多通道微电极记录在帕金森病脑深部电刺激定位中的作用

目的丘脑底核(STN)是帕金森病(PD)脑深部电刺激(DBS)治疗的主要靶点,使用多通道微电极记录可以准确地发现STN的感觉运动区,提高治疗精准度,提高DBS治疗效果;但多通道微电极记录的方法和风险目前介绍的比较少。现通过10例帕金森病STN-DBS手术中应用多通道微电极记录的方法,探讨多通道微电极记录的精准定位作用与风险。方法 2012年10月至2013年5月10例帕金森病患者在STNDBS手术中,应用多通道微电极记录(4~5个通道),同步使用评分法记录,结合宏电极刺激结果,选择最终置入刺激电极的通道,比较术前预设的放置靶点与最终放置靶点的不同,测量通道的长度。结果不同的通道显示了不同的神经元放电模式以及其放电的强度与长度。比较最后电极植入通道与术前的预设中心靶点显示:左侧STN:放置中心位置6例,非中心4例,其中前方2例,外侧1例,内侧1例;右侧STN:中心位置5例,非中心5例,其中外侧4例,内侧1例,STN感觉运动区的通道长度:左侧STN感觉运动区信号长度为(4.85±1)mm(3~6 mm),右侧STN感觉运动区信号长度为(4.83±0.7)mm(4~6 mm)。10例患者手术中未见出血并发症。结论 10例患者中选择预设靶点即中心靶点的比例只有50%~60%,有40%~50%的患者最终放置植入电极的位置与预设的靶点不同。多通道微电极记录可以覆盖整个STN,通过记录其电信号并分析比较,可以准确显示出STN的运动区域,选择最佳的通道植入电极,提高DBS治疗的效果;未见明显的出血并发症。因此多通道微电极记录是DBS手术中一种可以提高精准定位,同时也非常安全有效监测的方法。     

Motor Evoked Potentials Improve Targeting in Deep Brain Stimulation Surgery

ObjectivesOne of the main challenges posed by the surgical deep brain stimulation (DBS) procedure is the successful targeting of the structures of interest and avoidance of side effects, especially in asleep surgery. Here, intraoperative motor evoked potentials (MEPs) might serve as tool to identify the pyramidal tract. We hypothesized that intraoperative MEPs are useful to define the distance to the pyramidal tract and reduce the occurrence of postoperative capsular side effects.Materials and MethodsMotor potentials were evoked through both microelectrode and DBS-electrode stimulation during stereotactic DBS surgery on 25 subthalamic nuclei and 3 ventral intermediate thalamic nuclei. Internal capsule proximity was calculated for contacts on microelectrode trajectories, as well as for DBS-electrodes, and correlated with the corresponding MEP thresholds. Moreover, the predictivity of intraoperative MEP thresholds on the probability of postoperative capsular side effects was calculated.ResultsIntraoperative MEPs thresholds correlated significantly with internal capsule proximity, regardless of the stimulation source. Furthermore, MEPs thresholds were highly accurate to exclude the occurrence of postoperative capsular side effects.ConclusionsIntraoperative MEPs provide additional targeting guidance, especially in asleep DBS surgery, where clinical value of microelectrode recordings and test stimulation may be limited. As this technique can exclude future capsular side effects, it can directly be translated into clinical practice.     

Myths and facts about the EARLYSTIM study

DBS of the STN improves quality of life (QoL) and motor function not only in advanced Parkinson's disease (PD), but also in PD with early motor complications, as shown in the recent EARLYSTIM study. In spite of the evidence in favor of STN‐DBS, the findings of the EARLYSTIM study have recently been controversially debated. Here, we argue that a placebo or lessebo effect is unlikely to have relevantly contributed to the favorable outcome of STN‐DBS in the EARLYSTIM study. The method of quantification of the placebo effect of DBS in a previous publication reveals flaws leading to implausible results, and therefore the placebo effect of DBS remains currently elusive, especially because blinding of PD patients with STN‐DBS as a crucial preassumption for assessing a placebo effect is practically impossible. Moreover, we claim that the extent of such a placebo effect is most likely very small. Specific challenges of STN‐DBS at an earlier stage of PD and inclusion criteria are the risk of inclusion of patients who later evolve to atypical parkinsonism, the risk of a floor effect for the benefit from DBS, the need for experienced multidisciplinary care including prevention of suicidal behavior, and the need for highly qualified long‐term follow‐up. The EARLYSTIM study has shown that STN‐DBS may be proposed earlier on in the course of PD, as soon as motor complications start to cause relevant disability despite proper medical management. This can lead to a gain of several years of improved QoL. © 2014 International Parkinson and Movement Disorder Society     

Deep brain stimulation hardware complications: The role of electrode impedance and current measurements

Deep brain stimulation (DBS) is an effective therapy for advanced Parkinson's disease patients. Successful DBS outcomes depend on appropriate patient selection, surgical placement of the lead, intact hardware systems, optimal programming, and medical management. Despite its importance, there is little guidance in reference to hardware monitoring, hardware troubleshooting, and patient management. Technical manuals produced by the hardware manufacturer (Medtronic, Minneapolis, MN) are not presented in an applied clinical format, making impedance and current measurements difficult to interpret when the results are not straightforward. We present four patients with evolving DBS hardware complications that occurred during long‐term follow‐up, that shaped our clinical protocol for long‐term care management and hardware troubleshooting. © 2007 Movement Disorder Society     

Surgical therapy for multiple sclerosis tremor: a 12‐year follow‐up study

Background and purpose: Severe multiple sclerosis (MS) tremor causes disability poorly responsive to medication. Deep brain stimulation (DBS) or thalamotomy can suppress tremor, but long‐term outcomes are unclear. Methods: Nine patients with MS tremor underwent disability measures at baseline and 12 months post‐surgery (six thalamotomy, three DBS) in 1997–1998 (previously reported, Matsumoto et al., Neurology 2001;57:1876–82). We report the prospective 12‐year follow‐up of this cohort for tremor, disability, and death. Results: Surgery was initially successful in all. Tremor recurred in all patients within median 3 months, although two DBS patients were tremor‐free for 5 years. Median tremor‐free survival (tremor‐free time/survival time) was 4.3%. At 12‐year follow‐up, four survivors (two thalamotomy, two DBS) (Expanded Disability Status Scale scores 8–8.5) were severely disabled. Five patients were dead (four thalamotomy, one DBS) median 5.8 years post‐operative. Conclusions: Surgery benefit for severe tremor was overall short‐lived (median 3 months), with long‐term poor prognosis. Although two DBS patients had sustained 5‐year tremor‐suppression, the observed progressive disability and death in this cohort bear importance for long‐term success in future MS tremor surgery trials.     

Cortical Evoked Potentials Used for Placement of a Laminotomy Lead Array: A Case Report

Objective: We describe a technique for placement of a cervical spinal cord electrode under general anesthesia using the contacts as cortical evoked potential stimulating electrodes. Methods: A 37‐year‐old man required revision of the percutaneous lead of a spinal cord stimulator system placed for right upper extremity pain. A Resume‐TL® laminotomy lead was inserted at the C5‐6 interspace in the prone position under general anesthesia. The contacts were functionally over the right dorsal column by evoked potential recording, despite the apparent midline position of the lead. Results: Postoperatively, the patient had excellent coverage and pain relief at the right shoulder and extremity. There was no stimulation perceived on the left side of the body. Conclusion: This technique allows for intraoperative testing under general anesthesia in laminotomy lead placement to localize the optimal position of the lead.     

Sustained Dyskinesias Following Elective Cessation and Reactivation of Chronic Subthalamic Nucleus Deep Brain Stimulation for a Surgical Procedure

Objectives: Subthalamic nucleus deep brain stimulation (STN DBS) is effective for treatment of levodopa‐induced dyskinesias in patients with Parkinson's disease (PD). Medical or surgical procedures requiring electrocautery may require inactivation of the pulse generators to avoid damage to the lead or extension wire or possible reprogramming of the stimulators. This generally causes only mild and temporary disability. We report a patient with previously well‐controlled dyskinesias who had severe and prolonged dyskinesias following reactivation of deep brain stimulation (DBS) following an orthopedic procedure. Materials and Methods: Retrospective chart review. Results: The patient underwent two orthopedic procedures, each requiring inactivation of DBS. After reactivation of DBS, the patient experienced severe dyskinesias that ultimately required sedation and ventilation to control large‐amplitude dyskinesias. Conclusions: Clinicians caring for PD patients treated with STN DBS should be aware of the possible reappearance of severe dyskinesias arising from routine inactivation and reactivation of pulse generators for medical or surgical procedures.     

Two‐year follow‐up on the effect of unilateral subthalamic deep brain stimulation in highly asymmetric Parkinson's disease

Although bilateral subthalamic deep brain stimulation (STN DBS) provides greater relief from the symptoms of Parkinson's disease (PD) than unilateral STN DBS, it has been suggested that unilateral STN DBS may be a reasonable treatment option in selected patients, especially those with highly asymmetric PD. In previous studies on the effect of unilateral STN DBS, the asymmetry of PD symptoms was not prominent and the mean follow‐up durations were only 3 to 12 months. In this study, we report our findings in a series of 8 patients with highly asymmetric PD who were treated with unilateral STN DBS and were followed for 24 months. Serial changes in Unified Parkinson's Disease Rating Scale (UPDRS) motor score and subscores in the ipsilateral, contralateral, and axial body parts were analyzed. Unilateral STN DBS improved the UPDRS motor score and the contralateral subscore in the on‐medication state for 5 nonfluctuating patients and in the off‐medication state for 3 fluctuating patients. However, the ipsilateral subscore progressively worsened and reversed asymmetry became difficult to manage, which led to compromised medication and stimulator adjustment. At 24 months, all the patients were considering the second‐side surgery. Our results suggest that bilateral STN DBS should be considered even in highly asymmetric PD. © 2008 Movement Disorder Society     

丘脑底核电刺激治疗继发性肌张力障碍

目的 探讨丘脑底核（STN）的脑深部电剌激（DBS）治疗继发性肌张力障碍的可行性、适应证和并发症。方法 5例行双侧STN—DBS，1例行单侧STN—DBS。结果 术中利用微电极记录的电信号获得STN的准确靶点定位，电刺激后患者肌张力有不同程度下降，但扭转改善不明显。随访半年至3年，6例患者中，药物引起的迟发性肌张力障碍及外伤性肌张力障碍的患者疗效理想，BFMDRS评分改善均在90％以上，且随着随访时间的延长，效果持续不断改善；其余4例患者疗效不佳，4例均肌张力略有改善，其中1例扭转略改善，1例语言及步态略有改善。手术后患者均无明显合并症，但1例术后16个月发现左侧电极折断，后取出。结论 DBS治疗迟发性和外伤性继发性肌张力障碍效果理想，而对于缺氧或脑基底节区弥漫性损害的继发性肌张力障碍效果不佳；STN可以成为治疗本病的理想靶点；术中应根据电生理记录结果和肌张力的轻度改善作为靶点定位的指标；手术无明显合并症。     

脑深部电刺激术的手术并发症及防治

目的 探讨脑深部电极刺激术(DBS)手术并发症的产生原因及防治方法.方法 对278例(531侧)接受DBS治疗的患者发生的手术并发症及其处理方法进行回顾性分析.结果 DBS手术并发症的发生主要与手术操作、治疗靶点的选择与定位、刺激器装置等方面有关.其中与手术相关的并发症为脑内血肿、术后癫痫、脑脊液漏等;与刺激靶点选择和定佗相关的并发症有异动症、构音障碍、眼睑下垂等;与植入装置相关的并发症有电极折断、电极移位、装置故障等.结论 严格与细致的手术操作、选择正确的手术方式、精细的术后程控可有效地减少和预防DBS手术并发症的发生.