History and evolution of surgical treatment for spasticity: a journey from neurotomy to selective dorsal rhizotomy.

The evolution of neurosurgical approaches to spasticity spans centuries, marked by key milestones and innovative practitioners. Probable ancient descriptions of spasmodic conditions were first classified as spasticity in the 19th century through the interventions of Dr. William John Little on patients with cerebral palsy. The late 19th century witnessed pioneering efforts by surgeons such as Dr. Charles Loomis Dana, who explored neurotomies, and Dr. Charles Sherrington, who proposed dorsal rhizotomy to address spasticity. Dorsal rhizotomy rose to prominence under the expertise of Dr. Otfrid Foerster but saw a decline in the 1920s due to emerging alternative procedures and associated complications. The mid-20th century saw a shift toward myelotomy but the revival of dorsal rhizotomy under Dr. Claude Gros' selective approach and Dr. Marc Sindou's dorsal root entry zone (DREZ) lesioning. In the late 1970s, Dr. Victor Fasano introduced functional dorsal rhizotomy, incorporating electrophysiological evaluations. Dr. Warwick Peacock and Dr. Leila Arens further modified selective dorsal rhizotomy, focusing on approaches at the cauda equina level. Later, baclofen delivered intrathecally via an implanted programmable pump emerged as a promising alternative around the late 1980s, pioneered by Richard Penn and Jeffrey Kroin and then led by A. Leland Albright. Moreover, intraventricular baclofen has also been tried in this matter. The evolution of these neurosurgical interventions highlights the dynamic nature of medical progress, with each era building upon and refining the work of significant individuals, ultimately contributing to successful outcomes in the management of spasticity.

Case-based explanation of standard work tools for selective dorsal rhizotomy for cerebral palsy.

OBJECTIVE: Spasticity is a challenging feature of cerebral palsy (CP) that may be managed with selective dorsal rhizotomy (SDR). Although standard work tools (SWTs) have recently been utilized to inform a standard of care for neurosurgical procedures, no SWTs for SDR have been previously described. The authors present the multidisciplinary approach SWTs for SDR used at their institutions to promote consistency in the field and minimize complication rates. METHODS: A multidisciplinary approach was used to define all steps in the SDR pathway. Preoperative, intraoperative, and postoperative workflows were synthesized, with specific efforts to improve mobility through inpatient rehabilitation and minimize infection. RESULTS: The SWTs have been implemented at two institutions for 7 years. An illustrative case of a patient aged 3 years 10 months with a history of premature birth at 29 weeks, spastic-diplegic CP, right-sided periventricular leukomalacia, and developmental delay who underwent L2-S1 SDR is presented. CONCLUSIONS: The authors detail SWTs for SDR developed by a multidisciplinary team with specific steps at all points in the patient pathway. The illustrative case emphasizes that SWTs may help ensure the safety of SDR while maximizing its long-term efficacy for individuals with CP.

Palliative single-level selective dorsal rhizotomy for children with spastic cerebral palsy Gross Motor Function Classification System level IV and V: a case series and systematic review of the literature.

OBJECTIVE: Single-level selective dorsal rhizotomy (SDR), typically indicated for ambulatory patients, is a controversial topic for severe spastic cerebral palsy (CP) with Gross Motor Function Classification System (GMFCS) level IV or V. The objective of this case series and systematic literature review was to outline the indication and outcome of palliative SDR for nonambulatory patients with CP and GMFCS level IV and V, focusing on improvement of spasticity and of patient and caregiver reported quality of life assessment. METHODS: A retrospective case series of patients with CP and GMFCS level IV or V who underwent single-level SDR at the authors' institution is presented. Furthermore, two databases (PubMed and Embase) were searched and a systematic review with a search string based on the terms "selective dorsal rhizotomy," "cerebral palsy," and "outcome" was conducted. The primary outcome was the reduction of spasticity based on the modified Ashworth scale (MAS). Secondary outcomes were change on the Gross Motor Function Measure-66 (GMFM-66), evaluation of patient-reported outcome measures (PROMs), surgical morbidity, and mortality. RESULTS: Eleven consecutive children under the age of 25 years undergoing palliative single-level SDR were included. All patients showed a reduction in MAS score (mean 1.09 ± 0.66 points) and no surgical morbidity and mortality occurred. For the systematic review results from our case series, in addition to 4 reports, 274 total patients were included. Reduction of spasticity based on MAS score was noted in all studies (mean range 1.09-3.2 points). Furthermore, in 2 studies spasticity of the upper extremities showed a MAS score reduction as well (range 1.7-2.8 points). The GMFM-66 score improved in 72% of the patients, while bladder function improved in 78% of the patients. Based on the PROMs, 92% of the patients/caregivers were satisfied with the outcome and their quality of life after the procedure. Two wound infections (2.7%) and one CSF leak (1.3%) occurred, while no surgery-related deaths were described. CONCLUSIONS: This analysis showed an improvement in spasticity, daily care, and comfort for patients with CP and GMFCS levels IV and V. Larger cohorts analyzing the outcome of palliative single-level SDR, based on the MAS, GMFM-66, and PROMs, are still needed and should be the focus of future studies. Systematic review registration no.: CRD42024495762 (https://www.crd.york.ac.uk/prospero/).

Spinal catheter revision in pediatric intrathecal baclofen pumps: risk factors and postoperative outcomes.

OBJECTIVE: Intrathecal baclofen (ITB) pumps are commonly used in pediatric patients with cerebral palsy (CP) and medically refractory spasticity. However, catheter malfunction and associated risk factors are not well understood. The aim of this study was to examine potential risk factors for spinal catheter malfunction and characterize postoperative follow-up to understand the clinical consequences. METHODS: Patients who received ITB pump replacement or revision at Boston Children's Hospital between 2010 and 2023 were retrospectively reviewed. The spinal catheter revision cohort (SCRC) included patients whose spinal catheter was occluded requiring lumbar catheter revision. The second cohort included abdominal pump replacements only (APRC). Between-group comparisons and multivariable regression identified factors associated with catheter revision and postoperative outcomes. RESULTS: Forty-one (33.6%) patients underwent spinal catheter revision and were compared with 81 patients (66.4%) who underwent abdominal pump replacement only. Younger age at surgery and an elevated preoperative lower-extremity modified Ashworth scale grade were associated with spinal catheter revision (p < 0.05). Catheter model type, tip location, and history of spinal fusion were not associated with obstruction. Postoperatively, SCRC patients experienced a higher rate of infection (17.1%) relative to APRC patients (0%) within 30 days from their ITB pump replacement procedure (p < 0.05) and greater likelihood of subsequent ITB system removal compared with the APRC (24.4% vs 7.4%, p < 0.05). Although not differing preoperatively, SCRC patients had lower postoperative ITB doses when compared with the APRC group (median dose 143 vs 350 µg/day, p < 0.05) at hospital discharge and remained statistically different at the 6-month and 1-year follow-ups (p < 0.05). There were no postoperative differences in baclofen overdose, withdrawal, or median number of hospital readmissions within 30 days. Overall, 31.7% of spinal catheter revisions were unanticipated by the clinical team at time of surgery. CONCLUSIONS: Younger age at surgery and increased preoperative lower-extremity tone may be risk factors for catheter obstruction, resulting in a higher rate of postoperative infection and subsequent ITB pump removal compared with pump replacement alone. Spinal catheter occlusion can complicate revision or replacement procedures, especially when unanticipated. Routine clinical assessment may be inadequate for diagnosing insidious catheter malfunction. Catheter occlusion deserves further study, and routine assessment of catheter patency may be warranted to prevent suboptimal tone therapy.

Evaluation of the long-term effect of selective tibial neurotomy for the treatment of spastic foot using a personal goal-centered approach.

OBJECTIVE: The objective of this study was to evaluate the long-term effectiveness of selective tibial neurotomy (STN) for the treatment of the spastic foot using a goal-centered approach. METHODS: Between 2011 and 2018, adult patients with a spastic foot (regardless of etiology) who received STN followed by a rehabilitation program were included. The primary outcome was the achievement of individual goals defined preoperatively (T0) and compared at 1-year (T1) and 5-year (T5) follow-up by using the Goal Attainment Scaling methodology (T-score). The secondary outcomes were the presence of spastic deformities (equinus, varus, and claw toes), modified Ashworth scale (MAS) score for the targeted muscles, and modified Rankin Scale (mRS) score at T0, T1, and T5. RESULTS: Eighty-eight patients were included. At T5, 88.7% of patients had achieved their goals at least "as expected." The mean T-score was significantly higher at T1 (62.5 ± 9.5) and T5 (60.6 ± 11.3) than at T0 (37.9 ± 2.8) (p < 0.0001), and the difference between T1 and T5 was not significant (p = 0.2). Compared to T0, deformities (equinus, varus, and claw toes; all p < 0.0001), MAS score (p < 0.0001), and mRS score (p < 0.0001) were significantly improved at T1 and T5. Compared to T1, MAS score increased slightly only at T5 (p = 0.05) but remained largely below the preoperative value. There was no difference between T1 and T5 regarding other clinical parameters (e.g., deformities, walking abilities, mRS score). CONCLUSIONS: This study found that STN associated with a postoperative rehabilitation program can enable patients to successfully achieve personal goals that are sustained within a 5-year follow-up period.

Neurosurgical treatment of spasticity: a potential return to the cerebellum.

OBJECTIVE: Neurosurgical targeting of the cerebellar dentate nucleus via ablative dentatotomy and stimulation of the dentate nucleus was historically used for effective treatment of spasticity. Yet for decades, neurosurgical treatment of spasticity targeting the cerebellum was bypassed in favor of alternative treatments such as intrathecal baclofen pumps and selective dorsal rhizotomies. Cerebellar neuromodulation has recently reemerged as a promising and effective therapy for spasticity and related movement disorders. METHODS: In this narrative review, the authors contextualize the historical literature of cerebellar neuromodulation, comparing it with modern approaches and exploring future directions with regard to cerebellar neuromodulation for spasticity. RESULTS: Neurosurgical intervention on the cerebellum dates to the use of dentatotomy in the 1960s, which had progressed to electrical stimulation of the cerebellar cortex and dentate nucleus by the 1980s. By 2024, modern neurosurgical approaches such as tractography-based targeting of the dentate nucleus and transcranial magnetic stimulation of cerebellar cortex have demonstrated promise for treating spasticity. CONCLUSIONS: Cerebellar neuromodulation of the dentate nucleus and cerebellar cortex are promising therapies for severe cases of spasticity. Open areas for exploration in the field include the following: tractography-based targeting, adaptive cerebellar stimulation, and investigations into the network dynamics between the cerebellar cortex, deep cerebellar nuclei, and the subcortical and cortical structures of the cerebrum.

Percutaneous thermal radiofrequency rhizotomy of L2-S1 spinal nerve roots in children with cerebral palsy.

OBJECTIVE: This study presents the results of an evaluation of the effectiveness of percutaneous thermal radiofrequency (RF) ablation of spinal nerve roots to reduce spasticity and improve motor function in children with cerebral palsy (CP). METHODS: A retrospective analysis was conducted on the surgical treatment outcomes of 26 pediatric patients with severe CP (Gross Motor Function Classification System levels IV-V). The assessment protocol included muscle tone assessment using the modified Ashworth scale (MAS), evaluation of passive and active range of motion, gait video recording, and locomotor status evaluation using the Gross Motor Function Measure (GMFM)-88 scale. Thermal RF rhizotomy (ablation of spinal nerve roots) was performed on all patients at the L2-S1 levels at 70°C for 90 seconds. The statistical data analysis was conducted using the t-test and Mann-Whitney U-test. A p value < 0.05 was considered statistically significant. RESULTS: Before the operation, the average level of spasticity in the lower-limb muscles of all patients was 3.0 ± 0.2 according to the MAS. In the early postoperative period, the spasticity level in all examined muscle groups significantly decreased to a mean of 1.14 ± 0.15 (p < 0.001). In the long-term postoperative period, the spasticity level in the examined muscle groups averaged 1.49 ± 0.17 points on the MAS (p < 0.001 compared to baseline, p = 0.0416 compared to the early postoperative period). Despite the marked reduction of spasticity in the lower limbs, no significant change in locomotor status according to the GMFM-88 scale was observed in the selected category of patients. In the long-term period, during the control examination of patients, the GMFM-88 level increased on average by 3.6% ± 1.4% (from 22.2% ± 3.1% to 25.8% ± 3.6%). CONCLUSIONS: The findings of this study offer preliminary yet compelling evidence that RF ablation of spinal nerve roots can lead to a significant and enduring decrease in muscle tone among children with severe spastic CP. Further studies and longer-term data of the impact on functionality and quality of life of patients with CP after spinal root RF ablation are needed.

Dentate nucleus: a review and implications for dentatotomy.

PURPOSE: The dentate nucleus (DN) is the largest, most lateral, and phylogenetically most recent of the deep cerebellar nuclei. Its pivotal role encompasses the planning, initiation, and modification of voluntary movement but also spans non-motor functions like executive functioning, visuospatial processing, and linguistic abilities. This review aims to offer a comprehensive description of the DN, detailing its embryology, anatomy, physiology, and clinical relevance, alongside an analysis of dentatotomy. METHODS AND RESULTS: We delve into the history, embryology, anatomy, vascular supply, imaging characteristics, and clinical significance of the DN. Furthermore, we thoroughly review the dentatotomy, emphasizing its role in treating spasticity. CONCLUSIONS: Understanding the intricacies of the anatomy, physiology, vasculature, and projections of the DN has taken on increased importance in current neurosurgical practice. Advances in technology have unveiled previously unknown functions of the deep cerebellar nuclei, predominantly related to non-motor domains. Such discoveries are revitalizing older techniques, like dentatotomy, and applying them to newer, more localized targets.

Trends and insights review. Nerve procedures in the management of upper limb spasticity.

This article reviews the recent advances or nerve-oriented surgical procedures in the treatment of the spastic upper limb. The idea to intervene on the nerve is not recent, but new trends have developed in nerve surgery over the past few years, stimulating experiments and research. Specific surgical procedures involving the nerves have been described at different levels from proximal to distal: at the cervical spinal cord and the dorsal root entry zone (rhizotomy), at the level of the roots (contralateral C7 transfer) or in the peripheral nerve, within the motor trunk (selective neurectomy) or as its branches penetrate the muscles (hyperselective neurectomy). All of these neurosurgical procedures are only effective on spasticity but do not address the other deformities, such as contractures and motor deficit. Additional procedures may have to be planned in conjunction with nerve procedures to optimize outcomes.

Pediatric Spastic Wrist Contractures Can Be Well Managed With Wrist Arthrodesis.

BACKGROUND: Severe spastic wrist contractures secondary to cerebral palsy (CP) or alike can have significant implications for patient hand function, hygiene, skin breakdown, and cosmesis. When these contractures become rigid, soft tissue procedures alone are unable to obtain or maintain the desired correction. In these patients' wrist arthrodesis is an option-enabling the hand to be stabilized in a more functional position for hygiene, dressing, and general cosmesis, though are patients satisfied? METHODS: All children who had undergone a wrist arthrodesis for the management of a severe wrist contracture at Shriners Hospital, Portland between January 2016 and January 2021 were identified (n=23). A chart review was undertaken to obtain data-demographic, operative, clinical, and radiographic. All patients were then contacted to participate in 2 patient-reported outcome questionnaires (74% response agreement), a numerical rating scale (NRS), based on the visual analog scale (VAS) and the disability analog scale (DAS). Results were assessed with the aid of descriptive statistics, means and percentages with the primary focus of determining overall patient satisfaction with the procedure. RESULTS: Twenty-three patients were included in the review, and 74% took part in the prospective survey. Included were 10 patients with hemiplegia, 4 with triplegia, 7 with quadriplegia, 1 with a diagnosis of Rhett syndrome, and 1 with a history of traumatic brain injury. All patients achieved radiologic union by a mean of 8 weeks, and 87% obtained a neutral postoperative wrist alignment. The NRS showed 88% of patients were highly satisfied with their results; specifically, 82% had an improved appearance, 53% improved function, 71% improved daily cares, and 65% improved hygiene. The postoperative DAS score averaged 4.7 of 12 indicating mild disability. When looking at how a patient's diagnostic subtype affected outcome results, patients with triplegia reported less improvement and greater disability on the NRS and DAS, averaging 9.5 (severe disability on the DAS). The GMFCS classification had less correlation with outcomes. CONCLUSION: Wrist arthrodesis is a good option for the management of pediatric spastic wrist contractures, with limited complications and an overall high patient/carer satisfaction rate. LEVEL OF EVIDENCE: Level IV-case series.

[Selective Neurectomy in Spastic Paralysis of the Upper Extremity]. / Die hyperselektive Neurektomie bei spastischen Lähmungen der oberen Extremität.

Selective neurectomy refers to the targeted transection of motor nerve fibres at their entry into the muscle in order to reduce the increased muscle tone in cases of spastic paralysis. This procedure has regained popularity in recent years, especially in the upper extremity. First and foremost, it requires an exact knowledge of the topographical anatomy of muscle innervation. To be able to control the extent and localisation of the denervation, the terminal nerve branches must be visualized precisely during the procedure. For a meaningful reduction of muscle tone, 2/3 to 4/5 of nerve fibres must be resected. This article presents the historical development, principles and operative details of this technique as well as clinical results.

Cervical dorsal rhizotomy for upper limbs spasticity. Case report.

Spasticity is a prevalent symptom of upper motor neuron syndrome, becoming debilitating when hindering voluntary movement and motor function and causing contractures and pain. Functional neurosurgery plays a crucial role in treating severe spasticity. Despite extensive literature on SDR for lower limb spasticity, there is a scarcity of papers regarding the procedure in the cervical region to alleviate upper limb spasticity. This case report details a cervical dorsal rhizotomy (CDR) performed for upper limb spasticity, resulting in significant improvement in spasticity with sustained outcomes and low complication rates. Neuroablative procedures like CDR become an option to treat spasticity.

Functional outcomes following surgery for spastic hip adductor muscles in ambulatory and non-ambulatory adults.

OBJECTIVE: To evaluate functional outcomes of surgery of spastic hip adductor muscles (obturator neurotomy with or without adductor longus tenotomy) in ambulatory and non-ambulatory patients, using preoperatively defined personalized goals. DESIGN: Retrospective observational descriptive study. PATIENTS: Twenty-three patients with adductor spasticity who underwent obturator neurotomy between May 2016 and May 2021 at the Clinique des Cèdres, Cornebarrieu, France, were included. METHODS: Postoperative functional results were evaluated in accordance with the Goal Attainment Scaling method. Patients were considered "responders" if their score was ≥ 0. Secondary outcomes included spasticity, strength, hip range of motion and change in ambulatory capacity. When data were available, a comparison of pre- and postoperative 3-dimensional instrumented gait analysis was also performed. RESULTS: Among the 23 patients only 3 were non-walkers. Seventeen/22 patients achieved their main goal and 14/23 patients achieved all their goals. Results were broadly similar for both walking goals (inter-knee contact, inter-feet contact, fluidity, walking perimeter, toe drag) and non-walking goals (intimacy, transfer, pain, posture, dressing). CONCLUSION: Surgery of spastic hip adductor muscles results in functional improvement in ambulation, hygiene, dressing and posture and can be offered to patients with troublesome adductor overactivity. The use of a motor nerve block is recommended to define relevant goals before the surgery.

Quality of life and clinical outcomes in severely involved cerebral palsy patients and spastic hips undergoing Castle surgery: a cross-sectional study.

PURPOSE: As progressive hip dislocation causes pain in children with spastic cerebral palsy (CP) and spasticity needs surgical correction, we aimed to describe clinical and radiographic outcomes in CP patients with painful hip deformity treated with the Castle salvage procedure. METHODS: We included all patients operated in the same hospital between 1989 and 2017 with painful spastic hips and femoral head deformity making joint reconstruction unfeasible. We collected clinical and functional data from medical records and evaluated radiographies to classify cases for femoral head shape and migration, type of deformity, spinal deformity, and heterotopic ossification. We investigated quality of life one year after surgery. RESULTS: We analyzed 41 patients (70 hips) with complete medical records. All had severe function compromise GMFCS V (Gross Motor Function Classification System) and heterotopic ossifications, all but one had scoliosis, and most had undergone other surgeries before Castle procedure. Patients were followed up for 77.1 months (mean) after surgery. The mean initial migration index was 73%. Seven patients had complications, being three patients minor (two femur and one tibial fracture) and four majors (patients requiring surgical revision). Quality of life was considered improved by most of the carers (35 children; 85.3%) as level 4/5 according to CPCHILD instrument. No child was able to stand or walk, but moving in and out of bed, of vehicles, and to a chair, remaining seated, or visiting public places was "very easy." CONCLUSION: We considered most patients (37 patients-90%, 66 hips-94%) as having satisfactory outcomes because they had no or minor complications, absence of pain, free mobility of the lower limbs and were able to sit in a wheelchair.

A preliminary study on the spasticity reduction of quadriceps after selective dorsal rhizotomy in pediatric cases of spastic cerebral palsy.

OBJECTIVE: This study aimed to evaluate the potential alleviation of quadriceps spasticity in children diagnosed with spastic cerebral palsy (CP) following selective dorsal rhizotomy (SDR). METHODS: A retrospective study was conducted on children suffering from spastic CP who underwent SDR at the Department of Neurosurgery, Shanghai Children's Hospital, from July 2018 to September 2020. Inclusion criteria comprised children exhibiting quadriceps spasticity exceeding modified Ashworth Scale grade 2. Muscle tone and motor function were assessed before the operation, at short-term follow-up and at the last follow-up after SDR. Additionally, intraoperative neurophysiological monitoring data were reviewed. RESULTS: The study comprised 20 eligible cases, where, prior to surgery, 35 quadriceps muscles exhibited spasticity exceeding modified Ashworth Scale grade 2. Following short-term and mid-term follow-up, specifically an average duration of 11 ± 2 days and 1511 ± 210 days after SDR, it was observed that muscle tension in adductors, hamstrings, gastrocnemius, and soleus decreased significantly. This reduction was accompanied by a decrease in quadriceps muscle tone in 24 out of 35 muscles (68.6%). Furthermore, the study found that intraoperative electrophysiological parameters can predict postoperative spasticity relief in the quadriceps. The triggered electromyographic (EMG) output of the transected sensory root/rootlets after single-pulse stimulation revealed that the higher the EMG amplitudes in quadriceps, the greater the likelihood of postoperative decrease in quadriceps muscle tension. CONCLUSIONS: SDR demonstrates the potential to reduce muscle spasticity in lower extremities in children diagnosed with CP, including a notable impact on quadriceps spasticity even they are not targeted in SDR. The utilization of intraoperative neurophysiological monitoring data enhances the predictability of quadriceps spasticity reduction following SDR.

Dorsal Rhizotomy in the Pediatric Patient.

SUMMARY: The majority of cases of dorsal rhizotomy surgeries in children are done to improve the spasticity associated with cerebral palsy, and more recent techniques are selective in nature and referred to as selective dorsal rhizotomy (SDR). The techniques applied to selective dorsal rhizotomy surgery has changed since it was first described and continues to undergo modifications. Approaches to surgery and monitoring vary slightly among centers. This article provides a review of the rationale, variety of surgical approaches, and intraoperative neurophysiologic monitoring methods used along with discussion of the risks, complications and outcomes in these surgeries.

The effect of selective dorsal rhizotomy on the improvement of the quality of life of children with stage GMFCS IV and V cerebral palsy: Pain, nursing, positioning, and dressing.

AIM: The objective of this study is to evaluate the benefit of selective dorsal rhizotomy on the quality of life of patients with severe spasticity with significant impairment of gross motor functions (GMFCS stages IV and V) according to 4 items: pain, nursing care, positioning, and dressing. MATERIALS AND METHODS: We conducted a monocentric retrospective cohort study including patients who underwent selective dorsal rhizotomy between March 2008 and May 2022 at the University Hospital of Marseille. RESULTS: Seventy percent of patients showed an improvement in quality of life criteria: dressing, nursing, positioning, and pain at the last follow-up. A small proportion of patients still showed a worsening between the first 2 follow-ups and the last follow-up. Postoperatively, 27.3% of patients were free of joint spasticity treatment, and we have shown that there was a significant decrease in the number of children who received botulinum toxin postoperatively. However, there was no significant reduction in the number of drug treatments or orthopaedic procedures following RDS. For the CPCHILD© scores, an overall gain is reported for GMFCS IV and V patients in postoperative care. The gain of points is more important for GMFCS IV patients. Improvement was mainly observed in 2 domains, "comfort and emotions" and "hygiene and dressing". For the "quality of life" item, only 3 parents out of the 8 noted a positive change. CONCLUSION: Our study shows an improvement in nursing care, positioning, and dressing which are associated with a reduction in pain in children with a major polyhandicap GMFCS IV and V who have benefited from a selective dorsal rhizotomy.