Impact of Reconstructing Intercostal Artery on Spinal Cord Circulation During Open Surgery for Thoracoabdominal Aortic Aneurysm

ABSTRACT Introduction: We evaluated the outcomes of the selective intercostal artery reconstruction for preventing spinal cord injury during thoracoabdominal aortic aneurysm repair. Methods: We retrospectively assessed 84 consecutive patients who underwent thoracoabdominal aortic aneurysm repairs between 2004 and 2016. The mean age of the patients was 57.3 years. We performed preoperative multidetector computed tomography in 74 patients (88.0%) to identify the Adamkiewicz artery. Spinal cord injury preventive measures included motor evoked potential monitoring, hypothermia induction, Adamkiewicz artery or other intercostal artery reconstruction, and cerebrospinal fluid drainage. Results: The hospital death rate was 5.9%, and paraplegia occurred in four patients (4.7%). The Adamkiewicz artery or other intercostal arteries were reconstructed selectively in 46 patients (54.7%). Of these patients, 41 underwent postoperative multidetector computed tomography, which revealed occlusion of the reconstructed grafts in 23 patients (56.0%). There was no paraplegia in the patients who underwent reconstruction of the Adamkiewicz artery, which was patent on postoperative multidetector computed tomography. Univariate analysis showed no significant effect of various risk factors on the development of spinal cord injury. Conclusion: Outcome of open surgery for thoracoabdominal aortic aneurysm in our institution regarding spinal cord injury was satisfactory. The benefits of Adamkiewicz artery reconstruction remain inconclusive, and further larger studies are required to identify its validation for spinal cord protection in thoracoabdominal aortic aneurysm repair.

A novel spinal cord classification system: predict Intraoperative Neuromonitoring Event during correction of congenital kyphosis / 中华骨科杂志

Objective:To propose a novel classification system based on the morphology and relative position of spinal cord in the spinal canal at sagittal T2-MRI, and to investigate the incidence and risk factors of the intraoperative neuromonitoring event (IONME) across these classifications.Methods:From January 2016 to December 2021, a consecutive cohort of 85 patients who underwent surgical correction of congenital kyphosis with pedicle screw/rod constructs were retrospectively reviewed, including 43 males and 42 females, aged 14.6±6.1 years old. According to the morphology and relative location of spinal cord at the apex of the curve on the sagittal-T2 MRI, patients were divided into three groups. Type A (5 cases) is characterized by the spinal cord centrally positioned within the spinal canal, surrounded by discernible cerebrospinal fluid (CSF). Type B (33 cases) depicts the spinal cord abutting the spinal canal's anterior wall, maintaining its intrinsic morphology. In Type C (47 patients), the spinal cord is contorted by the apical vertebral body, devoid of interposing CSF. The global kyphosis (GK) and sagittal deformity ratio (SDAR) of patients were measured before surgery. The incidence of IONME were recorded. All patients included in the study were further divided into the IONME group and the non-IONME group. Potential risk factors were identified using univariate testing. Binary Logistic Regression was used to analyze the independent risk factors for IONM.Results:All of 85 patients were reviewed: 5 (5.9%) Type A; 33 (38.8%) Type B; and 47 (55.3%) Type C spinal cords. Intraoperatively, 27 (31.8%) instances presented with lost trans-cranial motor-evoked potentials (MEPs) and/or somatosensory evoked potentials (SSEPs). Of these, 2 (7.4%) were Type B, and 25 (92.6%) were Type C, reflecting a statistically significant variance in IONME occurrences across types (χ 2=27.15, P<0.001). Notable differences were observed between IONME and non-IONME groups concerning GK, SDAR, and apex location ( t=5.41, P<0.001; t=3.65, P<0.001; χ 2=7.71, P=0.005). Univariate analysis showed that potential risk factors of IONME included Type C spinal cord ( OR=20.46, P<0.001), higher GK ( OR=1.07, P<0.001), SDAR ( OR=1.15, P=0.002) and apical vertebrae located at middle thoracic( OR=4.30, P=0.008). Independent predictors identified on binary Logistics regression modeling included higher GK ( OR=1.05, P=0.015), Type C spinal cord ( OR=6.22, P=0.042) and apex located at middle thoracic ( OR=6.43, P=0.021). Specifically, within Type C, 79% of cases where the apical vertebra was mid-thoracic experienced IONME, contrasting the 42% incidence observed in those with a lower thoracic apex positioning, signifying a notably elevated IONME likelihood for the mid-thoracic region (χ 2=5.16, P=0.023). Conclusion:Risk factors of IONME included Type C spinal cord, higher GK and apex located at middle thoracic during correction of congenital kyphosis. Preoperative MRI spinal cord typing showed great predictive value for IONME.

Comparison of multi-mode and single-mode intraoperative neurophysiological monitoring in the treatment of severe ossification of the cervical posterior longitudinal ligament with anterior cervical corpectomy with fusion / 中国骨伤

OBJECTIVE@#To compare the application of multi-mode and single-mode intraoperative neurophysiological monitoring in the treatment of severe ossification of posterior longitudinal ligament of cervical spine with anterior cervical corpectomy with fusion.@*METHODS@#From April 2015 to June 2018, 32 patients with severe ossification of the posterior longitudinal ligament were treated in the Shuguang Hospital Affiliated to Shanghai University of Traditional Chinese Medicine. There were 21 males and 11 females, aged 45 to 73 years old, with a mean age of 59 years old. The duration of the disease ranged from 6 to 72 months, with a mean of 39 months. The main manifestations were numbness, numbness and weakness of limbs, cotton feeling of foot stepping on lower limbs, instability of standing and walking. With the gradual aggravation of symptoms, quadriplegia, dysfunction of urine and defecation may occur. Patients with ossification of posterior longitudinal ligament of cervical spine were monitored by somatosensory evoked potentials, motor evoked potentials and electromyogram patterns.@*RESULTS@#During the operation, 8 patients had abnormal amplitude of somatosensory evoked potential(SEP); 5 of them had bleeding during anterior cervical decompression procedure and were placed with too much hemostatic cotton, which caused compression of spinal cord and resulted in abnormal SEP waveform. After removal of the hemostatic cotton, SEP waveform returned ot normal; 3 patients had abnormal SEP waveform due to decreased systolic pressure, which was corrected by increased systolic pressure. Twelve patients had abnormal amplitude of motor evoked potential during monitoring, 9 of which were caused by intraoperative mis-contact with nerve root, and turned to normal after timely adjustment of position, 3 of which were caused by intraoperative inhalation of muscle relaxant during surgery. Among 11 patients with abnormal EMG waveform, 9 patients recovered to normal waveform after adjusting operation, 2 patients recovered to normal waveform after short observation, and all patients recovered to normal waveform of motor evoked potential after operation(<0.05). There were 2 cases of cerebrospinal fluid leakage after operation, which healed spontaneously 7 days after operation, and no complications of spinal cord and nerve occurred in all patients after operation.@*CONCLUSIONS@#In anterior cervical corpectomy with fusion operation for the treatment of severe cervical ossification of posterior longitudinal ligament, various modes of intraoperative neurophysiological monitoring can real-time understand spinal cord and nerve function status, significantly reduce the incidence of spinal cord and nerve injury during operation, and effectively improve the safety of operation.

Comparing the effects of vecuronium and cisatracurium on electrophysiologic monitoring during neurosurgery: a randomized controlled study

BACKGROUND: The differences between neuromuscular blocking (NMB) drugs on the efficacy of intraoperative motor-evoked potential (MEP) monitoring have not been established through clinical study. We compared the effects of vecuronium and cisatracurium on the efficacy of intraoperative MEP monitoring. METHODS: We enrolled 72 patients who had undergone neurosurgery with MEP monitoring. We randomly allocated the subjects into one of two groups, in whom we maintained continuous intravenous vecuronium (Group V) or cisatracurium (Group C) infusion during the surgeries; the target partial NMB for maintenance was T1/Tc 50% (T1, first twitch of TOF response; Tc, control response of T1 before NMB drug injection). We compared the means and coefficients of variation (CV, %) of all measured MEP amplitudes and the frequencies of NMB drug dose changes. RESULTS: The means and CVs of MEP amplitude and latency in all four limbs did not differ significantly between the groups, although we did change the continuous NMB drug doses in group V significantly less often than in group C. CONCLUSIONS: There were no significant differences between vecuronium and cisatracurium on the MEP variability and mean amplitudes. However, cisatracurium needed more frequent dose changes to maintain T1/Tc 50%.

Correlation analysis of the exercise test and hypokalemic periodic paralysis / 中国医师杂志

Objectve To explore the application of exercise test use in diagnosis of periodic paraly sis.Methods Forty five cases of hypokalemic periodic paralysis were collected,and 40 health persons as control group.Both groups were measured serum potassium,serum creatase and thyroid function tests.All of them were taken exercise test (ET) and observe 50 minutes,measured before and after the test to seek the changes of compound muscle action potentials (CMAP),and its decreased more than 33％ were considered abnormal.The application of exercise test use was analyzed in diagnosis of periodic paralysis.Results In patients with periodic paralysis,the incidence of ET positive was higher than the control subjects (80％ vs 3.3％,P ＜ 0.001).This trend was significant after 20 minutes,such as 30 min[(37.8 ± 13.2)％ vs (6.2±3.2)％,P＜0.01],40min [(40.3 ±17.6)％ vs (3.2±1.9)％,P＜0.01],50min [(45.26 ± 19.9) ％ vs (-5.1 ± 2.6) ％,P ＜ 0.01].Moreover,linear correlation analysis showed that the serum potassium had negative correlation with serum creatase (r =-0.483,P =0.024).ALL of symptoms improved after a week treatment,the ET positive rate was still higher in patients with periodic paralysis than the control subjects (80.0％ vs 71.1％,P =0.824).Conclusions Exercise test was one of the important objective basis in the diagnosis of low potassium type periodic paralysis,and was not affected by treatment and testing time.

Application of descending neurogenic evoked potentials monitoring during spinal deformity surgery / 中华骨科杂志

Objective To elevate the efficacy and safety of descending neurogenic evoked potentials (DNEP) monitoring during severe rigid spinal deformity surgery.Methods All of 108 patients (43 males,65 females) who underwent surgical treatment for spinal deformity in our spinal center from July 2010 to August 2013 were retrospectively reviewed.The average age (17.5±5.8) ys(range 12-50 ys),the average following period is 38.6 months(range 24-52 months).Combined monitoring of SEP,MEP and DNEP model were used during surgery.All subjects with no neurological deficits preoperatively and got satisfied outcomes.Respectively evaluate the results of neurophysiological intraoperative monitoring (IOM).Data were collected to elevate the efficacy and safety of DNEP monitoring.Results All of 108 patients,15 patients (13.9％,15/108) showed significant changes of neurophysiological parameters,of which 9 cases (60％,9/15) were identified as true positive and 6 cases (40％,6/15) were identified as false positive.During the following-up period,2 patients developed permanent neurological deficit,and 3 patients showed transient neurological deficit who got fully recovered within 6 months after operation.DNEP showed alert in all 5 patients with truepositive alarm,of which 2 patients developed permanent neurological dysfunction and 3 cases showed postoperative short nerve dysfunction that got fully recovery within 6 months after operation.The sensitivity and specificity of SEP+MEP and DNEP were 100％ and 97.98％,100％ and 98.99％,respectively.Conclusion Combining use of MEP+SEP+DNEP monitoring during surgical treatment of spinal deformities presented to be a highly reliable method for the detection and prevention of iatrogenic injury.The results confirmed a high efficacy and safety of DNEP monitoring during spinal surgery.

The study and application of intraoperative neurophysiological monitoring in oblique lateral interbody fusion combined with posterior transpedicle internal fixation / 中华骨科杂志

Objective To investigate a reliable and practicable model of intraoperative neurophysiological monitoring (IONM) in oblique lateral interbody fusion (OLIF) combined with posterior transpedicle internal fixation.Methods A total of 34 consecutive patients who underwent OLIF combined with posterior transpedicle internal fixation with IONM at the SRRSH from November 2014 to July 2016 were collected and follow-up at least for 3 months postoperative.The intraoperative somatosensory evoked potentials (SEP),motor evoked potentials (MEP),dermatomal somatosensory evoked potential (DSEP) and spontaneous electromyography (sEMG) were used and evaluated,besides,triggered electromyography (tEMG) was used to monitor the implantation of pedicle screws,the possible reasons and treating procedures of monitoring alerts were summarized.Results A total of 34 cases of patients were effectively monitored during OLIF combined with posterior transpedicle internal fixation.SEP monitoring was successful in all patients,and no abnormal SEPs were observed in all cases.DSEP monitoring was successful in 20 cases (58.8％),and no abnormal DSEPs were observed in these patients.MEP was successfully monitored in all cases,eliminating the anesthesia factor,no abnormal MEPs were observed in all cases.The sensitivity and positive predictive value of SEP,MEP,DSEP were 0％.3 cases had abnormal sEMG reactions during the channel establishment which disappeared after adjustment of channel,and 2 cases which appeared abnormal wave recovered after brief observation.Among the 5 patients with abnormal wave,one case got numbness,one patient felt pain in front of the thigh postoperative.Among the other 29 patients without abnormal wave during channel establishment,one case appeared numbness.These 3 patients with neurologic symptoms recovered in 3 months after conservative treatment.The sensitivity and specificity of sEMG was 66.7％ and 90.3％ respectively,negative predictive value and positive predictive value were 96.6％ and 40％ respectively.6 screws got tEMG response after tapping even the intensity was less than 10mA,which showed broken codex of pedicle according to postoperative CT scan.Cornclusion Intraoperative application of sEMG monitoring in OLIF can obviously reduce the incidence of the neurological deficit,which was an effective method,tEMG monitoring during lumbar pedicle screw fixation can detect the mal-positioned screws and protect the nerve roots.SEP,MEP and DSEP did not seem well suited for OLIF.

A transcranial magnetic stimulation study on Alzheimer's disease and behavioral variant frontotemporal dementia / 中华神经科杂志

Objective To investigate the changes in cortical excitability and inhibitory circuits of patients with Alzheimer's disease (AD) or behavioral variant frontotemporal dementia (bvFTD) using transcranial magnetic stimulation (TMS).Methods Forty-four patients with AD,30 patients with bvFTD and 44 healthy controls were enrolled in the study.The epidemiological data of all subjects were collected.Each participant received a neurological evaluation and neuropsychologic tests which included Mini-Mental State Examination (MMSE),Activities of Daily Living (ADL) and Hamilton Rating Scale for Depression (HAMD).Neurophysiological evaluations including resting motor threshold (rMT),active motor threshold (aMT) and cortical silent period (CSP) were conducted by means of TMS.Neurophysiological parameters were compared among groups.Results There were significant differences in MMSE,ADL and HAMD assessments among 3 groups,but no significant differences between AD and bvFTD groups.There were significant changes in left rMT(46.52％ ± 8.77％,52.00％ ± 7.30％ and 52.14％ ± 8.27％,F =6.295,P=0.003),left aMT(29.68％ ±7.01％,35.13％ ±8.46％ and 35.39％ ±7.24％,F=7.735,P=0.001) and right rMT(47.82％ ±7.94％,52.07％ ±8.77％ and 53.12％ ±8.61％,F=4.772,P=0.010) among 3 groups.AD patients showed significantly reduced left rMT and aMT comparing to bvFTD patients (P =0.017 and 0.008 respectively) and controls (P =0.005 and 0.002 respectively).In addition,AD patients had a significant decrease in right rMT comparing to controls (P =0.011).There were no statistically significant differences in TMS parameters between bvFTD patients and controls.Conclusions AD is associated with hyperexcitability of the motor cortex,whereas the lack of changes in motor cortical excitability is found in bvFTD.TMS technique may be helpful in differential diagnosis between AD and bvFTD.

Partition-type spinal cord catheter combined with bone marrow stromal stem cells in the repair of spinal cord transection injury in rats / 中国组织工程研究

BACKGROUND:There is a high morbidity after spinal cord injury, and the therapeutic strategy is limited to early surgical intervention, medication and post-treatment exercise that only can improve the motor function slightly. However, there is no effective cure method. OBJECTIVE:To study the effect of partition-type spinal cord catheter combined with bone marrow stromal stem cels on T8 spinal cord transection damage in rats. METHODS:Fifty rats were randomized into five groups (n=10 per group): group I, T8 spinal cord transection (5 mm) was made in rats with no treatment; group II, the partition-type tube was inserted into the injured site after modeling; group III, partition-type tube combined with bone marrow stromal stem cels was implanted into the injured site after modeling; group IV, partition-type tube combined with polyglycolic acid fibers was implanted into the injured site after modeling; group V, partition-type tube combined with bone marrow stromal stem cels and polyglycolic acid fibers was implanted into the injured site after modeling. RESULTS AND CONCLUSION:At 2 and 12 weeks postoperatively, Basso, Beattie and Bresnahan scores were significantly higher in the groups III and IV than the groups I, II, IV (P < 0.05). At 12 weeks postoperatively, the latency of motor evoked potential below the injury plane was significantly decreased in group V compared with groups I, II, III, IV (P < 0.05). Immunohistochemical results displayed that in the groups III and V, regenerated nerve fibers grew positively and arranged orderly among the tubes, and there was no obvious winding phenomenon. Under transmission electron microscopy, a certain number of myelinated nerve fibers were found as bridges among groups. These findings indicate that the partition-type chitosan tube combined with bone marrow stromal stem cels has a good connection with the injured spinal cord a good connection to restore part of electrophysiological properties, accelerate the axon regeneration, recover the motor function, thereby providing a new direction for the treatment of spinal cord injury. Cite this article:Zhao XW, Liu X, Yu DP, Rong H, Yu XS, Yang CS, Liu T, Zhao TB. Partition-type spinal cord catheter combined with bone marrow stromal stem cels in the repair of spinal cord transection injury in rats. Zhongguo Zuzhi Gongcheng Yanjiu. 2016;20(1):42-48.

Influence of sevoflurane concentration and stimulation voltage on motor evoked potentials in intraspinal tumor surgery / 北京大学学报(医学版)

Objective:To evaluate the effects of increasing end-tidal concentrations of sevoflurane and increasing stimulation voltage on motor evoked potentials,so as to provide evidence in making anesthesia plan for intraspinal tumor surgery.Methods:In the study,48 patients scheduled to undergo intraspinal tumor surgery [American Society of Anesthesiology,(ASA)Ⅰ-Ⅱ,18-65 years old]were enrolled. After general anesthesia induction,the patients were assigned to receive sevoflurane anesthesia of increa-sing end-tidal concentration in the sequence of 0.0%,0.5%,1 .0% and 1 .5% respectively,under a background of propofol and remifentanil.All the observations were done before the important steps of sur-gery.Remifentanil infusion rate was 0.2 μg /(kg·min),while the propofol infusion rate was adjusted to maintain the bispectral index values within the range of 30-50.At each concentration,4 stimulation voltages of 300 V,400 V,500 V and 600 V were employed to elicit motor evoked potentials (MEPs). The amplitude and latency of each MEP were compared.The success ratio was also recorded.Results:The concentration of sevoflurane and the stimulation voltage had impacts on the amplitude and latency of MEPs.Under each stimulation voltage,the MEPs amplitude decreased following increasing end-tidal sevoflurane concentrations,and significant differences were found in comparing 1 .5% sevoflurane (left 20.50 μV,70.71 μV,135.97 μV,190.00μV ,right 14.29 μV,50.71 μV,73.10μV,77.50μV) with 0.0% sevoflurane (left 143.00 μV,388.10 μV,484.53 μV,500.00 μV,right 176.00 μV, 407.60 μV,384.35 μV,451.00 μV)and 0.5% sevoflurane (left 100.00 μV,362.57 μV,444.05μV,435.00 μV,right 115.00 μV,207.15 μV,258.34 μV,358.50 μV),left χ2 =27.46,P<0.01,right χ2 =60.49,P<0.01;left χ2 =20.73,P<0.01,right χ2 =55.05,P<0.01;left χ2 =34.25,P<0.01,right χ2 =33.58,P<0.01;left χ2 =28.61,P<0.01 ,right χ2 =49.04,P<0.01;while there were no statistical differences in the latency changes (P =0.26 ).Under each end-tidal sevoflurane concentration,the MEPs amplitude increased following increasing stimulation voltages,and significant differences were found in comparing 300 V (left 143.00 μV,100.00 μV,61.50 μV,20.50μV ,right 176.00 μV,115.00 μV,41.07 μV,14.29 μV)with 400 V (left 388.10 μV,362.57μV,198.81 μV,70.71 μV,right 407.60 μV,207.15 μV,89.00 μV,50.71 μV)and 500 V (left 484.53 μV,444.05 μV,216.24μV,135.97 μV,right 384.35 μV,258.34μV,187.50μV,73.10μV)and 600 V (left 500.00 μV,435.00 μV,344.00 μV,190.00 μV,right 451.00 μV,385.50μV,156.00μV,77.50μV),leftχ2 =45.55,P<0.01,rightχ2 =25.73,P<0.01;leftχ2 =46.67, P<0.01,right χ2 =55.30,P<0.01;left χ2 =47.36,P<0.01,right χ2 =47.82,P<0.01;left χ2 =38.67,P<0.01,right χ2 =45.87,P<0.01;while the latencies were decreased,and significant dif-ferences were found in comparing 300 V with 400 V and 500 V and 600V(left F=7.50,P=0.01 ,right F=13.33,P<0.01),but the differences had little clinical significance.The success ratio decreased by increasing end-tidal sevoflurane concentration,and significant differences were found in comparing 1 .5%sevoflurane (left 43.8%,70.8%,77.1%,81.3%,right 37.5%,60.4%,75.0%,66.7%)with 0.0%sevoflurane (left 79.2%,87.5%,95.8%,93.8%,right 75.0%,95.8%,95.8%,95.8%)and 0.5%sevoflurane (left 72.9%,89.6%,95.8%,95.8%,right 66.7%,89.6%,95.8%,97.9%);the suc-cess ratio increased by increasing stimulation voltage,and significant differences were found in comparing 300 V(left 79.2%,72.9%,62.5%,43.8%,right 75.0%,66.7%,60.4%,37.5%)with 400 V(left 87.5%,89.6%,77.1%,70.8% ,right 95.8%,89.6%,79.2%,60.4%)and 500 V(left 95.8%, 95 .8%,9 1 .7%,77 .1%,right 95 .8%,95 .8%,8 1 .3%,75 .0%)and 600 V (left 93 .8%,95 .8%, 89.6%,81.3%,right 95.8%,97.9%,89.6%,66.7%),but there were no statistical differences in the success ratio of MEPs between the group with stimulation voltage of 600 V ,end tidal sevoflurane concen-tration of 1 .5% and the group with stimulation voltage of 300 V,end tidal sevoflurane concentration of 0.0% (P=0.22).Conclusion:Sevoflurane inhibited MEPs in a dose-dependent manner.It can de-crease the amplitudes and prolong the latencies.But increasing stimulation voltage will facilitate MEPs monitoring and increase the success ratio.Sevoflurane can be used in larger parts of MEPs monitoring surgery by increasing the stimulation voltage.

Application of intraoperative neurophysiological monitoring in cervical intraspinal tumor surgery / 中华骨科杂志

Objective To investigate the efficiency of intraoperative neurophysiological monitoring in cervical spinal tumor surgery.Methods Retrospective case-control study comparing 23 cervical spinal tumor patients received surgery under neurophysiological monitoring (case) and 23 cases without neurophysiological monitoring (control).Results All of 46 cases,there were no significant differences of age,gender and preoperative neurological function.Duration of operation and estimated blood loss in the IONM cohort was less than the control group with significant difference.The preoperative JOA score of IONM group and control group were 12.0±2.4 and 12.7±2.1,with no significant difference.The postoperative JOA score of each group were 15.0±1.5 and 15.2±1.7,with no significant difference.The rate of cervical cord neurological improvement of IONM group was higher than control group,but there was no significant difference.In the IONM cohort,abnormal signal appeared in 8 cases,with 1 case developed new postoperative deficit,and the sensitivity and specificity of SEP were 100％ and 77.3％,the sensitivity and specificity of MEP were 100％ and 86.4％.Compared with preoperative SEP,4 cases showed major improvement (baseline increase ＞ 40％),2 cases showed moderate improvement (baseline increase:15％-40％).The coincidence rate of the SEP improvement and the AISA grade was 66.7％.Conclusion IONM could reduce the duration of operation and intraoperative blood loss.Changes of IONM were correlated with postoperative neurological function improvement.

Potencial evocado miogenico vestibular (VEMP) com estimulo galvanico em individuos normais / Vestibular evoked myogenic potential (VEMP) with galvanic stimulation in normal subjects

Introdução: O potencial evocado miogênico vestibular (VEMP) gerado por estimulação galvânica (GVS) reflete uma resposta vestíbulo-espinhal. A resposta obtida no músculo sóleo é bifásica, primeiro com componente de curta latência (CL), em torno de 60 ms, e depois com o de média latência (ML), em torno de 100 ms. O componente de CL associa-se à função otolítica (sáculo e utrículo), e o de ML, aos ductos semicirculares. Objetivo: Descrever os valores de referência do VEMP com estimulação galvânica em indivíduos normais. Casuística e método: Forma de estudo transversal; o VEMP foi gerado por GVS de 2mA/400 ms, aplicada bilateralmente, sob frequência de 5-6 ms. Testou-se resposta no músculo sóleo de 13 sujeitos saudáveis, com idade média de 56 anos. Os sujeitos permaneceram de pé, com cabeça girada contralateral ao GVS aplicado na mastoide. Na configuração catodo direito, anodo esquerda, 30 GVS foi aplicado, seguidos de mais 30 com configuração inversa. Os componentes de CL e de ML da resposta vestibular foram analisados. Resultado: Os componentes de CL e de ML foram semelhantes em ambas as pernas. O valor médio de CL foi 54 ms, e o de ML, 112 ms. Conclusão: Os componentes de CL e de ML do VEMP solear foram replicáveis, sendo medidas úteis de função do trato vestíbulo-espinhal. .

Introduction: The vestibular evoked myogenic potential (VEMP) generated by galvanic vestibular stimulation (GVS) is related to the vestibulo-spinal pathway. The response recorded from soleus muscle is biphasic with onset of short latency (SL) component around 60 ms and medium latency (ML) component around 100 ms. The first component reflects otolith function (sacule and utricle) and the last deals with semicircular canals. Aim: To describe VEMP generated by GVS. Methods: In this cross-sectional clinical study, VEMP was generated by 2mA/400 ms binaural GVS, frequency of 5-6 ms that was recorded from soleus muscles of 13 healthy adults, mean age 56 years. The subjects remained standing, head turned contralateral to the GVS applied to the mastoid. Thirty GVS were applied to the mastoid in the position cathode right anode left, followed by 30 in inverted position. SL and ML were measured. Results: SL and ML components were recorded from both legs of all participants and were similar. The average of SL component was 54 ms and of ML was 112 ms. Conclusion: The components SL and ML of the VEMP response in soleus were reproducible and are useful measures of vestibular-spinal function. .

Mouse nerve growth factor injection via different ways for treatment of peripheral nerve injury / 中国组织工程研究

BACKGROUND:Mouse nerve growth factor can promote the repair and regeneration of injured nerves, but current experimental research shows that the effects of different treatment methods are stil controversial. OBJECTIVE:To evaluate the effect of mouse nerve growth factor injection via different ways on the treatment of peripheral nerve injury. METHODS:Total y 52 patients with peripheral nerve injury were randomly assigned into two groups:experimental group (local injection of mouse nerve growth factor, n=27) and control group (systemic administration of mouse nerve growth factor, n=25). The treatment was performed once a day, and lasted for 4 weeks. Then, the clinical efficacy and recovery of neurological function were compared. RESULTS AND CONCLUSION:The good and effective rates were 85%(n=23) and 93%(n=25) in the experimental group, while 72%(n=18) and 84%(n=21) in the control group, respectively, which were significantly better in the experimental group than the control group (P<0.05). In the experimental group, 13 cases developed transient pain at injection site, including one case of remission undergoing oral analgesics;in the control group, 12 cases had transient pain at injection site, without any treatment. The results suggest that both local and total body injection of mouse nerve growth factor are safe and effective for treatment of peripheral nerve injury, but local injection is superior to systemic administration.

Animal models of spinal cord injury：application and research progress of evoked potentials / 中国组织工程研究

BACKGROUND:With the development of industrial society and traffic, the incidence of spinal cord injury has gradualy increased. In addition to radiological laboratory examinations, the neurophysiological test also becomes an effective way of auxiliary examination. Due to the high accuracy and easy operating, neurophysiological test is widely used and the evoked potentials play a role in this project. OBJECTIVE:To summarize the application of somatosensory evoked potentials and motor evoked potentials in rabbits of spinal cord injury. METHODS:A computer-based online research of CNKI and PubMed databases was performed with the key words of “spinal cord injury; evoked potentials; animal models” in Chinese and English. Finaly 33 articles were included in the analysis according to the inclusion and exclusion criteria. RESULTS AND CONCLUSION:The operational approach, waveform analysis, application value, influencing factor of somatosensory evoked potentials and motor evoked potentials were determined in details, the correlation between evoked potentials and prognosis assessment in animals was also detected. Somatosensory evoked potentials is a good indicator for the evaluation of dorsal funiculus of spinal cord, it is easy to operate and reflects the changes of sensory functions. Motor evoked potentials can provide sensitive diagnosis of spinal cord diseases, and they wil be used as a means to assess the spinal cord injury during rehabilitation. The combination of the two can provide a more accurate result.

Potencial miogênico evocado vestibular e suas implicações no domínio das frequências / Vestibular evoked myogenic potential and its implications in the frequency domain

OBJETIVO: Verificar a existência de associação entre o VEMP no domínio do tempo e no domínio das frequências. MÉTODOS: A amostra foi composta por 18 indivíduos (36 orelhas), sendo seis do gênero masculino e 12 do gênero feminino. No exame de VEMP no domínio do tempo, foram promediados 200 estímulos tone burst na frequência de 500 Hz, com taxa de estimulação de 5,1 estímulos/s na intensidade de 95 dBNAn. Seguiu-se com a captação no domínio das frequências, onde foram promediados 200 estímulos constituídos por tons puros de 500 Hz (frequência portadora), modulados na frequência de 40 Hz. Foi realizado o cálculo do Odds ratio e aplicado o teste Qui-quadrado para a comparação entre as respostas dos dois domínios. Estudo de coorte contemporânea com corte transversal. RESULTADOS: O VEMP no domínio do tempo foi registrado por meio da estimulação e captação unilateral, com morfologia adequada, em 88,88% das orelhas. Na realização do exame no domínio das frequências, foi registrada a presença de pico de estado estável em 30 (83,33%) dos 36 exames. Quando realizado o teste Qui-quadrado e o cálculo do Odds ratio, foi possível observar a existência de forte relação entre os dois domínios. CONCLUSÃO: Conclui-se que existe forte associação entre os exames de VEMP no domínio do tempo e no domínio das frequências, o que habilita sua utilização na prática clínica.

PURPOSE: Determine whether there is an association between VEMP in the time domain and the frequency domain. METHODS: The sample was composed of 18 individuals (36 ears), six men and 12 women. In the VEMP test in the time domain, 200 tone burst stimuli were promediated at a frequency of 500 Hz, with 5.1 stimulations/s at an intensity of 95 dBNAn. This was followed by capture in the frequency domain, where 200 stimuli consisting of 500 Hz (carrier frequency) pure tones were promediated and modulated at a frequency of 40 Hz. Odds ratio was calculated and the chi-squared test was applied to compare the responses of two domains. This is a cross-sectional contemporary cohort study. RESULTS: VEMP in the time domain was recorded by unilateral stimulation and capture, with adequate morphology, in 88.88% of the ears. In the frequency domain test, a steady-state peak was found in 30 of the 36 tests (83.33%). The chi-squared test and odds ratio calculation showed a strong relationship between the two domains. CONCLUSION: There is a significant association between the VEMP tests in the time and frequency domains, a finding that suppports its use in clinical practice.

Effects of total intravenous anesthesia without muscle relaxants on motor evoked potential monitoring during scoliosis surgery / 中华麻醉学杂志

Objective To evaluate the effects of total intravenous anesthesia without muscle relaxants on motor evoked potential (MEP) monitoring during scoliosis surgery.Methods Fifty ASA Ⅰ or Ⅱ patients of both sexes,aged 18-25 yr,scheduled for posterior spinal fusion surgery,were randomly divided into 2 groups with 25 patients in each group: muscle relaxants combined with total intravenous anesthesia group (group Ⅰ) and total intravenous anesthesia without muscle relaxant group (group Ⅱ).In both groups,a loading dose of dexmedetomidine 1 μg/kg was infused over 20 min,followed by infusion at 0.2 μg· kg-1 · h-1.After the loading dose of dexmedetomidine was given,anesthesia was induced,the patients were tracheal intubated and mechanically ventilated.Anesthesia was maintained with remifentanil 0.2μg· kg-1 · min-1 and propofol 80-120 μg· kg-1 · min-1.The bispectral index value was maintained at 40-60.Train of four stimulation of ulnar nerve was used to monitor the neuro-muscu-lar block.Cisatracurium was infused at 0.5-1.5 μg·kg-1 ·min-1,T1 was maintained at 45％-55％,and the infusion was stopped 30 min before the isolation of paraspinal muscles was completed in group Ⅱ.MEP were monitored and recorded during the period when the administration of the muscle relaxation was stopped,and the degree of muscle relaxation was assessed by the surgeon.The successful wake-up test was recorded.Results The incidence of successful MEP monitoring was significantly higher in group Ⅱ than in group Ⅰ (P ＜ 0.05).There was no significant difference in the degree of muscle relaxation between the two groups (P ＞ 0.05).All the patients were successfully woken up.Conclusion Total intravenous anesthesia without muscle relaxants can provide satisfactory muscle relaxation for scoliosis surgery and increase the probability of successful MEP monitoring simultaneously.

Comparison of accuracy of jugular venous oxygen saturation, somatosensory evoked potentials and motor evoked potentials in estimation of occurrence of intraoperative cerebral ischemia in patients undergoing clipping of intracranial aneurysm / 中华麻醉学杂志

Objective To compare the accuracy of jugular venous oxygen saturation (SjvO2),somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) in estimation of the occurrence of intraoperative cerebral ischemia in patients undergoing clipping of intracranial aneurysm.Methods Forty-three ASA Ⅰ or Ⅱ patients of both sexes,aged 18-64 yr,with a body mass index of 20-25 kg/m2,undergoing clipping of intracranial aneurysm,were studied.Anesthesia was induced with sufentanil,rocuronium and propofol.The patients were tracheal intubated and mechanically ventilated.Anesthesia was maintained with remifentanil and propofol.Blood samples were taken from the jugular bulb for detection of SjvO2 before aneurysm clipping or temporary occlusion of parent artery and at 1,3,10,20 and 30 min after clipping aneurysm or temporary occlusion of parent artery.The amplitude and latency of SSEPs and MEPs were recorded simultaneously.The occurrence of cerebral ischemia estimated by SjvO2,SSEPs and MEPs was recorded.The condition of nerve defect was recorded within 3 days after operation and the gold standard of cerebral ischemia was defined as the occurrence of nerve defect.Results Among 43 patients,14 cases were diagnosed as having brain ischemia.The sensitivity and specificity of SjvO2 in estimation of the occurrence of intraoperative brain ischemia were 71％ and 93％,respectively (P ＜ 0.01).The sensitivity and specificity of SSEPs in estimation of the occurrence of intraoperative brain ischemia were 71％ and 62％,respectively (P ＜ 0.05).When the diagnostic criterion of cerebral ischemia was defincd as a decrease in the amplitude of MEPs or prolongation of the latency MEPs,the sensitivity and specificity of MEPs in estimation of the occurrence of intraoperative brain ischemia were 79 ％ and 52 ％,respectively (P ＞ 0.05).When the diagnostic criterion of cerebral ischemia was defined as a loss of the amplitude of MEPs,the sensitivity and specificity of MEPs in estimation of the occurrence of intraoperative brain ischemia were 57％ and 93％,respectively (P ＜0.05).Conclusion The sensitivity of SjvO2 and SSEPs in estimation of the occurrence of intraoperative brain ischemia is higher,however,the specificity of SjvO2 and MEPs is higher,indicating that SjvO2 is a reliable criteria for estimation of the occurrence of intraoperative brain ischemia in patients undergoing clipping of intracranial aneurysm.

Influence of gender on the vestibular evoked myogenic potential / Influência do gênero no potencial miogênico evocado vestibular

There is no consensus on the relevance of factors that influence gender differences in the behavior of muscles. Some studies have reported a relationship between muscle tension and amplitude of the vestibular evoked myogenic potential; others, that results depend on which muscles are studied or on how much load is applied. AIMS: This study aims to compare vestibular evoked myogenic potential parameters between genders in young individuals. METHODS: Eighty young adults were selected - 40 men and 40 women. Stimuli were averaged tone-bursts at 500 Hz, 90 dBHL intensity, and a 10-1000 Hz bandpass filter with amplification of 10-25 microvolts per division. The recordings were made in 80 ms windows. STUDY TYPE: An experimental and prospective study. RESULTS: No significant gender differences were found in wave latency - p = 0.19 and p = 0.50 for waves P13 and N23, respectively. No differences were found in amplitude values - p = 0.28 p = 0.40 for waves P13 and N23, respectively. CONCLUSION: There were no gender differences in latency and amplitude factors; the sternocleidomastoid muscle strain was monitored during the examination.

Não existe consenso sobre a relevância dos fatores que influenciam as diferenças entre gêneros no comportamento dos músculos. Alguns estudos relatam existir uma relação entre tensão muscular e amplitude do potencial miogênico evocado vestibular, outros apenas que os resultados dependem dos músculos estudados ou do aumento da carga imposta. OBJETIVOS: Este estudo tem como objetivo comparar os parâmetros do potencial miogênico evocado vestibular, entre os gêneros, em indivíduos jovens. MATERIAL E MÉTODO: Selecionaram-se 80 adultos jovens, sendo 40 homens e 40 mulheres. Foram promediados estímulos tone burts na frequência de 500Hz, na intensidade de 90 dBNA, utilizando-se um filtro passa banda de 10 a 1000 Hz, com amplificação de 10 a 25 microvolts por divisão. Os registros foram realizados em janelas de 80 ms. FORMA DE ESTUDO: experimental e prospectivo. RESULTADOS: Ao comparar os achados em função do gênero, não se constatou diferenças expressivas em relação à latência das ondas, p =0,19 e p =0,50, para as ondas P13 e N23, respectivamente, nem em relação ao valor de amplitude, p =0,28 p =0,40, para as ondas P13 e N23, respectivamente. CONCLUSÃO: Não houve diferença entre os gêneros quanto aos fatores latência e amplitude por haver um monitoramento da tensão do músculo esternocleidomastoideo durante o exame.

Relation between fractional anisotropy in the cerebral peduncles and changes in motor evoked potential after acute middle cerebral artery territory infarction / 国际脑血管病杂志

Objective To investigate the changing characteristics of the fractional anisotropy (FA) in cerebral peduncles and its relation with motor evoked potential (MEP) after acute cerebral infarction and to clear the clinical sigiificance of the low limit value of the FA in cerebral peduncles. Methods The low limit value of the FA in normal cerebral peduncles was determined based on mean - 1. 64 standard deviation. The patients with acute cerebral infarction (n = 58) were divided into MEP positive group and MEP negative group according to the absence and presence of MEP, in which the patients in the MEP positive group were redivided into the FA in cerebral peduncles ＜ the low limit value and≥ the low limit value groups according to the FA in cerebral peduncles on the affected sides. Results The low limit value of the FA in normal cerebral peduncles was 0. 36. There was significant difference in the FA in cerebral peduncles on the affected sides between the MEP negtive and MEP positive groups. The MEP negative group was the lowest (P=0. 000). The FA in cerebral peduncles on the affected sides in the positive group was significantly lower than that on the unaffected sides (P=0. 000), and the latency on the affected sides was longer than that on the normal sides (P=0. 000). The FA in cerebral peduncles on the affected sides was negatively correlated with the MEP latency (r=-0.332,P=0. 042). The MEP latency in the FA＜the low limit value group was significantly longer than that in the FA ≥ low limit value group (P=0. 002). There were no significant differences in the FA in cerebral peduncles on the normal sides and the MEP latency among an groups. The detection rate of the FA in cerebral peduncle＜0. 36 on the affected sides was the highest (50%). Conclusions In the evaluation of the prognosis of the patients, the changes of the FA in cerebral peduncles on the affected sides in patients with acute cerebral infarction had correlation,consistency, and complementarity with MEP.The detection rate of the low limit value of the FA in normal cerebral peduncles was the highest in the MEP negative patients. When the FA in cerebral peduncles was＜0.36 on the affected sides, particularly when MET was negative, it might predict that the prognosis was poor.

Efficacy of combined monitoring with TES-MEP and CSEP during anterior or posterior surgery for cervical spondylitic myelopathy / 中华创伤杂志

Objective To evaluate of the efficacy of transcranial electrical stimulation motor evoked potential (TES-MEP)in combination with cortical somatosensory evoked potential (CSEP) monitoring during the anterior or posterior approach spinal surgery for cervical spondylitie myelopathy (CSM).Methods TES-MEP on the bilateral anterior tibial muscle and flexor hallucal brevis and thenar muscles and CSEP on the bilateral posterior tibial nerve and ulnar nerve were observed simultaneously in 135 patients during spinal surgery.Intravenous anesthesia was employed in all the patients.The results of TES-MEP,CSEP and combined monitoring were analyzed statistically.Pre-oporative and post-operative motor and sensory functions of the spinal cord were compared. Result Success rate of TES-MEP,CSEP and the combined monitoring was 87.4%.97.8%and 100%,respectively.Out of 135 patients,nine patients (6.7%) were detected with the positive evoked potentials due to surgical operation.The sensitivity of TES-MEP and CSEP in assessing the spinal cord motor function was 100%and 83.3%,respectively,while that in assessing the spinal cord sensory function was 77.8%and 100%,respectively.The sensitivity and specificity of the combined monitoring was both 100%. Conclusion The successful detection rate and accuracy of the combined monitoring for spinal cord function are apparently higher than that of simple TES-MEP or CSEP.The causes for operative maneuvers evoking a positive evoked potential include complete anterior decompression of the spinal canal,intervertebral bone graft,laminoplasty for OPLL and hematoma compression caused by a failed drainage in a posterior-anterior approach surgery.