Nerve transfer strategies for spinal cord injury

Impact of Upper Limb Motor Recovery on Functional Independence After Traumatic Low Cervical Spinal Cord Injury

Cervical spinal cord injury (SCI) causes devastating loss of upper limb function and independence. Restoration of upper limb function can have a profound impact on independence and quality of life. In low-cervical SCI (level C5-C8), upper limb function can be restored via reinnervation strategies such as nerve transfer surgery. The translation of recovered upper limb motor function into functional independence in activities of daily living (ADLs), however, remains unknown in low cervical SCI (i.e., tetraplegia). The objective of this study was to evaluate the association of patterns in upper limb motor recovery with functional independence in ADLs. This will then inform prioritization of reinnervation strategies focused to maximize function in patients with tetraplegia. This retrospective study performed a secondary analysis of patients with low cervical (C5-C8) enrolled in the SCI Model Systems (SCIMS) database. Baseline neurological examinations and their association with functional independence in major ADLs-i.e., eating, bladder management, and transfers (bed/wheelchair/chair)-were evaluated. Motor functional recovery was defined as achieving motor strength, in modified research council (MRC) grade, of ≥ 3 /5 at one year from ≤ 2/5 at baseline. The association of motor function recovery with functional independence at one-year follow-up was compared in patients with recovered elbow flexion (C5), wrist extension (C6), elbow extension (C7), and finger flexion (C8). A multi-variable logistic regression analysis, adjusting for known factors influencing recovery after SCI, was performed to evaluate the impact of motor function at one year on a composite outcome of functional independence in major ADLs. Composite outcome was defined as functional independence measure score of 6 or higher (complete independence) in at least two domains among eating, bladder management, and transfers. Between 1992 and 2016, 1090 patients with low cervical SCI and complete neurological/functional measures were included. At baseline, 67% of patients had complete SCI and 33% had incomplete SCI. The majority of patients were dependent in eating, bladder management, and transfers. At one-year follow-up, the largest proportion of patients who recovered motor function in finger flexion (C8) and elbow extension (C7) gained independence in eating, bladder management, and transfers. In multi-variable analysis, patients who had recovered finger flexion (C8) or elbow extension (C7) had higher odds of gaining independence in a composite of major ADLs (odds ratio [OR] = 3.13 and OR = 2.87, respectively, p < 0.001). Age 60 years (OR = 0.44, p = 0.01), and complete SCI (OR = 0.43, p = 0.002) were associated with reduced odds of gaining independence in ADLs. After cervical SCI, finger flexion (C8) and elbow extension (C7) recovery translate into greater independence in eating, bladder management, and transfers. These results can be used to design individualized reinnervation plans to reanimate upper limb function and maximize independence in patients with low cervical SCI.

Characterization of Spinal Cord Injury Patients for Arm Functional Restoration through Nerve Transfer

INTRODUCTION

Traumatic spinal cord injuries (tSCI) are common, often leaving patients irreparably debilitated. Therefore, novel strategies such as nerve transfers (NT) are needed for mitigating secondary SCI damage and improving function. Although different tSCI NT options exist, little is known about the epidemiological and injury-related aspects of this patient population. Here, we report such characteristics to better identify and understand the number and types of tSCI individuals who may benefit from NTs.

MATERIALS AND METHODS

Two peripheral nerve experts independently evaluated all adult tSCI individuals < 80 years old admitted with cervical tSCI (C1-T1) between 2005 and 2019 with documented tSCI severity using the ASIA Impairment Scale for suitability for NT (nerve donor with MRC strength ≥ 4/5 and recipient ≤ 2/5). Demographic, traumatic injury, and neurological injury variables were collected and analyzed.

RESULTS

A total of 709 tSCI individuals were identified with 224 (32%) who met the selection criteria for participation based on their tSCI level (C1-T1). Of these, 108 (15% of all tSCIs and 48% of all cervical tSCIs) were deemed to be appropriate NT candidates. Due to recovery, 6 NT candidates initially deem appropriate no longer qualified by their last follow-up. Conversely, 19 individuals not initially considered appropriate then become eligible by their last follow-up.

CONCLUSION

We found that a large proportion of individuals with cervical tSCI could potentially benefit from NTs. To our knowledge, this is the first study to detail the number of tSCI individuals that may qualify for NT from a large prospective database.

Therapeutic Strategies Targeting Respiratory Recovery after Spinal Cord Injury: From Preclinical Development to Clinical Translation

High spinal cord injuries (SCIs) lead to permanent functional deficits, including respiratory dysfunction. Patients living with such conditions often rely on ventilatory assistance to survive, and even those that can be weaned continue to suffer life-threatening impairments. There is currently no treatment for SCI that is capable of providing complete recovery of diaphragm activity and respiratory function. The diaphragm is the main inspiratory muscle, and its activity is controlled by phrenic motoneurons (phMNs) located in the cervical (C3-C5) spinal cord. Preserving and/or restoring phMN activity following a high SCI is essential for achieving voluntary control of breathing. In this review, we will highlight (1) the current knowledge of inflammatory and spontaneous pro-regenerative processes occurring after SCI, (2) key therapeutics developed to date, and (3) how these can be harnessed to drive respiratory recovery following SCIs. These therapeutic approaches are typically first developed and tested in relevant preclinical models, with some of them having been translated into clinical studies. A better understanding of inflammatory and pro-regenerative processes, as well as how they can be therapeutically manipulated, will be the key to achieving optimal functional recovery following SCIs.

Upper Limb Nerve Transfer Surgery in Patients With Tetraplegia

IMPORTANCE

Cervical spinal cord injury (SCI) causes devastating loss of upper extremity function and independence. Nerve transfers are a promising approach to reanimate upper limbs; however, there remains a paucity of high-quality evidence supporting a clinical benefit for patients with tetraplegia.

OBJECTIVE

To evaluate the clinical utility of nerve transfers for reanimation of upper limb function in tetraplegia.

DESIGN, SETTING, AND PARTICIPANTS

In this prospective case series, adults with cervical SCI and upper extremity paralysis whose recovery plateaued were enrolled between September 1, 2015, and January 31, 2019. Data analysis was performed from August 2021 to February 2022.

INTERVENTIONS

Nerve transfers to reanimate upper extremity motor function with target reinnervation of elbow extension and hand grasp, pinch, and/or release.

MAIN OUTCOMES AND MEASURES

The primary outcome was motor strength measured by Medical Research Council (MRC) grades 0 to 5. Secondary outcomes included Sollerman Hand Function Test (SHFT); Michigan Hand Outcome Questionnaire (MHQ); Disabilities of Arm, Shoulder, and Hand (DASH); and 36-Item Short Form Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS) scores. Outcomes were assessed up to 48 months postoperatively.

RESULTS

Twenty-two patients with tetraplegia (median age, 36 years [range, 18-76 years]; 21 male [95%]) underwent 60 nerve transfers on 35 upper limbs at a median time of 21 months (range, 6-142 months) after SCI. At final follow-up, upper limb motor strength improved significantly: median MRC grades were 3 (IQR, 2.5-4; P = .01) for triceps, with 70% of upper limbs gaining an MRC grade of 3 or higher for elbow extension; 4 (IQR, 2-4; P < .001) for finger extensors, with 79% of hands gaining an MRC grade of 3 or higher for finger extension; and 2 (IQR, 1-3; P < .001) for finger flexors, with 52% of hands gaining an MRC grade of 3 or higher for finger flexion. The secondary outcomes of SHFT, MHQ, DASH, and SF36-PCS scores improved beyond the established minimal clinically important difference. Both early (<12 months) and delayed (≥12 months) nerve transfers after SCI achieved comparable motor outcomes. Continual improvement in motor strength was observed in the finger flexors and extensors across the entire duration of follow-up.

CONCLUSIONS AND RELEVANCE

In this prospective case series, nerve transfer surgery was associated with improvement of upper limb motor strength and functional independence in patients with tetraplegia. Nerve transfer is a promising intervention feasible in both subacute and chronic SCI.

Nerve transfers in a patient with asymmetrical neurological deficit following traumatic cervical spinal cord injury: simultaneous bilateral restoration of pinch grip and elbow extension. Illustrative case

BACKGROUND

Cervical spinal cord injury (CSCI) causes severe motor deficit in upper extremities. The mixed segmental CSCI pattern is reflected in the combination of time-sensitive (TS) and non-TS myotomes in the upper extremities. Nerve transfers (NTs) restore upper extremity function yet remain TS procedures. A combination of neurological, magnetic resonance imaging (MRI), and electromyography (EMG) studies allows the identification of TS and non-TS myotomes in the upper extremities.

OBSERVATIONS

Nineteen months after NTs, flexor pollicis longus (FPL) and deep flexor of the index finger (FDP2) recovered to M4 (right UE), FPL recovered to M3 and FDP2 to M2 (left EU). The long head of the triceps brachii muscle recovered to M4 bilaterally. The Capabilities of Upper Extremity Questionnaire (CUE-Q) score for unilateral arm functionality increased by 44% (right) and 112.5% (left) and for bilateral arm functionality by 400%; the CUE-Q score for unilateral hand and finger function increased by 283% (right) and 166% (left).

LESSONS

The combination of neurological, MRI, and EMG studies before surgery and data obtained during surgery provides reliable information on the CSCI pattern, specifically the availability of motor donor nerves. Simultaneous bilateral restoration is required in the event of CSCI and significantly improves the unilateral and bilateral function of the UEs.

Clinical electrodiagnostic evaluation for nerve transfer surgery in spinal cord injury: a new indication and clinical pearls

In this review, we highlight the important role of the clinical electrodiagnostic (EDX) evaluation after cervical spinal cord injury (SCI). Our discussion focuses on the need for timely, frequent, and accurate EDX evaluations in the context of nerve transfer surgery to restore critical upper limb functions, including elbow extension, hand opening, and hand closing. The EDX evaluation is crucial to define the extent of lower motor neuron lesions and determine candidacy for surgery. We also discuss the important role of the postoperative EDX evaluation in determining prognosis and supporting rehabilitation. We propose a practical framework for EDX evaluation in this clinical setting.

Fourteen-year change in activities of daily living of a quadriplegic, ventilator-managed patient injured by high cervical spinal cord injury during infancy: a case report

Background

Rehabilitation of patients with high cervical spinal cord injury (CSCI) to improve activities of daily living (ADL) is challenging due to severe paralysis. In addition, pediatric patients with CSCI are rare, and literature describing ADL changes as the patient grows are limited. In this case report, we present the long-term change in ADL over time in a girl with severe high CSCI from an injury during infancy.

Case presentation

A 2 years and 6 months old girl, who was injured in a traffic accident, was diagnosed with C3 CSCI, resulting in complete quadriplegia and respiratory paralysis below C3. Thus, she was managed with a ventilator. Rehabilitation for quadriplegia, respiratory dysfunction, and autonomic neuropathy was started on the fifth day after the injury while she was in the intensive care unit. Six months after the injury, the patient was transferred to a hospital. Thereafter, she was discharged with nursing and care guidance provided to her family and environmental changes at home. Afterwards, she continued to acquire skills through writing training using a mouse stick, computer operation training, and electric wheelchair operation training, which enabled her to improve her ADL despite her severe disability. In terms of education, she was able to go through a regular elementary school, a regular junior high school, and then to a senior high school of a support school.

Conclusions

We believe that training that utilizes current technology and changes in the environment that are appropriate for daily life are important for improving the ADL of children with severe CSCI.

Pre-operative electrodiagnostic planning for upper limb peripheral nerve transfers in cervical spinal cord injury: A Narrative Review

Peripheral nerve transfer (PNT) to improve upper limb function following cervical spinal cord injury (SCI) involves the transfer of supralesional donor nerves under voluntary control to intralesional or sublesional lower motor neurons not under voluntary control. Appropriate selection of donor and recipient nerves and surgical timing impact functional outcomes. While the gold standard of nerve selection is intra-operative nerve stimulation, preoperative electrodiagnostic (EDX) evaluation may help guide surgical planning. Currently there is no standardized preoperative EDX protocol. This study reviews the EDX workup preceding peripheral nerve transfer surgery in cervical SCI, and proposes an informed EDX protocol to assist with surgical planning. The PICO (Population, Intervention, Comparison, Outcome) framework was used to formulate relevant MeSH terms and identify published cases of PNT in cervical SCI in Medline, Embase, CINAHL, and Emcare databases in the last 10 years. The electrodiagnostic techniques evaluating putative donor nerves, recipient nerve branches, time-sensitivity of nerve transfer and other electrophysiological parameters were summarized to guide creation of a preoperative EDX protocol. Needle electromyography (EMG) was the most commonly used EDX technique to identify healthy donor nerves. Although needle EMG has also been used on recipient nerves, compound muscle action potential (CMAP) amplitudes may provide a more accurate determination of recipient nerve health and time-sensitivity for nerve transfer. While there has been progress in pre-surgical EDX evaluation, EMG and NCS approaches are quite variable, and each has limitations in their utility for pre-operative planning. There is need for standardization in the EDX evaluation preceding peripheral nerve transfer surgery to assist with donor and recipient nerve selection, surgical timing and to optimize outcomes. Based on results of this review, herein we propose the PreSCIse (PRotocol for Electrodiagnosis in SCI Surgery of the upper Extremity) pre-operative EDX panel to achieve said goals through an interdisciplinary and patient-centered approach. This article is protected by copyright. All rights reserved.

Donor activation focused rehabilitation approach to hand closing nerve transfer surgery in individuals with cervical level spinal cord injury

STUDY DESIGN

Case Series.

OBJECTIVES

To describe the donor activation focused rehabilitation approach (DAFRA) in the setting of the hand closing nerve transfers in cervical spinal cord injury (SCI) so that therapists may apply it to treatment of individuals undergoing this procedure.

SETTING

United States of America-Academic Level 1 Trauma Center.

METHODS

We reviewed the records of individuals with cervical SCI who underwent nerve transfer to restore hand closing and post-surgery DAFRA therapy at our institution. The three post-surgery phases of DAFRA included (1) early phase (0-12 months) education, limb preparation, and donor activation exercises, (2) middle phase (12-24 months) volitional recipient muscle activation and (3) late phase (18 + months) strengthening and incorporation of motion in activities of daily living.

RESULTS

Subtle gains in hand closing were first observed at a mean of 8.4 months after hand closing nerve transfer surgery. Remarkable improvements including discontinuation of assistive devices, independence with feeding and urinary function, and measurable grip were observed. Function continued to improve slowly for one to two more years.

CONCLUSIONS

A deliberate, slow-paced (monthly for >2 years post-surgery) and incremental therapy program-DAFRA-can be used to improve outcomes after nerve transfer to restore hand closing in cervical SCI.

SPONSORSHIP

This work was made possible by funding from the Craig H. Neilsen Foundation Spinal Cord Injury Research on the Translation Spectrum (SCIRTS) Grant: Nerve Transfers to Restore Hand Function in Cervical Spinal Cord Injury (PI: Ida Fox).

Diaphragmatic Activity and Respiratory Function Following C3 or C6 Unilateral Spinal Cord Contusion in Mice

The majority of spinal cord injuries (SCIs) are cervical (cSCI), leading to a marked reduction in respiratory capacity. We aimed to investigate the effect of hemicontusion models of cSCI on both diaphragm activity and respiratory function to serve as preclinical models of cervical SCI. Since phrenic motoneuron pools are located at the C3-C5 spinal level, we investigated two models of preclinical cSCI mimicking human forms of injury, namely, one above (C3 hemicontusion-C3HC) and one below phrenic motoneuron pools (C6HC) in wild-type swiss OF-1 mice, and we compared their effects on respiratory function using whole-body plethysmography and on diaphragm activity using electromyography (EMG). At 7 days post-surgery, both C3HC and C6HC damaged spinal cord integrity above the lesion level, suggesting that C6HC potentially alters C5 motoneurons. Although both models led to decreased diaphragmatic EMG activity in the injured hemidiaphragm compared to the intact one (-46% and -26% in C3HC and C6HC, respectively, both p = 0.02), only C3HC led to a significant reduction in tidal volume and minute ventilation compared to sham surgery (-25% and -20% vs. baseline). Moreover, changes in EMG amplitude between respiratory bursts were observed post-C3HC, reflecting a change in phrenic motoneuronal excitability. Hence, C3HC and C6HC models induced alteration in respiratory function proportionally to injury level, and the C3HC model is a more appropriate model for interventional studies aiming to restore respiratory function in cSCI.

Patient perspectives and self-rated knowledge of nerve transfer surgery for restoring upper limb function in spinal cord injury

BACKGROUND

Nerve transfer surgery has the potential to restore upper limb function in patients with spinal cord injury (SCI); however, there has been limited exploration of patient perception of nerve transfer.

OBJECTIVE

To explore the perspectives of patients with chronic SCI (>2 years from injury) on nerve transfer surgery, and to determine if an educational intervention improved participants' perceived knowledge levels about the procedure.

DESIGN

Mixed-methods study including qualitative semi-structured interviews and self-reported rating scales. Pre- and post-interviews were completed following an educational presentation.

SETTING

Two local SCI clinics.

PARTICIPANTS

Ten patients with chronic traumatic SCI and neurological level of injury C3-C7 (motor complete or incomplete), recruited via snowball sampling (six male, four female).

INTERVENTION

An educational slide presentation on nerve transfer concepts.

MAIN OUTCOME MEASURES

The primary study outcome measure is the participants' responses to interview questions. The secondary study outcome measure is their self-reported knowledge levels of nerve transfer before and after education.

RESULTS

Regaining upper limb function was a priority for all participants. Although most participants had heard of nerve transfer, none were offered it at the time of their SCI, and only two stated that they had any peers who had undergone the procedure. The educational module significantly increased self-rated scores on understanding of nerve transfer (p < .05). Although all participants were open to nerve transfer after the educational module, they described weighing different factors, including (1) potential for loss versus gain of function, (2) inadequate knowledge about nerve transfer, (3) recovery time, and (4) determining their eligibility for the surgery.

CONCLUSIONS

These findings suggest that people with SCI have limited understanding of nerve transfer as a potential option and would benefit from educational opportunities to help them make informed decisions. This study may inform the development of patient resources to improve pre-surgical consultation and informed decision-making.

Optimizing the timing of peripheral nerve transfers for functional re-animation in cervical spinal cord injury: a conceptual framework

Loss of upper extremity function following spinal cord injury (SCI) can have devastating consequences on quality of life. Peripheral nerve transfer surgery aims to restore motor control of upper extremities following cervical SCI and is poised to revolutionize surgical management in this population. The surgery involves dividing an expendable donor nerve above the level of the spinal lesion and coapting it to a recipient nerve arising from the lesional or infralesional segment of the injured cord. In order to maximize outcomes in this complex patient population, refinements in surgical technique need to be integrated with principles of spinal cord medicine and basic science. Deciding on the ideal timing of nerve transfer surgery is one aspect of care that is critical to maximizing recovery and has received very little attention to date in the literature. This complex topic is reviewed, with a focus on expectations for spontaneous recovery within upper motor neuron components of the injury, balanced against the need for expeditious reinnervation for lower motor neuron elements of the injury. The discussion also considers the case of a patient with C6 motor complete SCI where myotomes without electrodiagnostic evidence of denervation spontaneously improved by 6 months post-injury, thereby adjusting the surgical plan. The relevant concepts are integrated into a clinical algorithm with recommendations that consider maximal opportunity for spontaneous clinical improvement post-injury while avoiding excessive delays that may adversely affect patient outcomes.

Surgical restoration of the upper limb in cervical spinal cord injury patients

Prior to the 1950s, relatively few patients who suffered a transection of the cervical spinal cord survived their injury. Improved medical care and better coordination have resulted in greater numbers of patients surviving and leaving the hospital. The pioneering work of individual surgeons during the 1960s and 1970s stimulated interest in surgical restoration of upper limb function in tetraplegic patients. Since the publication of Moberg's monograph in 1978, surgical improvement of the upper limbs is regarded as one of the options that should be offered to tetraplegic individuals to improve their function. Patients are classified according to the level of spinal cord injury and the residual motor function (international classification: groups 1 to 9). Surgical procedures are adapted to the motor level for each group of patients. Indications for these procedures are well standardized, the techniques are well mastered, and predictable results can be expected. New nerve transfer techniques have been developed in recent years; they are currently being evaluated.

Sciatic-to-Femoral Nerve End-to-End Coaptation for Proximal Lower Extremity Function in Patients With Acute Flaccid Myelitis: Technical Note and Review of the Literature

BACKGROUND

Acute flaccid myelitis (AFM) is an acute-onset anterior horn disease resulting in flaccid paralysis of extremities, trunk, facial, and cervical musculature in children following upper respiratory or gastrointestinal viral illness. Nerve transfer procedures have been shown to restore function.

OBJECTIVE

To present a technical description of sciatic-to-femoral nerve transfers in 4 children with AFM.

METHODS

Retrospective review of relevant cases was performed.

RESULTS

A total of 4 cases are presented of young children with persistent quadriparesis in the setting of AFM, presenting between 4 and 15 mo following initial diagnosis. Electromyography showed denervation of muscles innervated by the femoral nerve, with sparing of the sciatic distribution. The obturator nerve was also denervated in all patients. We therefore elected to pursue sciatic-to-femoral transfers to restore active knee extension. These transfers involved end-to-end coaptation of a sciatic nerve fascicle to the femoral nerve motor branches supplying quadriceps muscles.

CONCLUSION

We present technical descriptions of bilateral sciatic-to-femoral nerve neurotization for the restoration of quadriceps function in 4 patients with AFM. The sciatic nerve fascicles are a reasonable alternative donor nerve for patients with proximal muscle paralysis and limited donor options in the lower extremity.

Nerve transfer rehabilitation in tetraplegia: Comprehensive assessment and treatment program to improve upper extremity function before and after nerve transfer surgery, a case report

CONTEXT

A 28-year-old male, sustained a traumatic Spinal Cord Injury (SCI) in January 2015, and was classified as AIS A, neurological level of injury (NLI) C4. As an inpatient at the SCI rehabilitation unit, he underwent multidisciplinary assessment involving SCI specialists, peripheral nerve surgeons, psychologists, occupational and physical therapists. Team consensus determined he was a candidate for nerve transfer surgery to improve upper extremity function. The patient undertook a pre-surgical neurorehabilitation program of 3 months duration. Surgery was performed bilaterally at 11 and 13 months after SCI (right and left arm respectively).

FINDINGS

Upon completion of surgical procedures, the patient underwent an intensive post-surgical rehabilitation program based on established goals, with follow-up every 3 months, up to 24 months after the surgery. Notable improvements were wheelchair propulsion, the ability to relieve pressure, grasp, pinch, and release an object. Standardized measures for SCI individuals (SCIM-III, CUE-Q, LiSAT-9 and UEMS) showed significant improvements.

CLINICAL RELEVANCE

Nerve transfers in tetraplegia are an underused technique. The benefits of surgery along with an intensive neurorehabilitation program, can improve independence and function in daily living activities for a properly selected group of individuals.

Nerve transfers in tetraplegia: a review and practical guide

INTRODUCTION

Spinal cord injury (SCI) may lead to tetraplegia. Several nerve transfers have been successfully used for the restoration of the upper limb in tetraplegia. Reconstruction of an upper limb is individualized based on the functional level. In this study, the authors reviewed nerve transfers based on the injury level for the restoration of upper limb function in tetraplegia.

EVIDENCE ACQUISITION

We performed this study to review nerve transfers in tetraplegia by searching MEDLINE and EMBASE databases to identify relevant articles published through December 2020. We selected studies that reported cases in tetraplegia and extracted information on demographic data, clinical characteristics, operative details, and strength outcomes based on each injury level after surgery.

EVIDENCE SYNTHESIS

Total of 29 journal articles reporting on 275 nerve transfers in 172 upper limbs of 121 patients were included in the review. The mean time between SCI and nerve transfer surgery was 21.37 months (range: 4-156 months), and the follow-up time was 21.34 months (range: 3-38 months). The best outcomes were achieved for the restoration of wrist/finger extension and elbow extension.

CONCLUSIONS

Nerve transfer can provide a new function in tetraplegic patients' upper limbs to improve daily living activities. The type of surgical procedure should be performed based on the functional level of SCI and the individual's needs. Functional recovery occurs more in extensor muscles than flexors. Nerve transfer is a promising option in the reconstruction of upper limb function in tetraplegia.

Lower Motor Neuron Abnormality in Chronic Cervical Spinal Cord Injury: Implications for Nerve Transfer Surgery

Nerve transfer surgery (NT) constitutes an exciting option to improve upper limb functions in chronic spinal cord injury (SCI), but requires intact sublesional lower motor neuron (LMN) health. The purpose of this study was to characterize patterns of LMN abnormality in nerve-muscle groups that are the potential recipients of NT, using a standardized electrodiagnostic examination, in individuals with chronic SCI (injury duration >2 years, injury levels C4-T1). The LMN abnormality was determined using a semihierarchical approach, combining the amplitude compound muscle action potential (CMAP) and abnormal spontaneous activity on needle electromyography (EMG). Ten participants (46 potential recipient muscles) were included (median age, 42.5 years; six males and four females; median duration from injury, 15.5 years). A high frequency of LMN abnormality was observed (87%), although there was substantial variation within and between individuals. No statistically significant discordance was observed between LMN abnormality on CMAP and EMG (p = 0.24), however, 50% of muscles with normal CMAP demonstrated abnormal spontaneous activity. The high frequency of LMN abnormality in recipient nerve-muscle groups has implications to candidate selection for NT surgery in chronic SCI and supports the important role of the pre-operative electrodiagnostic examination. Our results further support the inclusion of both CMAP and needle EMG parameters for characterization of LMN health. Although the number of nerve-muscle groups with normal LMN health was small (13%), this underscores the neurophysiological potential of some patients with chronic injuries to benefit from NT surgery.

[Selective neurotization of the median nerve in young patients with CV-CVIIcomplicated spinal cord injury]

BACKGROUND

Complicated spinal cord injury occurs in 1-5 cases per 100.000. In children, cervical trauma makes up 72% of all spinal trauma. Spinal cord injury complicates vertebral trauma in 25-50% of cases that usually results severe disability. Rehabilitation of these patients is usually ineffective or results a little improvement. Restoration of even minimal movements is essential in these patients. There are reports devoted to surgical rehabilitation of important hand functions after cervical spinal cord injury.

OBJECTIVE

To demonstrate the restoration of key hand functions in patients with C_V-C_VII complicated spinal cord injury using selective neurotization of the median nerve.

MATERIAL AND METHODS

Three patients aged 17-19 years with complicated C_V-C_VII spinal cord injury and ASIA class A have been selected for surgery for 2 years. Mean period after rehabilitation was 11.3 months. Prior to surgery, all patients recovered flexion/extension in the elbow joints, forearm rotation, flexion and extension of hands. However, there were no active movements in distal phalanges of the fingers, and initial signs of flexor contracture were observed.

RESULTS

Surgical strategy included selective neurotization of the median nerve with a motor branch of musculocutaneous nerve. In one case, we used additional neurotization of posterior interosseous nerve. Two patients recovered cylindrical grip up to M4 and pinch grip up to M3 within 15 months. In the third patient, postoperative data were not assessed due to short-term follow-up.

CONCLUSION

Selective neurotization of anterior interosseous nerve may be considered as a stage or independent surgery for restoration of key hand functions. This approach improves the quality of life in patients with complicated spinal cord injury.

Nerves transfers for functional hand recovery in traumatic lower brachial plexopathy

Background:

Distal nerve transfers are an innovative modality for the treatment of C8-T1 brachial plexus lesions. The purpose of this case series is to report the authors’ results with hand restoration function by nerve transfer in patients with lower brachial plexus injury.

Methods:

Three consecutive nerve transfers were performed in a series of 11 patients to restore hand function after injury to the lower brachial plexus: brachialis motor branch to anterior interosseous nerve (AIN) and supinator branch to the posterior interosseous nerve (PIN) in a first surgical procedure, and AIN to pronator quadratus branch of ulnar nerve between 4 and 6 months later.

Results:

In all, 11 male patients underwent 33 surgical procedures. Time between brachial plexus injury and surgery was a mean of 11 months (range 4–13 months). Postoperative follow-up ranged from 12 to 24 months. We observed recovery of M3 or better finger flexion strength (AIN) and wrist extension (PIN) in 8 of the 11 surgically treated upper limbs. These patients recovered full thumb and finger extension between 6 and 12 months of surgery, without significant loss of donor function.

Conclusion:

Nerve transfers represent a way of restoring volitional control of upper extremity function in patients with C8-T1 brachial plexus injury.

Hand Reconstruction in Children with Spinal Cord Injury

Comprehensive programs for children who sustain traumatic spinal cord injury should incorporate optimizing hand and upper extremity function along with the other traditional pillars of rehabilitation. Children's smaller anatomy, open growth plates, and future skeletal growth, combined with the age-related psychosocial impact of these injuries, require protocols suited to these age-related issues. There is a role for surgical reconstruction, as is the case for adults with traumatic tetraplegia, and surgical outcomes are equally beneficial and long lasting. Strict adherence to surgical indications, and surgical strategies and protocols that incorporate their age-related challenges, are the keys to successful management.

Nothing to lose: a phenomenological study of upper limb nerve transfer surgery for individuals with tetraplegia

Purpose: For individuals with tetraplegia, regaining upper limb function forms the highest priority for improving quality of life. Use of nerve transfers to reconstruct upper limb function is increasing, however little is known about individual's decision to have and experience of the surgery and associated rehabilitation outcomes. This qualitative study aimed to understand the experience of surgery on the lives of individuals with tetraplegia 18 months post-surgery.Method: In-depth, semi-structured interviews were conducted with five purposively selected individuals who have undergone upper limb nerve transfers at a metropolitan health service, Melbourne, Australia, specializing in spinal cord injury rehabilitation. Collaizi's phenomenological framework guided data analysis, resulting in an essence statement describing the individuals' experience.Results: An essence statement comprising three themes; Deciding on Surgery, Facing Challenges: Surgery to Recovery and Evaluating Surgical Outcomes, was developed.Conclusion: The study suggests that for individuals with tetraplegia, hope to regain lost upper limb function forms a core consideration in the decision to have surgery. For clinicians supporting patient's decision, balancing hope with the realities of surgery is important. Even small changes in upper limb function had an important influence on participant's confidence in social situations through enhanced participation in a range of everyday activities.IMPLICATIONS FOR REHABILITATIONIn making a decision to have surgery, individuals with tetraplegia benefit from two way discussions with the healthcare team and others who have already undergone surgery.Healthcare teams need to help prepare individuals for the challenges of surgery including: expectations of pain, hospital stay, initial loss of independence and the time it may take to see re-innervation of target muscles and subsequent functional changes.Surgery should be routinely considered as individuals' report that even small changes in upper limb function positively increases participation in everyday tasks and confidence in social situations.When evaluating changes in upper limb function, patient-centered measures should be used.

Nerve transfers in the upper extremity following cervical spinal cord injury. Part 1: Systematic review of the literature

OBJECTIVE

Patients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly being used to treat patients with cervical SCIs. In this study, the authors performed a systematic review summarizing the published literature on nerve transfers to restore upper-extremity function in tetraplegia.

METHODS

A systematic literature search was conducted using Ovid MEDLINE 1946-, Embase 1947-, Scopus 1960-, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, and clinicaltrials.gov to identify relevant literature published through January 2019. The authors included studies that provided original patient-level data and extracted information on clinical characteristics, operative details, and strength outcomes after nerve transfer procedures. Critical review and synthesis of the articles were performed.

RESULTS

Twenty-two unique studies, reporting on 158 nerve transfers in 118 upper limbs of 92 patients (87 males, 94.6%) were included in the systematic review. The mean duration from SCI to nerve transfer surgery was 18.7 months (range 4 months-13 years) and mean postoperative follow-up duration was 19.5 months (range 1 month-4 years). The main goals of reinnervation were the restoration of thumb and finger flexion, elbow extension, and wrist and finger extension. Significant heterogeneity in transfer strategy and postoperative outcomes were noted among the reports. All but one case report demonstrated recovery of at least Medical Research Council grade 3/5 strength in recipient muscle groups; however, there was greater variation in the results of larger case series. The best, most consistent outcomes were demonstrated for restoration of wrist/finger extension and elbow extension.

CONCLUSIONS

Motor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. Flexor reinnervation strategies show variable treatment effect sizes; however, extensor reinnervation may provide more consistent, meaningful recovery. Despite numerous published case reports describing good patient outcomes with nerve transfers, there remains a paucity in the literature regarding optimal timing and long-term clinical outcomes with these procedures.

Nerve transfers in the upper extremity following cervical spinal cord injury. Part 2: Preliminary results of a prospective clinical trial

OBJECTIVE

Patients with cervical spinal cord injury (SCI)/tetraplegia consistently rank restoring arm and hand function as their top functional priority to improve quality of life. Motor nerve transfers traditionally used to treat peripheral nerve injuries are increasingly used to treat patients with cervical SCIs. In this article, the authors present early results of a prospective clinical trial using nerve transfers to restore upper-extremity function in tetraplegia.

METHODS

Participants with American Spinal Injury Association (ASIA) grade A-C cervical SCI/tetraplegia were prospectively enrolled at a single institution, and nerve transfer(s) was performed to improve upper-extremity function. Functional recovery and strength outcomes were independently assessed and prospectively tracked.

RESULTS

Seventeen participants (94.1% males) with a median age of 28.4 years (range 18.2-76.3 years) who underwent nerve transfers at a median of 18.2 months (range 5.2-130.8 months) after injury were included in the analysis. Preoperative SCI levels ranged from C2 to C7, most commonly at C4 (35.3%). The median postoperative follow-up duration was 24.9 months (range 12.0-29.1 months). Patients who underwent transfers to median nerve motor branches and completed 18- and 24-month follow-ups achieved finger flexion strength Medical Research Council (MRC) grade ≥ 3/5 in 4 of 15 (26.7%) and 3 of 12 (25.0%) treated upper limbs, respectively. Similarly, patients achieved MRC grade ≥ 3/5 wrist flexion strength in 5 of 15 (33.3%) and 3 of 12 (25.0%) upper limbs. Among patients who underwent transfers to the posterior interosseous nerve (PIN) for wrist/finger extension, MRC grade ≥ 3/5 strength was demonstrated in 5 of 9 (55.6%) and 4 of 7 (57.1%) upper limbs 18 and 24 months postoperatively, respectively. Similarly, grade ≥ 3/5 strength was demonstrated in 5 of 9 (55.6%) and 4 of 7 (57.1%) cases for thumb extension. No meaningful donor site deficits were observed. Patients reported significant postoperative improvements from baseline on upper-extremity-specific self-reported outcome measures.

CONCLUSIONS

Motor nerve transfers are a promising treatment option to restore upper-extremity function after SCI. In the authors' experience, nerve transfers for the reinnervation of hand and finger flexors showed variable functional recovery; however, transfers for the reinnervation of arm, hand, and finger extensors showed a more consistent and meaningful return of strength and function.

Advanced Assessment of the Upper Limb in Tetraplegia: A Three-Tiered Approach to Characterizing Paralysis

Background: More than half of all individuals who sustain a spinal cord injury (SCI) experience some degree of impairment in the upper limb. Functional use of the arm and hand is of paramount importance to these individuals. Fortunately, the number of clinical trials and advanced interventions targeting upper limb function are increasing, generating optimism for improved recovery and restoration after SCI. New interventions for restoring function and improving recovery require more detailed examination of the motor capacities of the upper limb. Objectives: The purpose of this article is to introduce a three-tiered approach to evaluating motor function, with specific attention to the characteristics of weak and fully paralyzed muscles during acute rehabilitation. The three tiers include (1) evaluation of voluntary strength via manual muscle testing, (2) evaluation of lower motor neuron integrity in upper motor neuron-paralyzed muscles using surface electrical stimulation, and (3) evaluation of latent motor responses in paralyzed muscles that exhibit a strong response to electrical stimulation, using surface electromyographic recording electrodes. These characteristics contribute important information that can be utilized to mitigate potential secondary conditions such as contractures and identify effective interventions such as activity-based interventions or reconstructive procedures. Our goal is to encourage frontline clinicians - occupational and physical therapists who are experts in muscle assessment - to consider a more in-depth analysis of paralysis after SCI. Conclusion: Given the rapid advancements in SCI research and clinical interventions, it is critical that methods of evaluation and classification evolve. The success or failure of these interventions may depend on the specific characteristics identified in our three-tiered assessment. Without this assessment, the physiological starting point for each individual is unknown, adding significant variability in the outcomes of these interventions.

[Hand function reconstruction by tendon transfers in patients with cervical spinal cord injury]

Objective

To explore the effectiveness of functional reconstruction of hand grasp and pinch by tendon transfers in patients with cervical spinal cord injury.

Methods

Between July 2013 and January 2016, tendon transfer surgery were performed in 21 patients (41 hands) with cervical spinal injury that motion level was located at C ₆ to reconstruct hand grasp and pinch function. There were 18 males and 3 females with a mean age of 42.3 years (range, 17-65 years). Nineteen patients were with complete spinal cord injury [American Spinal Injury Association (ASIA) grading A], 1 patient was with central cord syndrome whose bilateral hands were completely paralyzed and lower limbs were normal (ASIA grading D), and 1 patient was with cervical spondylotic myelopathy (AISA grading D). The time from injury to hospitalization was 12-22 months (mean, 16.8 months). According to the International classification of surgery of the hand in tetraplegia (ICSHT), there were 6 cases of grade O3, 10 of grade O4, 3 of grade OCu5, and 2 of grade O5. The surgery was divided into two stages with an interval of 6-11 months. At the first stage, grip function was reconstructed in all patients by transfering the extensor carpi radialis longus from radialis side to palmar side through subcutaneous tunnel, and braided and sutured with the flexor pollicis longus and flexor digitorum profundus. At the second stage, the lateral pinch function of the thumb and index finger was reconstructed by braiding and suturing the radial half of the extensor carpi ulnaris (the patients graded as ICSHT O3) or pronator tere (the patients graded above ICSHT O3) with extensor pollicis longus and abductor pollicis longus. The grasp force, the thumb and index finger lateral pinch force, and the maximum fingertips distance between the thumb and index finger were measured at preoperation and at different time points after operation. The modified Lamb and Chan questionnaire, based upon the activities of daily living, was used to evaluate the hand function of all patients at 6 months after sencond stage surgery.

Results

There was 1 patient with elbow skin lesion, 1 patient with wrist stiffness; both of them recovered after corresponding treatment. All the 21 patients were followed up 15-32 months (mean, 19.6 months) without wound infection, tendon adhesion, tendon rupture, and other complications. The grasp forces of all patients were significantly improved at 4 weeks, 3 months, 6 months, and 1 year after the first stage surgery when compared with preoperative value ( P<0.05); and no significant difference was found between different time points after operation ( P>0.05). The thumb and index finger lateral pinch force and the maximum fingertips distance between the thumb and index finger of all patients were also significantly improved at 4 weeks, 3 months, 6 months, and 1 year after the second stage surgery when compared with preoperative values ( P<0.05); and no significant difference was found between different time points after operation ( P>0.05). And there was no significant difference of above indexes between the patients graded as ICSHT O3 and above ICSHT O3 ( P>0.05). The functional outcome was good in 19 cases, fair in 1 case, and poor in 1 case according to modified Lamb and Chan questionnaire at 6 months after second stage surgery.

Conclusion

Tendon transfer can significantly improve the hand function and the quality of life of the patients with complete cervical spinal cord injury.

Novel Model of Somatosensory Nerve Transfer in the Rat

Nerve transfer (neurotization) is a reconstructive procedure in which the distal denervated nerve is joined with a proximal healthy nerve of a less significant function. Neurotization models described to date are limited to avulsed roots or pure motor nerve transfers, neglecting the clinically significant mixed nerve transfer. Our aim was to determine whether femoral-to-sciatic nerve transfer could be a feasible model of mixed nerve transfer. Three Sprague Dawley rats were subjected to unilateral femoral-to-sciatic nerve transfer. After 50 days, functional recovery was evaluated with a prick test. At the same time, axonal tracers were injected into each sciatic nerve distally to the lesion site, to determine nerve fibers' regeneration. In the prick test, the rats retracted their hind limbs after stimulation, although the reaction was moderately weaker on the operated side. Seven days after injection of axonal tracers, dyes were visualized by confocal microscopy in the spinal cord. Innervation of the recipient nerve originated from higher segments of the spinal cord than that on the untreated side. The results imply that the femoral nerve axons, ingrown into the damaged sciatic nerve, reinnervate distal targets with a functional outcome.

Lumbar to sacral root rerouting to restore bladder function in a feline spinal cord injury model: Urodynamic and retrograde nerve tracing results from a pilot study

AIMS

Lumbar to sacral rerouting surgery can potentially allow voiding via a skin-central nervous system-bladder reflex pathway. Here, we assessed if this surgery was effective in treating neurogenic bladder dysfunction/sphincter in felines.

METHODS

Eight cats underwent spinal cord transection (SCT) at thoracic level 10/11. Unilateral L7 to S1 ventral root anastomosis was performed 1 month later in six cats. Two cats served as transection-only controls. Electrical and manual stimulation of L6-S1 dermatomes, and urodynamics were performed at 3, 5, 7, and 9/10 months post transection. At 9/10 months, cats were also evaluated by direct electrophysiological testing of anastomosed roots with urodynamics, then tissue collection and examination of the root anastomosis site and lumbosacral cord ventral horns for cells retrogradely labeled from tracer dye injected 2 weeks earlier into the bladder wall.

RESULTS

At 9/10 months, four of six rerouted cats exhibited increased detrusor pressure provoked by cutaneous stimulation, one cat bilaterally. Two cats presented with a voiding stream after ipsilateral cutaneous stimulation at 7 and 9 months. All six rerouted animals showed regrowth of axons from the L7 ventral horn to the bladder, although some aberrant axonal regrowth was also observed.

CONCLUSION

L7 to S1 ventral root rerouting below the level of SCT showed successful axonal regrowth to the bladder from the L7 spinal cord segment in all rerouted animals, and induced increased detrusor pressure response to cutaneous stimulation in a subset. This feasibility study paves the way for future animal studies for bladder reinnervation.

Evolution of Neuroprosthetic Approaches to Restoration of Upper Extremity Function in Spinal Cord Injury

Background: Spinal cord injury (SCI) occurring at the cervical levels can result in significantly impaired arm and hand function. People with cervical-level SCI desire improved use of their arms and hands, anticipating that regained function will result in improved independence and ultimately improved quality of life. Neuroprostheses provide the most promising method for significant gain in hand and arm function for persons with cervical-level SCI. Neuroprostheses utilize small electrical currents to activate peripheral motor nerves, resulting in controlled contraction of paralyzed muscles. Methods: A myoelectrically-controlled neuroprosthesis was evaluated in 15 arms in 13 individuals with cervical-level SCI. All individuals had motor level C5 or C6 tetraplegia. Results: This study demonstrates that an implanted neuroprosthesis utilizing myoelectric signal (MES)-controlled stimulation allows considerable flexibility in the control algorithms that can be utilized for a variety of arm and hand functions. Improved active range of motion, grip strength, and the ability to pick up and release objects were improved in all arms tested. Adverse events were few and were consistent with the experience with similar active implantable devices. Conclusion: For individuals with cervical SCI who are highly motivated, implanted neuroprostheses provide the opportunity to gain arm and hand function that cannot be gained through the use of orthotics or surgical intervention alone. Upper extremity neuroprostheses have been shown to provide increased function and independence for persons with cervical-level SCI.

Reinnervation of the diaphragm by the inferior laryngeal nerve to the phrenic nerve in ventilator-dependent tetraplegic patients with C3-5 damage

The aim of this study was to evaluate the feasibility of unilateral diaphragmatic reinnervation in humans by the inferior laryngeal nerve. This pilot study included chronically ventilated tetraplegic patients with destruction of phrenic nerve motoneurons. Five patients were included. They all had a high level of tetraplegia, with phrenic nerve motor neuron destruction. They were highly dependent on ventilation, without any possibility of weaning. They did not have other chronic pathologies, especially laryngeal disease. They all had diaphragmatic explorations to diagnose the destruction of the motoneurons of the phrenic nerves and nasoendoscopy to be sure that they did not have laryngeal or pharyngeal disease. Then, surgical anastomosis of the right phrenic nerve was performed with the inferior laryngeal nerve, by a cervical approach. A laryngeal reinnervation was performed at the same time, using the ansa hypoglossi. One patient was excluded because of a functional phrenic nerve and one patient died 6 months after the surgery of a cardiac arrest. The remaining three patients were evaluated after the anastomosis every 6 months. They did not present any swallowing or vocal alterations. In these three patients, the diaphragmatic explorations showed that there was a recovery of the diaphragmatic electromyogram of the right and left hemidiaphragms after 1 year. Two patients had surgical diaphragmatic explorations for diaphragmatic pacing 18-24 months after the reinnervation with excellent results. At 36 months, none of the patients could restore their automatic ventilation. In conclusion, this study demonstrated that diaphragmatic reinnervation by the inferior laryngeal nerve is effective, without any vocal or swallowing complications.

The feasibility study of extradural nerve anastomosis technique for canine bladder reinnervation after spinal cord injury

OBJECTIVE

Intradural nerve anastomosis for bladder innervation has been demonstrated to be useful. However, its clinical application remains limited because of the complex surgery, its complications and extensive bony destruction. The purpose of the current study was to demonstrate the feasibility of extradural spinal root anastomosis for bladder innervation in canines.

METHODS

Ten beagle dogs were used. The length of the extradural segment of the nerve root, upper nerve root outlet (the point at which it emerges from the spinal dura mater) to S2 (dS2), the S3 (dS3) nerve root outlet distance, and the diameters of the extradural spinal roots were measured. The numbers of nerve fibers from L6 to S3 ventral roots were calculated using immunohistochemical staining.

RESULTS

The extradural spinal roots could be divided into a ventral root (VR) and a dorsal root (DR) before the ganglionic enlargement of the dorsal root, and the extradural motor nerve roots situate ventrally to their corresponding sensory nerve roots. The extradural nerve root lengths of S1 and parts of L7 were longer than the corresponding dS2. The numbers of nerve and motor nerve fibers, and the diameters of extradural nerve roots, were gradually descending from L6 to S3.

CONCLUSION

The S1 VRs and parts of the L7 VRs can be extradurally anastomosed to the S2 nerves without tension. A nerve graft was needed for extradural anastomosis of L6 VRs and parts of L7 VRs to S2 VRs. This study demonstrated the feasibility of extradural spinal nerve anastomosis for treating neurogenic bladder in canines.

Congenital subaxial cervical subluxation presenting as a bilateral Erb's palsy: surgical management, rehabilitation, and outcome

INTRODUCTION

Subaxial spine injuries during infancy are uncommon.

CASE REPORT

We present the case of an infant referred to our brachial plexus clinic with proximal weakness of both arms noted immediately following a complicated breech delivery. Nerve conduction studies were consistent with bilateral proximal upper plexus injury; however, radiological evaluation revealed a C4-C5 subluxation and MRI features of bilateral C5 root avulsions. He was immobilized in a cervical-body orthosis and underwent open reduction and posterior C4-C5-C6 fixation at 10 weeks age using luque rods, sublaminar wires, and rib graft. The spine was immobilized in a custom molded cervicothoracic brace for a total of 3 months, and a home exercise program prescribed. Follow-up radiographic evaluation showed good posterior bony fusion by 2 months but persistent bilateral proximal upper limb weakness with reduced compound motor action potential (CMAP) amplitudes of the axillary and musculocutaneous nerves. Bilateral supraclavicular exploration and C5 root neurotization using the ipsilateral C7 nerve roots were performed at 7 months of age. Voluntary biceps activity followed by voluntary external rotation with gravity eliminated was noted within the next 2-3 months. He progressed to develop near normal motor control of bilateral upper limbs within 1 year.

CONCLUSIONS

We wish to report this rare entity and our favorable outcome using a strategy of early spinal stabilization and neurotization repair to restore function following proximal nerve root injury.

Review of Upper Extremity Nerve Transfer in Cervical Spinal Cord Injury

OBJECTIVE

 Several nerve transfers have now been successfully performed for upper limb reanimation in tetraplegia. This study was performed to review the use of nerve transfers for upper limb reanimation in tetraplegia.

METHODS

 Medline and Embase (1950 to February 11, 2015) were searched using a search strategy designed to include any studies that reported cases of nerve transfer in persons with cervical spinal cord injury (SCI).

RESULTS

 A total of 103 manuscripts were selected initially and full-text analysis produced 13 studies with extractable data. Of these manuscripts, 10 reported single cases and 3 reported case series. Eighty-nine nerve transfers have been performed in 57 males and 2 females with a mean age of 34 years. The mean SCI level was C6 (range: C5-7), time to surgery post-SCI was 19.9 months (range: 4.1-156 months), and follow-up time was 18.2 months (range: 3-60 months). All case reports recorded a Medical Research Council (MRC) score of 3 or 4 for recipient muscle power, but two early case series reported more variable results.

CONCLUSION

 This review documents the current status of nerve transfer surgery for upper limb reanimation in tetraplegia and summarizes the functional results in 59 cases with 89 nerve transfers performed, including 15 cases of double-nerve transfer and 1 case of triple-nerve transfer.

Motor Nerve Transfers

Brachial plexus and peripheral nerve injuries are exceedingly common. Traditional nerve grafting reconstruction strategies and techniques have not changed significantly over the last 3 decades. Increased experience and wider adoption of nerve transfers as part of the reconstructive strategy have resulted in a marked improvement in clinical outcomes. We review the options, outcomes, and indications for nerve transfers to treat brachial plexus and upper- and lower-extremity peripheral nerve injuries, and we explore the increasing use of nerve transfers for facial nerve and spinal cord injuries. Each section provides an overview of donor and recipient options for nerve transfer and of the relevant anatomy specific to the desired function.

Transfer of the brachialis to the anterior interosseous nerve as a treatment strategy for cervical spinal cord injury: technical note

Study Design Technical report. Objective To provide a technical description of the transfer of the brachialis to the anterior interosseous nerve (AIN) for the treatment of tetraplegia after a cervical spinal cord injury (SCI). Methods In this technical report, the authors present a case illustration of an ideal surgical candidate for a brachialis-to-AIN transfer: a 21-year-old patient with a complete C7 spinal cord injury and failure of any hand motor recovery. The authors provide detailed description including images and video showing how to perform the brachialis-to-AIN transfer. Results The brachialis nerve and AIN fascicles can be successfully isolated using visual inspection and motor mapping. Then, careful dissection and microsurgical coaptation can be used for a successful anterior interosseous reinnervation. Conclusion The nerve transfer techniques for reinnervation have been described predominantly for the treatment of brachial plexus injuries. The majority of the nerve transfer techniques have focused on the upper brachial plexus or distal nerves of the lower brachial plexus. More recently, nerve transfers have reemerged as a potential reinnervation strategy for select patients with cervical SCI. The brachialis-to-AIN transfer technique offers a potential means for restoration of intrinsic hand function in patients with SCI.

Extradural nerve anastomosis technique for bladder reinnervation in spinal cord injury: anatomical feasibility study in human cadavers

STUDY DESIGN

An anatomic study of extradural spinal root in 9 embalmed cadavers.

OBJECTIVE

To ascertain the anatomical parameters of the extradural spinal root and to demonstrate the feasibility of spinal root anastomoses without opening the spinal dura mater.

SUMMARY OF BACKGROUND DATA

Intradural anastomosis of the spinal root has made breakthrough progress in treating neurogenic bladder in spinal cord injury. However, because of the complex surgical procedures and extensive bony destruction, its clinical use is not widely promoted.

METHODS

Nine formalin-fixed cadavers were used. The distance between the nerve root outlet and ganglion center, the neighboring nerve root-outlet distance, and the gross anatomy of the extradural spinal root were measured with a surgical microscope. The number of nerve fibers from the T7 to S4 ventral roots (VRs) was calculated by immunohistochemical staining.

RESULTS

The longest and shortest lengths of the extradural spinal root were observed at the S4 and T7 levels, with average values of 33.29 and 6.06 mm, respectively. The longest distance between the adjacent nerve root outlets was observed at L1-L2 (mean, 29.16 mm), and shortest at S3-S4 (mean, 11.79 mm). After leaving the dural sac, the spinal root descends in the spinal canal until reaching the corresponding intervertebral foramina, and the motor nerve roots still lie ventrally to the sensory nerve roots. The largest and smallest numbers of nerve fibers were observed at the L3 and S4 levels (mean, 9169 and 1356, respectively).

CONCLUSION

The dorsal roots and VRs can both be successfully harvested and identified outside the dural sac. The S1 VR can be anastomosed to the S2 VR extradurally without nerve grafts. For extradural neuroanastomosis of the thoracic VRs to the S2 VR, a nerve graft is required. In addition, there are a sufficient number of nerve fibers for functional bladder recovery at the T7-T12 and S1 levels. This study supports the feasibility of extradural spinal root anastomosis as a modified surgical method for treating neurogenic bladder.

LEVEL OF EVIDENCE

N/A.