Selective dorsal rhizotomy for spastic cerebral palsy: a review

Objective The purpose of this report is to review the historical development, current operative techniques, selection criteria, outcomes, and complications of selective dorsal rhizotomy (SDR) for treatment of spastic cerebral palsy (CP). Materials and methods This review is based on a review of literature and personal observations. Results SDR has evolved from the 1960s onwards into a standard neurosurgical procedure for spastic CP. There is much variation in the operative technique among surgeons with respect to the level of exposure, electrophysiological guidance, and extent of rhizotomies. Appropriate selection of patients for SDR requires determination that spasticity, not dystonia, is the major disabling hypertonia and that the lower limbs are maximally involved. Positive outcomes have been well demonstrated in the impairment, functional limitations, and disability dimensions, as per the National Center for Medical Rehabilitation Research Model of Dimensions of the Disabling Process. Complications have been relatively few. Conclusions SDR is the procedure of choice for treatment of spasticity in spastic diplegic CP and in selected children with spastic quadriplegic CP. Optimal selection and outcomes are achieved using a multidisciplinary approach.     

Selective posterior rhizotomy: a long-term follow-up study

Fifty-one spastic children who had undergone selective posterior lumbar rhizotomy between 1981 and 1984 were re-examined to determine whether the gains achieved had persisted and to look at other aspects that had not previously been explored in detail. The reduction of tone was maintained in all cases, while motor function continued to improve in 42 cases. Functional gains were greatest in children operated on under the age of 8, but pleasing results were also achieved in older children. Forty-five children continued to receive physiotherapy, particular attention being paid to building up muscle strength. Sensory disturbances were minimal, and there was no evidence of spinal instability. Post-rhizotomy orthopaedic surgery for fixed-joint contractures generally brought further improvement. Parents and older children were also questioned and almost all were enthusiastic about the outcome. Rhizotomy can be of considerable benefit to spastic children, but great care must be taken in the selection of suitable cases.     

Selective dorsal rhizotomy in cerebral palsy to improve functional abilities: evaluation of criteria for selection

Objectives The aim of this study is to evaluate the effect of selective dorsal rhizotomy (SDR) on functional abilities in a well-defined group of ambulatory children with spastic diplegia.Methods Nine children were selected for SDR (mean age 65 months, range 43–82 months). Gross motor function was measured with the Gross Motor Function Measure (GMFM-88). Self-care was assessed with the Pediatric Evaluation of Disability Inventory (PEDI) and gait pattern was measured with the Edinburgh Visual Gait Score (EGS). There were nine single-case research designs with a 12-month follow-up after surgery.Results After 12 months the mean improvement in the total GMFM-88 scores was 8.8%. On an individual level, all patients improved significantly in comparison with baseline. Functional skills and care-giver assistance measured with the PEDI showed significant improvement. Improvement in gait was also found; in particular, better initial contact and heel-lift resulted in an increased EGS.Conclusion In this well-defined group of ambulatory children SDR had a small but significant positive effect on gross motor function, self-care and gait pattern.     

Outcomes after selective dorsal rhizotomy for spastic cerebral palsy

Object: The purpose of this article was to review the published outcomes after selective dorsal rhizotomy (SDR) for treatment of spastic cerebral palsy. Methods: A literature search identified all articles related to outcomes after SDR. The outcomes were reviewed according to a paradigm developed by the National Center for Medical Rehabilitation Research (NCMRR). The quality of the evidence for each outcome was assessed using Sackett’s criteria and the classification system developed by the Brain Trauma Foundation and the American Association of Neurological Surgeons. Results: There is very strong evidence for benefits of SDR in the impairment domain of the NCMRR classification. SDR has been shown conclusively to decrease lower limb spasticity and increase lower limb range of motion. There is strong, but not as conclusive evidence that SDR has a positive impact in the functional limitation dimension, with improvements in motor function, and in particular the Gross Motor Function Assessment (GMFM). There is a moderate degree of certainty that SDR results in improvements in the disability dimension, as evidenced particularly by improvements in the Functional Independence Measure for Children (WeeFIM) and Pediatric Evaluation of Disability Inventory (PEDI). There is a moderate degree of certainty that SDR results in positive suprasegmental effects, especially related to upper limb function and cognition. There is weak evidence that SDR may reduce the need for orthopedic procedures in patients with spastic cerebral palsy, and the impact on hip subluxation relative to the natural history of this problem is unclear. Conclusions: This information could help to define the role of SDR in the management of the child with spastic cerebral palsy, in the light of alternative therapies, such as intrathecal baclofen and botulinum toxin, which have been introduced more recently. It also reveals the need for further studies, particularly dealing with quality of life and economic impact. Received: 15 May 2000     

脊神经部分切断联合肌腱延长治疗痉挛型脑瘫

目的探讨选择性脊神经后根部分切断术,同期联合肌腱延长术治疗下肢痉挛型脑瘫的方法和疗效。方法下肢痉挛型脑瘫患者23例,选择性脊神经后根部分切断,同期对伴有的下肢肌腱部分挛缩行肌腱延长术治疗。分别于手术前、术后6个月、12个月行神经功能评估。结果所有病例随访12～17个月,平均14个月。术后肌张力明显降低,痉挛及挛缩状态明显缓解,髋、膝、踝关节活动范围明显改善。术后经康复训练,运动能力改善效果明显,有效率81％,无明显手术并发症。结论选择性脊神经后根部分切断术同期联合肌腱延长术治疗下肢痉挛型脑瘫,可有效的改善痉挛状态,纠正肢体部分挛缩畸形,降低患者残障程度,提高患者的生活质量。     

Limited benefit of electrophysiological studies during dorsal rhizotomy

Using a formula for standard deviation and several assumptions, the potential benefit of electrophysiological recording (ER) during dorsal rhizotomy for cerebral palsy is calculated and expressed in a ratio, the electrophysiological recording benefit ratio (ERBR). ERBR is approximately 1.1 in most of the examples, but other factors may reduce this ratio. Severing an additional rootlet appears to be a viable alternative to ER in most of the examples. Advantages of dorsal rhizotomy without ER include reduced expense and operative time. Prospective studies are recommended to evaluate further the benefit of ER during dorsal rhizotomy. If stimulation of dorsal rootlets is abandoned during dorsal rhizotomy, stimulation of whole dorsal and ventral roots may still be necessary to prevent inadvertent severing of motor fibers. © 1994 John & Sons, Inc.     

Selective posterior rhizotomy: experience of 30 cases

The increasing interest in selective posterior rhizotomy for reduction of spasticity in children with cerebral palsy and other neurological disorders comes from the selectivity that this procedure has achieved with intra-operative electromyographic monitoring. Thirty patients were operated on between April 1989 and October 1991. Spasticity was of cerebral origin in 27 cases and secondary to spinal cord lesion in 3 others. A reduction in the abnormally high muscle tone was observed in all cases, mainly in the lower extremities, but also, to a lesser degree, in the upper extremities. All patients showed functional improvements that depended on the individual preoperative condition.Even severely disabled patients with quadriplegia and intellectual impairment, whose spasticity interfered with their daily care, had a significantly improved quality of life after rhizotomy. These patients became much looser, with better swallowing and less drooling, and were much more easily managed by their caretakers. Preliminary results with follow-up from 1 to 30 months indicates that selective posterior rhizotomy is a safe procedure which contributes to significant functional improvement in spastic patients.The clinical aspect of this paper was presented at the XIII Congress of the European Society for Paediatric Neurosurgery, Berlin 1992, and the surgical aspect and results were presented at the XX Annual Meeting of the International Society for Pediatric Neurosurgery, Prague 1992     

Cerebrospinal alterations of immunoreactive dynorphin A after unilateral dorsal rhizotomy in the rat

Possible alterations of immunoreactive dynorphin A (ir-dyn A) were investigated at different levels of the spinal cord and in discrete brain regions of male rats 10, 30 and 60 days after unilateral dorsal rhizotomy, i.e., during the development of deafferentation pain and autotomy behavior that follows afferent nerve interruption. Dorsal rhizotomy caused an increase of spinal ir-dyn A at 10 days in the cervical segment; subsequent assays showed a progressive increase in other spinal regions too. At the last observation, 60 days after rhizotomy, neuropeptide levels were still significantly higher than in sham-lesioned animals in the cervical, thoracic and lumbosacral spinal cord. The spinal ir-dyn A changes were both ipsi- and contralateral to the lesion. No alterations were found in the brainstem and midbrain and a not significant decrease was observed in the hypothalamus. In the striatum and cortex, however, there was a bilateral significant increase 30 days after surgery and a constant and significant elevation was detected in the hippocampus at all three intervals. These data cast additional light on the neurochemical changes caused by the interruption of afferent nerves, followed by development of the deafferentation pain syndrome in laboratory animals and human beings. They also support the concept of central neuroplasticity in pathological pain and indicate that the opioid neuropeptide dynorphin is involved.     

辅加单侧脊神经S2后根选择性切断治疗脑瘫踝痉挛的疗效观察

目的评价脊神经S2后根选择性切断术治疗脑瘫踝痉挛疗效。方法25例痉挛性脑瘫患者均为双下肢受累,对踝痉挛较重的一侧下肢采用L2~S2SPR术,对另一侧踝痉挛相对较轻者采用L2~S1SPR术。术中将各后根分为3~5个小束,采用同心圆电极进行刺激,通过肉眼观察及肌电图记录显示肌肉收缩情况,将肌肉收缩范围明显异常的小束切断。踝痉挛情况按照Ashworth法进行评估,随访16.3±4.9个月,观察疗效并比较两侧肢体踝痉挛改善情况。结果S2后根的切断率为32%。病人术后踝痉挛均明显缓解,行走功能改善,无括约肌功能障碍。手术范围包括S2后根时,该侧踝痉挛改善更佳。结论对踝痉挛严重的脑瘫患者,采用选择性脊神经后根切断术治疗时,手术范围应包括S2后根。     

Predictors for the benefit of selective dorsal rhizotomy

Selective dorsal rhizotomy (SDR) is a spasticity reducing treatment option for children with spastic cerebral palsy. Selection criteria for this procedure are inconclusive to date. Clinical relevance of the achieved functional improvements and side effects like the negative impact on muscle strength are discussed controversially. In this prospective cohort study one and two year results of 54 children with a mean age of 6.9 (±2.9) years at the time of SDR are analyzed with regard to gross motor function and factors affecting the functional benefit. Only ambulatory children who were able to perform a gross motor function measure test (GMFM-88) were included in this study. Additionally, the modified Ashworth scale (MAS), a manual muscle strength test (MFT), and the body mass index (BMI) were evaluated as possible outcome predictors. MAS of hip adductors and hamstrings decreased significantly (p < 0.001) and stayed reduced after two years, while GMFM improved significantly from 79% to 84% 12 months after SDR (p < 0.001) and another 2% between 12 and 24 months (p = 0.002). Muscle strength did improve significantly concerning knee extension (p = 0.008) and ankle dorsiflexion (p = 0.006). The improvement of function correlated moderately with age at surgery and preoperative GMFM and weakly with the standard deviation score of the BMI, the dorsiflexor and plantarflexor strength preoperatively as well as with the reduction of spasticity of the hamstrings and the preoperative spasticity of the adductors and hamstrings. Correctly indicated SDR reduces spasticity and increases motor skills sustainably in children with spastic cerebral palsy corresponding to clinically relevant changes of GMFM without compromising muscular strength. Outcome correlates to GMFM and age rather than to MAS and maximal strength testing. The data of this evaluation suggest that children who benefit the most from SDR are between 4 and 7 years old and have a preoperative GMFM between 65% and 85%.     

辅加双侧S2后根选择性切断治疗脑瘫踝痉挛

目的 对双下肢痉挛伴严重踝痉挛的的27脑瘫患者(A组),行L2～S2选择性脊神经后根切断术(SPR),并与以往一组接受L2～S1SPR的24例患者进行比较(B组),观察踝痉挛改善情况.方法 全麻下行T12～L1椎板切除,显露并确认脊髓圆锥及各脊神经后根.将各后根均匀分为3～5个神经束,对每个神经束进行电刺激,对下肢多组肌肉及肛门括约肌收缩情况进行肌电图监测,切断扩散范围异常的神经束,同时保留刺激后出现明显括约肌收缩的神经小束.结果 A组S2后根的切断比例为32.14%.比较两组患者手术前后踝痉挛改善情况,A组效果好于B组.结论 对踝痉挛症状严重,Ashworth评分≥4的患者,建议SPR的手术范围应包括S2后根,且应在肌电图监测下进行.正确识别S2后根,保护与括约肌功能有关的S2后根小束,对保证疗效,防止并发症具有重要意义.     

Selective posterior rhizotomy for children with cerebral palsy: a 7-year experience

Although selective posterior rhizotomy (SPR) was pioneered as early as 1913, only over the past decade has the procedure gained popular use for the treatment of spasticity in cerebral palsy. The medical knowledge base regarding this procedure is expanding, and surgical techniques continue to be revised. We present our 7 years of experience in treating spastic cerebral palsy using SPR. The aspects of preoperative evaluation used by the multidisciplinary team to determine candidacy are outlined. The surgical procedure is detailed with a particular emphasis on the role of intraoperative nerve root stimulation to aid in selection for rootlet sectioning. Historical nerve stimulation protocols are reviewed and compared to our findings over the years. The functional goals are discussed in the context of the postoperative evaluation and therapies. Specific outcome in relation to joint range of motion, self care tasks, and ambulation is reported. The paper outlines a concise overview of our experiences and will assist the clinician in defining a protocol and expectations for SPR.     

Predictors of poor outcome after selective dorsal rhizotomy in treatment of spastic cerebral palsy

Objectives The purpose of the study was to determine if there are preoperative clinical characteristics that might be predictive of a poor outcome after selective dorsal rhizotomy (SDR) surgery in children with spastic cerebral palsy (CP).Methods A retrospective analysis was performed on 174 children who had undergone SDR from 1983 to 2001. Patients were divided into two groups according to their outcome at approximately 1 year after surgery: acceptable or poor outcome. As predictors of outcome, the factors compared were age at operation, types of CP (diplegia, quadriplegia), history of prematurity, prior lower limb orthopedic surgeries, history of seizures, dystonic limbs, opisthotonic posturing, lumbar hyperlordosis, truncal hypotonia, preoperative ambulatory function, preoperative Gross Motor Function Classification System (GMFCS) scores, and presence of intellectual delay and speech delay.Results Eleven children (6.3%) had a poor outcome. The type of CP (P<0.001) and intellectual delay (P=0.015) were significant predictors of outcome in the univariate regression analysis, but only the type of CP retained significant predictive power in the multivariate analysis.Conclusion These data suggest that preoperative diagnosis is the strongest predictor of outcome after SDR. Intellectual delay demonstrated predictive power only in the univariate model, suggesting that it might have some prognostic value but less than the diagnosis.     

Incidence of spinal deformity in children after multiple level laminectomy for selective posterior rhizotomy

Fifty-five children with cerebral palsy had multiple-level laminectomies for selective posterior rhizotomies for the relief of spasticity. They were followed up clinically and radiologically to assess their spinal stability and the possible development of post-laminectomy deformity of the spine. The majority of the deformities found were related to cerebral palsy and did not appear to be due to the laminectomy: 16% had scoliosis, 5% kyphosis, 7% lordosis, and 9% spondylolysis/spondylolisthesis. Spondylolysis is the only abnormality that appeared to be more common in this group than in children with cerebral palsy.     

Continuous epidural morphine/butorphanol infusion following selective dorsal rhizotomy in children

The authors prospectively evaluated 15 patients who had undergone selective dorsal rhizotomy who were given a continuous morphine/butorphanol infusion, to determine whether variations in the postoperative pain control and side effects seen using a bolus technique could be reduced. Patients had an epidural catheter placed at the end of the operative procedure through which 50–60 g/kg preservative-free morphine and 15–20 g/kg butorphanol was administered. A continuous epidural infusion of 5 g/kg h morphine and 1.2 g/kg h butorphanol was then initiated. Postoperatively, mean pain scores were excellent. No patient required additional systemic analgesics during the 72-h investigational period. A low incidence of nausea, and no vomiting, pruritus, or respiratory depression was reported by the cohort. All patients maintained oxygen saturations above 95%. This indicates that the use of a continuous epidural infusion provides excellent pain control, decreases the occurrence of untoward side effects, and allows the early initiation of occupational and physical therapy postoperatively.     

Two cases of improvement of smooth pursuit eye movements after selective posterior rhizotomy

Objective  Selective posterior rhizotomy (SPR) represents a standard neurosurgical approach in the treatment of spasticity in children with cerebral palsy (CP). Beside the reduction of spasticity in lower limbs, SPR may have suprasegmental effects, considerably above the surgery site. In this communication, we report on the improvement of smooth pursuit eye movements (SPEM) in two children after SPR. Material and methods  Four children with CP underwent SPR. Eye movements were registered by infrared video-oculography before and after the surgery. Results  The analysis of SPEM showed the improvement of the correlation coefficient of the eye response to the stimulus after SPR in two subjects. Improvement of SPEM performance was largely due to suppression of spontaneous fixation nystagmus. Conclusion  SPR may lead to the improvement of SPEM in children with CP. The influence of SPEM improvement on quality of life in a group of severely disabled nonambulant children with CP remains to be assessed.     

Gentle dorsal root retraction and dissection can cause areflexia: implications for intraoperative monitoring during "selective" partial dorsal rhizotomy

During partial dorsal rhizotomy (PDR), intraoperative dorsal rootlet stimulation often evokes nonreflex, rather than reflex, motor responses that are due to costimulation of adjacent ventral roots. Intraoperative areflexia typically predicts that motor responses evoked by dorsal rootlet stimulation are nonreflexive. The cause of areflexia during PDR is in part due to anesthesia, but other mechanisms are likely to play a role as well. In this study of three consecutive patients undergoing lumbosacral neurosurgery, soleus H-reflexes evoked by tibial nerve stimulation at the popliteal fossa were found to suddenly decline in amplitude following retraction and gentle dissection of the S-1 dorsal root. In one areflexic patient, dorsal rootlet stimulation proximal to the main site of dissection evoked soleus H-reflexes, although they could not be evoked by tibial nerve stimulation. We conclude that the gentle retraction and dissection of dorsal rootlets that occurs during PDR can induce conduction block of reflex afferents. High-intensity dorsal rootlet stimulation distal to the site of conduction block may then evoke not reflex responses, but rather nonreflex motor responses, due to the costimulation of adjacent ventral roots.     

H reflex studies in cerebral palsy patients undergoing partial dorsal rhizotomy

H reflex studies were performed in ten spastic children with cerebral palsy who underwent partial dorsal rhizotomy (PDR). Under anesthesia prior to PDR, H reflex amplitude evoked by percutaneous peripheral nerve stimulation gradually declined in all patients and became unobtainable in five. Motor responses could still be evoked by apparent dorsal root stimulation in these five, but since it was shown that they were M responses and not reflexes, PDR was performed randomly. In the other five patients, in whom H reflexes were still evokable, dorsal root stimulation evoked motor responses which were true reflex responses, and PDR was performed “selectively.” Compared to preoperative values, postoperative H_max/M_max ratios declined, but no more so in selective than in random PDR. We conclude that current intraoperative methods for selection of “abnormal” dorsal rootlets for section may be invalid and may have no bearing on successful outcome, since spasticity improves even with random PDR. © 1994 John & Sons, Inc.     

术中电生理监测在选择性脊神经后根切断术治疗痉挛型脑瘫中的应用

目的探讨术中肌电图及脑电双频指数监测对选择性脊神经后根切断术(SPR)治疗痉挛型脑瘫的指导意义。方法对27例痉挛型脑瘫行SPR术,术中利用脑电双频(BIS)指数监测麻醉深度,将L2-S2各后根均匀分为3-5个神经束后行电刺激,并对下肢多组肌肉及肛门括约肌收缩情况进行肌电图(EMG)监测。将电刺激后肌肉反应情况分为0～4分,3-4分为异常。切断扩散范围异常的神经束,保留出现明显括约肌收缩的神经束。结果BIS指数在60～80时,电刺激强度适宜,反应适中,生命体征平稳,适宜手术操作。各后根的切断比例为44.4%-54.2%,所有患者术后痉挛均有改善,无大小便功能障碍及其他并发症。结论BIS指数监测对控制麻醉深度,维持麻醉平稳具有重要作用。术中电刺激是施行脊神经后根选择性切断的合理方法,电刺激后反应为Ⅲ-Ⅳ级者为异常小束,可根据具体情况予以切断。术中EMG监测对提高手术疗效,保护括约肌功能具有重要意义。     

Functional posterior rhizotomy: the Tokyo experience

Purpose The author describes the history of functional posterior rhizotomy (FPR), the surgical procedure currently used, and the results together with its future perspective in Japan. The modern form of FPR was introduced to Japan in 1995, and the first surgery was carried out in 1996. Despite initial resistance from orthopedic surgeons, the procedure has eventually gained wide recognition in the country. Materials and Methods The author has operated on 98 patients (60 boys and 38 girls, aged from 2 to 19 years old) by the end of 2006. Most patients were mild to severely disabled children with spastic hypertonia because of cerebral palsy and other diseases. The surgical procedure used is based on the Peacock’s procedure with some modification for the mildly disabled children whose spasticity was predominantly the muscles of the ankle joint. Intraoperative neurophysiology was an indispensable tool for preserving urogenital function and for judging which root/rootlet to be cut. Results Seventeen to 83% of the root/rootlets were found to be abnormal and were cut, clearly correlating with the degree of disability. However, there was a wide difference in the cutting rate, even in children with the same degree of disability. The result of surgery in this group of patients was the same as in previously published data. Twenty out of 51 patients (39%) followed for more than a year at the current institute showed improved locomotion after FPR. Thirty patients (59%) demonstrated suprasegmental effects after FPR. Conclusion The role of FPR will grow in importance as a treatment for spasticity in Japan in the future.