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 i...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.展开更多
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...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.展开更多
It remains unclear whether spinal cord ischemia-reperfusion injury caused by ischemia and other non-mechanical factors can be monitored by somatosensory evoked potentials. Therefore, we monitored spinal cord ischemia-...It remains unclear whether spinal cord ischemia-reperfusion injury caused by ischemia and other non-mechanical factors can be monitored by somatosensory evoked potentials. Therefore, we monitored spinal cord ischemia-reperfusion injury in rabbits using somatosensory evoked potential detection technology. The results showed that the somatosensory evoked potential latency was significantly prolonged and the amplitude significantly reduced until it disappeared during the period of spinal cord ischemia. After reperfusion for 30-180 minutes, the amplitude and latency began to gradually recover; at 360 minutes of reperfusion, the latency showed no significant difference compared with the pre-ischemic value, while the somatosensory evoked potential amplitude in- creased, and severe hindlimb motor dysfunctions were detected. Experimental findings suggest that changes in somatosensory evoked potentia~ ~atency can reflect the degree of spinat cord ischemic injury, while the amplitude variations are indicators of the late spinal cord reperfusion injury, which provide evidence for the assessment of limb motor function and avoid iatrogenic spinal cord injury.展开更多
Objective: Optimization of combining electroencephalography (EEG), short latency somatosensory evoked potentials (SLSEP) and transcranial Doppler (TCD) techniques to diagnose brain death. Methods: One hundred and elev...Objective: Optimization of combining electroencephalography (EEG), short latency somatosensory evoked potentials (SLSEP) and transcranial Doppler (TCD) techniques to diagnose brain death. Methods: One hundred and eleven patients (69 males, 42 females) from the major hospitals of Zhejiang Province were examined with portable EEG, SLSEP and TCD devices. Re-examinations occurred ≤12 h later. Results: The first examination revealed that the combination of SLSEP and EEG led to more sensitive diagnoses than the combination of SLSEP and TCD. Re-examination confirmed this and also revealed that the combination of TCD and EEG was the most sensitive. Conclusion: The results show that using multiple techniques to diagnose brain death is superior to using single method, and that the combination of SLSEP and EEG is better than other combinations.展开更多
in this study, conical somatosensory evoked potentials (SEPs)following electrical stimulation of the skin of LS and SI dermatomes were recorded cephalically and observed in 19 patients with clinically proved unilatera...in this study, conical somatosensory evoked potentials (SEPs)following electrical stimulation of the skin of LS and SI dermatomes were recorded cephalically and observed in 19 patients with clinically proved unilateral L5 or S1 nerve root compression, and the results were compared with those of the control group or 20 healthy volunteers and showed that dermatomal SEPs were abnormal in 12 with the rate of 63%,most or which showed abnomalities or the lateral latency difference. It is concluded that dermatomal SEP is a useful addition to the diagnosis or lumbosacral nerve root compression. When the unilateral nerve root is compressed the lateral latency dirference is a most sensitive criterion for indicating abnomality.展开更多
This study observed the changes in somatosensory evoked potentials between patients with amyotrophic lateral sclerosis （ALS） and healthy controls to evaluate the function of the central deep somatosensory pathway. I...This study observed the changes in somatosensory evoked potentials between patients with amyotrophic lateral sclerosis （ALS） and healthy controls to evaluate the function of the central deep somatosensory pathway. In patients with ALS, 28 patients （54%） showed an abnormality in somatosensory evoked potentials. All had abnormal lower limb somatosensory evoked potentials. Compared with healthy controls, the abnormality in somatosensory evoked potential was characterized by prolonged N20, P2, N2 latency and central conduction time, with or without a decrease in wave amplitude or disappearance of waveform. Results showed marked alterations in the somatosensory evoked potential in cortical components of the upper and lower limb in 54% of patients with ALS, and confirmed that patients with ALS may also have a defective deep somatosensory pathway, particularly an abnormal central deep somatosensory pathway.展开更多
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 assessme...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.展开更多
Somatasensory evoked potentials (SEP), sciatic nerve conduction velocity (CV), sciatic nerve Na+-K+-ATPase activity, and lipid peroxide content (LPO) were determined in 8 rats with chronic renal failure induced with 5...Somatasensory evoked potentials (SEP), sciatic nerve conduction velocity (CV), sciatic nerve Na+-K+-ATPase activity, and lipid peroxide content (LPO) were determined in 8 rats with chronic renal failure induced with 5/6 nephrectomy. Meanwhile, the histological changes were also oserved. Ten rats wtih sham operation served as the control. It was found that in the group with chronic renal failure, the mean peak latency of SEP was significantly prolonged and CV slower than those of the control. In the sciatic nerve tissue, Na+-K+-ATPase activity was loyer and LPO content higher in the tested group than in the control. No significant histological changes of the sciatic nerve were found under optical microscope. These findings suggest that the decrease of nerve conductivity after chronic renal failure might result from the insufficient activity of Na+-K+-ATPase and enhanced generation of free oxygen radicals.展开更多
Conical somatosensory evoked potential(CSEP) examination of posterior tibial nerve was performed Pre-and postoperatively smong 20 patients with diastematomyelia and 20 normal people as control group at the same time.T...Conical somatosensory evoked potential(CSEP) examination of posterior tibial nerve was performed Pre-and postoperatively smong 20 patients with diastematomyelia and 20 normal people as control group at the same time.The results indicated CSEP changes were statistically significant between patients and normal people(P< 0.05);postoperative P40, Peak latencies and amplitudes changed significantly and CSEPs had apparent difference in bilateral lower extremities among preoperative patients.This shows that CSEP is an objective,sensitive and reliable diagnostic tool that may be used to judge the severity of neural damage and evaluate the surgical results.展开更多
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...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.展开更多
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 it...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.展开更多
A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University...A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University in China. Somatosensory evoked potentials were graded as normal, abnormal or absent （grades I-III） according to N20 amplitude and central conduction time. The outcome in patients with grade III somatosensory evoked potential was in each case unfavorable. The prognostic accuracy of grade III somatosensory evoked potential for unfavorable and non-awakening outcome was 100% and 80%, respectively. The prognostic accuracy of grade I somatosensory evoked potential for favorable and wakening outcome was 86% and 100%, respectively. These results suggest that somatosensory evoked potential grade is closely correlated with coma severity and degree of recovery. Somatosensory evoked potential is a valuable diagnostic tool to assess prognosis in prolonged coma patients with diffuse axonal injury.展开更多
Aim: The effect of a renewed SS-cream (RSSC) on the treatment of premature ejaculation (PE) was evaluated and compared with the original SS-cream (OSSC). Methods: Sixty male white New Zealand rabbits, weighing 2.5kg-3...Aim: The effect of a renewed SS-cream (RSSC) on the treatment of premature ejaculation (PE) was evaluated and compared with the original SS-cream (OSSC). Methods: Sixty male white New Zealand rabbits, weighing 2.5kg-3.0 kg, were divided at random into 3 groups: the RSSC, OSSC and placebo groups. The spinal somatosensory evoked potential (SSEP) elicited by electric stimulation of the glans penis with disk electrode was investigated with an electrophysiograph (Poseidomn, Shanghai, China) before and 10, 30 and 60 min after drug or placebo application on the glans. The Onset and the N1 latencies and the amplitude of SSEP were recorded and analyzed. Results: There was no significant difference (P>0.05) in the mean Onset and Nl latency of SSEP among the 3 groups before drug application. Compared with the pre-application value, the mean Onset and Nl latencies in the RSSC and OSSC groups were significantly prolonged at 10, 30 and 60 min after treatment (P<0.05), while they were not significantly changed (P>0.05) in the placebo group. The mean Onset latency of RSSC at 10 and 30 min and that of OSSC at 30 min were significantly delayed (P<0.05) compared with the placebo group. The mean Nl latency of RSSC at 30 and 60 min and that of OSSC group at 30 min were also significantly delayed (P<0.05). Conclusion: RSSC delays the latencies of SSEP, suggesting a local desensitizing effect on the sensory receptor of the glans penis dorsal nerve, which provides the potential for PE treatment. The desensitizing effect of RSSC is higher than that of OSSC.展开更多
BACKGROUND： Computed Tomography （CT） and Magnetic Resonance Imaging （MRI） can display the site of lumbar spinal stenosis and predict nervous compression at the morphological level; however, pure morphological cha...BACKGROUND： Computed Tomography （CT） and Magnetic Resonance Imaging （MRI） can display the site of lumbar spinal stenosis and predict nervous compression at the morphological level; however, pure morphological changes cannot reflect functional alterations in a compressed nerve root. Dermatomal somatosensory evoked potential （DSEP） provides a means to assess the functional state of a nerve root. OBJECTIVE： To evaluate the clinical significance of DSEP, assessing the degree of nerve root injury following lumbar spinal stenosis. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Orthopaedic Surgery, Hainan People＇s Hospital, China, between September 2004 and December 2007. PARTICIPANTS： Forty-seven patients diagnosed with lumbar spinal stenosis by CT or MRI were selected as the case group; fifty healthy subjects were collected as the control group. METHODS： A KEYPOINT myoelectric evoked potential apparatus （DANTEC Company, Denmark） was used to measure DSEP, and stimulative spots were determined in accordance with the skin key sensory spot standards established by The American Spinal Injury Association： L4 in the medial malleolus, L5 in the third metatarsophalangeal joint of the dorsum of foot and S1 in the lateral heel. The needle electrode used as the recording electrode was located at the Cz point of the cranium, and the reference electrode at the Fz point. MAIN OUTCOME MEASURES： Latency of the P40 peak of DSEP, P1-N1 amplitude, P40 waveform and differentiation and disappearance of various waves. RESULTS： The sensitivity and diagnostic concurrence with surgery of nerve root injury following lumbar spinal stenosis evaluated by DSEP was 95.7 %. P40 latencies at L4, L5 and S1 in the case group were significantly longer than in the control group （P 〈 0.05）, and the P1-N1 amplitude in the case group was significantly lower than the control group （P 〈 0.05-0.01）. Nerve root injury was categorized according to DSEP latency as follows： severe damage （disappearance of the P40 wave in 103 dermatomes）, moderate damage （prolongation of the P40 peak latency ≥ 3.0 times the standard deviation of the normal mean in 60 dermatomes） and mild damage （prolongation of the P40 peak latency ≥ 2.5 times the standard deviation of the normal mean in 31 dermatomes）. CONCLUSION： DSEP can be used to determine the severity of nerve root injury following lumbar spinal stenosis with high sensitivity and specificity.展开更多
BACKGROUND： It has been reported that dermatomal somatosensory evoked potential （DSEP） can be used for diagnosing nerve root injury in patients with lumbar disc herniation （LDH）, and that 83% 95% of patients suff...BACKGROUND： It has been reported that dermatomal somatosensory evoked potential （DSEP） can be used for diagnosing nerve root injury in patients with lumbar disc herniation （LDH）, and that 83% 95% of patients suffer from the disease. Body height correction is not performed prior to determinations of latency and latency difference between the healthy and affected sides. However, latency noticeably correlates to body height. OBJECTIVE： This study aims to determine the lumbosacral nerve root injury in patients with LDH by DSEP, and to evaluate the sensitivity of the DSEP difference between the healthy and affected sides using a diagnostic index following body height correction. DESIGN： A case-control observation. SETTING： Department of Orthopedic Surgery, Hainan Provincial People＇s Hospital. PARTICIPANTS： Ninety-six patients, comprised of 67 males and 29 females, with an average age of 43 years and a mean body height of 1.65 m （range 1.48-1.81 m）, were recruited for this study. These patients suffered from unilateral lower limb radiation pain and received treatment at the Department of Orthopedic Surgery, Hainan Provincial People＇s Hospital between January 2004 and December 2006. All patients were confirmed to suffer from LDH at the L3-4, L-5, and/or Ls-SI by CT and/or MRI examinations. Central nervous system diseases were excluded. In order to obtain a normal reference value, DSEP was determined for a group of 50 subjects, who concurrently received health examinations in the same department. The subjects had no previous history of back leg pain or nervous system disease. The group of healthy controls included 26 males and 24 females, with an average age of 37 years and a mean body height of 1.63 m （range 1.50-1.80 m）. Written informed consent was obtained from all subjects for laboratory samples. The protocol was approved by the Hospital＇s Ethics Committees. DSEP was determined with myoelectricity-evoked potential equipment （Keypoint, Batch No. 9020A0042591, Dantec Company, Denmark）. METHODS： DSEP of patients with LDH was determined. Constant-voltage square pulse stimulation was used to determine DSEP, with the following parameters： a pulse wave width of 0.2 milliseconds; a saddle-like stimulating electrode; a stimulation intensity 3 times greater than the sensation threshold; a stimulation frequency of 1.5 Hz; mean superposition greater than 100 times; and inter-electrode impedance 〈 5 k Q. The stimulation point was a skin key sensation point confirmed by the American Spinal Injury Association, i.e. L4 at medial malleolus, L5 at the third metatarsophalangeal joint on the dorsum of the foot, and SI at the lateral heel. The recording electrode was a needle electrode, the recording point was Cz, and the reference electrode was Fz. DSEP latency of P40, and latency differences of P40, between the healthy side and the affected side, were determined. DSEP at L4, L5, and S1 nerve roots of the lower limbs of 50 healthy controls were bilaterally determined. The normal values of P40 latency and P40 N50 amplitude were statistically obtained. MAIN OUTCOME MEASURES： Determination of DSEP values. RESULTS： Ninety-six patients with LDH and fifty healthy controls participated in the final analysis. In the healthy controls, the amplitude of DSEP varied greatly, with a mean amplitude co-efficient of variation of 58% for L4, L5, and SI dermatomes. P40 latency was stable, with a mean latency coefficient of variation of 4.7%. In patients with LDH, the P40 wave disappeared. P40 latency was 2.5 times prolonged compared to normal mean value. P40 latency difference between the healthy and the affected side was 2.5 times higher than the normal mean value of the healthy side. CONCLUSION： DSEP can reflect the functional status of lumbosacral nerve root. P40 latency difference between the healthy side and the affected side is the most sensitive diagnosis index for patients with LDH suffering from unilateral lower limb radiation pain.展开更多
The effects of acupuncture on the sensory evoked cortical potentials were investigated in 31 rabbits anaesthetized with urethane of conscious, so as to see what happened to the functional state of cerebral cortex in t...The effects of acupuncture on the sensory evoked cortical potentials were investigated in 31 rabbits anaesthetized with urethane of conscious, so as to see what happened to the functional state of cerebral cortex in the meantime. The visual, auditory and somatosensory evoked potentials as well as raw EEGs were recorded from the animal’s scalp. In most cases, an electro-acupuncture instrument was used instead of manual acupuncture. The main component amplitudes of evoked potentials,the frequency band powers and the total integral values of raw EEGs were analyzed. Results showed that during acupuncture the main components of evoked potentials were significantly depressed and the raw EEGs appeared desynchronized while the experimental animals were slightly activated. Moreover,both the total integral values of raw EEGs and the powers of lower frequency waves (1 - 3. 99 Hz)were decreased and positively correlated well with the amplitudes of main components of the evoked potentials. Therefore, the possibility that the effects of acupuncture on the evoked potentials are secondary to the changes of raw EEGs remains to be ruled out, and it is suggested that the inhibition of evoked potentials during acupuncture does not necessarily mean that the cerebral cortex is in an inhibitory展开更多
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 con...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.展开更多
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. H...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 ischemia-reperfusion 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 ischemiareperfusion 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 ischemia-reperfusion 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.②Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.展开更多
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 prec...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.展开更多
文摘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.
基金supported by the National Natural Science Foundation of China,No.81871768(to YH)Natural Science Foundation of Tianjin,China,No.18JCYBJC29600(to HYC)High Level-Hospital Program,Health Commission of Guangdong Province,China,No.HKUSZH201902011(to YH)。
文摘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.
基金supported by the National Natural Science Foundation of China,No.81101370,81101399,81272018the Natural Science Foundation of Jiangsu Province in China,No.BK2011303+2 种基金Jiangsu Province Science and Technology Support Program(Social Development)in China,No.BE2011672University Natural Science Research Foundation of Jiangsu Province for Higher Education,No.12KJB320008College Graduate Research and Innovation Plan of Jiangsu Province in China,No.CXZZ11_0126
文摘It remains unclear whether spinal cord ischemia-reperfusion injury caused by ischemia and other non-mechanical factors can be monitored by somatosensory evoked potentials. Therefore, we monitored spinal cord ischemia-reperfusion injury in rabbits using somatosensory evoked potential detection technology. The results showed that the somatosensory evoked potential latency was significantly prolonged and the amplitude significantly reduced until it disappeared during the period of spinal cord ischemia. After reperfusion for 30-180 minutes, the amplitude and latency began to gradually recover; at 360 minutes of reperfusion, the latency showed no significant difference compared with the pre-ischemic value, while the somatosensory evoked potential amplitude in- creased, and severe hindlimb motor dysfunctions were detected. Experimental findings suggest that changes in somatosensory evoked potentia~ ~atency can reflect the degree of spinat cord ischemic injury, while the amplitude variations are indicators of the late spinal cord reperfusion injury, which provide evidence for the assessment of limb motor function and avoid iatrogenic spinal cord injury.
文摘Objective: Optimization of combining electroencephalography (EEG), short latency somatosensory evoked potentials (SLSEP) and transcranial Doppler (TCD) techniques to diagnose brain death. Methods: One hundred and eleven patients (69 males, 42 females) from the major hospitals of Zhejiang Province were examined with portable EEG, SLSEP and TCD devices. Re-examinations occurred ≤12 h later. Results: The first examination revealed that the combination of SLSEP and EEG led to more sensitive diagnoses than the combination of SLSEP and TCD. Re-examination confirmed this and also revealed that the combination of TCD and EEG was the most sensitive. Conclusion: The results show that using multiple techniques to diagnose brain death is superior to using single method, and that the combination of SLSEP and EEG is better than other combinations.
文摘in this study, conical somatosensory evoked potentials (SEPs)following electrical stimulation of the skin of LS and SI dermatomes were recorded cephalically and observed in 19 patients with clinically proved unilateral L5 or S1 nerve root compression, and the results were compared with those of the control group or 20 healthy volunteers and showed that dermatomal SEPs were abnormal in 12 with the rate of 63%,most or which showed abnomalities or the lateral latency difference. It is concluded that dermatomal SEP is a useful addition to the diagnosis or lumbosacral nerve root compression. When the unilateral nerve root is compressed the lateral latency dirference is a most sensitive criterion for indicating abnomality.
基金the National Natural Science Youth Foundation of China, No. 81000524
文摘This study observed the changes in somatosensory evoked potentials between patients with amyotrophic lateral sclerosis （ALS） and healthy controls to evaluate the function of the central deep somatosensory pathway. In patients with ALS, 28 patients （54%） showed an abnormality in somatosensory evoked potentials. All had abnormal lower limb somatosensory evoked potentials. Compared with healthy controls, the abnormality in somatosensory evoked potential was characterized by prolonged N20, P2, N2 latency and central conduction time, with or without a decrease in wave amplitude or disappearance of waveform. Results showed marked alterations in the somatosensory evoked potential in cortical components of the upper and lower limb in 54% of patients with ALS, and confirmed that patients with ALS may also have a defective deep somatosensory pathway, particularly an abnormal central deep somatosensory pathway.
文摘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.
文摘Somatasensory evoked potentials (SEP), sciatic nerve conduction velocity (CV), sciatic nerve Na+-K+-ATPase activity, and lipid peroxide content (LPO) were determined in 8 rats with chronic renal failure induced with 5/6 nephrectomy. Meanwhile, the histological changes were also oserved. Ten rats wtih sham operation served as the control. It was found that in the group with chronic renal failure, the mean peak latency of SEP was significantly prolonged and CV slower than those of the control. In the sciatic nerve tissue, Na+-K+-ATPase activity was loyer and LPO content higher in the tested group than in the control. No significant histological changes of the sciatic nerve were found under optical microscope. These findings suggest that the decrease of nerve conductivity after chronic renal failure might result from the insufficient activity of Na+-K+-ATPase and enhanced generation of free oxygen radicals.
文摘Conical somatosensory evoked potential(CSEP) examination of posterior tibial nerve was performed Pre-and postoperatively smong 20 patients with diastematomyelia and 20 normal people as control group at the same time.The results indicated CSEP changes were statistically significant between patients and normal people(P< 0.05);postoperative P40, Peak latencies and amplitudes changed significantly and CSEPs had apparent difference in bilateral lower extremities among preoperative patients.This shows that CSEP is an objective,sensitive and reliable diagnostic tool that may be used to judge the severity of neural damage and evaluate the surgical results.
文摘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.
文摘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.
基金funded by Zhejiang Medicines &Health Sciences Research Fund (Class A) in 2009, No.2009A086
文摘A total of 43 prolonged coma patients with diffuse axonal injury received the somatosensory evoked potential examination one month after injury in the First Affiliated Hospital, School of Medicine, Zhejiang University in China. Somatosensory evoked potentials were graded as normal, abnormal or absent （grades I-III） according to N20 amplitude and central conduction time. The outcome in patients with grade III somatosensory evoked potential was in each case unfavorable. The prognostic accuracy of grade III somatosensory evoked potential for unfavorable and non-awakening outcome was 100% and 80%, respectively. The prognostic accuracy of grade I somatosensory evoked potential for favorable and wakening outcome was 86% and 100%, respectively. These results suggest that somatosensory evoked potential grade is closely correlated with coma severity and degree of recovery. Somatosensory evoked potential is a valuable diagnostic tool to assess prognosis in prolonged coma patients with diffuse axonal injury.
文摘Aim: The effect of a renewed SS-cream (RSSC) on the treatment of premature ejaculation (PE) was evaluated and compared with the original SS-cream (OSSC). Methods: Sixty male white New Zealand rabbits, weighing 2.5kg-3.0 kg, were divided at random into 3 groups: the RSSC, OSSC and placebo groups. The spinal somatosensory evoked potential (SSEP) elicited by electric stimulation of the glans penis with disk electrode was investigated with an electrophysiograph (Poseidomn, Shanghai, China) before and 10, 30 and 60 min after drug or placebo application on the glans. The Onset and the N1 latencies and the amplitude of SSEP were recorded and analyzed. Results: There was no significant difference (P>0.05) in the mean Onset and Nl latency of SSEP among the 3 groups before drug application. Compared with the pre-application value, the mean Onset and Nl latencies in the RSSC and OSSC groups were significantly prolonged at 10, 30 and 60 min after treatment (P<0.05), while they were not significantly changed (P>0.05) in the placebo group. The mean Onset latency of RSSC at 10 and 30 min and that of OSSC at 30 min were significantly delayed (P<0.05) compared with the placebo group. The mean Nl latency of RSSC at 30 and 60 min and that of OSSC group at 30 min were also significantly delayed (P<0.05). Conclusion: RSSC delays the latencies of SSEP, suggesting a local desensitizing effect on the sensory receptor of the glans penis dorsal nerve, which provides the potential for PE treatment. The desensitizing effect of RSSC is higher than that of OSSC.
基金the National Natural Science Foundation of Hainan Province,No.30318
文摘BACKGROUND： Computed Tomography （CT） and Magnetic Resonance Imaging （MRI） can display the site of lumbar spinal stenosis and predict nervous compression at the morphological level; however, pure morphological changes cannot reflect functional alterations in a compressed nerve root. Dermatomal somatosensory evoked potential （DSEP） provides a means to assess the functional state of a nerve root. OBJECTIVE： To evaluate the clinical significance of DSEP, assessing the degree of nerve root injury following lumbar spinal stenosis. DESIGN, TIME AND SETTING： A case-control study was performed in the Department of Orthopaedic Surgery, Hainan People＇s Hospital, China, between September 2004 and December 2007. PARTICIPANTS： Forty-seven patients diagnosed with lumbar spinal stenosis by CT or MRI were selected as the case group; fifty healthy subjects were collected as the control group. METHODS： A KEYPOINT myoelectric evoked potential apparatus （DANTEC Company, Denmark） was used to measure DSEP, and stimulative spots were determined in accordance with the skin key sensory spot standards established by The American Spinal Injury Association： L4 in the medial malleolus, L5 in the third metatarsophalangeal joint of the dorsum of foot and S1 in the lateral heel. The needle electrode used as the recording electrode was located at the Cz point of the cranium, and the reference electrode at the Fz point. MAIN OUTCOME MEASURES： Latency of the P40 peak of DSEP, P1-N1 amplitude, P40 waveform and differentiation and disappearance of various waves. RESULTS： The sensitivity and diagnostic concurrence with surgery of nerve root injury following lumbar spinal stenosis evaluated by DSEP was 95.7 %. P40 latencies at L4, L5 and S1 in the case group were significantly longer than in the control group （P 〈 0.05）, and the P1-N1 amplitude in the case group was significantly lower than the control group （P 〈 0.05-0.01）. Nerve root injury was categorized according to DSEP latency as follows： severe damage （disappearance of the P40 wave in 103 dermatomes）, moderate damage （prolongation of the P40 peak latency ≥ 3.0 times the standard deviation of the normal mean in 60 dermatomes） and mild damage （prolongation of the P40 peak latency ≥ 2.5 times the standard deviation of the normal mean in 31 dermatomes）. CONCLUSION： DSEP can be used to determine the severity of nerve root injury following lumbar spinal stenosis with high sensitivity and specificity.
基金the Natural Science Foundation of Hainan Province, No. 30318
文摘BACKGROUND： It has been reported that dermatomal somatosensory evoked potential （DSEP） can be used for diagnosing nerve root injury in patients with lumbar disc herniation （LDH）, and that 83% 95% of patients suffer from the disease. Body height correction is not performed prior to determinations of latency and latency difference between the healthy and affected sides. However, latency noticeably correlates to body height. OBJECTIVE： This study aims to determine the lumbosacral nerve root injury in patients with LDH by DSEP, and to evaluate the sensitivity of the DSEP difference between the healthy and affected sides using a diagnostic index following body height correction. DESIGN： A case-control observation. SETTING： Department of Orthopedic Surgery, Hainan Provincial People＇s Hospital. PARTICIPANTS： Ninety-six patients, comprised of 67 males and 29 females, with an average age of 43 years and a mean body height of 1.65 m （range 1.48-1.81 m）, were recruited for this study. These patients suffered from unilateral lower limb radiation pain and received treatment at the Department of Orthopedic Surgery, Hainan Provincial People＇s Hospital between January 2004 and December 2006. All patients were confirmed to suffer from LDH at the L3-4, L-5, and/or Ls-SI by CT and/or MRI examinations. Central nervous system diseases were excluded. In order to obtain a normal reference value, DSEP was determined for a group of 50 subjects, who concurrently received health examinations in the same department. The subjects had no previous history of back leg pain or nervous system disease. The group of healthy controls included 26 males and 24 females, with an average age of 37 years and a mean body height of 1.63 m （range 1.50-1.80 m）. Written informed consent was obtained from all subjects for laboratory samples. The protocol was approved by the Hospital＇s Ethics Committees. DSEP was determined with myoelectricity-evoked potential equipment （Keypoint, Batch No. 9020A0042591, Dantec Company, Denmark）. METHODS： DSEP of patients with LDH was determined. Constant-voltage square pulse stimulation was used to determine DSEP, with the following parameters： a pulse wave width of 0.2 milliseconds; a saddle-like stimulating electrode; a stimulation intensity 3 times greater than the sensation threshold; a stimulation frequency of 1.5 Hz; mean superposition greater than 100 times; and inter-electrode impedance 〈 5 k Q. The stimulation point was a skin key sensation point confirmed by the American Spinal Injury Association, i.e. L4 at medial malleolus, L5 at the third metatarsophalangeal joint on the dorsum of the foot, and SI at the lateral heel. The recording electrode was a needle electrode, the recording point was Cz, and the reference electrode was Fz. DSEP latency of P40, and latency differences of P40, between the healthy side and the affected side, were determined. DSEP at L4, L5, and S1 nerve roots of the lower limbs of 50 healthy controls were bilaterally determined. The normal values of P40 latency and P40 N50 amplitude were statistically obtained. MAIN OUTCOME MEASURES： Determination of DSEP values. RESULTS： Ninety-six patients with LDH and fifty healthy controls participated in the final analysis. In the healthy controls, the amplitude of DSEP varied greatly, with a mean amplitude co-efficient of variation of 58% for L4, L5, and SI dermatomes. P40 latency was stable, with a mean latency coefficient of variation of 4.7%. In patients with LDH, the P40 wave disappeared. P40 latency was 2.5 times prolonged compared to normal mean value. P40 latency difference between the healthy and the affected side was 2.5 times higher than the normal mean value of the healthy side. CONCLUSION： DSEP can reflect the functional status of lumbosacral nerve root. P40 latency difference between the healthy side and the affected side is the most sensitive diagnosis index for patients with LDH suffering from unilateral lower limb radiation pain.
文摘The effects of acupuncture on the sensory evoked cortical potentials were investigated in 31 rabbits anaesthetized with urethane of conscious, so as to see what happened to the functional state of cerebral cortex in the meantime. The visual, auditory and somatosensory evoked potentials as well as raw EEGs were recorded from the animal’s scalp. In most cases, an electro-acupuncture instrument was used instead of manual acupuncture. The main component amplitudes of evoked potentials,the frequency band powers and the total integral values of raw EEGs were analyzed. Results showed that during acupuncture the main components of evoked potentials were significantly depressed and the raw EEGs appeared desynchronized while the experimental animals were slightly activated. Moreover,both the total integral values of raw EEGs and the powers of lower frequency waves (1 - 3. 99 Hz)were decreased and positively correlated well with the amplitudes of main components of the evoked potentials. Therefore, the possibility that the effects of acupuncture on the evoked potentials are secondary to the changes of raw EEGs remains to be ruled out, and it is suggested that the inhibition of evoked potentials during acupuncture does not necessarily mean that the cerebral cortex is in an inhibitory
基金the National Natural Science Foundation of China, No. 30300075China Postdoctoral Science Foundation, No. 20080440995Sichuan Science Fund for Out-standing Youths, No. 05ZQ026-020
文摘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.
基金Technological Developing Plan of Science and Technology Bureau of Shandong Province, No. 032050116
文摘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 ischemia-reperfusion 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 ischemiareperfusion 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 ischemia-reperfusion 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.②Ligustrazine can improve P-wave latencies and amplitudes of SEP of rabbits with cerebral ischemia-reperfusion injury.
基金supported by the National Natural Science Foundation of China,No.81871768(to YH)the Natural Science Foundation of Tianjin of China,No.18JCYBJC29600(to HYC)High Level-Hospital Program,Health Commission of Guangdong Province of China,No.HKUSZH201902011(to YH).
文摘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.
