苍白球的计算机三维重建与应用

苍白球是脑立体定向手术领域中选择的重要“靶区”之一。国内曾有将苍白球作为单独的研究对象,在2～5mm厚的脑片上进行过观测。但对完整的苍白球进行0．1～0．2mm冰冻连续水平磨片连续摄片,三维成像的详细报道,鲜为人知。本研究采用计算机成像技术,图形学方法,先通过计算机重建苍白球的“三维形态”,再对其进行立体几何分析,取得苍白球的位置、体积、前后径、左右径、上下径和坐标值等三维解剖学数据,获得逼真图像,     

帕金森病人苍白球神经元放电的自适应阈值检测

自动选取合适的阈值以适应不同信噪比的信号,达到检测神经元放电的目的。依据微电极记录的信号,采用闭环方式自动递归调整阈值,逐次检测神经元放电。对合成的模拟神经放电信号及临床手术中微电极记录的112个病人的神经元放电信号处理,检测出了不同信噪比信号中的神经元放电脉冲,这些放电脉冲反映了神经核团的电生理特征。根据检测的神经元放电,可以对不同神经核团放电特征进行客观定量的分析,准确识别手术中微电极所在的神经核团,对于指导靶点定位具有重要的意义。     

壳和苍白球三维空间形态与位置的研究

目的为获得壳和苍白球三维空间形态和位置的解剖学资料，为脑的立体定向手术提供形态学基础。方法将６１个整脑制成２ｍｍ厚的三维连续切片，并在各脑片上直接进行观测。     

锥形束CT引导机器人辅助反肩关节肩盂基座螺钉导针置入精准度研究

目的 评估锥形束CT(cone beam CT,CBCT)引导下机器人辅助置入反肩关节肩盂基座螺钉导针的精准度,为机器人辅助反肩关节置换手术的开展提供理论支持.方法 使用CBCT对12例SYNBONE肩胛骨模型置入反肩关节肩盂基座螺钉导针前后行断层扫描.采用TiRobot软件术前规划螺钉导针入针点、尾端止点及导针置入路径的位置坐标.计算机根据规划位置控制机械臂定位并辅助置入肩盂基座螺钉导针,术后比较规划入止点、路径与实际入止点、路径的差异.结果 所有肩胛骨模型均一次完成导针置入.规划与实际入针点位置偏差为(1.155±0.517)mm,规划与实际尾端止点位置偏差为(1.047±0.288)mm,计划路径与实际路径夹角偏差为(1.564±0.888)°.结论 CBCT引导下机器人辅助反肩关节肩盂基座螺钉导针置入精确度高,为临床中反肩关节置换精准治疗手术重要步骤提供可行性选择.     

基于立体视觉的手术导航光学定位系统

背景：以立体视觉技术为基础的手术导航定位系统可为医生实时显示手术器械相对于病灶部位的位置和方向,提高手术定位精度。 目的：利用双目立体视觉技术对手术持针器导航标志物进行立体定位。 方法：采用带阈值的重心法提取手术持针器导航标志物的球心特征,采用张氏平面标定法得到立体摄像机的内外参数,利用最小二乘法原理确定手术持针器导航标志物三维坐标,进而确定穿刺针相对于病灶部分的位置关系。 结果与结论：在现有的实验条件下,立体光学定位系统能够对手术用持针器标志物进行实时定位,且手术精度能够满足导航的需求。     

基于小波变换和非线性能量算子的神经元放电检测

微电极导向的立体定向手术中,微电极记录的神经元放电信号噪声干扰严重,信噪比变化大,影响着神经元放电脉冲的分析。利用小波变换和非线性能量算子相结合的一种新的方法能检测出神经元放电。通过对临床不同病人、不同特点的神经元放电信号处理,结果表明:该方法能成功地检测出细胞放电,提取出放电波形。     

锁骨钩钢板内固定治疗肩锁关节脱位疗效评价

肩锁关节脱位是常见的肩部损伤,Rowe和Marle报告肩锁关节损伤的发生率为3.2%。在锁骨钩钢板未使用之前,传统的手术方法尽管取得了一定疗效,但因固定为静力固定仍然存在着固定不牢固、断针、退针、针道感染、再脱位等并发症。2004年1     

唐都医院治疗帕金森病获重大突破

用１根细针样的电极先标测出大脑深部引起身体震颤和僵直病变细胞的准确位置，然后再用１个微电流发生器毁损其神经传导通路，达到控制状态的目的，并能长期保持疗效。西安第四军医大学唐都医院的这项创新成果标志着我国微电极引导手术治疗帕金森病获重大突破。西安第四军医大学唐都医院采用这种办法已对８００余名患者实施手术治疗，有效率达９９．１７％，并发症为２．３％，一年复发率为２．４％，日前经专家现场考察和鉴定，认为此项技术属于国内领先并已达到国际先进水平。唐都医院治疗帕金森病获重大突破     

一种磁性耦合的多微电极系统

在所描述的多微电极系统中,微电极分别被磁化并一个一个地被对每个微电极起作用的磁力耦合。这种排列增加了纤细微电极的机械力,而且还约束着每根微电极电线的弯曲。这种多微电极结构允许许多纤细微电极在局部的神经组织区域内,独立地,并平行地穿透。这些特点使得每个电极均以良好的信噪比对神经电位加以记录。此外,微电极尖端间的距离在实验操作期间能清楚地识别和保持。本文描述了这种多微电极结构的制作和特性,它的实用性由从几个局部神经区域的神经细胞的神经电位的同时记录说明。前言解剖学上的、生理学上的和关于行为的     

框架式并联骨科手术机器人辅助椎弓根螺钉置入北大核心

背景:课题组与上海大学机器人研究所以及上海禾璞医疗科技有限公司共同开发了框架式并联骨科手术机器人,希望为国产骨科手术机器人的发展做出贡献。目的:通过动物腰椎实验测试框架式并联骨科手术机器人辅助腰椎手术的可行性,验证其操作性能及辅助置钉的准确度。方法:将12具山羊腰椎随机分成2组,实验组(6具,60个钉道)使用手术机器人根据三维CT数据规划钉道,并应用框架式并联骨科手术机器人辅助置入克氏针;对照组(6具,60个钉道)由医生根据二维X射线数据手动置入克氏针。记录钉道规划时间、克氏针置入时间、X射线暴露时间。实验结束后采集两组CT影像,依据改良Gertzbein-Robbins分类标准评估置入克氏针的准确性与优良率。结果与结论:(1)实验组钉道规划时间长于对照组(P <0.001),两组间克氏针置入时间及X射线暴露时间比较差异无显著性意义(P> 0.05);(2)标本CT扫描显示,实验组置钉成功率、优良率分别为100%,96.7%,对照组置钉成功率、优良率分别为98.3%,85.0%,实验组置钉优良率明显高于对照组(P <0.05);(3)结果表明,与术中C臂机透视引导徒手置钉相比,应用框架式并联骨科手术机器人进行辅助椎弓根螺钉置钉的准确率更高,可以有效提高手术安全性。     

Identification and characterization of neurons with tremor-frequency activity in human globus pallidus

 Many previous studies have demonstrated the existence of neurons with tremor-frequency activity (”tremor cells”) in the thalamus of Parkinson’s disease (PD) patients and these neurons are presumed to play a role in the pathogenesis of tremor. Since a major input to motor thalamus (Voa and Vop) is from the internal segment of the globus pallidus (GPi), neurons with tremor-frequency activity in motor thalamus may receive input from neurons in GPi. The aim of this study was to quantify the characteristics of tremor cells in human globus pallidus. In three PD patients with tremor undergoing microelectrode exploration of the globus pallidus prior to pallidotomy, 228 neurons were sampled, and 28 (12.3%) were identified to fire at the same frequency as the tremor. These ”tremor cells” were located in the ventral portion of GPi. Autocorrelogram analysis of the sampled spike trains of these 28 tremor cells was carried out over sequential 10-s time segments, and autocorrelograms showing maximal oscillatory activity were graded from 0 to 10. Average tremor cell oscillation grades ranged from 6.8 to 7.8, similar to those reported in the MPTP-induced primate model of parkinsonism. The average tremor cell oscillation grade varied between patients, as did the clinical measures of tremor severity. Tremor cells had oscillations in spike discharges at the same average frequency (4.2–5.2 Hz) as the patient’s tremor determined from the electromyogram and accelerometry records of one or more limbs (4.0–5.4 Hz), and the individual values were correlated (r ²=0.73) over the total range (3.7–5.6 Hz). The results of this study demonstrate the presence of neurons with 4–6 Hz tremor-frequency activity in GPi, supporting a role of the globus pallidus in the production of rest tremor in PD patients. Received: 27 February 1996 / Accepted: 18 October 1996     

帕金森病外科定位手术的解剖学基础及其临床应用

帕金森病在老龄化社会的发病率很高,是常见的神经系统退行性疾病之一。毁损过度兴奋的内侧苍白球和底丘脑是外科定位手术治疗帕金森病的解剖学基础,单侧苍白球毁损术对控制进展性的帕金森病及药物治疗无效的患者有作用,术后生活质量有明显的改善。尽管底丘脑核团深部刺激术的解剖学基础仍需进一步研究并存有争议,但Krack等采用“联合PD分级标准”(UPDRS)临床评价量表对49例行底丘脑深部刺激术患者术后5年的长期观察发现,术后运动总评分提高54%(P<0.001)。通过单侧苍白球毁损术及底丘脑深部刺激术治疗帕金森病具有较好的临床效果。     

Neurophysiologisches Monitoring in der funktionellen Neurochirurgie bei Bewegungsstörungen: Intraoperative Mikroelektrodenableitungen

Intraoperative microelectrode recordings serve as an exploratory guide for many stereotactic neurosurgeons in order to objectively localize deep brain sites to be operated for the control of movement disorders. In this context, microelectrode recordings are used to (i) map structural boundaries, (ii) provide a physiologic delineation of the sensorimotor territory within the surgical target and (iii) to identify and localize neuronal activities related to pathologic brain function such as tremor or dystonia. This article provides an overview of discharge characteristics of single cell activity in the three most common targets for movement disorder surgery: subthalamic nucleus (STN), pars interna of the globus pallidus (GPi) and thalamic nucleus ventro-intermedius (Vim).     

Activation of subthalamic neurons by contralateral subthalamic deep brain stimulation in Parkinson disease

Multiple studies have shown bilateral improvement in motor symptoms in Parkinson disease (PD) following unilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) and internal segment of the globus pallidus, yet the mechanism(s) underlying this phenomenon are poorly understood. We hypothesized that STN neuronal activity is altered by contralateral STN DBS. This hypothesis was tested intraoperatively in humans with advanced PD using microelectrode recordings of the STN during contralateral STN DBS. We demonstrate alterations in the discharge pattern of STN neurons in response to contralateral STN DBS including short latency, temporally precise, stimulation frequency-independent responses consistent with antidromic activation. Furthermore, the total discharge frequency during contralateral high frequency stimulation (160 Hz) was greater than during low frequency stimulation (30 Hz) and the resting state. These findings demonstrate complex responses to DBS and imply that output activation throughout the basal ganglia-thalamic-cortical network rather than local inhibition is a therapeutic mechanism of DBS.     

Effects of apomorphine on subthalamic nucleus and globus pallidus internus neurons in patients with Parkinson's disease.

This study examines the effect of apomorphine (APO), a nonselective D(1)- and D(2)-dopamine receptor agonist, on the firing activity of neurons in the subthalamic nucleus (STN) and internal segment of the globus pallidus (GPi) in patients with Parkinson's disease (PD). Single-unit microelectrode recordings were conducted in 13 patients undergoing implantation of deep brain stimulation electrodes in STN and 6 patients undergoing a pallidotomy. Doses of APO (2.5-8 mg) were sufficient to produce an ON state, but not intended to induce dyskinetic movements. Following baseline recordings from a single neuron, APO was administered and the activity of the neuron followed for an average of 15 min. The spontaneous discharge of neurons encountered before (n = 309), during (n = 146, 10-60 min), and after the effect of APO had waned (n = 127, >60 min) was also sampled, and the response to passive joint movements was noted. In both nuclei, APO increased the overall proportion of spikes in burst discharges (as detected with Poisson "surprise" analysis), and a greater proportion of cells with an irregular discharge pattern was observed. APO significantly decreased the overall firing rates of GPi neurons (P < 0.01), but there was no change in the overall firing rate of neurons in the STN (P = 0.68). However, the mean firing rates of STN neurons during APO-induced movements (choreic or dystonic dyskinesias) that occurred in four patients were significantly lower than OFF-period baseline values (P < 0.05). Concurrent with a reduction in limb tremor, the percentage of cells with tremor-related activity (TCs) was found to be significantly reduced from 19 to 6% in the STN and 14 to 0% in the GPi following APO administration. APO also decreased the firing rate of STN TCs (P < 0.05). During the OFF state, more than 15% of neurons tested (STN = 93, GPi = 63) responded to passive movement of two or more joints. After APO, this proportion decreased significantly to 7% of STN cells and 4% of GPi cells (STN = 28, GPi = 26). These findings suggest that the APO-induced amelioration of parkinsonian symptoms is not solely due to a decrease in overall activity in the GPi or STN as predicted by the current model of basal ganglia function in PD.     

In vivo microelectrode localization in the brain of the alert monkey: a combined radiographic and magnetic resonance imaging approach

A technique is described for in vivo localization of microelectrodes during single-unit recording in the alert monkey. Four hollow glass spheres filled with copper sulfate and iohexol were affixed to the surface of the animal's skull prior to the acquisition of a series of coronal magnetic resonance (MR) images. These reference beads were visible in both X-ray and MR images. Cranial recording chambers were then implanted bilaterally over the amygdaloid complex. A microelectrode was advanced to various depths in the subject's brain. At each selected microelectrode site, five radiographs were obtained and a small electrolytic lesion was made. Based on the data from the radiographs, we computed the position of the microelectrode tip at each site relative to the reference beads. With a precision of 625 m, this method was used to predict the neuroanatomical location of ten microlesions placed in both subcortical and cortical structures. Postmortem histological analysis revealed that the actual location of the lesions closely matched predictions arrived at using the X-ray/MRI localization technique. This technique thus provides an accurate, reliable and noninvasive method for in vivo localization of microelectrode recording sites.     

The pedunculopontine nucleus: its role in the genesis of movement disorders

The pedunculopontine nucleus (PPN) is located in the dorso-lateral part of the ponto-mesencephalic tegmentum. The PPN is composed of two groups of neurons: one containing acetylcholine, and the other containing non-cholinergic neurotransmitters (GABA, glutamate). The PPN is connected reciprocally with the limbic system, the basal ganglia nuclei (globus pallidus, substantia nigra, subthalamic nucleus), and the brainstem reticular formation. The caudally directed corticolimbic-ventral striatal-ventral pallidal-PPN-pontomedullary reticular nuclei-spinal cord pathway seems to be involved in the initiation, acceleration, deceleration, and termination of locomotion. This pathway is under the control of the deep cerebellar and basal ganglia nuclei at the level of the PPN, particularly via potent inputs from the medial globus pallidus, substantia nigra pars reticulata and subthalamic nucleus. The PPN sends profuse ascending cholinergic efferent fibers to almost all the thalamic nuclei, to mediate phasic events in rapid-eye-movement sleep. Experimental evidence suggests that the PPN, along with other brain stem nuclei, is also involved in anti-nociception and startle reactions. In idiopathic Parkinson's disease (IPD) and parkinson plus syndrome, overactive pallidal and nigral inhibitory inputs to the PPN may cause sequential occurrences of PPN hypofunction, decreased excitatory PPN input to the substantia nigra, and aggravation of striatal dopamine deficiency. In addition, neuronal loss in the PPN itself may cause dopamine-resistant parkinsonian deficits, including gait disorders, postural instability and sleep disturbances. In patients with IPD, such deficits may improve after posteroventral pallidotomy, but not after thalamotomy. One of the possible explanations for such differences is that dopamine-resistant parkinsonian deficits are mediated to the PPN by the descending pallido-PPN inhibitory fibers, which leave the pallido-thalamic pathways before they reach the thalamic targets.     

Direct validation of atlas-based red nucleus identification for functional radiosurgery

Treatment targets in functional neurosurgery usually consist of selected structures within the thalamus and basal ganglia, which can be stimulated in order to affect specific brain pathways. Chronic electrical stimulation of these structures is a widely used approach for selected patients with advanced movement disorders. An alternative therapeutic solution consists of producing a lesion in the target nucleus, for example by means of radiosurgery, a noninvasive procedure, and this prevents the use of intraoperative microelectrode recording as a method for accurate target definition. The need to have accurate noninvasive localization of the target motivated our previous work on atlas-based identification; the aim of this present work is to provide additional validation of this approach based on the identification of the red nuclei (RN), which are located near the subthalamic nucleus (STN). Coordinates of RN were obtained from the Talairach and Tournoux (TT) atlas and transformed into the coordinates of the Montreal Neurological Institute (MNI) atlas, creating a mask representation of RN. The MNI atlas volume was nonrigidly registered onto the patient magnetic resonance imaging (MRI). This deformation field was then applied to the RN mask, providing its location on the patient MRI. Because RN are easily identifiable on 1.5 T T2-MRI images, they were manually delineated; the coordinates of the centers of mass of the manually and automatically identified structures were compared. Additionally, volumetric overlapping indices were calculated. Ten patients were examined by this technique. All indices indicated a high level of agreement between manually and automatically identified structures. These results not only confirm the accuracy of the method but also allow fine tuning of the automatic identification method to be performed.     

Features of the spike activity of globus pallidus neurons and pallido-thalamic functional interactions during targeted verbally cued movements in humans

This paper reports the results of an analysis of evoked spike activity in neurons of the human globus pallidus during performance of a targeted verbally cued movement, along with a comparison with the results of previous experiments on evoked spike activity of neurons in the reticular and ventrolateral thalamic nuclei in an identical test, recorded during stereotaxic surgery with a microelectrode technique in patients with Parkinson’s disease. The following observations are reported for the first time: 1) The existence in the outer segment of the human pallidus of neurons with convergent properties, selectively responding with activation to significant “stimulatory” verbal command stimuli initiating the launch and performance of a targeted movement; 2) similarity in the dynamics of concordantly occuring responses of convergent neurons in the integrative centers of the striopallidothalamic circuit in functionally important phases of movement act performance. It is suggested that the similar concordantly developing dynamics of neuronal rearrangements during the performance of a targeted movement act within the structures of this circuit reflects functional interstructural and interneuronal interactions occurring in the striopallidothalamocortical system of the human brain, which is involved in organizing verbally cued targeted forms of activity. Laboratory of Human Cellular Neurophysiology, Institute of Chemical Physics, Russian Academy of Sciences. N. N. Burdenko Institute of Neurosurgery, Russian Academy of Medical Sciences, 4 Kosygin Street, Moscow 117977, Russia. Translated from Rossiiki Fiziologicheskii Zhurnal imeni I. M. Sechenova, Vol. 83, No. 7. pp. 37–44, July, 1997.     

High-resolution three-dimensional microelectrode brain mapping using stereo microfocal X-ray imaging

Much of our knowledge of brain function has been gleaned from studies using microelectrodes to characterize the response properties of individual neurons in vivo. However, because it is difficult to accurately determine the location of a microelectrode tip within the brain, it is impossible to systematically map the fine three-dimensional spatial organization of many brain areas, especially in deep structures. Here, we present a practical method based on digital stereo microfocal X-ray imaging that makes it possible to estimate the three-dimensional position of each and every microelectrode recording site in "real time" during experimental sessions. We determined the system's ex vivo localization accuracy to be better than 50 microm, and we show how we have used this method to coregister hundreds of deep-brain microelectrode recordings in monkeys to a common frame of reference with median error of <150 microm. We further show how we can coregister those sites with magnetic resonance images (MRIs), allowing for comparison with anatomy, and laying the groundwork for more detailed electrophysiology/functional MRI comparison. Minimally, this method allows one to marry the single-cell specificity of microelectrode recording with the spatial mapping abilities of imaging techniques; furthermore, it has the potential of yielding fundamentally new kinds of high-resolution maps of brain function.