Nerve transfers for the restoration of hand function after spinal cord injury

Peripheral nerve transfers for dysfunctions in central nervous system injuries: a systematic review

BACKGROUND

The review highlights recent advancements and innovative uses of nerve transfer surgery in treating dysfunctions caused by central nervous system (CNS) injuries, with a particular focus on spinal cord injury (SCI), stroke, traumatic brain injury, and cerebral palsy.

METHODS

A comprehensive literature search was conducted regarding nerve transfer for restoring sensorimotor functions and bladder control following injuries of spinal cord and brain, across PubMed and Web of Science from January 1920 to May 2023. Two independent reviewers undertook article selection, data extraction, and risk of bias assessment with several appraisal tools, including the Cochrane Risk of Bias Tool, the JBI Critical Appraisal Checklist, and SYRCLE's ROB tool. The study protocol has been registered and reported following PRISMA and AMSTAR guidelines.

RESULTS

Nine hundred six articles were retrieved, of which 35 studies were included (20 on SCI and 15 on brain injury), with 371 participants included in the surgery group and 192 in the control group. These articles were mostly low-risk, with methodological concerns in study types, highlighting the complexity and diversity. For SCI, the strength of target muscle increased by 3.13 of Medical Research Council grade, and the residual urine volume reduced by more than 100 ml in 15 of 20 patients. For unilateral brain injury, the Fugl-Myer motor assessment (FMA) improved 15.14-26 score in upper extremity compared to 2.35-26 in the control group. The overall reduction in Modified Ashworth score was 0.76-2 compared to 0-1 in the control group. Range of motion (ROM) increased 18.4-80° in elbow, 20.4-110° in wrist and 18.8-130° in forearm, while ROM changed -4.03°-20° in elbow, -2.08°-10° in wrist, -2.26°-20° in forearm in the control group. The improvement of FMA in lower extremity was 9 score compared to the presurgery.

CONCLUSION

Nerve transfer generally improves sensorimotor functions in paralyzed limbs and bladder control following CNS injury. The technique effectively creates a 'bypass' for signals and facilitates functional recovery by leveraging neural plasticity. It suggested a future of surgery, neurorehabilitation and robotic-assistants converge to improve outcomes for CNS.

Long-term functional recovery in C5-C6 avulsions treated with distal nerve transfers

BACKGROUND

In patients suffering from traction lesions of the brachial plexus, complete C5 and/or C6 root avulsion patients with C7 root preservation are relatively uncommon occurrences, but represent excellent candidates for surgical treatment, with satisfactory results. Shoulder abduction and extra-rotation, elbow flexion and forearm supination are lost functions restorable with surgical treatment.

METHODS

This single-center, prospective observational study involved a series of 27 young adults with C5 and/or C6 root complete avulsion and C7 preservation, which underwent surgical repair with double or triple nerve transfer.

RESULTS

Patients recovered a useful elbow flexion. Electromyographic and clinical signs of biceps reinnervation were observed in each UN-MC nerve transfer. The abduction strength recovery was M5 in 10 patients, M4 in 14 patients and M3 in 3 patients. The external rotation strength recovery was M5 in 4 patients, M4 in 18 patients, M3 in 3 patients and M2 in 2 patients. The elbow flection strength was M5 in 5 patients, M4 in 15 patients and M3 in 7 patients. Elbow extension was preserved in all cases.

CONCLUSIONS

The concept of 'peripheral rewiring procedures' represents an advance in the repair of the peripheral nerve injuries. Triple nerve transfer can be nowadays considered a standard treatment for isolated C5-C6 avulsions. We report our experience with the second-biggest casuistry in the literature on patients treated with this technique. We consider our outcome concerning functional recovery to be satisfying and comparable to data reported in the literature.

Differences in the surgical treatment of adult and pediatric brachial plexus injuries among peripheral nerve surgeons

OBJECTIVES

Peripheral nerve surgeons disagree on the optimal timing and treatment of brachial plexus injuries (BPI). This study aims to survey peripheral nerve surgeons on their management of BPI, including disagreement.

METHODS

Surgeons responded to a case-based survey involving traumatic and birth injuries leading to BPI involving the upper and lower trunks, and pre- and post-ganglionic injuries.

RESULTS

Out of 255 invited surgeons, 154 participated, with specialties of Neurosurgery (33.7%), Plastic surgery (32.5%), and Orthopedics (32.5%). For the adult C5-6 avulsion injury, 97.4% agreed they would operate. There was 46.2% disagreement regarding the pediatric upper trunk neuroma-in-continuity case, and similar disagreement (50.0%) was recorded on exploring the brachial plexus for a pediatric lower trunk injury case. High percentages of surgeons were more likely to explore the plexus, such as at upper BPI. Also, most participants reported nerve transfer for the upper and lower trunk avulsion injuries, but there was 55.6% disagreement regarding nerve transfer for the infant with the upper trunk neuroma-in-continuity. Among those elected to perform nerve transfer, most (70.0%-84.5%) would perform an accessory-to-suprascapular nerve transfer for upper BPI, while brachialis-to-anterior interosseous and supinator branch of the radial nerve-to-posterior interosseous were preferred for lower BPI (30.0%-55.9%).

CONCLUSIONS

Substantial disagreement exists among peripheral nerve surgeons in managing adult and pediatric BPI. In adult BPI, most prefer to operate at the time of the presentation and perform extensive nerve transfers. The accessory-suprascapular transfer was recommended for upper BPI, while brachialis and radial nerves were preferred for lower BPI. The most significant disagreements exist in operation and nerve transfer for pediatric upper BPI and brachial plexus explorations. Geography, specialty, and operative volume contribute to the differences seen.

Ulnar fascicle to brachialis branch of musculocutaneous nerve for restoration of elbow flexion associated with spinal cord tumor and radiation-induced lower motor neuron disease

Transfer of the ulnar fascicle to the biceps branch of the musculocutaneous nerve, or Oberlin transfer, has been widely used for the treatment of elbow flexion weakness in the setting of upper trunk brachial plexus palsy. The authors present a modified application of this technique for restoration of functional elbow flexion in a 30-year-old woman with a history of recurrent upper cervical spinal cord pilocytic astrocytoma, complex spinal deformity, and radiation-induced lower motor neuron disease. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID2299.

An Examination of Utilization Rates Over Time of Nerve and Tendon Transfers in Canada to Improve Upper Limb Function in Cervical Spinal Cord Injury

Introduction: Upper limb function loss in cervical spinal cord injury (SCI) contributes to substantial disability, and negatively impacts quality of life. Nerve transfer and tendon transfer surgery can provide improved upper limb function. This study assessed the utilization of nerve and tendon transfer surgery for individuals with tetraplegia in Canada. Methods: Data from the Canadian Institute for Health Information's Discharge Abstracts Database and the National Ambulatory Care Reporting System were used to identify the nerve and tendon transfer procedures performed in individuals with tetraplegia (2004-2020). Cases were identified using cervical SCI ICD-10-CA codes and Canadian Classification of Intervention codes for upper extremity nerve and tendon transfers. Data on sex, age at time of procedure, province, and hospital stay duration were recorded. Results: From 2004 to 2020, there were ≤80 nerve transfer procedures (81% male, mean age 38.3 years) and 61 tendon transfer procedures (78% male, mean age 45.0 years) performed (highest in Ontario and British Columbia). Using an estimate of 50% eligibility, an average of 1.3% of individuals underwent nerve transfer and 1.0% underwent tendon transfer. Nerve transfers increased over time (2004-2009, n = <5; 2010-2015, n = 27; 2016-2019, n = 49) and tendon transfers remained relatively constant. Both transfer types were performed as day-surgery or single night stay. Conclusions: Nerve and tendon transfer surgery to improve upper limb function in Canadians with tetraplegia remains low. This study highlights a substantial gap in care for this vulnerable population. Identification of barriers that prevent access to care is required to promote best practice for upper extremity care.

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).

Combined Nerve and Tendon Transfers for C7-T1 Brachial Plexus Avulsion Injury

BACKGROUND

In patients with C7-T1 brachial plexus avulsions, complete loss of hand function is commonly seen. However, the reconstruction of hand function is difficult.

OBJECTIVE

To report the outcomes of hand function recovery after combined nerve and tendon transfers in C7-T1 brachial plexus injury.

METHODS

From 2012 to 2019, 8 patients with C7-T1 brachial plexus injury underwent combined nerve and tendon transfers for hand function restoration, which included the following: (1) the pronator teres motor branch to the anterior interosseous nerve and brachialis motor branch to the flexor digitorum superficialis branch for finger flexion, (2) the supinator motor branch to the posterior interosseous nerve for finger extension, (3) the brachioradialis tendon transfer for thumb opposition, and (4) the radial branch of the superficial radial nerve to the sensory branch of the ulnar nerve for sensory reconstruction. Patients were evaluated for functional improvement of finger flexion, finger extension, thumb opposition, and sensory recovery.

RESULTS

No clinical donor deficits were observed. Seven of eight patients recovered finger and thumb flexion (4 patients scored British Medical Research Council grade M4 and 3 scored M3). The average grip strength was 3.4 kg. All patients regained finger extension (4 scored M4 and 4 scored M3), thumb opposition, and protective sensation on the ulnar hand. Patients were able to use their reconstructed hands in daily lives.

CONCLUSION

Combined nerve and tendon transfers are reliable and effective. This strategy could be an option for hand function reconstruction after C7-T1 brachial plexus injury.

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.

Dissemination and Implementation Science in Plastic and Reconstructive Surgery: Perfecting, Protecting, and Promoting the Innovation That Defines Our Specialty

SUMMARY

Plastic and reconstructive surgery has an illustrious history of innovation. The advancement, if not the survival, of the specialty depends on the continual development and improvement of procedures, practices, and technologies. It follows that the safe adoption of innovation into clinical practice is also paramount. Traditionally, adoption has relied on the diffusion of new knowledge, which is a consistent but slow and passive process. The emerging field of dissemination and implementation science promises to expedite the spread and adoption of evidence-based interventions into clinical practice. The field is increasingly recognized as an important function of academia and is a growing priority for major health-related funding institutions. The authors discuss the contemporary challenges of the safe implementation and dissemination of new innovations in plastic and reconstructive surgery, and call on their colleagues to engage in this growing field of dissemination and implementation science.

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.

Nerve transfers in the upper extremity: A review

Injury of the brachial plexus and peripheral nerve often result in significant upper extremity dysfunction and disability. Nerve transfers are replacing other techniques as the gold standard for brachial plexus and other proximal peripheral nerve injuries. These transfers require an intimate knowledge of nerve topography, a technically demanding Intraneural dissection and require extensive physical therapy for retraining. In this review, we present a summary of the most widely accepted nerve transfers in the upper extremity described in the current literature.

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.

Upper-Extremity Reconstruction in Tetraplegia: A Critical Analysis Review

Management of tetraplegia should be individualized to a patient's particular deficiencies and functional goals. Surgical decision-making for upper-extremity reconstruction in patients with tetraplegia relies on a thorough physical examination to determine which nerves and muscles remain under volitional control with adequate strength for transfer. Peripheral nerve transfers, either in conjunction with or in place of traditional tendon transfers, enable providers to offer an expanded set of surgical options for patients with tetraplegia who are seeking upper-extremity reconstruction. All upper-extremity reconstructive efforts should be carefully considered with regard to their potential effects on the availability of future reconstructive efforts.

A Self-Operating Time Crystal Model of the Human Brain: Can We Replace Entire Brain Hardware with a 3D Fractal Architecture of Clocks Alone?

Time crystal was conceived in the 1970s as an autonomous engine made of only clocks to explain the life-like features of a virus. Later, time crystal was extended to living cells like neurons. The brain controls most biological clocks that regenerate the living cells continuously. Most cognitive tasks and learning in the brain run by periodic clock-like oscillations. Can we integrate all cognitive tasks in terms of running clocks of the hardware? Since the existing concept of time crystal has only one clock with a singularity point, we generalize the basic idea of time crystal so that we could bond many clocks in a 3D architecture. Harvesting inside phase singularity is the key. Since clocks reset continuously in the brain–body system, during reset, other clocks take over. So, we insert clock architecture inside singularity resembling brain components bottom-up and top-down. Instead of one clock, the time crystal turns to a composite, so it is poly-time crystal. We used century-old research on brain rhythms to compile the first hardware-free pure clock reconstruction of the human brain. Similar to the global effort on connectome, a spatial reconstruction of the brain, we advocate a global effort for more intricate mapping of all brain clocks, to fill missing links with respect to the brain’s temporal map. Once made, reverse engineering the brain would remain a mere engineering challenge.

Evidence for efficacy of new developments in reconstructive upper limb surgery for tetraplegia

Nerve transfers are increasingly utilized for upper limb reconstruction in tetraplegia. We reviewed the literature for results achieved by nerve transfers for elbow extension, wrist control and finger and thumb flexion and extension. Muscle strength grading was the only outcome measure consistently reported. The results confirm that nerve transfers can effectively reanimate muscles in selected cases, with comparable strength with those achieved with tendon transfer for elbow extension but inferior strength for finger and thumb flexion. Transfer of supinator nerve branches to the posterior interosseous nerve appears to be reliable and offers increased span and better hand opening than is observed after tendon transfers. Only one publication demonstrated how reinnervation of muscles with nerve transfers translated into improved function, activity and participation for patients. More prospective studies, using standardized outcome measures, are needed to define the precise role of nerve transfers.

Nerve Transfers-A Paradigm Shift in the Reconstructive Ladder

In this review, we present the current role of nerve transfers in the management of nerve injuries. The outcome of a literature review comparing the results of nerve graft versus nerve transfer and the experience of select surgical societies' members regarding experience and adoption of nerve transfer are reported. Nerve transfer publications have increased more than nerve graft or repair articles. The surgeon survey revealed an increase in nerve transfers and that more motor nerve transfers have been adopted into practice compared to sensory nerve transfers. The meta-analyses and systematic reviews of motor nerve transfers for shoulder and elbow function presented variable outcomes related to donor nerve selection. Comprehensive patient assessment is essential to evaluate the immediate functional needs and consider future reconstruction that may be necessary. Optimal outcome following nerve injury may involve a combination of different surgical options and more than one type of reconstruction. Nerve transfer is a logical extension of the paradigm shift from nerve repair and nerve graft and offers a new rung on the reconstruction ladder.

Nerve transfer surgery in cervical spinal cord injury: a qualitative study exploring surgical and caregiver participant experiences

PURPOSE

To investigate perceptions of surgical participants and their caregivers regarding novel nerve transfer surgery to restore upper extremity function in cervical level spinal cord injury.

MATERIALS AND METHODS

A qualitative study design was used. A multidisciplinary team developed semi-structured interview guides. Interviews were recorded, transcribed and analyzed using basic text analysis.

RESULTS

Participants had limited information about procedures to improve function after spinal cord injury. When discussing their choice to undergo nerve (as compared to traditional tendon) transfer surgery, they describe a desire to avoid post-operative immobilization. Barriers included the pre-operative testing, cost and inconvenience of travel for surgery, and understanding complex health information related to the procedure. While expectations matched descriptions of outcomes among participants and were generally positive, caregivers expressed disappointment. The long time interval for gains in function to be realized and relatively incremental gains achieved were frustrating to all.

CONCLUSIONS

People with cervical spinal cord injury and their caregivers need more information about options to restore function and about realistic range of improvements with treatment. Further work to mitigate barriers and develop health information materials around nerve transfer surgery may improve medical decision making around and appropriate use of this newer treatment option.IMPLICATIONS FOR REHABILITATIONNerve transfer surgery is a novel and acceptable means of improving upper extremity function in the setting of cervical spinal cord injury.People with cervical spinal cord injury and their caregivers need information about options to restore hand and arm function and mitigation of barriers around these treatment options.

Expanding traditional tendon-based techniques with nerve transfers for the restoration of upper limb function in tetraplegia: a prospective case series

BACKGROUND

Loss of upper extremity function after cervical spinal cord injury greatly affects independence, including social, vocational, and community engagement. Nerve transfer surgery offers an exciting new option for the reanimation of upper limb function in tetraplegia. The aim of this study was to evaluate the outcomes of nerve transfer surgery used for the reanimation of upper limb function in tetraplegia.

METHODS

In this prospective case series, we consecutively recruited people of any age with early (<18 months post-injury) cervical spinal cord injury of motor level C5 and below, who had been referred to a single centre for upper extremity reanimation and were deemed suitable for nerve transfer. All participants underwent single or multiple nerve transfers in one or both upper limbs, sometimes combined with tendon transfers, for restoration of elbow extension, grasp, pinch, and hand opening. Participants were assessed at 12 months and 24 months post-surgery. Primary outcome measures were the action research arm test (ARAT), grasp release test (GRT), and spinal cord independence measure (SCIM).

FINDINGS

Between April 14, 2014, and Nov 22, 2018, we recruited 16 participants (27 limbs) with traumatic spinal cord injury, among whom 59 nerve transfers were done. In ten participants (12 limbs), nerve transfers were combined with tendon transfers. 24-month follow-up data were unavailable for three patients (five limbs). At 24 months, significant improvements from baseline in median ARAT total score (34·0 [IQR 24·0-38·3] at 24 months vs 16·5 [12·0-22·0] at baseline, p<0·0001) and GRT total score (125·2 [65·1-154·4] vs 35·0 [21·0-52·3], p<0·0001) were observed. Mean total SCIM score and mobility in the room and toilet SCIM score improved by more than the minimal detectable change and the minimal clinically important difference, and the mean self-care SCIM score improved by more than the minimal detectable change between baseline and 24 months. Median Medical Research Council strength grades were 3 (IQR 2-3) for triceps and 4 (IQR 4-4) for digital extensor muscles after 24 months. Mean grasp strength at 24 months was 3·2 kg (SD 1·5) in participants who underwent distal nerve transfers (n=5), 2·8 kg (3·2) in those who had proximal nerve transfers (n=9), and 3·9 kg (2·4) in those who had tendon transfers (n=8). There were six adverse events related to the surgery, none of which had any ongoing functional consequences.

INTERPRETATION

Early nerve transfer surgery is a safe and effective addition to surgical techniques for upper limb reanimation in tetraplegia. Nerve transfers can lead to significant functional improvement and can be successfully combined with tendon transfers to maximise functional benefits.

FUNDING

Institute for Safety, Compensation, and Recovery Research (Australia).

Anatomical Study of Innervation of the Supinator Muscle to Reinnervate the Posterior Interosseous Nerve

Objective  The purpose of this anatomical study was to analyze the possibility of transferring radial nerve branches to the supinator muscle to reinnervate the posterior interosseous nerve (PIN) originating from the C7–T1 roots.

Methods  Thirty members of 15 cadavers, all male, prepared with an intra-arterial glycerol and formaldehyde solution injection, were dissected.

Results  All dissected limbs presented at least one branch intended for the superficial and the deep heads of the supinator muscle. These branches originated from the PIN. A branch to the supinator muscle, proximal to the arcade of Frohse, was identified in six members. In addition, 2 and 3 branches to the supinator muscle were found in 11 and 4 members, respectively. In two limbs, only one branch detached from the PIN, but it duplicated itself proximal to the arcade of Frohse. Seven limbs had no branches to the supinator muscle at the region proximal to the arcade of Frohse. The branches destined for the supinator muscle were sectioned at the neuromuscular junction for connection with no tension to the PIN. The combined diameter of the branches for the supinator muscle corresponded, on average, to 53.5% of the PIN diameter.

Conclusion  The radial nerve branches intended for the supinator muscle can be transferred, with no tension, directly to the PIN to restore thumb and finger extension in patients with C7–T1 brachial plexus lesions.

Motor Point Topography of Fundamental Grip Actuators in Tetraplegia: Implications in Nerve Transfer Surgery

The differentiation between an upper motoneuron (UMN) lesion and lower motoneuron (LMN) lesion of forearm muscles in patients with tetraplegia is critical for the choice of treatment strategy. Specifically, the M. pronator teres (PT), M. flexor digitorum profundus III (FDPIII), and M. flexor pollicis longus (FPL) were studied since they represent key targets in nerve transfer surgery to restore grasp function. Forearm muscles of 24 patients with tetraplegia were tested bilaterally with electrical stimulation (ES) to determine whether UMN or LMN lesion was present. For detecting and testing the nerve stimulation points, a standardized mapping was developed and clinically applied. The relationship between the anatomical segmental spinal innervation and the innervation pattern tested by ES was determined. The data of 44 arms were analyzed. For PT, 19 arms showed an intact UMN, 18 arms an UMN lesion, and seven arms partial denervation. For FDPIII, three arms demonstrated an intact UMN, 26 arms an UMN lesion, 10 arms partial denervation, and five arms denervation. For FPL, two arms presented an intact UMN, 16 arms an UMN lesion, 12 arms partial denervation, and 14 arms denervation. A total of 20.1% ES tested muscles were partially denervated. In four patients, only one arm could be tested because of surgery-related limitations. According to the level of lesion and the segmental spinal innervation, most denervated muscles were present in the patient group C6 to C8. The ES, together with the developed mapping system, is reliable and can be recommended for standardized testing in surgery and rehabilitation. It offers the possibility to detect if and to what extent UMN and LMN lesions are present for the target muscles. It allows for refined pre-operative diagnostics and prognostics in spinal cord injury neurotization surgery.

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.

Nerve Transfers-A Paradigm Shift in the Reconstructive Ladder

Supplemental Digital Content is available in the text.

In this review, we present the current role of nerve transfers in the management of nerve injuries. The outcome of a literature review comparing the results of nerve graft versus nerve transfer and the experience of select surgical societies’ members regarding experience and adoption of nerve transfer are reported. Nerve transfer publications have increased more than nerve graft or repair articles. The surgeon survey revealed an increase in nerve transfers and that more motor nerve transfers have been adopted into practice compared to sensory nerve transfers. The meta-analyses and systematic reviews of motor nerve transfers for shoulder and elbow function presented variable outcomes related to donor nerve selection. Comprehensive patient assessment is essential to evaluate the immediate functional needs and consider future reconstruction that may be necessary. Optimal outcome following nerve injury may involve a combination of different surgical options and more than one type of reconstruction. Nerve transfer is a logical extension of the paradigm shift from nerve repair and nerve graft and offers a new rung on the reconstruction ladder.

Rehabilitation of Upper Extremity Nerve Injuries Using Surface EMG Biofeedback: Protocols for Clinical Application

Motor recovery following nerve transfer surgery depends on the successful re-innervation of the new target muscle by regenerating axons. Cortical plasticity and motor relearning also play a major role during functional recovery. Successful neuromuscular rehabilitation requires detailed afferent feedback. Surface electromyographic (sEMG) biofeedback has been widely used in the rehabilitation of stroke, however, has not been described for the rehabilitation of peripheral nerve injuries. The aim of this paper was to present structured rehabilitation protocols in two different patient groups with upper extremity nerve injuries using sEMG biofeedback. The principles of sEMG biofeedback were explained and its application in a rehabilitation setting was described. Patient group 1 included nerve injury patients who received nerve transfers to restore biological upper limb function (n = 5) while group 2 comprised patients where biological reconstruction was deemed impossible and hand function was restored by prosthetic hand replacement, a concept today known as bionic reconstruction (n = 6). The rehabilitation protocol for group 1 included guided sEMG training to facilitate initial movements, to increase awareness of the new target muscle, and later, to facilitate separation of muscular activities. In patient group 2 sEMG biofeedback helped identify EMG activity in biologically "functionless" limbs and improved separation of EMG signals upon training. Later, these sEMG signals translated into prosthetic function. Feasibility of the rehabilitation protocols for the two different patient populations was illustrated. Functional outcome measures were assessed with standardized upper extremity outcome measures [British Medical Research Council (BMRC) scale for group 1 and Action Research Arm Test (ARAT) for group 2] showing significant improvements in motor function after sEMG training. Before actual movements were possible, sEMG biofeedback could be used. Patients reported that this visualization of muscle activity helped them to stay motivated during rehabilitation and facilitated their understanding of the re-innervation process. sEMG biofeedback may help in the cognitively demanding process of establishing new motor patterns. After standard nerve transfers individually tailored sEMG biofeedback can facilitate early sensorimotor re-education by providing visual cues at a stage when muscle activation cannot be detected otherwise.

Two Cases of Traumatic Brachial Plexus Injury With Complete Spinal Cord Injury

BACKGROUND

Traumatic brachial plexus injury (BPI) in patients with complete spinal cord injury (SCI) such as paraplegia or tetraplegia is a very rare and debilitating combined injury that can occur in high-energy traumas. Management of a BPI should be aimed at regaining strength for self-transfers and activities of daily living to restore independence. However, brachial plexus reconstruction (BPR) in this unique patient population requires considerable planning due to the combined elements of upper and lower motor neuron injuries.

METHODS

We present 2 cases of traumatic complete SCI with concomitant BPI with mean follow-up of 42 months after BPR. The first patient had a left C5-7 BPI with a T2 complete SCI. The second patient sustained a left C5-8 BPI with complete SCI at C8.

RESULTS

The first patient underwent BPR including free functioning muscle, intra- and extraplexal nerve transfers, and tendon transfers resulting in active elbow flexion and active elbow, finger, and thumb extension, but no recovery of shoulder function. While the second patient underwent extra-plexal nerve transfer to restore elbow flexion yet did not recover any function in the left upper extreimty.

CONCLUSIONS

Because extensive upper and lower motor neuron injuries are present in these combined injuries, treatment strategies are limited. Expectations should be tempered in these patients as traditional methods to reconstruct the brachial plexus may result in less than ideal functional outcomes due to the associated upper motor neuron injury.

Double nerve transfer for restoration of hand grasp and release in C7 tetraplegia following complete cervical spinal cord injury

Cervical spinal cord injury (SCI) can cause tetraplegia. Nerve transfer has been routinely utilized for reconstruction of hand in brachial plexus injuries. Here, we report reconstruction of finger flexion (hand grasp) and extension (hand release) in a victim of cervical spinal cord injury with tetraplegia. We also focus on importance of extension phase in restoration of hand function in the tetraplegic case, in addition to provision of a detailed description of both operations including text, photographs, and a video. We used double nerve transfer, namely brachialis branches of musculocutaneous nerve to anterior interosseous nerve (AIN) and supinator branch of radial nerve to posterior interosseous nerve (PIN). We found that brachialis nerve transfer to AIN (for finger flexion) and supinator branch nerve transfer to PIN (for finger extension) can provide finger flexion and extension simultaneously. Brachialis nerve transfer to AIN and supinator branch nerve transfer to PIN may be an acceptable surgical technique to restore hand grasp and release in tetraplegia after SCI.

Clinical Outcomes from a Multi-Center Study of Human Neural Stem Cell Transplantation in Chronic Cervical Spinal Cord Injury

Human neural stem cell transplantation (HuCNS-SC^®) is a promising central nervous system (CNS) tissue repair strategy in patients with stable neurological deficits from chronic spinal cord injury (SCI). These immature human neural cells have been demonstrated to survive when transplanted in vivo, extend neural processes, form synaptic contacts, and improve functional outcomes after experimental SCI. A phase II single blind, randomized proof-of-concept study of the safety and efficacy of HuCNS-SC transplantation into the cervical spinal cord was undertaken in patients with chronic C5-7 tetraplegia, 4-24 months post-injury. In Cohort I (n = 6) dose escalation from 15,000,000 to 40,000,000 cells was performed to determine the optimum dose. In Cohort II an additional six participants were transplanted at target dose (40,000,000) and compared with four untreated controls. Within the transplant group, there were nine American Spinal Injury Association Impairment Scale (AIS) B and three AIS A participants with a median age at transplant of 28 years with an average time to transplant post-injury of 1 year. Immunosuppression was continued for 6 months post-transplant, and immunosuppressive blood levels of tacrolimus were achieved and well tolerated. At 1 year post-transplantation, there was no evidence of additional spinal cord damage, new lesions, or syrinx formation on magnetic resonance (MR) imaging. In summary, the incremental dose escalation design established surgical safety, tolerability, and feasibility in Cohort I. Interim analysis of Cohorts I and II demonstrated a trend toward Upper Extremity Motor Score (UEMS) and Graded Redefined Assessment of Strength, Sensibility, and Prehension (GRASSP) motor gains in the treated participants, but at a magnitude below the required clinical efficacy threshold set by the sponsor to support further development resulting in early study termination.

Using nerve transfer to restore prehension and grasp 12 years following spinal cord injury: a case report

Introduction

Nerve transfers are used routinely for reconstruction of hand function following lower motor neuron lesions. In people with cervical spinal cord injury (SCI), this novel and alternate reconstruction option may be useful to restore prehension and grasp, and improve hand function.

Case presentation

A 34-year-old male presented 12 years post-mid-cervical SCI. Pre-operative electrodiagnostic studies revealed intact lower motor neurons below the SCI level. He elected to undergo nerve transfer surgery to restore hand function. Intraoperative evaluation led to the transfer of a brachialis nerve to several median nerve recipient branches. Post surgery, he was discharged home and resumed activities of daily living. He achieved independent thumb and finger flexion function and continued to exhibit functional improvement at 4 years post surgery.

Discussion

These results should prompt referral for consideration of nerve transfer surgery-an exciting alternative to tendon transfer and neuroprostheses.

The Use of Nerve Transfers to Restore Upper Extremity Function in Cervical Spinal Cord Injury

BACKGROUND

Nerve transfer surgery to restore upper extremity function in cervical spinal cord injury (SCI) is novel and may transform treatment. Determining candidacy even years post-SCI is ill defined and deserves investigation.

OBJECTIVE

To develop a diagnostic algorithm, focusing on electrodiagnostic (EDX) studies, to determine eligibility for nerve transfer surgery.

DESIGN

Retrospective descriptive case series.

SETTING

Tertiary university-based institution.

PATIENTS

Individuals with cervical SCI (n = 45).

METHODS

The electronic medical records of people referred to the Plastic Surgery Multidisciplinary Upper Extremity Surgery in SCI clinic from 2010-2015 were reviewed. People were considered for nerve transfers to restore elbow extension or finger flexion and/or extension. Data including demographic, clinical evaluation, EDX results, surgery, and outcomes were collected and analyzed.

MAIN OUTCOME MEASUREMENTS

EDX data, including nerve conduction studies and electromyography, for bilateral upper extremities of each patient examined was used to assess for the presence of lower motor neuron injury, which would preclude late nerve transfer.

RESULTS

Based on our criteria and the results of EDX testing, a substantial number of patients presenting even years post-SCI were candidates for nerve transfers. Clinical outcome results are heterogeneous but promising and suggest that further refinement of eligibility, long-term follow-up, and standardized assessment will improve our understanding of the role of nerve transfer surgery to restore function in people with midcervical SCI.

CONCLUSIONS

Many patients living with SCI are candidates for nerve transfer surgery to restore upper extremity function. Although the ultimate efficacy of these surgeries is not yet determined, this study attempts to report the criteria we are using and may ultimately determine the timing for intervention and which transfers are most useful for this heterogeneous population.

LEVEL OF EVIDENCE

IV.

Nerve and Tendon Transfer Surgery in Cervical Spinal Cord Injury: Individualized Choices to Optimize Function

Background: Recent adaption of nerve transfer surgery to improve upper extremity function in cervical spinal cord injury (SCI) is an exciting development. Tendon transfer procedures are well established, reliable, and can significantly improve function. Despite this, few eligible surgical candidates in the United States undergo these restorative surgeries. Evidence Acquisition: The literature on these procedures was reviewed. Results: Options to improve function include surgery to restore elbow extension, wrist extension, and hand opening and closing function. Tendon transfers are reliable and well tolerated but require weeks of immobilization and limits on extremity use. The role of nerve transfers is still being established. Early results indicate variable return of meaningful function with less immobilization but longer periods (up to years) required to gain appreciable function. Conclusion: Nerve and tendon transfer surgery sacrifice an expendable donor to restore a missing and more critical function. These procedures are well described in hand surgery; are reliable, well tolerated, and covered by insurance; and should be part of the SCI rehabilitation discussion.

Outcomes of Muscle Brachialis Transfer to Restore Finger Flexion in Brachial Plexus Palsy

BACKGROUND

In adults with lower trunk brachial plexus injury, proximal nerve surgery for restoration of prehension demonstrates poor outcomes secondary to long distances required for nerve regeneration and time-dependent degradation of motor endplates. Options for reconstruction are limited to distal tendon or nerve transfers and free-functioning muscle transfers. In this article, the authors describe the long-term outcomes of brachialis muscle-to-flexor digitorum profundus transfer to restore prehension in patients with traumatic lower trunk brachial plexus injuries.

METHODS

Eighteen adult patients with lower trunk brachial plexus palsy underwent brachialis muscle-to-flexor digitorum profundus transfer with the goal of restoring rudimentary prehensile function at a single institution. The patients were followed throughout their recovery with functional outcomes and patient satisfaction ratings.

RESULTS

Brachialis muscle transfer resulted in restoring modified British Medical Research Council grade 3 or better function in 11 of 18 patients and grade 4 function in eight of 18 patients. Eleven of the 18 patients demonstrated a postoperative functional grasp for assistance with activities of daily living. Overall patient satisfaction following brachialis muscle transfer was 56 percent. Patient preoperative wrist extension (p < 0.018) and finger extension (p < 0.029) strength correlated with improved outcomes, whereas concomitant upper extremity fracture (p < 0.023) was associated with poorer outcomes.

CONCLUSIONS

Brachialis muscle transfer is an option for reconstruction of prehensile function in patients with lower trunk brachial plexus palsy with preserved wrist extension. Brachialis muscle transfer is particularly useful in patients who are poor candidates for microsurgical free-functioning muscle transfer for grasp; however, its functional outcomes are not universally successful.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Diffusion Assessment of Cortical Changes, Induced by Traumatic Spinal Cord Injury

Promising treatments are being developed to promote functional recovery after spinal cord injury (SCI). Magnetic resonance imaging, specifically Diffusion Tensor Imaging (DTI) has been shown to non-invasively measure both axonal and myelin integrity following traumatic brain and SCI. A novel data-driven model-selection algorithm known as Diffusion Basis Spectrum Imaging (DBSI) has been proposed to more accurately delineate white matter injury. The objective of this study was to investigate whether DTI/DBSI changes that extend to level of the cerebral peduncle and internal capsule following a SCI could be correlated with clinical function. A prospective non-randomized cohort of 23 patients with chronic spinal cord injuries and 17 control subjects underwent cranial diffusion weighted imaging, followed by whole brain DTI and DBSI computations. Region-based analyses were performed on cerebral peduncle and internal capsule. Three subgroups of patients were included in the region-based analysis. Tract-Based Spatial Statistics (TBSS) was also applied to allow whole-brain white matter analysis between controls and all patients. Functional assessments were made using International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) as modified by the American Spinal Injury Association (ASIA) Scale. Whole brain white matter analysis using TBSS finds no statistical difference between controls and all patients. Only cervical ASIA A/B patients in cerebral peduncle showed differences from controls in DTI and DBSI results with region-based analysis. Cervical ASIA A/B SCI patients had higher levels of axonal injury and edema/tissue loss as measured by DBSI at the level of the cerebral peduncle. DTI Fractional Anisotropy (FA), Axial Diffusivity (AD) and Radial Diffusivity (RD) was able to detect differences in cervical ASIA A/B patients, but were non-specific to pathologies. Increased water fraction indicated by DBSI non-restricted isotropic diffusion fraction in the cerebral peduncle, explains the simultaneously increased DTI AD and DTI RD values. Our results further demonstrate the utility of DTI to detect disruption in axonal integrity in white matter, yet a clear shortcoming in differentiating true axonal injury from inflammation/tissue loss. Our results suggest a preservation of axonal integrity at the cortical level and has implications for future regenerative clinical trials.

Morphology of Donor and Recipient Nerves Utilised in Nerve Transfers to Restore Upper Limb Function in Cervical Spinal Cord Injury

Loss of hand function after cervical spinal cord injury (SCI) impacts heavily on independence. Multiple nerve transfer surgery has been applied successfully after cervical SCI to restore critical arm and hand functions, and the outcome depends on nerve integrity. Nerve integrity is assessed indirectly using muscle strength testing and intramuscular electromyography, but these measures cannot show the manifestation that SCI has on the peripheral nerves. We directly assessed the morphology of nerves biopsied at the time of surgery, from three patients within 18 months post injury. Our objective was to document their morphologic features. Donor nerves included teres minor, posterior axillary, brachialis, extensor carpi radialis brevis and supinator. Recipient nerves included triceps, posterior interosseus (PIN) and anterior interosseus nerves (AIN). They were fixed in glutaraldehyde, processed and embedded in Araldite Epon for light microscopy. Eighty percent of nerves showed abnormalities. Most common were myelin thickening and folding, demyelination, inflammation and a reduction of large myelinated axon density. Others were a thickened perineurium, oedematous endoneurium and Renaut bodies. Significantly, very thinly myelinated axons and groups of unmyelinated axons were observed indicating regenerative efforts. Abnormalities exist in both donor and recipient nerves and they differ in appearance and aetiology. The abnormalities observed may be preventable or reversible.

Nerve transfers for restoration of finger flexion in patients with tetraplegia

OBJECTIVE The purpose of this paper was to report the authors' results with finger flexion restoration by nerve transfer in patients with tetraplegia. METHODS Surgery was performed for restoration of finger flexion in 17 upper limbs of 9 patients (8 male and 1 female) at a mean of 7.6 months (SD 4 months) after cervical spinal cord injury. The patients' mean age at the time of surgery was 28 years (SD 15 years). The motor level according to the ASIA (American Spinal Injury Association) classification was C-5 in 4 upper limbs, C-6 in 10, and C-7 in 3. In 3 upper limbs, the nerve to the brachialis was transferred to the anterior interosseous nerve (AIN), which was separated from the median nerve from the antecubital fossa to the midarm. In 5 upper limbs, the nerve to the brachialis was transferred to median nerve motor fascicles innervating finger flexion muscles in the midarm. In 4 upper limbs, the nerve to the brachioradialis was transferred to the AIN. In the remaining 5 upper limbs, the nerve to the extensor carpi radialis brevis (ECRB) was transferred to the AIN. Patients were followed for an average of 16 months (SD 6 months). At the final evaluation the range of finger flexion and strength were estimated by manual muscle testing according to the British Medical Research Council scale. RESULTS Restoration of finger flexion was observed in 4 of 8 upper limbs in which the nerve to the brachialis was used as a donor. The range of motion was incomplete in all 5 of these limbs, and the strength was M3 in 3 limbs and M4 in 1 limb. Proximal retrograde dissection of the AIN was associated with better outcomes than transfer of the nerve to the brachialis to median nerve motor fascicles in the arm. After the nerve to the brachioradialis was transferred to the AIN, incomplete finger flexion with M4 strength was restored in 1 limb; the remaining 3 limbs did not show any recovery. Full finger flexion with M4 strength was demonstrated in all 5 upper limbs in which the nerve to the ECRB was transferred to the AIN. No functional downgrading of elbow flexion or wrist extension strength was observed. CONCLUSIONS In patients with tetraplegia, finger flexion can be restored by nerve transfer. Nerve transfer using the nerve to the ECRB as the donor nerve produced better recovery of finger flexion in comparison with nerve transfer using the nerve to the brachialis or brachioradialis.

Nerve Transfers in Tetraplegia

Hand and upper extremity function is instrumental to basic activities of daily living and level of independence in cervical spinal cord injury (SCI). Nerve transfer surgery is a novel and alternate approach for restoring function in SCI. This article discusses the biologic basis of nerve transfers in SCI, patient evaluation, management, and surgical approaches. Although the application of this technique is not new; recent case reports and case series in the literature have increased interest in this field. The challenges are to improve function, achieve maximal gains in function, avoid complications, and to primum non nocere.

Nerve Transfers to Restore Upper Extremity Function in Cervical Spinal Cord Injury: Update and Preliminary Outcomes

BACKGROUND

Cervical spinal cord injury can result in profound loss of upper extremity function. Recent interest in the use of nerve transfers to restore volitional control is an exciting development in the care of these complex patients. In this article, the authors review preliminary results of nerve transfers in spinal cord injury.

METHODS

Review of the literature and the authors' cases series of 13 operations in nine spinal cord injury nerve transfer recipients was performed. Representative cases were reviewed to explore critical concepts and preliminary outcomes.

RESULTS

The nerve transfers used expendable donors (e.g., teres minor, deltoid, supinator, and brachialis) innervated above the level of the spinal cord injury to restore volitional control of missing function such as elbow extension, wrist extension, and/or hand function (posterior interosseous nerve or anterior interosseous nerve/finger flexors reinnervated). Results from the literature and the authors' patients (after a mean postsurgical follow-up of 12 months) indicate gains in function as assessed by both manual muscle testing and patients' self-reported outcomes measures.

CONCLUSIONS

Nerve transfers can provide an alternative and consistent means of reestablishing volitional control of upper extremity function in people with cervical level spinal cord injury. Early outcomes provide evidence of substantial improvements in self-reported function despite relatively subtle objective gains in isolated muscle strength. Further work to investigate the optimal timing and combination of nerve transfer operations, the combination of these with traditional treatments (tendon transfer and functional electrical stimulation), and measurement of outcomes is imperative for determining the precise role of these operations.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

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.