Selective musculocutaneous neurotomy for spastic elbow

Nerve-Targeted Surgical Treatments for Spasticity: A Narrative Review

Spasticity is a potentially debilitating symptom of various acquired and congenital neurologic pathologies that, without adequate treatment, may lead to long-term disability, compromise functional independence, and negatively impact mental health. Several conservative as well as non-nerve targeted surgical strategies have been developed for the treatment of spasticity, but these may be associated with significant drawbacks, such as adverse side effects to medication, device dependence on intrathecal baclofen pumps, and inadequate relief with tendon-based procedures. In these circumstances, patients may benefit from nerve-targeted surgical interventions such as (i) selective dorsal rhizotomy, (ii) hyperselective neurectomy, and (iii) nerve transfer. When selecting the appropriate surgical approach, preoperative patient characteristics, as well as the risks and benefits of nerve-targeted surgical intervention, must be carefully evaluated. Here, we review the current evidence on the efficacy of these nerve-targeted surgical approaches for treating spasticity across various congenital and acquired neurologic pathologies.

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.

Outcomes of complete neurotomy and immediate repair of the musculocutaneous nerve for treatment of elbow spasticity

Neurotomy interrupts the stretch reflex and can be used for the treatment of spasticity. We hypothesized that neurotomy with nerve repair reduces spasticity while preserving motor function due to the preferential recovery of efferent over afferent fibres. This study reports the 1-year outcomes of neurotomy and immediate repair of the musculocutaneous nerve in the proximal arm for treatment of elbow flexor spasticity, comparing these to outcomes in the literature for neurectomy without nerve repair. A total of 10 adult patients with spasticity of the elbow flexors from stroke or traumatic brain injury who had undergone neurotomy and immediate repair of the musculocutaneous nerve were prospectively studied. The results suggest that this procedure effectively reduces elbow flexor spasticity, improves elbow resting position, active elbow extension and is useful for achieving patient goals with effects lasting at least 12 months.Level of evidence: IV (therapeutic).

Surgical Treatment in Post-Stroke Spastic Hands: A Systematic Review

Background: For more than two decades, the surgical treatment of post-stroke spastic hands has been displaced by botulinum toxin therapy and is currently underutilized. Objectives: This article aimed to assess the potential of surgery for treating a post-stroke spastic upper extremity through a systematic review of the literature on surgical approaches that are adopted in different profiles of patients and on their outcomes and complications. Methods: Medline PubMed, Web of Science, SCOPUS, and Cochrane Library databases were searched for observational and experimental studies published in English up to November 2022. The quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluations (GRADE) system. Results: The search retrieved 501 abstracts, and 22 articles were finally selected. The GRADE-assessed quality of evidence was low or very low. The results of the reviewed studies suggest that surgery is a useful, safe, and enduring treatment for post-stroke spastic upper extremities, although most studied patients were candidates for hygienic improvements alone. Patients usually require an individualized combination of techniques. Over the past ten years, interest has grown in procedures that act on the peripheral nerve. Conclusions: Despite the lack of comparative studies on the effectiveness, safety, and cost of the treatments, botulinum toxin has displaced surgery for these patients. Studies to date have found surgery to be an effective and safe approach, but their weak design yields only poor-quality evidence, and clinical trials are warranted to compare these treatment options.

[Selective Neurectomy in Spastic Paralysis of the Upper Extremity]

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.

The utility of selective partial neurectomy of the musculocutaneous nerve in children with bilateral spastic elbow

PURPOSE

This study aims to determine the utility of selective partial neurectomy of the musculocutaneous nerve (MCN) in pediatric patients with bilateral spastic elbow.

METHODS

A prospective, cross-sectional, case series study was performed in nine pediatric patients (four females and five males) with bilateral spastic elbow, all with a 11.4-year-old average age, where 18 selective partial neurectomies of the MCN were carried out. They were evaluated with goniometry of both spastic elbows at resting position and active amplitude, and staging spasticity employing the Modified Ashworth Scale (MAS) in the preoperative and postoperative period. The results are reported 1 year after surgery.

RESULTS

The etiology of the spasticity was secondary to cerebral palsy in eight patients (88.8%) and in one patient (11.11%) secondary to traumatic brain injury. A clinical improvement was observed in goniometry comparing the preoperative and postoperative resting position, a mean preoperative of 44.38 degrees (SD ± 7.61) versus 98.05 degrees (SD ± 24.44), respectively, and preoperative active amplitude a mean of 86.55 degrees (SD ± 15.97) versus the mean postoperative of 47.33 (SD ± 17.86). A relevant decrease on the MAS after surgical intervention was observed, resulting from an average preoperative state according to MAS of 3.78 (SD ± 0.42) to a postoperative state according to MAS of 1.44 (SD ± 0.51), these changes being statistically significant (p ≤ 0.001). No postoperative complications were observed.

CONCLUSIONS

Selective partial neurectomy of the MCN has shown good results in patients with bilateral spastic elbow in whom antispastic drugs and physical therapy have failed, and has prove permanent effects.

[Methods and results of neurosurgical treatment of cerebral palsy]

Treatment of spastic syndrome and muscular dystonia in patients with cerebral palsy is a complex clinical problem. Effectiveness of conservative treatment is not high enough. Modern neurosurgical techniques for spastic syndrome and dystonia are divided into destructive interventions and surgical neuromodulation. Their effectiveness is different and depends on the form of disease, severity of motor disorders and age of patients.

OBJECTIVE

To evaluate the effectiveness of various methods of neurosurgical treatment of spasticity and muscular dystonia in patients with cerebral palsy.

MATERIAL AND METHODS

We To evaluate the effectiveness of various methods of neurosurgical treatment of spasticity and muscular dystonia in patients with cerebral palsy.analyzed literature data in the PubMed database using the keywords «cerebral palsy», «spasticity», «dystonia», «selective dorsal rhizotomy», «selective neurotomy», «intrathecal baclofen therapy», «spinal cord stimulation», «deep brain stimulation».

RESULTS

Effectiveness of neurosurgery was higher for spastic forms of cerebral palsy compared to secondary muscular dystonia. Destructive procedures were the most effective among neurosurgical operations for spastic forms. Effectiveness of chronic intrathecal baclofen therapy decreases in follow-up due to secondary drug resistance. Destructive stereotaxic interventions and deep brain stimulation are used for secondary muscular dystonia. Effectiveness of these procedures is low.

CONCLUSION

Neurosurgical methods can partially reduce severity of motor disorders and expand the possibilities of rehabilitation in patients with cerebral palsy.

Hyperselective neurectomy for the treatment of upper limb spasticity in adults and children: a prospective study

Hyperselective neurectomy (HSN) procedures in the spastic upper limb aim to reduce tone by excising some branches of the involved peripheral motor nerves, at the point of entry of each motor ramus into the target muscle. In this prospective study, 42 patients with upper limb spasticity were treated by HSN for the muscles of elbow flexion, forearm pronation and wrist flexion and evaluated for their short-term results (average 6 months) and long-term outcomes (average 31 months). Results at both time points showed an effective reduction of the spastic tone, with no decrease of muscle strength in the operated spastic muscles. Comparison of results between the two time points showed durability of the improvement, which remained statistically significant despite a slight relapse in spasticity. The results of HSN compare favourably with the other techniques of partial neurectomy; however, the technique requires a detailed knowledge of upper limb motor anatomy.Level of evidence: II.

Nerve transfer in the spastic upper limb: anatomical feasibility study

PURPOSE

Nerve transfers represent an innovative tool in the surgical treatment of upper limb paralysis. Well-documented for brachial plexus sequalae and under evaluation for tetraplegic patients, they have not yet been described for spastic upper limbs. The typical spastic deformity involves active and spastic flexor, adductor and pronator muscles, associated with paralysed extensor and supinator muscles. Experience with selective neurectomy has shown an effective decrease in spasticity together with preservation of muscle strength. We conceptualized a combination of neurectomy and nerve transfer, by performing a partial nerve transfer from a spastic elbow flexor muscle to a paralyzed wrist extensor muscle, hypothesizing that this would reduce the spasticity of the former and simultaneously activate the latter.

METHODS

Ten cadaveric dissections were performed in order to establish the anatomic feasibility of transferring a motor branch of the brachioradialis (BR) onto the branch of the extensor carpi radialis longus (ECRL) or brevis (ECRB). We measured the emergence, length, muscle entry point and diameter of each branch, and attempted the transfer.

RESULTS

We found 1-4 motor nerve for the BR muscle and 1-2 for the ECRL muscle. In all cases, the nerve transfer was achievable, allowing a satisfactory coaptation. The ECRB branch emerged too distally to be anastomosed to one of the BR branches.

CONCLUSION

This study shows that nerve transfers from the BR to the ECRL are anatomically feasible. It may open the way to an additional therapeutic approach for spastic upper limbs.

Selective peripheral neurotomy (SPN) as a treatment strategy for spasticity

Spasticity can be caused by central nervous system dysfunction, such as cerebral palsy and stroke. The accepted pathogenesis of spasticity is that the muscles are in the state of uninhibited stretch reflex without enough control of central nervous system. So far, there is no ideal way about how to repair central nervous system. However, the uninhibited stretch reflex can be reduced, targeting the posterior root of the spinal cord and peripheral nerves innervating the limbs, which are called selective posterior rhizotomy (SPR) and selective peripheral neurotomy (SPN), respectively. SPN is indicated for focal or multifocal spasticity, which is well accepted due to its low invasiveness and ease of use. How does the operation work? What do we do before and during this operation? Is there any risk to the patients? Our review summarizes the mechanism, indications, preoperative assessments, techniques, and complications of SPN. We hope that the spastic patients, such as pediatric cerebral palsy patients and older stroke patients, will benefit from this surgery.

Cryoneurotomy as a Percutaneous Mini-invasive Therapy for the Treatment of the Spastic Limb: Case Presentation, Review of the Literature, and Proposed Approach for Use

Objective

To provide a proof-of-concept study demonstrating that the decades old procedure of cryoneurotomy, used traditionally for analgesia, is a safe adjunctive and effective treatment for limb spasticity.

Design

Case series.

Setting

Publicly funded outpatient hospital spasticity clinic and community interventional anesthesia clinic.

Participants

Patients (N=3) who had plateaued with standard of care spasticity treatments including botulinum toxin. Two hemiplegic stroke patients with elbow spasticity and 1 pregnant patient with multiple sclerosis and a spastic equinovarus foot for whom botulinum toxin was now contraindicated.

Interventions

Selective anesthetic diagnostic motor nerve blocks with ultrasound and e-stimulation with 1cc of 1% lidocaine to the motor nerve to the targeted spastic muscle were performed to either the musculocutaneous nerve to brachialis, radial nerve to the brachioradialis or the tibial nerve. If the benefits included improved active and passive range motion and or decreased clonus, a percutaneous cryoneurotomy was performed.

Main Outcome Measures

Active and passive range of motion were measured using the Modified Tardieu Scale. The change in resistance to passive stretch was measured using the Modified Ashworth Scale (MAS). Videos of the before and after treatment were collected.

Results

Both elbows’ treatments resulted in MAS improving from a 3 to a 1+. Greatly improved active range of motion was noted at 94 and 64 degrees, respectively, as well as improvements in passive range on the Modified Tardieu Scale. The tibial nerve cryoneurotomy resulted in improvements in all parameters with a much improved gait. Results were maintained up to 17 months of follow-up.

Conclusion

Cryoneurotomy as a treatment for spasticity is a novel safe adjuvant treatment. Our initial results suggest patients can achieve significantly increased active and passive range of motion in the upper extremity and decreased clonus, and improved gait after tibial nerve cryoneurotomy.

Botulinum toxin type A or selective neurotomy for treating focal spastic muscle overactivity?

OBJECTIVE

To discuss the effectiveness, indications, limitations and side effects of botulinum toxin type A and selective neurotomy for treating focal spastic muscle overactivity to help clinicians choose the most appropriate treatment.

METHODS

Expert opinion based on scientific evidence and personal experience.

RESULTS

Botulinum toxin type A can decrease muscle tone in different types of spastic muscle overactivity, which allows for treating a large variety of spastic patterns with several etiologies. The toxin effect is sometimes insufficient to improve functional outcome and is transient, thereby requiring repeated injections. Selective neurotomy is a permanent surgical treatment of the reflex component of the spastic muscle overactivity (spasticity) that is effective for spastic equinovarus foot. The neurotomy provides a greater and more constant reduction in spasticity. However, the long-lasting effect on the non-reflex muscle overactivity, especially dystonia, is doubted. The effectiveness, clinical indications, advantages, side effects and limitations of both techniques are discussed.

CONCLUSION

Botulinum toxin type A has the highest level of evidence and the largest range of indications. However, the botulinum toxin effect is reversible and seems less effective, which supports a permanent surgical treatment such as selective neurotomy, especially for the spastic foot. Further research is needed to compare the effect of botulinum toxin type A and selective neurotomy for the different types of spastic muscle overactivity and clinical patterns.

The Role of Selective Peripheral Neurectomy in the Treatment of Upper Limb Spasticity

Background: Management of upper limb spasticity remains challenging. Selective peripheral neurectomy (SPN) is a relatively recent intervention for cases refractory to medical therapy. The aim of this study was to conduct a systematic review looking at the efficacy and outcomes of SPN, in order to clarify the patient selection criteria and surgical technique.

Methods: A search of MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Web of Science Core Collection, Open Grey and CINAHL was conducted. Inclusion criteria included studies comparing pre- and post-operative outcomes for SPN, neurectomy, fasciculotomy and upper limb spasticity.

Results: Only case series were reported with no randomised controlled trials found. 7 studies met the inclusion criteria with a total of 174 patients. A meta-analysis was not possible due to the degree of baseline heterogeneity. All studies had no control arm for comparison of outcomes, with a high risk of bias due to poor internal and external validity, as well as design and performance bias. Surgical techniques differ vastly between studies, with percentage of fascicles ablated between 30–80% and length of neurectomy between 5–10 mm. Some advocated removing end branches while others performed fascicular SPN proximally. 13 patients underwent orthopaedic or neurosurgical procedures, which are both confounding factors. All studies reported an improvement in spasticity although functional outcomes were reported with non-standardized measures. Recurrence rates were reported to be 0–16.1% (mean 3.72%).

Conclusions: From this systematic review, SPN appeared to be a useful technique in selected cases, but overall no firm conclusions can be drawn regarding the best surgical technique, or the extent of functional improvement.

The role of neurectomy in the management of spasticity of the upper limb

Neurectomy is one of the treatments available to the surgeon treating patients with spasticity of the upper limb.

Its popularity has increased in recent years.

Accurate knowledge of the anatomical variations of the terminal branches to the muscles is required in order to achieve a successful outcome.

Although the anatomy has been thoroughly studied, there are still controversies regarding the percentage of the nerve to be resected for a successful result, and also regarding the terminology that has been used in the literature to describe the procedure.

The literature for neurectomies for the upper limb is reviewed and an agreement regarding terminology is proposed.

Cite this article: EFORT Open Rev 2017;2:469-473. DOI: 10.1302/2058-5241.2.160074