普鲁卡因对上肢短潜伏期体感诱发电位的影响

目的：探讨静滴普鲁卡因对短潜伏期体感诱发电位（ＳＬＳＥＰ）的影响。方法;对上肢感觉传导无异常的病人１５例,分别观察静脉滴注普鲁卡因前以及滴注１％普鲁卡因２０ｍｇ．ｋｇ＾０－１．ｈ＾－１１０分钟、４０ｍｇ．ｋｇ＾－１、ｈ．＾－１５分钟和６０ｍｇ．ｋｇ＾－１．ｈ＾－１５分钟的上肢ＳＬＳＥＰ,比较Ｎ１４,Ｎ２０,Ｐ２３各波的潜伏期,Ｎ１４－Ｎ２０波间潜伏期（ＣＣＴ）以及Ｎ２０Ｐ－Ｐ２０的峰间值。结果：Ｓ     

围脑干手术中体感诱发电位与心率监测的比较

目的：研究围脑干手术中体感诱发电位（ＳＥＰ）神经生理监测与ＨＲ监测的关系。方法：选择４３例全凭静脉麻醉的围脑干手术病例,对两侧正中神经分别进行刺激,记录相应ＳＥＰ的Ｎ２０波形,手术Ｎ２０发生明显变化（潜伏期延长超过１ｍｓ）或波辐降低超过５０％）,即通知术者调整操作,ＨＲ出现突然而明显的变化也及时通知术者。结果：３例术后出现神经病损者术中ＳＥＰ均表现为持续抑制,而其中１例ＨＲ并没有明显变化。术中ＳＥ     

体感诱发电位N20波能否反映全麻中的镇痛成份

目的：比较非镇生麻醉药异丙酚与镇痛性麻醉药芬太尼对上肢短潜伏期体感诱发电位（ＳＬＳＥＰ）Ｎ２０波影响的差异。方法：２０例择期全麻患者依异丙酚和芬太尼的给药顺序不同分为两组监测ＳＬＳＥＰＮ２０波的变化。结果：异丙酚使Ｎ２０波潜伏期显著延长，波幅显著升高。芬太尼对Ｎ２０波潜伏期及波幅均无显著影响。异丙酚－芬太尼复合使用时Ｎ２０波潜伏期显著延长，波幅则无明显改变。结论：ＳＬＳＥＰＮ２０波不能反映全麻中的     

硫喷妥钠对上肢短潜伏期体感诱发电位的影响

目的与方法：７例上肢感觉传导道无异常的病例,静脉注射硫喷妥钠５ｍｇ／ｋｇ后,分别观察注药前、注药后即刻、２、４和６ｍｉｎ上肢短潜伏期体感诱发电位,比较Ｐ１５、Ｎ２０、Ｐ２５各波的潜伏期以及Ｐ１５Ｎ２０、Ｎ２０Ｐ２５的峰间值。结果：各波潜伏期在注药后缩短,以注药后２、４ｍｉｎ最明显,６ｍｉｎ时已基本恢复,Ｐ１５Ｎ２０、Ｎ２０Ｐ２５峰间值在注药后减小,以２ｍｉｎ时减至最小,６ｍｉｎ时已基本恢复。结论：术中行体感诱发电位监测时,不宜使用硫喷妥钠。     

异丙酚对上肢正中神经体感诱发电位的影响

麻醉药物对体感诱发电位(ＳＥＰ)波形存在不同程度的影响,以致干扰术中监测神经病变的效果。本研究通过观察单次静脉注射不同剂量异丙酸对上肢正中神经ＳＥＰ(ＭＮＳＥＰ)波形的变化,了解异丙酚对ＳＥＰ监测的影响情况,为术中进行ＳＥＰ监测时选择合理的麻醉药物及对波形的正确分析提供依据。资料与方法一般资料　30例择期行神经外科手术患者,术前ＭＮＳＥＰ检测无异常,ＡＳＡⅠ～Ⅱ级,男女性别不限,年龄16～68岁,随机分成三组,每组10人。麻醉方法　入室前30分钟肌注阿托品05ｍｇ、苯巴比妥钠01ｇ。入室后记录ＭＮＳＥＰ波形两次。于踝部大…     

胫后神经皮层体感诱发电位在脊髓纵裂中应用价值的探讨

对２９例脊髓纵裂患者（手术组２０例，非手术组９例）行胫后神经皮层体感诱发电位（ＰＴＮＣＳＥＰ）测量研究，２０例正常儿童为对照组，结果显示：患病组ＰＴＮＣＳＥＰ明显异常，两下肢间的ＰＴＮＣＳＥＰ有显著性差异（Ｐ＜０．０５）；手术组患者手术后ＰＴＮＣＳＥＰ明显改善（Ｐ＜０．０５），非手术组患者随访发现ＰＴ－ＮＣＳＥＰ无改善（Ｐ＞０．０５）。结果表明：ＰＴＮＣＳＥＰ是一敏感、客观、可靠的诊断工具，可用来判断脊髓纵裂神经损害的程度及机理，评价手术效果，指导手术治疗     

脊髓纵裂神经缺陷机制探讨

对２９例脊髓纵裂的神经功能状态进行临床评价及胫后神经皮层体感诱发电位检查，结果 ：患病组２９例两下肢间神经缺陷的临床评分及ＰＴＮＣＳＥＰ有显著差异，患病组２９例的５８根ＰＴＮＣＳＥＰ明显异常；手术组２０例间隔切除术后神经缺陷的临床评分及ＰＴＮＣＳＥＰ异常明显改善，非手术组９例１年关随访时则无改善。     

磁刺激运动诱发电位在脊髓型颈椎病中的诊断价值研究

目的：采用磁刺激运动诱发电位（ＭＥＰｓ）与Ｆ波结合测定中枢运动传导时间（ＣＭＣＴ），并与体感诱发电位（ＳＥＰｓ）比较，评估该技术对脊髓型颈椎病脊髓传导功能异常的诊断价值。方法：对２０例影像学或手术证实的脊髓型颈椎病病人进行磁刺激ＭＥＰｓ与Ｆ波结合测定ＣＭＣＴ及ＳＥＰｓ的中枢感觉传导时间（ＣＳＣＴ）。并对年龄、身高匹配的２０例正常受试者进行相同的检查对比。结果：病人组ＭＥＰｓ的ＣＭＣＴ明显延长，与正常组相比差异有显著性意义（Ｐ＜０．０５），异常率为８０％，高于ＳＥＰｓ的ＣＳＣＴ异常率７０％。ＣＭＣＴ的延长与该病的受损程度相关。结论：无痛无创的磁刺激ＭＥＰｓ对脊髓型颈椎病运动下行通路受损程度可做定量判断，对该病有很大的诊断价值。     

脊髓纵裂手术前后胫后神经体感诱发电位分析

２０例脊髓纵裂患者手术前后进行了两下肢胫后神经皮层体感诱发电位（ＣＳＥＰ）检查，并选择了２０例正常人作为对照组，结果发现手术组与对照组ＣＳＥＰ有显著性差异，手术治疗后患者ＣＳＥＰ的Ｐ４０峰潜伏期及波幅明显改善，患者两下肢间的ＣＳＥＰ亦有明显差异。表明ＣＳＥＰ是一敏感、客观、可靠的诊断指标，可用来判断神经损害的程度，评价手术疗效。文中并讨论了神经缺陷的机理。     

咪唑安定对体感诱发电位的影响

目的：了解咪唑安定对体感诱发电位的影响。方法：选择３０例ＡＳＡＩ～Ⅱ级的脑外科手术病人，根据国际１０～２０系统，在Ｃ３或Ｃ４、ＦＰｚ（参考）和ＳＣ（第二颈椎棘突处）安放盘状记录电极，记录体感诱发电位。均分为三组按剂量（０．２ｍｇ／ｋｇ、０．３ｍｇ／ｋｇ和０．４ｍｇ／ｋｇ）静脉注射咪唑安定，连续观察皮层Ｎ２０、Ｐ２３和颈髓Ｎ１４电位的变化。结果：（１）用药后，皮层Ｎ２０和颈髓Ｎ１４电位的波幅降低，分别抑制到术前的６３．７５％和４８．７５％（Ｐ＜０．０５），苏醒后恢复到基础水平；（２）颈髓Ｎ１４、皮层Ｎ２０和Ｐ２３的潜伏期及中枢传导时间均无显著延长，（３）各剂量组间的ＳＥＰ变化无明显差别。结论：咪唑安定对ＳＥＰ一定程度的抑制作用临床意义不足，可用作ＳＥＰ监测时的静脉麻醉药。     

体感诱发电位结合脑电双频指数监测在脊柱矫形术中的应用

目的　在全凭静脉麻醉下行脊柱矫形术中 ,监测体感诱发电位 (SEP)预防手术操作对脊神经系统的损伤 ,并结合脑电双频指数 (BIS)监测麻醉深度。方法　 6 0例脊柱侧凸病人 ,术前均无神经系统损伤症状 ,诱导插管后以静脉复合用药维持全麻。在麻醉前及术中可能损伤神经的操作时段分别监测并记录SEP ,以P40或N5 0波幅下降 >5 0 %和潜伏期延长 10 %为脊神经损伤的阳性标志 ,术中BIS持续监测以观察麻醉深度。结果　全组病人在SEP监测下完成手术 ,术后均无神经系统并发症。麻醉中BIS值控制在 6 0以下 ,无术中知晓。结论　术中SEP监测可完全替代“唤醒试验” ,防止脊神经系统损伤。全凭静脉麻醉可基本消除麻醉药物对SEP的影响。     

Prevention and detection of spinal cord injury during thoracic and thoracoabdominal aortic repairs

BACKGROUND: Spinal cord injury is a most dreaded and unpredictable complication. In this study, based on our experimental results in dogs and early clinical results, we reviewed the incidence of paraplegia and the detection of spinal cord injury. METHODS: Eighty-two patients who underwent elective surgical repair of the descending thoracic and thoracoabdominal aorta over 17 years were subjects for this study. Sixty-two patients were male and 20 were female. Their mean age was 61.6 years (range, 17 to 81 years). Monitoring somatosensory evoked potentials (SEP) and measurement of mean distal aortic pressure and cerebrospinal fluid pressure were performed perioperatively. RESULTS: Sixty patients had no ischemic change in SEP. In 17 patients with significant ischemic changes of SEP, SEP recovered by increasing spinal cord perfusion pressure to more than 40 mm Hg. Two patients with complete loss of SEP experienced paraplegia. One patient had delayed paraplegia. CONCLUSIONS: These results strongly suggest that SEP, mean distal aortic pressure, cerebrospinal fluid pressure should be monitored during aortic cross-clamping. Maintaining spinal cord perfusion pressure at more than 40 mm Hg by increasing mean distal aortic pressure or withdrawal of cerebrospinal fluid is valuable for preventing paraplegia.     

体感诱发电位监测在脊柱外科手术应用中的影响因素

目的分析体感诱发电位(SEP)监测在脊柱外科手术应用中的影响因素,探讨其预测指标,初步建立SEP指标波幅差值异常变化时出血量及平均动脉压的预测模型。方法回顾性分析接受多节段椎板切除减压手术的86例患者的SEP监测资料,以SEP波幅差值异常变化作为SEP受影响的指标,与性别、年龄、身高、体质量、平均动脉压范围、出血量、手术时间、皮下针电极导线长度、电磨钻应用情况、气磨钻应用情况、电动手术床电源接通情况等11个指标进行Pearson或Spearman相关分析及多元线性回归,筛选影响SEP的相关因素。结果 SEP指标(波幅差值P40/N50)和出血量(P0.05)、平均动脉压波动范围(P0.05)、电磨钻使用情况(P0.05)、气磨钻使用情况(P0.05)、电动手术床电源接通情况(P0.05)5个因素存在相关关系,而与性别(P0.05)、年龄(P0.05)、身高(P0.05)、体质量(P0.05)、手术时间(P0.05)、皮下针电极导线长度(P0.05)不具有相关关系。平均动脉压50 mm H(1 mm Hg g=0.133 k Pa)或在50 mm Hg左右波动时,以及出血量较多且1 249 m L时,SEP的波幅将明显发生变化,接近甚至会低于基线水平,与术中脊髓、神经损伤表现相似。结论出血量、平均动脉压范围、电磨钻使用情况、气磨钻使用情况和电动手术床电源接通情况是SEP指标(P40/N50)的影响因素。     

脊柱手术中体感诱发电位监护

目的：研究体感诱发监护脊柱手术的监测技术。方法：采用皮层体感秀发电位（CSEP）监测90例手术，记录每个重要手术步骤前、中、后CSEP，观察基分析原因。结果；麻醉深度与麻药咱类对CSEP有影响，其中以异氟醚为明显。脊柱手术中的操作均可引起CSEP改变。1例CSEP波形离散持续5min的患者术后出现可逆性脊髓损伤。结论：CSEP有简便、灵敏和及时监护等特点，波幅下降50％，潜做期延长10％是术中监护的预警值，对同时出现波形了散2min应予以高度重视。     

Prevention of spinal cord ischemia after cross-clamping of the thoracic aorta--monitoring of spinal cord perfusion pressure and somatosensory evoked potentials

The pressure difference between the mean distal aortic pressure (MDAP) and the cerebrospinal fluid pressure (CSFP), defined as the spinal cord perfusion pressure (SCPP), as well as somatosensory evoked potentials (SEP) were monitored intraoperatively to detect and prevent intraoperative spinal cord ischemia in 24 patients who required cross-clamping of the descending thoracic aorta. A temporary axillo-femoral shunt, utilizing a 10 mm woven Dacron tube graft, was employed in 10 patients and partial cardiopulmonary bypass was employed in fourteen. Ischemic SEP changes were seen in six patients. Two patients, whose SCPPs were 32 and 35 mmHg, showed a complete loss of SEP and subsequently developed paraplegia. In the other four cases, increase of the MDAP and/or withdrawal of cerebrospinal fluid were performed to increase the SCPP to more than 60 mmHg when ischemic SEP changes occurred. The SEP gradually recovered in two of these cases. The ischemic SEP changes seen in one patient, who had the longest aortic cross-clamping time, (175 minutes) returned to normal immediately after unclamping. In another case, who had a thoracoabdominal aortic aneurysm, the intercostal arteries were reimplanted since the ischemic SEP changes did not revert. These four patients recovered without any neurological deficit. In the other 18 cases without ischemic SEP change, SCPP was kept at more than 40 mmHg during aortic cross-clamping. We conclude that the SCPP should be maintained at more than 40 mmHg during aortic occlusion, and increased to more than 60 mmHg when ischemic SEP changes occur, by increasing MDAP and/or withdrawing cerebrospinal fluid in order to prevent postoperative paraplegia.     

Pitfalls in cortical localization by intraoperative recording of cortical somatosensory evoked potentials]

Cortical somatosensory evoked potential (SEP) recordings were made in 11 patients who had lesions located in or near the somatosensory or motor gyri to localize the central sulcus and sensorimotor cortex during neurosurgical operations. Cortical localization was successful in 7 of the 11 patients by recording phase reversal waveforms of N20 and P20 at electrode sites in the hand area on opposite sides of the central sulcus. There were 4 cases in which the cortical localization failed. Locations of craniotomy were far distant from the central sulcus retrospectively in 2 of the 4 patients. Cortical SEPs couldn't be recorded despite probable exposure of the hand area and apparently adequate stimulation and recording conditions in 2 patients who had showed no or low amplitude scalp SEP preoperatively. In one of these 2 patients only low amplitude negative waves were recorded at the cortex which was thought far field potentials originated from subcortical structures. In 2 patients cortical SEP was monitored during the removal of the tumors and was useful to estimate the effects of the operative procedures on the sensorimotor cortex. It is concluded that the localization of cortical functions using cortical SEP is useful for reducing risk associated with intracranial surgery. However, we must be aware that there are some pitfalls in this method.     

Effects of thiopental, fentanyl, and etomidate on upper extremity somatosensory evoked potentials in humans

The effects of three anesthetic induction agents on somatosensory evoked potentials (SEP) were assessed in unpremedicated patients who were without neurologic abnormality of the upper extremities. SEP was assessed by stimulation of the nondominant median nerve and responses were recorded over Erbs point (N10), second cervical vertebra (N14), and the contralateral cortex (P15, N20, P23 latencies, and P15-N20 and N20-P23 amplitudes). Nine patients received thipental (4 mg/kg, iv bolus), nine patients received fentanyl (25 micrograms/kg, iv bolus), and nine patients received etomidate (0.4 mg/kg, iv bolus). SEP was assessed before and after drug administration at motor threshold stimulus intensity. Thiopental increased the latency of N10, N14, and N20. The amplitudes of N10-, N14-, and scalp-recorded waves were not altered by thiopental. Fentanyl increased N20 and P23 latency and decreased the amplitude of P15-N20. Etomidate increased latency of N20 and P23 without alteration of latencies of N10 or N14 and increased the amplitude of P15-N20 and N20-P23, while the amplitude of N10 was unchanged and the amplitude of N14 was decreased. It is concluded that thiopental or fentanyl causes only modest alterations in early waves of upper extremity SEP, whereas etomidate increases the amplitude of scalp-recorded waves. The effect of etomidate on SEP may make diagnosis of neurologic injury more difficult because of the changing waveform.     

Somatosensory evoked potential monitoring during intracranial surgery

In the neurosurgical approach to intracranial aneurysms which are often accompanied by arterial spasm and cortical ischaemia, monitoring procedures aim to obtain useful information on cerebral function. SEPs evoked by stimulation of the median nerve at the wrist and of the tibial nerve at the medial malleolus were registered in 45 patients with intracranial aneurysms during neurosurgical procedures. Our results show SEP abnormalities during different stages of neurosurgical procedures in 36 patients out of the monitored 45. Significant abnormalities of SEPs with respect to the control group were decrease of the amplitude of N 20-P 25 complex, lengthening of the absolute latency of the waves N 20- and P 25 and lengthening of the central conduction time (CCT) (N 13-N 20). The greatest SEP abnormalities were registered during the neurosurgical approach to aneurysm and during the clipping procedure. However, the changes were reversible in the majority of the patients. The aim of this paper was to focus on early detection of some cerebral function disturbances during the neurosurgical procedure as well as the prevention of possible brain damage.     

脊髓造影联合感觉诱发电位检测在下腰段脊神经根性卡压伤治疗中的临床指导意义

目的探讨脊髓造影(myelography,MG)联合感觉诱发电位(somatosensory evoked potential,SEP)检测在治疗下腰段脊神经根性卡压性病变治疗中的临床价值。方法2004年3月~2006年10月对46例患有不同程度腰腿疼痛1年以上且有手术意向的患者常规行MG和双下肢胫神经及L5、S1皮节SEP检测,分别记录硬膜囊受压部分占椎管直径的比例、N40峰潜伏期及H反射延迟状况,综合分析两种检查结果,最终决定是否行手术处理并预测愈后。结果7例单节段硬膜囊受压未超过椎管直径30%的患者,有2例患者SEP检测N40延迟比对照组超出10%,另5例延迟在0.15s之内<10%。前者手术治疗,后者采用非手术治疗处理。34例患者硬膜囊单节段(26例)和双节段(8例)受压程度大于椎管直径的30%,其中MG检查单节段单侧根管不显影21例,双侧不显影5例;多节段8例存在单侧根管不显影2例和双侧不显影6例,而此34例患者SEP检测H反射延迟均>10%,皆选用手术治疗。还有5例患者虽然MG下硬膜囊受压小于椎管直径的30%,其SEP延迟又>10%,但是其振幅却正常,其中2例患者单侧根管显示不清,此2例患者行手术治疗。结论MG和SEP检查可以作为下腰段脊神经受损害的量化指标,二者互为补充,指导临床治疗方式并提示愈后,对尚无CT或MRI设备的基层医疗单位有较高的应用价值。     

Total intravenous anesthesia for improvement of intraoperative monitoring of somatosensory evoked potentials during aneurysm surgery.

Two anesthetic regimens for monitoring somatosensory evoked potentials (SEPs) during intracranial aneurysm surgery were compared. Eighty-four sequential cases of intracranial aneurysms were operated on employing SEP monitoring. The first group of 22 cases was anesthetized with "balanced anesthesia" and the second group of 62 cases received total intravenous anesthesia (TIVA) consisting of propofol and alfentanil. In the TIVA group, the amplitude of early cortical SEP responses (N20-P25, or P40-N50) was significantly higher than that of responses in the balanced anesthesia group. In median nerve SEPs, the averaged amplitude of N20-P25 was 3.22 microV with TIVA and 1.69 microV with balanced anesthesia (P = 0.006). Similarly, posterior tibial nerve SEPs showed a P40-N50 response of 1.85 microV and 1.00 microV, respectively (P = 0.017). The superior signal-to-noise ratio obtained with TIVA allowed more frequent and reliable intraoperative SEP recordings than was possible with balanced anesthesia, resulting in rapid and reliable feedback for the surgeon. In 19% of median nerve SEPs recorded with TIVA, the cortical responses were over 5 microV in amplitude, so that reproducible N20-P25 responses were obtainable by averaging only 10 to 50 serial responses, that is, two to three recordings per minute. The higher amplitude of posterior tibial nerve SEPs recorded with TIVA made monitoring during surgery for anterior communicating artery aneurysms possible in all cases. This was not always the case with balanced anesthesia. The late deflection of median nerve SEPs (N30) was more frequently observed with TIVA.(ABSTRACT TRUNCATED AT 250 WORDS)