The evolution of nerve transfers for spinal cord injury

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

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

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.

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.

Advancements in autologous peripheral nerve transplantation care: a review of strategies and practices to facilitate recovery

Autologous peripheral nerve transplantation, a pioneering technique in nerve injury treatment, has demonstrated remarkable progress. We examine recent nursing strategies and methodologies tailored to various anatomical sites, highlighting their role in postoperative recovery enhancement. Encompassing brachial plexus, upper limb, and lower limb nerve transplantation care, this discussion underscores the importance of personalized rehabilitation plans, interdisciplinary collaboration, and innovative approaches like nerve electrical stimulation and nerve growth factor therapy. Moreover, the exploration extends to effective complication management and prevention strategies, encompassing infection control and pain management. Ultimately, the review concludes by emphasizing the advances achieved in autologous peripheral nerve transplantation care, showcasing the potential to optimize postoperative recovery through tailored and advanced practices.

Symptomatic Treatment of Myelopathy

OBJECTIVE

This article discusses the effects of myelopathy on multiple organ systems and reviews the treatment and management of some of these effects.

LATEST DEVELOPMENTS

Recent advances in functional electrical stimulation, epidural spinal cord stimulation, robotics, and surgical techniques such as nerve transfer show promise in improving function in patients with myelopathy. Ongoing research in stem cell therapy and neurotherapeutic drugs may provide further therapeutic avenues in the future.

ESSENTIAL POINTS

Treatment for symptoms of spinal cord injury should be targeted toward patient goals. If nerve transfer for upper extremity function is considered, the patient should be evaluated at around 6 months from injury to assess for lower motor neuron involvement and possible time limitations of surgery. A patient with injury at or above the T6 level is at risk for autonomic dysreflexia, a life-threatening condition that presents with elevated blood pressure and can lead to emergent hypertensive crisis. Baclofen withdrawal due to baclofen pump failure or programming errors may also be life-threatening. Proper management of symptoms may help avoid complications such as autonomic dysreflexia, renal failure, heterotopic ossification, and fractures.

Supinator to Posterior Interosseous Nerve Transfer for Recovery of Hand Opening in the Tetraplegic Patient: A Case Series

BACKGROUND AND OBJECTIVES

Cervical spinal cord injury results in devastating loss of function. Nerve transfers can restore functional use of the hand, the highest priority function in this population to gain independence. Transfer of radial nerve branches innervating the supinator to the posterior interosseous nerve (SUP-PIN) has become a primary intervention for the recovery of hand opening, but few outcome reports exist to date. We report single-surgeon outcomes for this procedure.

METHODS

The SUP-PIN transfer was performed on adults with traumatic spinal cord injury resulting in hand paralysis. Outcome measures include Medical Research Council strength grade for extension of each digit, and angles representing critical apertures: the first web space opening of the thumb, and metacarpophalangeal angle of the remaining fingers. Factors affecting these measurements, including preserved tone and spasticity of related muscles, were also assessed.

RESULTS

Twenty-three adult patients with a C5-7 motor level underwent SUP-PIN transfers on 36 limbs (median age 31 years, interquartile range [21.5, 41]). The median interval from injury to surgery was 10.5 (8.2, 6.5) months, with 9 (7.5, 11) months for the acute injuries and 50 (32, 66) months for the chronic (>18 months) injuries. Outcomes were observed at a mean follow-up of 22 (14, 32.5) months. 30 (83.3%) hands recovered at least antigravity extension of the thumb and 34 (94.4%) demonstrated successful antigravity strength for the finger extensors, providing adequate opening for a functional grasp. Chronic patients (>18 months after injury) showed similar outcomes to those who had earlier surgery. Supination remained strong (at least M4) in all but a single patient and no complications were observed.

CONCLUSION

SUP-PIN is a reliable procedure for recovery of finger extension. Chronic patients remain good candidates, provided innervation of target muscles is preserved. Higher C5 injuries were more likely to have poor outcomes.

Axillary to Radial Nerve Transfer for Recovery of Elbow Extension After Spinal Cord Injury

BACKGROUND AND OBJECTIVES

Cervical spinal cord injuries (SCI) result in severe loss of function and independence. Nerve transfers have become a powerful method for restoring upper extremity function, the most critical missing function desired by this patient population. Recovery of active elbow extension allows for expansion of one's workspace to reach for objects and stabilizes control at the elbow joint. Without triceps function, a patient with a cervical SCI is rendered entirely helpless when in the supine position. Our objective was to provide a concise description of the transfer of branches of the axillary nerve (AN) to the long head of the triceps branch of the radial nerve (RN) for restoration of elbow extension after cervical SCI.

METHODS

An anterior, axillary approach is used for the transfer of the nerve branches of the AN (which may include branches to the teres minor, posterior deltoid, or even middle deltoid) to the long head of the triceps branch of the RN. Preoperative assessment and intraoperative stimulation are demonstrated to direct optimal selection of axillary branch donors.

RESULTS

The axillary approach provides full access to all branches of the AN in optimal proximity to triceps branches of the RN and allows for tension-free coaptation to achieve successful recovery of elbow extension. Final outcomes may not be achieved for 18 months. Of our last 20 patients with greater than 12-month follow-up, 13 have achieved antigravity strength in elbow extension, 4 are demonstrating ongoing progression, and 3 are definitive failures by 18 months.

CONCLUSION

The axillary to RN transfer is an important intervention for recovery of elbow extension after cervical SCI, which significantly improves quality of life in this patient population. Further large population outcomes studies are necessary to further establish efficacy and increase awareness of these procedures.

Incidence, prevalence and disability of spinal cord injury in China from 1990 to 2019: a systematic analysis of the Global Burden of Disease Study 2019

PURPOSE

We aimed to estimate the incidence, prevalence and years lived with disability (YLDs) of spinal cord injury (SCI) in China in 2019 and temporal trends from 1990 to 2019.

METHODS

The Global Burden of Disease Study 2019 was used to obtain data. Outcome measures included age-standardized incidence rate (ASIR), prevalence rate (ASPR) and YLDs rate (ASYR). A Bayesian meta-regression tool, DisMod-MR 2.1, was used to produce the estimates of each value after adjustments.

RESULTS

In 2019, there were 234.19 [95% uncertainty interval (UI) 171.84-312.87] thousand incident cases of SCI in China, with an ASIR of 13.87 (95% UI 10.15-18.66) per 100,000. ASIR and ASYR increased by 40.81% (95% UI 32.92-49.14%) and 11.44% (95% UI 5.16-17.29%) compared with 1990, individually. Males had higher ASIR and ASYR in each year from 1990 to 2019, but the incidence and YLDs rates of females exceeded males after 70 years old. Incidence and YLDs rates both ascended with age. SCI at neck level had slightly higher incidence rate but much higher YLDs rate than that below neck level. The average incidence age increased from 38.97 in 1990 to 54.59 in 2019. Falls were the leading cause of SCI.

CONCLUSION

The incidence and burden of SCI in China increased significantly during the past three decades. The age structure of SCI patients showed a shift from the young to the elderly as population aging. Urgent efforts are needed to relieve the health pressure from 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.

Optimal timing of referral for nerve transfer surgery for postoperative C5 palsy

OBJECTIVE

Cervical nerve 5 palsy can occur following surgery for cervical spine pathology. The prognosis of C5 palsy is generally favorable, and most patients recover useful function. However, some patients do not recover useful strength. Nerve transfers are a potential effective treatment of postoperative severe C5 palsy. This study aimed to further delineate the natural history of recovery from postoperative C5 palsy, determine whether lack of recovery at specific time points predicts poor recovery prognosis, and thereby determine a reasonable time point for referral to a complex peripheral nerve specialist.

METHODS

The authors conducted a retrospective review of 72 patients who underwent surgery for cervical spondylosis and stenosis complicated by C5 palsy. Medical Research Council (MRC) motor strength grades were recorded preoperatively; immediately postoperatively; at discharge; and at 2 weeks, 3 months, 6 months, and 12 months postoperatively. Univariate and multivariate logistic regression models were used to identify demographic and clinical risk factors associated with recovery of useful strength after severe C5 palsy.

RESULTS

The mean patient age was 62.5 years, and 36.1% of patients were female. Thirty patients (41.7%) experienced severe C5 palsy with less than antigravity strength (MRC grade 2 or less) at discharge. Twenty-one (70%) of these patients recovered useful strength (MRC grade 3 or greater) at 12 months postoperatively, and 9 patients (30%) did not recover useful strength at 12 months. Of those patients with persistent severe C5 palsy at 3 months postoperatively, 50% recovered useful strength at 12 months. Of those patients with persistent severe C5 palsy at 6 months postoperatively, 25% recovered useful strength at 12 months. No patient with MRC grade 0 or 1 strength at 6 months postoperatively recovered useful strength. A history of diabetes was associated with the occurrence of severe C5 palsy. On multivariate analysis, female sex was associated with recovery of useful strength.

CONCLUSIONS

Most patients with severe C5 palsy recover useful strength in their C5 myotome within 12 months of onset. However, at 3 months postoperatively, patients with persistent severe C5 palsy had only a 50% chance of recovering useful strength by 12 months. Lack of recovery of useful strength at 3 months postoperatively is a reasonable time point for referral to a complex peripheral nerve center to establish care and to determine candidacy for nerve transfer surgery if severe C5 palsy persists.

Nerve transfers in the forearm: potential use in spastic conditions

PURPOSE

Deformities of the spastic upper limb result frequently from the association of spasticity, muscle contracture and muscle imbalance between strong spastic muscles and weak non-spastic muscles. This study was designed to evaluate the feasibility of combining selective neurectomy of the usual spastic and strong muscles together with transfer of their motor nerves to the usual weak muscles, to improve wrist and fingers motion while decreasing spasticity.

METHODS

Twenty upper limbs from fresh frozen human cadavers were dissected. All motor branches of the radial and median nerve for the forearm muscles were identified. We attempted all possible end-to-end nerve transfers between the usually strong "donor" motor branches, namely FCR and PT, and the usually weak "recipient" motor branches (ERCL, ECRB, PIN, AIN).

RESULTS

 The PT had two nerve branches in 80%, thus allowing selective neurectomy. The proximal PT branch could be anastomosed end-to-end in 45% (AIN) to 85% (ECRL) of cases with the potential recipient branches. The distal PT branch could be anastomosed end to end to all potential recipient nerves. The FCR had a single branch in all cases. End-to-end anastomosis was possible in 90% for the ECRL and in 100% for all other recipient branches, but sacrificed all FCR innervation, ruling out hyperselective neurectomy.

CONCLUSION

 Selective neurectomies can be associated with distal nerve transfers at the forearm level in selected cases. The motor nerve to the PT is the best donor for nerve transfer combined with selective neurectomy, transferred to the ECRL, ECRB, PIN or AIN.

Spinal motor neuron transplantation to enhance nerve reconstruction strategies: Towards a cell therapy

Nerve transfers have become a powerful intervention to restore function following devastating paralyzing injuries. A major limitation to peripheral nerve repair and reconstructive strategies is the progressive, fibrotic degeneration of the distal nerve and denervated muscle, eventually precluding recovery of these targets and thus defining a time window within which reinnervation must occur. One proven strategy in the clinic has been the sacrifice and transfer of an adjacent distal motor nerve to provide axons to occupy, and thus preserve (or "babysit"), the target muscle. However, available nearby nerves are limited in severe brachial plexus or spinal cord injury. An alternative and novel proposition is the transplantation of spinal motor neurons (SMNs) derived from human induced pluripotent stem cells (iPSCs) into the target nerve to extend their axons to occupy and preserve the targets. These cells could potentially be delivered through minimally invasive or percutaneous techniques. Several reports have demonstrated survival, functional innervation, and muscular preservation following transplantation of SMNs into rodent nerves. Advances in the generation, culture, and differentiation of human iPSCs now offer the possibility for an unlimited supply of clinical grade SMNs. This review will discuss the previous reports of peripheral SMN transplantation, outline key considerations, and propose next steps towards advancing this approach to clinic. Stem cells have garnered great enthusiasm for their potential to revolutionize medicine. However, this excitement has often led to premature clinical studies with ill-defined cell products and mechanisms of action, particularly in spinal cord injury. We believe the peripheral transplantation of a defined SMN population to address neuromuscular degeneration will be transformative in augmenting current reconstructive strategies. By thus removing the current barriers of time and distance, this strategy would dramatically enhance the potential for reconstruction and functional recovery in otherwise hopeless paralyzing injuries. Furthermore, this strategy may be used as a permanent axon replacement following destruction of lower motor neurons and would enable exogenous stimulation options, such as pacing of transplanted SMN axons in the phrenic nerve to avoid mechanical ventilation in high cervical cord injury or amyotrophic lateral sclerosis.

Plasticity of the Central Nervous System Involving Peripheral Nerve Transfer

Peripheral nerve injury can lead to partial or complete loss of limb function, and nerve transfer is an effective surgical salvage for patients with these injuries. The inability of deprived cortical regions representing damaged nerves to overcome corresponding maladaptive plasticity after the reinnervation of muscle fibers and sensory receptors is thought to be correlated with lasting and unfavorable functional recovery. However, the concept of central nervous system plasticity is rarely elucidated in classical textbooks involving peripheral nerve injury, let alone peripheral nerve transfer. This article is aimed at providing a comprehensive understanding of central nervous system plasticity involving peripheral nerve injury by reviewing studies mainly in human or nonhuman primate and by highlighting the functional and structural modifications in the central nervous system after peripheral nerve transfer. Hopefully, it will help surgeons perform successful nerve transfer under the guidance of modern concepts in neuroplasticity.

Supinator to Posterior Interosseous Nerve Transfer for Restoration of Finger Extension

BACKGROUND

Cervical spinal cord injuries result in a severe loss of function and independence. The primary goal for these patients is the restoration of hand function. Nerve transfers have recently become a powerful intervention to restore the ability to grasp and release objects. The supinator muscle, although a suboptimal tendon transfer donor, serves as an ideal distal nerve donor for reconstructive strategies of the hand. This transfer is also applicable to lower brachial plexus injuries.

OBJECTIVE

To describe the supinator to posterior interosseous nerve transfer with the goal of restoring finger extension following spinal cord or lower brachial plexus injury.

METHODS

Nerve branches to the supinator muscle are transferred to the posterior interosseous nerve supplying the finger extensor muscles in the forearm.

RESULTS

The supinator to posterior interosseous nerve transfer is effective in restoring finger extension following spinal cord or lower brachial plexus injury.

CONCLUSION

This procedure represents an optimal nerve transfer as the donor nerve is adjacent to the target nerve and its associated muscles. The supinator muscle is innervated by the C5-6 nerve roots and is often available in cases of cervical SCI and injuries of the lower brachial plexus. Additionally, supination function is retained by supination action of the biceps muscle.

Comparative study of the reorganization in bilateral motor and sensory cortices after spinal cord hemisection in mice

OBJECTIVE

The effects of spinal cord injury (SCI) on sensorimotor cortex plasticity have not been well studied. Therefore, to explore the reorganization after SCI, we dynamically monitored postsynaptic dendritic spines of pyramidal neurons in vivo.

METHODS

Thy1-YFP transgenic mice were randomly divided into two groups: the control and SCI group. We then opened the spinal vertebral plates of all mice and sectioned one-half of the spinal cord in SCI group. The relevant areas were imaged bilaterally at 0, 3, 14 and 28 days post-SCI. The rates of elimination, formation and stable spines were evaluated.

RESULTS

At the early stage, the rate of stable and elimination spines experienced a similar change trend. But the rate of formation spines in the contralateral sensory cortex was significantly increased after SCI compared with those in the control group. At the late stage, spines of three types remodeled very differently between the sensory and motor cortex. Compared with those in the control group, spines in the bilateral sensory cortex demonstrated obvious differences in the rate of stable and elimination spines but not formation spines, while spines in the motor cortex, especially in the contralateral cortex increased significantly in the rate of formation after SCI. As for survival rate, differences mainly appeared in time frame instead of cortex type or region.

CONCLUSIONS

The dendritic spines in hindlimb representation area of the sensorimotor cortex experienced bilaterally remodeling after SCI. And those spines in the sensory and motor cortex experienced great but different change trends after SCI.

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.

Prelude to the special issue on novel neurocircuit, cellular and molecular targets for developing functional rehabilitation therapies of neurotrauma

The poor endogenous recovery capacity and other impediments to reinstating sensorimotor or autonomic function after adult neurotrauma have perplexed modern neuroscientists, bioengineers, and physicians for over a century. However, despite limited improvement in options to mitigate acute pathophysiological sequalae, the past 20 years have witnessed marked progresses in developing efficacious rehabilitation strategies for chronic spinal cord and brain injuries. The achievement is mainly attributable to research advancements in elucidating neuroplastic mechanisms for the potential to enhance clinical prognosis. Innovative cross-disciplinary studies have established novel therapeutic targets, theoretical frameworks, and regiments to attain treatment efficacy. This Special Issue contained eight papers that described experimental and human data along with literature reviews regarding the essential roles of the conventionally undervalued factors in neural repair: systemic inflammation, neural-respiratory inflammasome axis, modulation of glutamatergic and monoaminergic neurotransmission, neurogenesis, nerve transfer, recovery neurobiology components, and the spinal cord learning, respiration and central pattern generator neurocircuits. The focus of this work was on how to induce functional recovery from manipulating these underpinnings through their interactions with secondary injury events, peripheral and supraspinal inputs, neuromusculoskeletal network, and interventions (i.e., activity training, pharmacological adjuncts, electrical stimulation, and multimodal neuromechanical, brain-computer interface [BCI] and robotic assistance [RA] devices). The evidence suggested that if key neurocircuits are therapeutically reactivated, rebuilt, and/or modulated under proper sensory feedback, neurological function (e.g., cognition, respiration, limb movement, locomotion, etc.) will likely be reanimated after neurotrauma. The efficacy can be optimized by individualizing multimodal rehabilitation treatments via BCI/RA-integrated drug administration and neuromechanical protheses.