大鼠腓肠肌神经终支肌电H反射的实验研究

在治疗痉挛性脑瘫时,选择性脊神经后根切断术(SPR)术中肌电监测的方法是用刺激电极钩住每个后根小束,以肌电图仪电刺激器刺激各小束诱发痉挛。在肌电监测下测各小束诱发痉挛的阈值,以便选择阈值低的后根小束加以切断。Cohen等[1]采用较为简便的直接电刺激神经小束,通过观察测肢动收缩来确定其电刺激阈值。刘小林等[2]在行周围神经干内选择性神经切断实验研究后,建议使用导致肌肉出现可视收缩反射的神经小束电刺激强度阈值作为指标。无论选择何种方法,目的都是为在神经束中能更准确地选择所代表Ia类纤维的部分。根据牵张反射产生的原理。用…     

高选择性腰脊神经后根定量切断治疗痉挛性脑瘫

目的:评定高选择性腰脊神经后根定量切断治疗痉挛性脑瘫的临床疗效,为痉挛性脑瘫患者临床治疗提供依据。方法:本组198例,男103例,女95例;年龄4~20岁。按脑瘫诊断分型标准:双下肢痉挛型120例,四肢痉挛型62例,混合型16例。手术采取限制性椎板切除,神经阈值测定仪测量腰脊神经后根的兴奋性后,行腰脊神经后根的高选择性定量切断。结果:194例下肢痉挛消除,按Ash-worth肌张力标准,下肢肌张力平均下降3·0级,12例上肢肌张力平均下降1·1级,眼斜视、流涎及语言障碍等伴随症状也有改善。根据疗效评定标准:优172例,良18例,一般8例。结论:高选择性腰脊神经后根切断术能够有效地解除下肢痉挛,降低下肢肌张力。定量法使腰脊神经后根的切断量更为精确,提高了疗效。     

小儿脑瘫选择性脊神经后根切断术的麻醉

选择性脊神经后根切断术（selective posterior rhizotomy，SPR）是治疗痉挛性脑瘫（spastic cerebral palsy，SCP）的有效方法，其选择性表现为需在麻醉状态下对相应的脊神经后根进行电刺激，根据肌肉收缩反应确定异常神经后根小束后将其切断。在此阶段，麻醉深度的控制对电刺激时的肌肉反应有重要影响，也决定了手术治疗效果。因此SPR对麻醉管理提出了较高要求。     

选择性脊神经后根切断术中神经小束电刺激阈值的临床分析

研究选择性脊神经后根切断术（ｓｅｌｅｃｔｉｖｅｐｏｓｔｅｒｉｏｒｒｈｉｚｏｔｏｍｙ，ＳＰＲ）中，电刺激阈值观察与肢动收缩直接观察法区别肌梭传入纤维的可行性，并探索神经小束的电刺激阈值与痉挛的临床关系。对３６例ＳＰＲ中使用电刺激阈值法所取得各脊神经后根内的神经小束的电刺激阈值进行统计学处理，分析彼此间的联系和可能的临床意义。结果表明：在ＳＰＲ术中所切断的神经小束与保留束的电刺激阈值有高度显著性差异，每一神经根内切断神经小束与保留神经小束的电刺激阈值亦有显著差异。证明，用脊神经后根内神经小束的电刺激阈值方法来施行ＳＰＲ简单、可靠，并符合不同性质神经小束的电刺激兴奋特点     

选择性脊神经后根切断（SPR）治疗下肢痉挛性脑瘫

目的：探讨选择性脊神经后根切断术（SPR）治疗下肢痉挛性脑瘫疗效。方法：对38例下肢痉挛性脑瘫,将L2－S1各神经后根分开,分为5－8个亚束,用神经阈值探测仪检测,将阈值低的亚束切断1cm,切除比例据病情定。结果：术后肌张力平均下降Ⅲ级,关节畸形平均减轻5－10,腱反射消失30例,正常8例,病理征全部消失,未发现严重并发症。结论：选择性脊神经后根切断术（SPR）是治疗下肢痉挛性的有效方法。     

选择性腰骶神经后根切断术治疗痉挛型脑瘫82例随访观察

[目的]探讨选择性脊神经后根切断术（SPR）治疗痉挛型脑瘫方法和临床疗效。[方法]自1999年采用SPR手术治疗82例脑瘫患者，其中男53例，女29例；年龄3～19岁，平均8岁。根据术前判断下肢痉挛的范围并参考痉挛所造成的下肢主要畸形，施行SPR手术。[结果]通过6～60个月的随访观察，所有病例肌张力均较术前下降Ⅰ～Ⅲ级，下肢痉挛均有不同程度的缓解或消失。[结论]选择性脊神经后根切断术能有效地解除肢体痉挛，改善肢体功能。     

改良式选择性脊神经后根切断术十例报告

目的 探索选择性脊神经后根切断术（ＳＰＲ）改进的方法,以期减少手术创伤和对脊柱后柱的破坏,减少术后远期并发症发生的危险。方法 利用磁共振定位,切除一个半椎板,在圆锥部马尾发出处鉴别分离出Ｌ２￣Ｓ１神经后根,根据电刺激阈值选择性切断部分神经小束,以缓解小儿痉挛性脑瘫人的痉挛状态。手术的关键在于对脊神经后根的节段鉴别。 结果 术后随访４￣６个月,单纯痉挛型９例病人肌张力均下降、交叉腿解除,关节活动度增     

选择性脊神经后根切断术治疗痉挛性下肢瘫痪初步报告

脑性瘫系先天或后天原因致大脑损害而引起的肢体运动障碍,其中痉挛性瘫痪约占60～70％。以往常规手术治疗方法效果多不确切及巩固,极易复发。本世纪初Foerster用切断脊神经后根的方法解除下肢痉挛但感觉功能亦丧失。70年代,Fasano创用选择性腰骶神经后根切断术(selective posteriorrhizotomy SPR)治疗痉挛性脑瘫,通过电刺     

脑瘫SPR术后遗留髋内收畸形的个体化手术治疗

目的评价痉挛型脑瘫患者腰骶段选择性脊神经后根切断术（SPR）后遗留髋内收畸形的手术方案选择及临床疗效。方法回顾性分析2008年8月至2012年8月北京中医药大学东直门医院收治的126例脑瘫SPR术后遗留髋内收畸形患者的临床资料,根据肌肉挛缩的范围和畸形程度采取不同的手术方式,包括长收肌、短收肌、股薄肌、髂腰肌、闭孔神经前支切断术等。观察患者术后髋外展角度及畸形矫正情况。结果 126例患者随访14~38个月（平均22个月）。术后髋内收畸形均较术前有明显改善,其中术后髋外展角度≥30°118例、20°~30°8例,缓解率100%（126/126）,满意率93.6%（118/126）。未出现下肢感觉障碍、髋外展或外旋畸形。结论对于脑瘫SPR术后遗留的髋内收畸形,根据个体情况不同,采用肌肉切断松解、闭孔神经前支切断术等个体化治疗方案,可取到满意的临床疗效。     

胫神经肌支选择性阻断术治疗脑瘫肌痉挛性垂足

脑瘫后遗症的症状和体征多种多样,治疗方法繁多。近年来由于选择性脊神经后根切除术(SPR)手术的开展,使重型脑瘫的治疗有了突破性进展,并得到了较好的手术效果[1,2]。但是,在实行SPR手术的实践中,我们也意识到了SPR手术对脊椎稳定性的干扰较大,在选择性切断各腰骶神经根后根时切断比例也不易准确掌握,有一些在SPR手术后尽管肌张力明显降低,肌痉挛得到缓解或改善,踝震挛消失,下肢尤其是踝关节稳定性明显好转。但是,术后肌力也有一定程度降低,造成下肢无力、腿软甚至容易摔倒;其中一些经过术后体疗和功能训练得以矫正,但仍有部分不能得到…     

Reliability of intraoperative electrophysiological monitoring in selective posterior rhizotomy.

OBJECT: Selective posterior rhizotomy is a well-established treatment for spasticity associated with cerebral palsy. At most medical centers, responses of dorsal rootlets to electrical stimulation are used to determine ablation sites; however, there has been some controversy regarding the reliability of intraoperative stimulation. The authors analyzed data obtained from the McGill Rhizotomy Database to determine whether motor responses to dorsal root stimulation were reproducible. METHODS: A series of 77 patients underwent selective dorsal rhizotomy at a single medical center. The dorsal roots from L-2 to S-2 were stimulated to determine the threshold amplitude. The roots were then stimulated at 2 to 4 times the highest threshold with a 1-second 50-Hz train. A second stimulation run of the entire dorsal root was performed before it was divided into rootlets. Rootlets were individually stimulated and sectioned according to the extent of abnormal electrophysiological propagation. Motor responses were recorded by electromyography and were also assessed by a physiotherapist, and grades of 0 to 4+ were assigned. The difference in grades between the first and second stimulation trains was determined for 752 roots. Statistical analysis demonstrated a clear consistency in motor responses between the two stimulation runs, both in the electromyographic readings and the physiotherapist's assessment. More than 93% of dorsal roots had either no change or a difference of only one grade between the two trials. Furthermore, the vast majority of dorsal roots assigned a grade of 4+ at the first trial maintained the same maximally abnormal electrophysiological response during the second stimulation run. CONCLUSIONS: This study indicates that currently used techniques are reproducible and reliable for selection of abnormal rootlets. Intraoperative electrophysiological stimulation can be valuable in achieving a balance between elimination of spasticity and preservation of underlying strength.     

How selective is selective posterior rhizotomy?

Although selective posterior rhizotomy has become an increasingly utilized surgical treatment for spasticity, the procedure is unstandardized and is performed differently at various medical centers. Most surgeons use some form of direct dorsal rootlet stimulation with intraoperative multichannel electromyographic response monitoring. Electrophysiological monitoring offers the theoretical advantage of identifying pathologic reflex circuits for interruption while preserving those pathways that are "normal." However, the monitoring technique most commonly used has not been critically evaluated and, therefore, its value remains uncertain. In 22 selective posterior rhizotomy procedures performed for spastic cerebral palsy, the authors were unable to identify a single electromyographic response that could be called normal by presently accepted criteria. Dorsal rootlets were chosen for division on the basis of relative degrees of abnormality. Intraoperative electromyographic monitoring of a nonspastic patient produced tracings suggestive of spasticity by presently accepted criteria. These discrepancies suggest that current electrophysiological monitoring in selective posterior rhizotomy should be reevaluated.     

Limited selective posterior rhizotomy for the treatment of spasticity secondary to infantile cerebral palsy: a preliminary report

A limited selective posterior rhizotomy was performed on 30 children suffering from spasticity secondary to infantile cerebral palsy. As opposed to standard techniques that stimulate and divide the dorsal rootlets from L2 to S1, we dissected L4, L5, and S1 dorsal roots through an L5 to S1 laminectomy. Eight to 12 rootlets from each root were electrically stimulated with two unipolar electrodes (pulse width, 50 microseconds; 10-50 V). The muscle responses were observed visually and registered by electromyography. Those rootlets associated with an abnormal motor response as evidenced by sustained muscular contraction or by prolonged electromyographic response were divided. Spasticity was scored from 0 to +. The muscular groups assessed were those involved in the flexion of the shoulder, elbow and wrist in the upper limbs, and those involved in flexion and adduction of the hip, flexion of the leg, and plantar flexion in the lower limbs. The patients were assessed 1 week before and 6 months after the operation. Reduction of spasticity was observed in all the muscular groups, and all the patients presented functional improvement of motor abilities. These preliminary results indicate that a limited procedure that reduces the extension of the laminectomy and the length of the operation could be effective for treating spasticity secondary to infantile cerebral palsy.     

Does ketamine affect intraoperative electrophysiological monitoring in children undergoing selective posterior rhizotomy?

Objective: Direct dorsal rootlet stimulation with intraoperative electrophysiological monitoring is an adjunct to clinical evaluation during selective posterior rhizotomy. The purpose of this study was to evaluate the impact of ketamine on intraoperative electrophysiological monitoring during selective posterior rhizotomy. Specifically, we sought to determine if low dose ketamine given as part of the anesthesia was associated with changes in intraoperative electrophysiological monitoring in patients who underwent selective posterior rhizotomy. Methods: A retrospective cohort study was conducted using anesthetic records and electrophysiological records of 32 children who had intraoperative electrophysiological monitoring during selective posterior rhizotomy under general anesthesia. Administration and dosage of ketamine preceding the stimulation of dorsal roots was determined from the anesthetic record. A pediatric neurologist, blinded to patient, and to ketamine exposure, evaluated different electrophysiological criteria. Results: Eight children received ketamine and 24 did not receive it. The mean average dose of ketamine was 0.18 mg·kg^?1 (sd : 0.04). We did not find any statistically significant difference in intraoperative electrophysiological response between the ketamine and the control groups. However, we noted some trends: Administration of ketamine preceding the stimulation of dorsal roots was associated with a lower maximal threshold (2.7 mA vs 3.5 mA, P = 0.663) and root thresholds compared with children who did not receive ketamine. In addition, the train response following delivery of the suprastimulation tended to last longer with the presence of ketamine. Conclusions: Administration of low dose ketamine preceding the stimulation of dorsal roots during selective posterior rhizotomy might be associated with lower maximal thresholds and a more sustained train response following stimulation. Physicians should be aware of this finding in order to avoid misinterpreting intraoperative electrophysiological monitoring.     

Nerve rootlets to be sectioned for spasticity resolution in selective dorsal rhizotomy

BACKGROUND: The goal of this study is to confirm the efficacy of the protocol for selective dorsal rhizotomy (SDR). In this protocol, rootlets to be sectioned are selected by palpable responses elicited by intraoperative electrical stimulation, without detailed electromyographic classifications. METHODS: Thirty-six children with spasticity due to cerebral palsy underwent SDR according to our protocol. Priority was given to sectioning rootlets that showed palpable clonic or bilateral responses, which were considered abnormal, over sectioning rootlets that merely had hyperactive responses to intraoperative stimulation. The results of intraoperative monitoring and sectioning amount were analyzed by physical evaluation. RESULTS: Significant improvements were obtained in passive range of motion and muscle tone of the lower extremities. The total percentages of rootlets with abnormal and hyperactive responses at L3 and S1 were bilaterally correlated with preoperative spasticity of the hip adductors and the plantar flexors, respectively. When rootlets with hyperactive responses were excluded from the correlation analysis, no bilateral correlation was observed. From the correlation analyses between the improvement in the physical evaluation and the amount of nerve sectioned, it was concluded that a greater improvement in muscle tone in all examined muscles, except the hamstrings, could be obtained if larger amounts of nerve roots were sectioned. CONCLUSION: The number of rootlets with palpable abnormal and hyperactive responses elicited by intraoperative stimulation reflects the preoperative spasticity of multiple muscles. This implies that only selecting rootlets with palpable responses can be reliable. Because more sectioning leads to better spasticity resolution, our protocol should be reviewed to increase the percentage of rootlets sectioned with hyperactive responses, especially for innervated levels of severely affected muscles.     

Histological differences between rootlets sectioned during selective posterior rhizotomy by two surgical techniques

During selective posterior rhizotomy, for the treatment of spasticity in infantile cerebral palsy, the rootlets to be divided are chosen by the type of electromyographic response elicited by intraoperative electrical stimulation. Two different surgical techniques were used for exposing the lumbar roots. The first approach was to expose the conus medullaris through a T 12-L 1 laminectomy, while the other approach to the dorsal roots was distally in the cauda equina through a L 2-L 3 to S1 laminectomy. Although the clinical results obtained with either of them are not very different, there is anatomical evidence that suggests that the histological structure of the divided rootlets may be different in the two techniques. We designed our study to determine of a significant difference in the number of large myelinated fibers was found between rootlets divided close to the conus medullaris and those divided distally in the cauda equina. Two groups of five children with spasticity secondary to cerebral palsy where randomly designed to be operated upon by one of the techniques. The divided rootlets were processed with standard histological techniques and the large myelinated fibers were counted on enlarged (40 x) photomicrograph of the rootlet. A significantly (p less than 0.001) larger number of large myelinated axons was found in the rootlets dissected and divided close to the conus medullaris.     

Selective posterior rhizotomy for lower extremity spasticity: how much and which of the posterior rootlets should be cut?

BACKGROUND: It is well known that selective posterior rhizotomy is effective for relieving spasticity associated with cerebral palsy. However, there is significant variation between surgeons in terms of how much and which of the posterior rootlets should be cut for the improvement of ambulatory function without causing adverse effects. METHODS: The study population was composed of 200 CP patients who underwent SPR more than 1 year before this study. The children were divided into 4 groups (Group A had their L1-S2 roots cut, Group B had the L2-S2 roots cut, Group C had the L2-S1 roots cut, and Group D had the L2-S1 roots and the unilateral S2 root cut). We assessed lower limb spasticity, passive range of motion, ambulatory function, and gait pattern in each group. RESULTS: Inclusion of L1 and S2 in the lesioning process of SPR was more effective at relieving spasticity in terms of hip adduction and ankle dorsiflexion respectively and improving ambulatory function (p < 0.01). Although lesioning of S2 carried a greater risk of urinary dysfunction, resection of less than 50% of S2 significantly improved ambulatory function without urinary complications (p < 0.01). Unilateral lesioning of S2 was an alternative option in selected cases with different amounts of spasticity in the ankles for the same purpose. CONCLUSIONS: We propose that L1 and S2 roots should be included in the lesioning process of SPR for effective improvement of gross motor function, but that resection of these roots should be less than 50% to prevent complications.     

Selective posterior rhizotomy for spastic cerebral palsy. A review

Selective posterior rhizotomy (SPR) is a neurosurgical procedure designed to alleviate spasticity in cerebral palsy. SPR depends on intraoperative monitoring of the electromyogram in conjunction with a careful preoperative assessment prior to the division of certain posterior nerve rootlets within the spinal canal. SPR is important to orthopedists, who are frequently called on to evaluate spastic patients. An outline of the physiology and clinical background of SPR is essential for an understanding of present efforts to alleviate spasticity.     

Limited (L4-S1, L5-S1) Selective Dorsal Rhizotomy for Reducing Spasticity in Cerebral Palsy

Summary  Selective posterior rhizotomy is effective for relieving spasticity associated with cerebral palsy. In current techniques dorsal roots from L1/L2 to S1/S2 are selectively divided. With transoperative electromyography (EMG) significant sensory loss has been prevented, but postoperative hypotonia following excessive reduction of the fusimotor drive is still of concern for surgeons and therapists. To decrease the volume of deafferentiated rootlets we proposed a limited selective posterior rhizotomy (LPSR) that limits the extent of the surgery to three (L4-S1) or two (L5-S1) dorsal roots. We present the results of two group of spastic children; group 1 (n=59, 32 quadriplegic and 27 diplegic) who had a L4-S1 LPSR. and group 2 (n=12) in whom L5 and S1 were selectively rhizotomized. Posture, passive movilization, range of joint movement, and muscle tone in hip flexors, adductors, leg flexors and plantar flexors were graded according to the method proposed by Sindou and Jeanmonod. In all groups there was a significant reduction of the mentioned parameters (Friedman test p<0.001) at 6, 12 and 18 months after surgery. The preoperative and postoperative ability to ambulate was classified into five grades. In all groups there was a significant (χ² between p<0.01 and p<0.001) improvement in the quality of their gait. A third of the patients achieved some form of independent ambulation. Our results suggest that extensive selective deafferentation of the lower limbs is not an absolute requisite for reducing muscle tone or achieving functional improvement in spastic children.     

Dorsal selective rhizotomy through a limited exposure of the cauda equina at L-1. Technical note

The technique of the dorsal selective rhizotomy as originally developed by Professor Fasano and by the author is described. The rhizotomy is performed through a one-level laminectomy at L-1. Exposure of the conus medullaris and the cauda equina at this level is adequate to thoroughly assess the reflex electrical response to stimulation of the lumbosacral roots and to section the selected roots/rootlets. This approach, based on over 100 surgical procedures, obviates the need for an extensive laminectomy in a growing child without compromising the clinical results.