磁共振微电极记录辅助脑内核团毁损治疗帕金森病

目的：探讨磁共振（MRI）扫描定位结合术中微电极记录技术及靶点选择在帕金森病立体定向手术治疗中的作用。方法：MRI扫描定位结合微电极记录,脑立体定向毁损法治疗帕金森病89例,其中Vim毁损6例,Gpi毁损71例,Gpi Vim毁损12例,结果：根据MRI扫描确定的靶点坐标与通过微电极记录确定的最终毁损靶点坐标不符的9例,变更范围1-3mm,患者震颤、僵直及运动减少等症状改善显著,术前及术后UPDRS评分经t检验统计有显著差异。结论：选择合适的靶点,MRI扫描结合术中微电记记录技术,提高了帕金森病手术疗效,减少了手术并发症。     

苍白球内侧部毁损术治疗帕金森病最佳靶点概率功能图谱的建立

目的建立苍白球内侧部(Gpi)毁损术治疗帕金森病最佳靶点的概率功能图谱。方法回顾分析帕金森病患者92例,在分析MRI影像学资料、电生理资料和术后帕金森病综合评分(UPDRS)基础上,对毁损电极尖端裸露区进行建模,然后利用Marching Cube算法,通过空间转换将Gpi最有效的毁损靶点转换成概率功能图谱。结果所建立的概率功能图谱清楚地显示了利用Gpi毁损术治疗帕金森病最佳靶点的空间分布。Z值范围在-3.0～-6.3mm之间,最佳功能靶点坐标值为5mm;X值范围在18～23mm之间,最佳功能靶点坐标值为21mm;Y值范围在2-3mm,最佳功能靶点坐标值为2.7mm。结论立体定向手术最佳靶点的概率功能图谱是立体定向功能神经外科有效的辅助工具。     

苍白球内侧部毁损术治疗帕金森病概率功能图谱再研究

目的建立改良的苍白球内侧部(Gpi)毁损术治疗帕金森病最佳靶点的概率功能图谱。方法回顾分析92例帕金森病患者MRI影像学资料、电生理资料和术后评分基础上,对毁损电极尖端裸区进行建模,然后利用Marching Cube算法,坐标归一化,通过空间转换构建Gpi毁损靶点概率功能图谱。结果通过坐标归一化所建立的概率功能图谱与之前的图谱比较能够更好显示帕金森病最佳靶点的空间分布。结论改良Gpi概率功能图谱是立体定向功能神经外科有效的辅助工具。     

Gpi、Vim联合同期毁损治疗帕金森病（附50例报告）

目的探讨Gpi、Vim联合同期毁损治疗帕金森病安全性与可行性.方法选择男性27例,女性23例.年龄47～74岁,平均51,5岁.病程2～10年,平均6,4年,术前开、关状态UPDRS评分,分别为34.9±17.3和51.2±17.5.采用CRW定向仪,应用Philips Gyroscan NT 1,0 tesla MR扫描,在轴位像直接确定Vim、Gpi解剖靶点,再测量距中线实际距离,读出靶点坐标数据.在冠状位先确定Vim、Gpi靶点,确定Gpi靶点距离视束2mm,再测量靶点至中线实际距离及深度.二者重建即为确定的Vim、Gpi手术靶点.靶点微电极记录一次.靶点射频毁损之前,行电刺激验证靶点.毁损温度80度、每次60秒,每间隔1mm毁损一次,毁损灶达4～6mm圆柱体.结果术后1～2周开、关状态UPDRS评分,分别改善为14.2±27.1和16.2±25.5.随访2～18个月,震颤完全消失,肌僵硬及运动迟缓改善,肢体活动灵活,步态和身体姿势显著进步.无语言障碍及视野缺损、无死亡.结论对Gpi、丘脑Vim核的毁损的先后次序、毁损范围、毁损的程度应该依据患者的症状而定.以肌僵硬为主要症状者,先毁损Gpi.如果仍有明显震颤,则增加Vim靶点.震颤较轻时,Vim靶点毁损范围应缩小3mm.以震颤为主要症状者,则先毁损Vim靶点,依据肌僵硬改善程度决定是否行Gpi毁损及毁损程度.采用Gpi、Vim靶点联合同期毁损并未增加手术危险性,相反,两个靶点作用互补,“开”“关”状态改善显著,震颤改善达百分之百,取得良好效果.     

苍白球腹后内侧部毁损治疗帕金森病靶点定位研究

目的　探讨MRI定位微电极引导的苍白球腹后内侧部毁损术治疗帕金森病靶点定位方法及其规律。方法　 39例原发PD病人施行PVP术 ,UPDRS评分改善率大于 35 %。采用MRI进行靶点解剖定位 ,同时在MRI操作台上测量有关参数。术中用电生理方法对靶点做必要的调整。结果　MRI具有较高的分辨率 ,对靶点定位具有直接、准确等优点 ,Gpi靶点坐标在不同的个体有很大差异 ;靶点坐标X与三脑室宽度 (W )和AC -PC线长度 (L)之间存在线性依从关系 ,即 :^X =10 .0 9 0 .30L 0 .4 8W。 结论　PVP术治疗帕金森病效果满意 :通过MRI扫描 ,实现了Gpi靶点解剖定位个体化 ,提高了定位精度 ;应用电生理学方法调整靶点是必要的 ,并实现了靶点的功能定位 ;靶点X坐标值与三脑室宽度和AC -PC线长度有相关性     

苍白球腹后内侧部毁损治疗帕金森病靶点定位研究

目的：探讨MRI定位,微电极引导的苍白球腹后内侧部毁损术,治疗帕金森病靶点定位方法及其规律。方法：39例原发PDU现人施行PVP术,UPDRS评分改善率大于35%。采用MRI进行靶点解剖定位,同时在MRI操作台上测量有关参数。术中用电生理方法对靶点做必要的调整。结果：MRI具有较高的分辨率,对靶点定位具有直接、准确等优点,Gpi靶点坐标在不同的个体有很大差异;靶点坐标X与三脑室宽度（W）和AC-PC线长度（L）之间存在线性依从关系即：X=10.09 0.30L 0.48W。结论：PVP术治疗帕金森病效果满意;MRI可对靶点进行直接定位,实现了Gpi靶点解剖定位个体化,提高了定位精度,应用电生理学方法调整靶点是必要的,并实现了靶点的功能定位;靶点X坐标值与三脑室宽度和AC-PC线长度有相关性。     

MRI引导立体定向射频颅内靶点毁损治疗帕金森病

目的：探讨立体定向射频毁损Vim和Gpi治疗帕金森病的作用。方法：对28例帕金森病患行MRI、CT定位，微电极引导，配合术中测量阻抗和电刺激确定Vim、Gpi靶点，以80℃，90″毁损。结果：术后即刻症状消除89．3％，症状减轻10．7％。结论：立体定向射频毁损Vim,Gpi治疗帕金森病有效率高，准确定位是手术成功的主要条件。     

微电极导向苍白球腹后部毁损术治疗帕金森病的初步报道

目的 :探讨苍白球腹后部毁损术 (PVP)治疗帕金森病 (PD)的手术方法及疗效。方法 :采用坐标定位结合MRI图象定位 ,在微电极导向下 ,完成对 6例病人单侧苍白球腹后部 (Gpi)的定位 ,并实施毁损。结果 :6例患者的震颤、僵硬及运动迟缓均得到明显改善 ,UPDRS运动部分积分下降 ,无永久并发症。结论 :坐标结合 MRI图象法能准确定位 Gpi,微电极记录是其必要的补充 ,PVP能全面改善 PD患者的症状 ,是一种安全有效的方法。     

苍白球腹后部毁损术中的靶点解剖定位和电生理定位

目的 总结苍白球腹后部毁损术中的靶点定位方法。方法 采用MRI扫描，前50例用坐标定位法计算靶点坐标，平均记录2．6个针道微电极信号；后191例采用坐标定位和图像定位相结合的方法计算靶点坐标，平均记录1．3个针道微电极信号。结果 MRI图像能显示苍白球各部分、内囊及视束等结构。微电极记录可确认苍白球内侧部边界、视束等结构。前50例患者坐标调整的百分数明显高于后191例患者。结论 MRI坐标定位和图像定位相结合，减少了个体差异引起的误差，使解剖定位更加准确。微电极记录技术是MRI定位方法的必要补充。     

帕金森病定向术磁共振靶点定位

目的　探讨帕金森病立体定向术核磁共振靶点定位最佳扫描方式。方法　 72例帕金森病患者行磁共振导向结合微电极记录定位 ,丘脑腹中间核 (Vim)毁损术。分为两组 ,采用中反转恢复序列 (IR)扫描直视定位和常规自旋回波 (SE)扫描解剖间接定位。以术中微电极记录和射频刺激验证确定的毁损靶点为标准 ,观察毁损靶点与影像定位靶点坐标的一致性 ,统计两种MRI定位方式下预定靶点与毁损靶点坐标符合率 ,结合疗效分析评价两种定位法。结果　 34例行IR扫描直视定位术中靶点符合率为 88.2 % ,38例行SE扫描间接定位术中靶点符合率为 31.6 %。两种定位法存在显著差异 (P <0 .0 5 )。MRI直视定位较解剖间接定位电生理靶点符合率高。结论　IR序列是MRI帕金森病立体定向靶点影像定位的优选扫描方式。其个体化直视定位靶点对提高疗效、减少并发症发生具有重要意义     

Clinical outcome of unilateral stereotactic pallidotomy without microelectrode recording for intractable Parkinson's disease

Objective: To study the effects of unilateral stereotactic pallidotomy performed without microelectrode recording for advanced Parkinson's disease. Methods: Stereotactic coordinates were calculated by comparing preoperative inversion recovery MRI sequences with intraoperative CT scans. Conventional stereotactic stimulation techniques were employed to confirm correct probe placement. Patients were assessed using a modified CAPIT protocol with the off-state UPDRS motor score as the primary efficacy measure. Results: A statistically significant decline in off-state UPDRS motor scores occurred at 2months (21% improvement in 32 patients) and also at 1year postoperatively (30% improvement in 12 patients). Levodopa-induced dyskinesias on the side contralateral to surgery were reduced 97% in the cohort with 1year of follow-up. No deleterious effects of surgery on global neuropsychological functioning were seen. A major surgical complication (mild but persistent hemiparesis) occurred in one patient. Conclusions: We believe that stereotactic pallidotomy can be performed safely and effectively without microelectrode recording when coordinates are calculated using CT with comparison to preoperative MRI sequences.     

帕金森病外科治疗中苍白球内侧部神经元电生理记录的有效针道方法

目的探讨微电极记录技术在帕金森病(PD)苍白球切开术(Pallidotomy)治疗中的实际作用及应用方法。方法对120例PD苍白球内侧部神经元的电生理特征进行记录和分析，术中同时行电刺激检测，随后行射频毁损，术后2周～3月内行MR确认毁损灶位置．1年后病情随访。结果苍白球内侧部(Gpi)运动相关细胞分布具有规律性：下肢运动神经元位于Gpi的背侧．面及咀嚼肌相关运动神绎元位于Gpi最腹侧，上肢运动神经元位于其中，此结果为最终毁损治疗提供了患肢部位的信息：微电极记录在PD手术治疗中的作用主要是用于提供Gpi内神经元信息，即对所行针道异常电生理信号及视束光反应的确认，而非一定要多针道对Gpi或STN生理空间制图或边缘定位，由此提出“有效针道”的方法。结论对于GDi靶点位置的确定，除影象学定位外，微电极记录和电刺激同样重要；微电极记录技术的有效针道方法操作简单，易于临床上对神经核团定位，对GDi靶点定位十分重要。     

苍白球腹后部切开术治疗帕金森病靶点定位规律探讨

目的 研究苍白球腹后部切开术(PVP)治疗帕金森病(PD)的靶点定位方法及其规律。方法 45例原发PD患者接受手术．采用MRI进行靶点解剖定位，术中用电生理方法对靶点做必要的调整，同时在MRI操作台上准确测量ACPC线的长度(L)、三脑室的宽度(W)、头颅的长度和宽度。结果 本组患者UPDRS评分改善率大于35％，手术效果满意；依据术中电生理方法调整靶点20例．调整范围1～3mm；靶点横坐标(X)与L和W之间存在线性依从关系即：X=10．09 0．30L 0．48W．决定系数R^2=0．7258．结论 PVP术中应用电生理方法调整靶点是非常重要的，实现了靶点的功能定位；X坐标值随L和W的增加而增大，且W对X的贡献大于L，靶点Z坐标与L和W之间无相关性，靶点坐标与颅长、颅宽无相关性。     

脑深部电刺激对帕金森病二次手术的临床应用价值

目的探讨帕金森病(Parkinson'sdisease,PD)毁损术后再行脑深部电刺激术(deepbrainstimulation,DBS)的可行性、靶点选择、术中电生理学特点和治疗结果。方法应用MRI和微电极记录技术进行靶点定位,对13例毁损术后的PD患者行DBS手术,其中7例曾行单侧苍白球毁损术(posteroventralpallidotomy,PVP),5例曾行单侧丘脑毁损术,1例曾行双侧丘脑及左侧苍白球毁损术。DBS的靶点包括单侧丘脑底核(subthalamicnucleus,STN)6例,单侧丘脑腹中间核(ventralintermediatnucleus,Vim)1例,双侧STN4例,一侧STN及对侧苍白球(globuspallidusinternus,Gpi)2例。结果DBS对毁损术后的PD患者症状有不同程度的改善,其中单侧毁损术后行双侧DBS效果最明显。术后3个月的UPDRS运动及ADL评分较术前明显减少(P<0.05或0.01),美多巴的用量明显减少(P<0.05),无新的手术合并症。结论曾行毁损术的PD患者如面临二次手术,可以选择DBS手术,以双侧STN的DBS效果最好,并可减少药物用量,不加重原有的术后并发症。     

Validation of CT‐MRI fusion for intraoperative assessment of stereotactic accuracy in DBS surgery

Deep brain stimulation is typically performed with intraoperative microelectrode recording and test stimulation for target confirmation. Recent studies have shown accurate, clinically efficacious results after lead placement without microelectrode recording or test stimulation, using interventional magnetic resonance imaging (MRI) or intraoperative computed tomography (CT; iCT) for verification of accuracy. The latter relies on CT–MRI fusion. To validate CT–MRI fusion in this setting, we compared stereotactic coordinates determined intraoperatively using CT–MRI fusion with those obtained on postoperative MRI. Deep brain stimulation electrodes were implanted with patients under general anesthesia. Direct targeting was performed on preoperative MRI, which was merged with preimplantation iCT images for stereotactic registration and postimplantation iCT images for accuracy confirmation. Magnetic resonance imaging was obtained 6 weeks postoperatively for comparison. Postoperative MRI was obtained for 48 patients, with 94 leads placed over a 1‐year period. Vector error of the targeted contact relative to the initial plan was 1.1 ± 0.7 mm on iCT and 1.6 ± 0.7 mm on postoperative MRI. Variance comparisons (F‐tests) showed that the discrepancy between iCT‐ and postoperative MRI‐determined errors was attributable to measurement error on postoperative MRI, as detected in inter‐rater reliability testing. In multivariate analysis, improved lead placement accuracy was associated with frame‐based stereotaxy with the head of the bed at 0° compared with frameless stereotaxy with the head of the bed at 30° (P = 0.037). Intraoperative CT can be used to determine lead placement accuracy in deep brain stimulation surgery. The discrepancy between coordinates determined intraoperatively by CT–MRI fusion and postoperatively by MRI can be accounted for by inherent measurement error. © 2014 International Parkinson and Movement Disorder Society     

Measurement of tissue electrical impedance confirms stereotactically localized internal segment of the globus pallidus during surgery

Lesions surgically made in the internal segment of the posteroventral globus pallidus (Gpi) reduce many medically intractable symptoms in patients with Parkinson's disease. The Gpi is localized for pallidotomy by stereotactic procedures. We sought to confirm the stereotactically localized Gpi segment by measuring impedance between the tip of an active electrode that was advanced toward the target and a remote reference electrode. A stereotactic instrument was used to place an active electrode in 53 conscious patients undergoing pallidotomy. The electrode was manually advanced slowly toward the Gpi segment by a microdrive. Impedance was measured every 10 mm initially and every 1 mm in the final 10 mm of the electrode's advancement, using an impedance monitor interconnected with a lesion generator. Measurements were continued for several millimeters after each patient's target was reached. Impedance values ranged from 250 to 350 ohms throughout of the electrode passage. Impedance increased by 25-35 ohms at 1-3 mm before the center of the target and then dropped abruptly when the electrode passed the target. Impedance values depended strongly on the electrode's configuration. The impedance measurement confirmed the location of each surgical target identified by stereotactic navigation. The accuracy of the impedance measurement is acceptable, and the procedure can be recommended as an aid to confirm the stereotactically localized Gpi during neurological surgery.     

Does stimulation of the GPi control dyskinesia by activating inhibitory axons?

A 69-year-old woman with Parkinson's disease and levodopa-induced dyskinesias had a deep brain stimulation (DBS) electrode inserted into the right globus pallidus internus (GPi). During the operation, the GPi was mapped with dual microelectrode recordings. Stimulation through one microelectrode in GPi inhibited the firing of GPi neurons recorded with another microelectrode 600--1,000 microm distant. The inhibition could be obtained with pulse widths of 150 micros and intensities as low as 10 microA. Single stimuli inhibited GPi neurons for approximately 50 ms. Trains of 300 Hz stimuli inhibited GPi neuron firing almost completely. Postoperatively, stimulation through macroelectrode contacts located in the posterior ventral pallidum controlled the patient's dyskinesias. The effect could be obtained with pulse widths of 50 micros and frequencies as low as 70--80 Hz. We postulate stimulation of the ventral pallidum controls dyskinesias by activating large axons which inhibit GPi neurons.     

Cortical visual evoked potentials recorded after optic tract near field stimulation during GPi-DBS in non-cooperative patients

Object

Neurophysiologic monitoring during deep brain stimulation (DBS) interventions in the globus pallidus internum (Gpi) for the treatment of Parkinson's disease or primary dystonia is generally based upon microelectrode recordings (MER); moreover, MER request sophisticated technology and high level trained personnel for a reliable monitoring. Recordings of cortical visual evoked potentials (CVEPs) obtained after stimulation of the optic tract may be a potential option to MER; since optic tract lies just beneath the best target for Gpi DBS, changes in CVEPs during intraoperative exploration may drive a correct electrode positioning.

Patients and methods

Cortical VEPs from optic tract stimulation (OT C-CEPs) have been recorded in seven patients during GPi-DBS for the treatment of Parkinson's disease and primary dystonia under general sedation. OT C-VEPs were obtained after near-field monopolar stimulation of the optic tract; recording electrodes were at the scalp. Cortical responses after optic tract versus standard visual stimulation were compared.

Results

After intraoperative near-field OT stimulation a biphasic wave, named N40-P70, was detected in all cases. N40-P70 neither change in morphology nor in latency at different depths, but increased in amplitude approaching the optic tract. The electrode tip was positioned just 1 mm above the point where OT-CVEPs showed the larger amplitude. No MERs were obtained in these patients; OT CVEPs were the only method to detect the Gpi before positioning the electrodes.

Conclusions

OT CVEPs seem to be as reliable as MER to detail the optimal target in Gpi surgery: in addition they are less expensive, faster to perform and easier to decode.