论"功能神经外科学"

神经外科学从治疗的疾病谱上主要划分为脑肿瘤、脑血管病、脑外伤和功能脑病。采用手术的方法修正神经系统功能异常的医学分支是为功能神经外科学(Functional Neurosurgery),早期亦称生理神经外科学(Physiologic Neurosurgery),或应用神经生理学     

功能神经外科发展十年

功能神经外科是神经外科的一个重要分支,它是运用各种外科手术技术改善中枢神经系统的功能失调,通过对中枢神经系统的某些结构进行刺激、破坏或重建,实现新的各系统之间的平衡,达到缓解症状、恢复神经功能的目的[1].功能神经外科治疗的常见疾病包括癫痫、运动障碍性疾病(帕金森病、肌张力障碍等)、疼痛(三叉神经痛、幻肢痛、癌性疼痛等)、脑神经疾病(面肌抽搐等)、精神疾病(强迫症、重度抑郁症、抽动秽语综合征、药物依赖等)以及脑瘫等.     

帕金森病的定向手术适应证

目的 确定各类帕金森病的定向手术适应证。方法 回顾分析1478例帕金森病定向手术，对手术后的手术疗效和某些相关并发症进行评估，进而推断各类帕金森病的定向手术适应证。结果 苍白球毁损术对服用左旋多巴类药物有效的震颤患者均有效，服用左旋多巴类药物震颤无效的患者，苍白球毁损术的手术疗效效果很差，单侧丘脑Vim核毁损术对震颤改善极佳，96.9%的患者彻底消失，同期同侧苍白球＋兵脑Vim核毁损术对震颤改善极佳，96.9%的患者彻底消失，同期同侧苍白球＋丘脑Vim核毁损术的患者震颤改善率为96.3%，苍白球毁损术对僵直、运动迟缓的疗效也显示出与左旋多巴服药的反应的规律性，服药效果好的手术效果好，但是，与震颤不同的是，服药无效的也有一定的疗效。启动不能患者，其手术效果都不佳，流涎、吞咽困难发生率在单侧苍折球毁损术患者中较低，乏力发生率较高，分期双侧苍白球毁损术中患者年龄较大的较易发生乏力、流涎、吞咽困难。结论 我们的临床实践认为左旋多巴类药物服药反应是一个非常重要的判定指标，僵直、运动迟缓、药物引起的“开－关”、异动症服药有效的患者，苍白球毁损术的效果较好；震颤则有所不同，凡是左旋多巴不能完全控制的，采用苍白球＋丘脑Vim核毁损术则手术效果非常满意，启动不能患者手术应该极其慎重，手术的帮助不大。我们不主张同期双侧苍白球毁损术，分期双侧苍白球毁损术也要慎重。     

High‐intensity focused ultrasound for noninvasive functional neurosurgery

Transcranial magnetic resonance (MR)‐guided high‐intensity focused ultrasound (tcMRgHIFU) implies a novel, noninvasive treatment strategy for various brain diseases. Nine patients with chronic neuropathic pain were treated with selective medial thalamotomies. Precisely located thermal ablations of 4mm in diameter were produced at peak temperatures of 51°C to 60°C under continuous visual MR guidance and MR thermometry. The resulting lesions are clearly visible on follow‐up MR imaging. All treatments were well tolerated, without side effects or neurological deficits. This is the first report on successful clinical application of tcMRgHIFU in functional brain disorders, portraying it as safe and reliable for noninvasive neurosurgical interventions. Ann Neurol 2009;66:858–861     

Radiosurgery for epilepsy

Radiosurgery is an emerging therapeutic approach for the treatment of medically intractable epileptogenic foci. A favourable seizure outcome was first reported in studies of the effects of radiosurgery in the treatment of arteriovenous malformations and tumours. Radiosurgery has since been applied to the treatment of complex partial seizures with mesial-temporal-lobe onset. Nearly simultaneously, experimental evidence supporting the usefulness of radiosurgery to improve or abolish seizures has confirmed that stereotactic irradiation can preferentially affect epileptogenic versus normal cortex. Further work is clearly needed, but this technique might become an important approach in the management of mesial-temporal and extratemporal epilepsy, especially if refractory seizures arise from eloquent cortex or surgically challenging regions of brain.     

Clinical application of functional MRI: a strategic tool for neurosurgery

The purpose was to incorporate preoperative functional imaging data into anatomic data of operative microscope for neurosurgical procedures of patients suffering from lesions contiguous to eloquent brain areas. The day before surgery, patients bearing scalp markers underwent fMRI, just before anatomical contrast-enhanced MR images. FMRI data analysis were realised using a t test (p<0.0001). The resulting functional-anatomical images were downloaded onto a surgical neuronavigation computer in order to outline tumoral target and functional areas. At surgery, cortical stimulation has been used to confirm functional data. Functional image-guided surgery of lesions abutting functional cortex can be safely performed.     

Targeting the caudal intralaminar nuclei for functional neurosurgery of movement disorders

The caudal intralaminar nuclei, in particular the Centrum-Medianum Parafascicularis (CM-Pf) nucleus complex, are involved in various functions, particularly in pain processing and in motor control, through their projections to the subthalamic nucleus and their afferents from the pallidum internus (GPi) (or entopeduncular nucleus in the rat). The nociceptive inputs received by the CM-Pf are modulated by the somato-sensory thalamus. The lateral habenula (HbL) receives noxious inputs and has an inhibitory influence on the nigral dopaminergic neurons. CM-Pf and the HbL share comparable response characteristics to noxious inputs and might play comparable, and perhaps complementary, roles in conveying the nociceptive information to the basal ganglia system, thereby modulating motor responses, such as freezing and dyskinesias. The interaction between CM-Pf, HbL, GPi, STN and SNC might provide a new template for high frequency stimulation strategies in the treatment of movement disorders.     

立体定向功能神经外科的发展趋势

功能神经外科疾病范围很广，本以帕金森病（Parkinson's disease)和顽固性疼痛两种疾病的外科治疗为例。探讨立体定向功能神经外科的发展趋势，在帕金森病治疗中，立体定向苍白球切开术得到了重新修正。神经组织移植的热情依然未减，深部脑刺激电极（DBS）治疗又增添新路。在癌痛和慢性疼痛的外科治疗中，阻断痛觉传导径路，DBS和植入吗啡微量泵等方法并存。随着现代影像学引导手术和放射外科的发展，立体定向功能神经外科这一综合学科正进入一个空前活跃的崭新阶段。     

Radiosurgery for arteriovenous malformations

Stereotactic radiosurgery is the term coined by Lars Leksell to describe the application of a single, high dose of radiation to a stereotactically defined target volume. In the 1970s, reports began to appear documenting the successful obliteration of arteriovenous malformations (AVMs) with radiosurgery. When an AVM is treated with radiosurgery, a pathologic process appears to be induced that is similar to the response-to-injury model of atherosclerosis. Radiation injury to the vascular endothelium is believed to induce the proliferation of smooth-muscle cells and the elaboration of extracellular collagen, which leads to progressive stenosis and obliteration of the AVM nidus thereby eliminating the risk of hemorrhage. The advantages of radiosurgery - compared to microsurgical and endovascular treatments - are that it is noninvasive, has minimal risk of acute complications, and is performed as an outpatient procedure requiring no recovery time for the patient. The primary disadvantage of radiosurgery is that cure is not immediate. While thrombosis of the lesion is achieved in the majority of cases, it commonly does not occur until two or three years after treatment. During the interval between radiosurgical treatment and AVM thrombosis, the risk of hemorrhage remains. Another potential disadvantage of radiosurgery is possible long term adverse effects of radiation. Finally, radiosurgery has been shown to be less effective for lesions over 10 cc in volume. For these reasons, selection of the optimal treatment for an AVM is a complex decision requiring the input of experts in endovascular, open surgical, and radiosurgical treatment. In the pages below, we will review the world's literature on radiosurgery for AVMs. Topics reviewed will include the following: radiosurgical technique, radiosurgery results (gamma knife radiosurgery, particle beam radiosurgery, linear accelerator radiosurgery), hemorrhage after radiosurgery, radiation induced complications, repeat radiosurgery, and radiosurgery for other types of vascular malformation.     

癫痫的放射外科

立体定向放射外科治疗难治性癫痫早有报道，具有定位精确，对周围组织损伤小，疗效好，安全、无创等优点。但对致痫灶的定位，照射剂量的选择及机理的研究目前尚无定论。近年来，采用PET、MEG等综合定位，低剂量照射靶区的治疗方法得到肯定。     

新中国功能神经外科学的发展历程及展望

中国的功能神经外科从立体定向手术技术起步,逐渐发展成为独立的功能神经外科学科, 治疗的疾病由帕金森病扩展形成完整的功能神经外科学疾病谱,手术技术也由以神经毁损为主,进步 为神经毁损与神经调控并重。功能神经外科在中国发展迅速,并保持着强劲的发展势头,成为神经外 科领域新兴的亚学科,发展前景广阔。     

神经导航在功能和常规神经外科手术中的初步应用(附32例病例报道)

目的 评价神经导航系统在神经外科手术中的临床价值.方法 2007年2月至10月,我科应用Medtronic公司StealthStation神经导航系统进行手术32例,其中男性11例,女性21例,年龄21~80岁.病变部位:额叶8例,顶叶2例,颞叶3例,枕叶1例,小脑1例,丘脑或脑室内2例,鞍区6例,多发病灶2例.病变性质:帕金森氏病和强迫症各1例,胶质瘤11例,转移瘤2例,脑膜瘤3例,垂体腺瘤4例,蝶鞍旁囊肿1例,海绵状血管瘤1例,脑积水3例.结果 本组2例深部脑刺激(deep brain stimulation,DBS)电极植入患者电极位置符合术前规划,达到手术要求.切除脑肿瘤25例,共29枚病灶;全切除23枚(79.3%)、次全切除6枚(20.7%).病灶邻近功能区的2例患者,1例术后肌力未受影响,1例出现一过性肌力下降,3周后恢复至术前水平.本组未发现应用神经导航系统导致的手术并发症.结论 神经导航系统具有定位准确、动态示踪、微侵袭、安全可靠等特点.神经导航在外科手术中有广泛的使用潜质且有助于提高脑肿瘤的全切除率,降低手术并发症.     

Minimally invasive procedures. Interventional MR image-guided functional neurosurgery

Intraoperative MR imaging techniques have the potential to greatly improve the stereotactic methods used for functional neurosurgery. No longer are neurosurgeons and patients always constrained by uncomfortable head frames and conventional stereotaxy. Accuracy and complication avoidance are improved by intraoperative imaging. Safety of operative machinery and equipment in an MR imaging operative suite is attainable, even with deep brain stimulating electrodes in depth electrodes for epilepsy. Although cost-effectiveness remains to be determined (see article by Kucharczyk et al in this issue), the minor inconveniences of operating within an iMRI environment seem to be significantly outweighed by the benefits.     

Physiological localisation in functional neurosurgery for movement disorders: a simple approach.

Controversy exists between anatomical methods and single cell recording as the preferred approach in target localisation in functional neurosurgery for movement disorders. The controversy centres on accuracy as compared to practicality. We describe a mapping technique of semi-microstimulation utilising threshold measurements which has been used in 66 procedures in 50 subjects. We compared the accuracy of anatomical localisation with the final chosen target using the above technique. We also compared the benefit, the side effects and the surgical complication rate with published data on single cell recording and anatomical localisation. The mean difference in 3-dimensional space between the anatomical target and the physiological target was 6.85 mm (P < 0.0001). A good response was obtained in 80% of procedures. Mortality was 1.5%. The surgical complication rate was 1.5%. Mild side effects, serious side effects, transient side effects and permanent side effects were evident in 4.5%, 10.6%, 6.1% and 9.1% of procedures. These figures compared better than anatomical studies and similar to single cell recording studies. It is concluded that this approach provides both accuracy and simplicity and is recommended as a compromise to the currently available methods.     

立体定向技术和神经调控技术与功能神经外科的现状

随着神经影像学、神经电生理、立体定向以及神经调控技术的广泛临床应用,功能神经外科疾病的诊治水平有了较快发展,手术定位从影像学解剖定位发展到神经电生理学的定位,立体定向设备从立体定向仪发展到神经导航设备,手术入路的设计从手工计算手术轨迹到计算机设计的手术计划系统,手术方式从脑深部核团立体定向毁损术到神经电刺激技术,促进了功能神经外科向纵深发展.     

功能神经外科主要疾病的治疗策略与展望

随着电生理技术、神经影像学、立体定向与神经调控技术的发展,功能神经外科疾病的诊疗范畴不断地深入与扩大,已成为发展最迅速、最有活力以及最具前景的分支学科之一。功能性神经外科疾病主要包括癫痫、运动障碍性疾病、颅神经疾患、痉挛状态、周围神经外科疾病以及顽固性疼痛等。本文主要围绕以上疾病的外科治疗策略和展望作一述评。     

Paradoxes of functional neurosurgery: Clues from basal ganglia recordings

Deep brain stimulation (DBS) can be remarkably effective in treating movement disorders such as Parkinson's disease, dystonia, and essential tremor. Yet these effects remain essentially unexplained, even paradoxical. Equally challenging is the fact that DBS of motor targets in the basal ganglia appears to reverse abnormalities of movement without any obvious deleterious effects on remaining aspects of movement. Here, we explore the extent to which the noisy signal hypothesis might help solve some of these apparent paradoxes. Essentially the hypothesis, first tentatively advanced by Marsden and Obeso (1994), suggests that disease leads to a pattern of basal ganglia activity that disrupts local and distant function and that surgery acts to suppress or override this noisy signal. Critical to the success this theory is that different disease phenotypes are associated with different patterns of noisy signal, and we survey the evidence to support this contention, with specific emphasis on different types of pathological synchronization. However, just as DBS may suppress or override noisy signals in the basal ganglia, it must equally antagonize any remaining physiological functioning in these key motor structures. We argue that the latter effect of DBS becomes manifest when baseline motor performance is relatively preserved, i.e., when pathological activity is limited. Under these circumstances, the deleterious effects of DBS are no longer obscured by its therapeutic actions in suppressing noisy signals. Whether true, oversimplified or simply incorrect, the noisy signal hypothesis has served to focus attention on the detailed character of basal ganglia discharge and its variation with disease and therapy. © 2007 Movement Disorder Society