencies and amplitudes of SEP of normal rabbits. ② Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.

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.

A translational study of somatosensory evoked potential time–frequency components in rats,goats,and humans

Somatosensory evoked potentials(SEPs)have been widely used to assess neurological function in clinical practice.A good understanding of the association between SEP signals and neurological function is helpful for precise diagnosis of impairment location.Previous studies on SEPs have been reported in animal models.However,few studies have reported the relationships between SEP waveforms in animals and those in humans.In this study,we collected normal SEP waveforms and decomposed them into specific time–frequency components(TFCs).Our results showed three stable TFC distribution regions in intact goats and rats and in humans.After we induced spinal cord injury in the animal models,a greater number of small TFC distribution regions were observed in the injured goat and rat groups than in the normal group.Moreover,there were significant correlations(P<0.05)and linear relationships between the main SEP TFCs of the human group and those of the goat and rat groups.A stable TFC distribution of SEP components was observed in the human,goat and rat groups,and the TFC distribution modes were similar between the three groups.Results in various animal models in this study could be translated to future clinical studies based on SEP TFC analysis.Human studies were approved by the Institutional Review Board of the University of Hong Kong/Hospital Authority Hong Kong West Cluster(approval No.UM 05-312 T/975)on December 5,2005.Rat experiments were approved by the Committee on the Use of Live Animals in Teaching and Research of Li Ka Shing Faculty of Medicine of the University of Hong Kong(approval No.CULART 2912-12)on January 28,2013.Goat experiments were approved by the Animal Ethics Committee of Affiliated Hospital of Guangdong Medical University(approval No.GDY2002132)on March 5,2018.

THE SIGNIFICANCE OF DERMATOMAL SOMATOSENSORY EVOKED POTENTIALS IN THE DIAGNOSIS OF LUMBOSACRAL NERVE ROOT COMPRESSION

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APPLICATION OF PRE－AND POSTOPERATIVE SOMATOSENSORY EVOKED POTENTIALS OF DIASTEMATOMYELIA

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Changes of somatosensory evoked potentials and sciatic nerve conductivity in chronic renal failure in rats

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Using Variations of Somatosensory Evoked Potentials to Quantify Spinal Cord Injury Level

Existing work indicates that the degree of variation of somatosensory evoked potential (SEP) signals between a healthy spinal pathway and spinal pathway affected by spinal cord injury (SCI) can be used to evaluate the integrity of the spinal pathway. This paper develops a metric that exploits the time-domain features of SEP signals (relative amplitude, time scaling, and time duration) in order to quantify the level of SCI. The proposed method is tested on actual SEP signals collected from rodents afflicted with focal demyelination SCI. Results indicate that the proposed method provides a robust assessment of the different degrees of demyelination in the spinal cord.

Dermatomal Somatosensory Evoked Potentials: An Indicator of Improvement of Breast Sensibility after Reduction Mammaplasty

Introduction: Many women think about reduction mammaplasty for different reasons. The effect of surgery on the beast sensibility is one of the greatest concerns after reconstructive reductive breast surgery through its affect on patient’s social life and psychological health. The dermatomal somatosensory evoked potential (D-SEP) is a new method to quantitatively evaluate breast sensibility. Patients and Methods: Twenty-five women enrolled in this study presenting with breast enlargement, underwent mammary reduction by using the inferior pyramidal breast reduction technique using the same operative technique described by Robbins with some modifications. All D-SEP amplitudes and latencies were calculated preoperatively and then were reassessed six and twelve months post-surgery in each breast. Result: The results revealed that there is a significant difference in the D-SEP latency pre- and post-operatively. The statistically significant decrease in latency and the breast size demonstrated indicates that the sensibility improved after breast reduction surgery both at six and twelve months. There is also a significant increase in the D-SEP amplitude pre- and post-operatively. The negative and statistically significant increase in amplitude with the decrease in breast size demonstrated indicates that the sensibility improved after breast reduction surgery both at six and twelve months. Conclusion: This study concluded that breast sensibility will improve after breast reduction as indicated by significant reduction of D-SEP latencies and increase of its amplitudes. Our results confirm an inverse relationship between breast size and sensibility, with improvement in sensibility after breast reduction.

Research on the Intervention Effect of Vibroacoustic Therapy in the Treatment of Patients with Depression

Research purpose:This study implemented somatosensory music therapy on patients with depressive disorders,and explored the effects of somatosensory music therapy on the degree of depression,positive and negative emotions,intuitive stress and autonomic nervous function of patients.Research method:We collected 66 patients diagnosed with depression from the Department of Psychological Medicine of Henan Provincial People’s Hospital,and divided them into a control group and an intervention group according to the random number table,with 33 people in each group.The control group received routine psychiatric treatment and nursing.On the basis of the control group,the intervention group received somatosensory music therapy 3 times a week,30 min each time,for 4 consecutive weeks.The Hamilton Depression Scale,Positive and Negative Emotion Scale,Perceived Stress Scale,and Heart Rate Variability Index were collected and analyzed at baseline(T0),2 weeks after treatment(T1)and 4 weeks after treatment(T2).Research results:After 4 weeks of treatment,the HAMD scores of the two groups decreased to varying degrees,and the difference between the groups was statistically significant(p<0.05).After 4 weeks of treatment,the scores of positive emotions in both groups increased to varying degrees,and the scores of negative emotions increased to varying degrees.The scores decreased to varying degrees,and there were statistically significant differences between the positive and negative emotion groups(p<0.05).After 4 weeks of treatment,the CPSS scores of the two groups decreased to varying degrees,and the difference between the two groups was statistically significant(p<0.05).Analyzing the main effect of intervention factors alone,after 4 weeks of treatment,SDNN and RMSSD indexes all increased to varying degrees,and the degree of increase in the intervention group was greater than that in the control group,and the difference between the groups was statistically significant(p<0.05).Research conclusion:assisting somatosensory music therapy for patients with depressive disorders can improve depressive symptoms,increase positive emotions,reduce negative emotions,and reduce perceived stress.These are beneficial to restore the balance of autonomic nervous system,and are effective for the treatment of depression.

Rat Navigation by Stimulating Somatosensory Cortex

One of the most important topics in neuroscience is the issue ofbrain electrical stimulation and its widespread use.Based on this issue,rat robot,a rat navigation system,was introduced in 2002,which has utilized brain electric stimulations as a guide and a reward for driving rats.Recently systems have been designed which are automatically navigated by a computer.One of the obstacles in the way of these systems is to select the stimulation frequency of the somatosensory cortex for the rotation action.In this paper,the stimulation parameters of the somatosensory cortex for rotation in the T-shaped maze were examined for the first time with applying only one pulse train.Then,the optimized parameters have been utilized in a complex maze.The results show that the performance is directly related to the pulse width and it has an inverse relationship with the pulse intervals.With optimal parameters,correctly controlling the animal in 90%of the trials in the T-maze,were managed,and in the complex maze,about 70%of the stimuli with optimized parameters were with only applying one pulse train.The results show that the stimulation parameters for navigation with only one pulse train are well optimized,and the results of this paper can be a trigger for an automatic navigation and reduce the computational costs and automatic system errors.

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.

Effect of Paired Associative Stimulation on Motor Cortex Excitability in Rats

Paired associative stimulation (PAS),combining transcranial magnetic stimulation (TMS) with electrical peripheral nerve stimulation (PNS) in pairs with an optimal interstimulus interval (ISI)in between,has been shown to influence the excitability of the motor cortex (MC)in humans.However,the underlying mechanisms remain unclear.This study was designed to explore an optimal protocol of PAS,which can modulate the excitability of MC in rats,and to investigate the underlying mechanisms. The resting motor thresholds (RMTs) of TMS-elicited motor evoked potentials (MEPs) recorded from the gastrocnemius muscle and the latency of P1 component of somatosensory evoked potentials (SEPs) induced by electrical tibial nerve stimulation were determined in male Sprague-Dawley rats (n=10).Sixty rats were then randomly divided into 3 groups:a PAS group (further divided into 10 subgroups at various ISIs calculated by using the latency of P1,n=5,respectively),a TMS (only)group (n=5)and a PNS (only)group (n=5).Ninety repetitions of PAS,TMS and PNS were administered to the rats in the 3 groups,respectively,at the frequency of 0.05 Hz and the intensity of TMS at 120% RMT and that of PNS at 6 mA.RMTs and motor evoked potentials'amplitude (MEPamp)were recorded before and immediately after the interventions.It was found that the MEPamp significantly decreased after PAS at ISI of 5 ms (P<0.05),while the MEPamp significantly increased after PAS at ISI of 15ms,as compared with those before the intervention (P<0.05).However,the RMT did not change significantly after PAS at ISI of 5 ms or 15 ms (P>0.05).PAS at other ISis as well as the sole use of TMS and PNS induced no remarkable changes in MEPamp and RMT.In conclusion,PAS can influence motor cortex excitability in rats.Neither TMS alone nor PNS alone shows significant effect.

Prevention effect of medical self-crosslinking sodium hyaluronate gel on epidural scar adhesion after laminectomy

Objective:To analyze the effect and medical sclf-crosslinking sodium hyaluronate gel on epidural scar adhesion after laminectomy.Methods:A total of 24 New Zealand L5 laminectomy rabbits were randomly divided into four groups,group A as the control group without any treatment:group B covered by sodium hyaluronate gel;group C and group D covered by 0.5 and1.0 mL medical self-crosslinking sodium hyaluronate gel.All rabbits were scored at various time points after 2.4,6,8,12 weeks,then the formation of scar was observed.Results:In Groups B,C,D loose scar tissue occurred after 2 weeks of the operation,scar tissues were significantly less than that in group A,with mild inflammatory reaction.After 8 weeks,the scar tissues of group B were significantly more than that of groups C,D.After two weeks,group B,C were back to the preoperative level;After 4 weeks,group D was back to the preoperative level;After four weeks,the CSEP of group A was increased significantly,which was significantly higher than that in groups B,C,D.The motor function score of group A,group B and group C were the same as preoperative,but that in group D it was decreased significantly,and then it gradually recovered.After 4 weeks it kept a stable level.The motor function score of group A was decreased gradually after the operation,which kept a stable level after 4 weeks,the motor function score was significantly lower man that in groups B,C,D.Conclusions:Determination of somatosensory evoked potentials is sensitive indicator of spinal cord injury;Application of medical selfcrosslinking sodium hyaluronate gel is effective on epidural scar adhesion after laminectomy.