Key Considerations for Nerve Transfer Rehabilitation After Surgical Reconstruction for Brachial Plexus and Peripheral Nerve Injuries.

Nerve transfer surgery is commonly used to treat patients with brachial plexus injuries. However, guidelines on postoperative rehabilitation are not clearly established. Nerve transfers require the patient to relearn how to recruit newly innervated muscle(s), which may not occur naturally or intuitively. Supervised therapy is a valuable resource to guide patients through their lengthy recovery (often >12 months) because target muscle strength is both obtained and functionally used in daily life. This article highlights 10 key principles that provide the foundation for rehabilitation following nerve transfer surgery after a brachial plexus injury. Due to the shortcomings of the current evidence base for nerve transfer rehabilitation, we have included our anecdotal experience to augment the existing literature. It is important to have a collaborative surgeon-therapist relationship to communicate regarding operative details, expected timelines for reinnervation, patient needs, and realistic expectations. We provide examples of how to tailor the exercise program to synergistically recruit both the donor and target muscle action, including how to appropriately advance exercises based on the current level of nerve return. We also discuss the role that fatigue plays in denervated muscle and how fatigue may affect the exercise demands placed on the target muscle during specific stages of recovery.

A Surgical Framework for the Management of Incomplete Axillary Nerve Injuries.

BACKGROUND: Axillary nerve injury is the most common nerve injury affecting shoulder function. Nerve repair, grafting, and/or end-to-end nerve transfers are used to reconstruct complete neurotmetic axillary nerve injuries. While many incomplete axillary nerve injuries self-resolve, axonotmetic injuries are unpredictable, and incomplete recovery occurs. Similarly, recovery may be further inhibited by superimposed compression neuropathy at the quadrangular space. The current framework for managing incomplete axillary injuries typically does not include surgery. METHODS: This study is a retrospective analysis of 23 consecutive patients with incomplete axillary nerve palsy who underwent quadrangular space decompression with additional selective medial triceps to axillary end-to-side nerve transfers in 7 patients between 2015 and 2019. Primary outcome variables included the proportion of patients with shoulder abduction M3 or greater as measured on the Medical Research Council (MRC) scale, and shoulder pain measured on a Visual Analogue Scale (VAS). Secondary outcome variables included pre- and postoperative Disabilities of the Arm, Shoulder, and Hand Questionnaire (DASH) scores. RESULTS: A total of 23 patients met the inclusion criteria and underwent nerve surgery a mean 10.7 months after injury. Nineteen (83%) patients achieved MRC grade 3 shoulder abduction or greater after intervention, compared with only 4 (17%) patients preoperatively (p = 0.001). There was a significant decrease in VAS shoulder pain scores of 4.2 ± 2.5 preoperatively to 1.9 ± 2.4 postoperatively (p < 0.001). The DASH scores also decreased significantly from 48.8 ± 19.0 preoperatively to 30.7 ± 20.4 postoperatively (p < 0.001). Total follow-up was 17.3 ± 4.3 months. CONCLUSION: A surgical framework is presented for the appropriate diagnosis and surgical management of incomplete axillary nerve injury. Quadrangular space decompression with or without selective medial triceps to axillary end-to-side nerve transfers is associated with improvement in shoulder abduction strength, pain, and DASH scores in patients with incomplete axillary nerve palsy.

Quantifying Donor Deficits Following Nerve Transfer Surgery in Tetraplegia.

PURPOSE: Nerve transfer (NT) surgery can improve function in people with cervical spinal cord injury (SCI). However, the impact of donor nerve deficits remains unclear. The purpose of this study was to quantify donor deficits experienced by individuals with cervical SCI following NT. METHODS: This prospective single-arm, comparative study included people with SCI undergoing upper extremity NTs. Myometry was used to assess muscle strength at baseline and follow-up. The Spinal Cord Independence Measure was used to measure the ability to perform activities of daily living. RESULTS: Ten individuals underwent 20 NTs to restore elbow extension (donor, posterior deltoid; n = 2), hand opening (donor, supinator; n = 7), and hand closing (donor, brachialis; n = 11). Shoulder abduction strength decreased (-5.6% at early and -4.5% late follow-up) in the elbow extension NT. Wrist extension strength decreased at early (-46.9% ± 30.3) and increased by late (76.4% ± 154.0) follow-up in the hand opening NT. No statistically significant change in elbow flexion strength was noted in the hand closing NT. Spinal Cord Independence Measure scores did not change significantly between baseline and early postoperative follow-up; they improved at late follow-up. CONCLUSIONS: Use of expendable donor nerves with redundant function to perform NT surgery has relatively little impact on strength or capacity to perform activities of daily living, even in the unique and highly vulnerable SCI population. Early, temporary loss in wrist extension strength can be seen after the supinator to posterior interosseous nerve transfer. This study offers quantitative data about possible diminution of donor function after NT, enabling hand surgeons to better counsel individuals contemplating upper extremity reconstruction. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic I.

Outcome Analysis of Medial Triceps Motor Nerve Transfer to Axillary Nerve in Isolated and Brachial Plexus-Associated Axillary Nerve Palsy.

BACKGROUND: Since 2007, the authors have performed the triceps-to-axillary nerve transfer using the medial triceps branch to reconstruct axillary nerve function in brachial plexus and isolated axillary nerve palsies. METHODS: A retrospective chart review was undertaken of patients reconstructed with this transfer, recording patient and injury demographics and time to surgery. Preoperative and postoperative function was graded using the Medical Research Council scale and the Disabilities of the Arm, Shoulder, and Hand questionnaire. RESULTS: Postoperatively, 31 patients (64.6 percent) reached Medical Research Council grade 3 or higher at final follow-up. The median Disabilities of the Arm, Shoulder, and Hand score was 59.9 (interquartile range, 38.8 to 70.5) preoperatively and 25.0 (interquartile range, 11.3 to 61.4) at final follow-up. Sixteen patients (33 percent) had isolated axillary nerve injury; the median Medical Research Council grade was 4.25 (interquartile range, 3 to 4.25), with 14 patients (87.6 percent) achieving grade 3 or higher. Thirty-two patients (77 percent) had brachial plexus-associated injury; median Medical Research Council grade was 3 (interquartile range, 2 to 3), with 17 patients (53.1 percent) achieving grade 3 or higher. CONCLUSION: Medial triceps nerve branch is a strong donor for triceps-to-axillary nerve transfer; however, injury factors may limit the motor recovery in this complex patient population, particularly in axillary nerve palsy associated with brachial plexus injury. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

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).

Video-based Learning in Surgery: Establishing Surgeon Engagement and Utilization of Variable-duration Videos.

OBJECTIVE: To measure surgeon engagement and preferred video duration in a video-based learning program for nerve surgery. BACKGROUND: Educational videos can improve, standardize, and democratize best practices in surgery. To improve care internationally, educators must optimize their videos for learning. However, surgeon engagement and optimal video duration remain undefined. METHODS: A YouTube channel and a video-based learning website, PASSIO Education (passioeducation.com), were examined from 2011 to 2017. We assessed views, geographic location, audience engagement (average percent of video watched), audience retention (percent of viewers at each timepoint), and usage of short (median 7.4, range 4.1-20.3 min) and long (median 17.2, range 6.1-47.7 min) video formats for the same procedures. A survey of PASSIO Education membership examined preferred video duration. RESULTS: Our 117 nerve surgery videos attained over 3 million views with 69% originating outside of the United States. While YouTube achieved more international exposure, PASSIO Education attained a greater mean engagement of 48.4% (14.3% absolute increase, P < 0.0001). Surveyed surgeons (n = 304) preferred longer videos when preparing for infrequent or difficult cases compared with routine cases (P < 0.0001). Engagement declined with video duration, but audience retention between short and long video formats was correlated (τB = 0.52, P < 0.0001). CONCLUSIONS: For effective spread of best practices, we propose the joint use of YouTube for audience outreach and a surgeon-focused platform to maximize educational value. Optimal video duration is surgeon- and case-dependent and can be addressed through offering multiple video durations and interactive viewing options.

Supercharge End-to-Side Anterior Interosseous-to-Ulnar Motor Nerve Transfer Restores Intrinsic Function in Cubital Tunnel Syndrome.

BACKGROUND: The supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer offers a viable option to enhance recovery of intrinsic function following ulnar nerve injury. However, in the setting of chronic ulnar nerve compression where the timing of onset of axonal loss is unclear, there is a deficit in the literature on outcomes after supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer. METHODS: A retrospective study of patients who underwent supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer for severe cubital tunnel syndrome over a 5-year period was performed. The primary outcomes were improvement in first dorsal interosseous Medical Research Council grade at final follow-up and time to reinnervation. Change in key pinch strength; grip strength; and Disabilities of the Arm, Shoulder and Hand questionnaire scores were also evaluated using paired t tests and Wilcoxon signed rank tests. RESULTS: Forty-two patients with severe cubital tunnel syndrome were included in this study. Other than age, there were no significant clinical or diagnostic variables that were predictive of failure. There was no threshold of compound muscle action potential amplitude below which supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer was unsuccessful. CONCLUSIONS: This study provides the first cohort of outcomes following supercharge end-to-side anterior interosseous nerve-to-ulnar motor nerve transfer in chronic ulnar compression neuropathy alone and underscores the importance of appropriate patient selection. Prospective cohort studies and randomized controlled trials with standardized outcome measures are required. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Refining Indications for the Supercharge End-to-Side Anterior Interosseous to Ulnar Motor Nerve Transfer in Cubital Tunnel Syndrome.

The supercharge end-to-side anterior interosseous to ulnar motor nerve transfer has gained popularity over the past decade as a method of augmenting intrinsic muscle reinnervation in patients with acute neurotmetic ulnar nerve injuries. Controversy remains regarding its efficacy and appropriate clinical indications in cubital tunnel syndrome, where the timing of onset of axonal loss is less clear. The authors present guidelines for patient selection, surgical technique, and postoperative rehabilitation based on their clinical experience with the technique in this patient population. CLINICAL QUESTION/LEVEL OF EVIDENCE:: Therapeutic, V.

Median Neuropathy After Blood Draw Mimics Painful Clenched Fist Syndrome in a Child.

Background: Clenched fist syndrome is a rare disorder, often attributed to a conversion disorder without anatomic basis. Here, we review the literature surrounding clenched fist syndrome and challenge the assumption it is always psychiatric in origin, via description of a case of clenched fist syndrome responsive to surgical nerve decompression. Methods: An unusual case of clenched fist syndrome is reviewed and discussed. Results: A child presenting with clenched fist syndrome failed conservative measures consisting of formal hand therapy, multidisciplinary pain management, and psychiatric treatment. On clinical examination, she had findings consistent with median nerve entrapment. After undergoing surgical decompression of the median nerve in the forearm and carpal tunnel, the clenched fist resolved immediately. Conclusions: Nerve compression may be an unrecognized factor underlying some cases of clenched fist syndrome. Evaluation by a hand surgeon or a hand therapist skilled in the detection of peripheral nerve entrapment or injury should be considered as part of the workup for this rare disorder.

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.

Preferences in Sleep Position Correlate With Nighttime Paresthesias in Healthy People Without Carpal Tunnel Syndrome.

BACKGROUND: Carpal tunnel syndrome has been associated with sleep position preferences. The aim of this study is to assess self-reported nocturnal paresthesias and sleeping position in participants with and without carpal tunnel syndrome diagnosis to further clinical knowledge for preventive and therapeutic interventions. METHODS: A cross-sectional survey study of 396 participants was performed in young adults, healthy volunteers, and a patient population. Participants were surveyed on risk factors for carpal tunnel syndrome, nocturnal paresthesias, and sleep preferences. Binary logistic regression analysis was performed comparing participants with rare and frequent nocturnal paresthesias. Subanalyses for participants without carpal tunnel syndrome under and over 21 years of age were performed on all factors significantly associated with subclinical compression neuropathy in the overall population. RESULTS: Thirty-three percent of the study population experienced nocturnal paresthesias at least weekly. Increased body mass index ( P < .001) and sleeping with the wrist flexed ( P = .030) were associated with a higher frequency of nocturnal paresthesias. Side sleeping was associated with less frequent nocturnal symptoms ( P = .003). In participants without carpal tunnel syndrome, subgroup analysis illustrated a relationship between nocturnal paresthesias and wrist position. In participants with carpal tunnel syndrome, sleeping on the side had a significantly reduced frequency of nocturnal paresthesias. CONCLUSION: This study illustrates nocturnal paresthesias in people without history of carpal tunnel syndrome including people younger than previously reported. In healthy patients with upper extremity subclinical compression neuropathy, sleep position modification may be a useful intervention to reduce the frequency of nocturnal symptoms prior to developing carpal tunnel syndrome.

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.

Important Details in Performing and Interpreting the Scratch Collapse Test.

The utility of the scratch collapse test has been demonstrated in examination of patients with carpal and cubital tunnel syndromes and long thoracic and peroneal nerve compressions. In the authors' clinic, this lesser known test plays a key role in peripheral nerve examination where localization of the nerve irritation or injury is not fully understood. Test utility and accuracy in patients with more challenging presentations likely correlate with tester understanding and experience. This article offers a clear outline of all stages of the test to improve interrater reliability. The nuances of test performance are described, including a description of situations where the scratch collapse test is deemed inappropriate. Four clinical scenarios where the scratch collapse test may be useful are included. Corresponding video content is provided to improve performance and interpretation of the scratch collapse test. CLINICAL QUESTION/LEVEL OF EVIDENCE: Diagnostic, V.

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.

Use of peripheral nerve transfers in tetraplegia: evaluation of feasibility and morbidity.

BACKGROUND: Peripheral nerve transfers are being used to improve upper extremity function in cervical spinal cord injury (SCI) patients. The purpose of this study was to evaluate feasibility and perioperative complications following these procedures. METHODS: Eligible SCI patients with upper extremity dysfunction were assessed and followed for a minimum of 3 months after surgery. Data regarding demographics, medical history, physical examination, electrodiagnostic testing, intraoperative nerve stimulation, recipient nerve histomorphometry, surgical procedure, and complications were collected. RESULTS: Seven patients had surgery on eight limbs, mean age of 28 ± 9.9 years and mean time from SCI injury of 5.1 ± 5.2 years. All patients had volitional elbow flexion and no volitional hand function. The nerve to the brachialis muscle was used as the expendable donor, and the recipients included the anterior interosseous nerve (AIN) (for volitional prehension), nerve branches to the flexor carpi radialis, and flexor digitorum superficialis. Two patients underwent additional nerve transfers: (1) supinator to extensor carpi ulnaris or (2) deltoid to triceps. No patients had any loss of baseline upper extremity function, seven of eight AIN nerve specimens had preserved micro-architecture, and all intraoperative stimulation of recipient neuromuscular units was successful further supporting feasibility. Four patients had perioperative complications; all resolved or improved (paresthesias). CONCLUSION: Nerve transfers can be used to reestablish volitional control of hand function in SCI. This surgery does not downgrade existing function, uses expendable donor nerve, and has no postoperative immobilization, which might make it a more viable option than traditional tendon transfer and other procedures.

Median to radial nerve transfers for restoration of wrist, finger, and thumb extension.

Radial nerve injury results in loss of wrist, finger, and thumb extension. Traditionally, radial nerve palsies that fail to recover spontaneously have been reconstructed with tendon transfers or nerve grafts. Nerve transfers are a novel approach to the surgical management of Sunderland grade IV and V radial nerve injuries. We describe our technique for median to radial nerve transfers. In this procedure, the flexor digitorum superficialis nerve is transferred to the extensor carpi radialis brevis nerve for wrist extension, and the flexor carpi radialis nerve is transferred to the posterior interosseous nerve for finger and thumb extension. Our experience with these nerve transfers has demonstrated excellent outcomes up to 10 months after injury. Indeed, unlike tendon transfers, median to radial nerve transfers have the potential to restore normal radial nerve function, including independent finger motion. Tension-free nerve coaptation and postoperative motor re-education are critical factors to achieving these successful outcomes.

Supercharged end-to-side anterior interosseous to ulnar motor nerve transfer for intrinsic musculature reinnervation.

Functional motor recovery after peripheral nerve injury is predominantly determined by the time to motor end plate reinnervation and the absolute number of regenerated motor axons that reach target. Experimental models have shown that axonal regeneration occurs across a supercharged end-to-side (SETS) nerve coaptation. In patients with a recovering proximal ulnar nerve injury, a SETS nerve transfer conceptually is useful to protect and preserve distal motor end plates until the native axons fully regenerate. In addition, for nerve injuries in which incomplete regeneration is anticipated, a SETS nerve transfer may be useful to augment the regenerating nerve with additional axons and to more quickly reinnervate target muscle. We describe our technique for a SETS nerve transfer of the terminal anterior interosseous nerve (AIN) to the pronator quadratus muscle (PQ) end-to-side to the deep motor fascicle of the ulnar nerve in the distal forearm. In addition, we describe our postoperative therapy regimen for these transfers and an evaluation tool for monitoring progressive muscle reinnervation. Although the AIN-to-ulnar motor group SETS nerve transfer was specifically designed for ulnar nerve injuries, we believe that the SETS procedure might have broad clinical utility for second- and third-degree axonotmetic nerve injuries, to augment partial recovery and/or "babysit" motor end plates until the native parent axons regenerate to target. We would consider all donor nerves currently utilized in end-to-end nerve transfers for neurotmetic injuries as candidates for this SETS technique.

Two-level motor nerve transfer for the treatment of long thoracic nerve palsy.

The authors report a case of long thoracic nerve (LTN) palsy treated with two-level motor nerve transfers of a pectoral fascicle of the middle trunk, and a branch of the thoracodorsal nerve. This procedure resulted in near-total improvement of the winged scapula deformity, and a return of excellent shoulder function. A detailed account of the postoperative physical therapy regimen is included, as this critical component of the favorable result cannot be overlooked. This case establishes the two-level motor nerve transfer as a new option for treating LTN palsy, and demonstrates that nerve transfers should be considered in the therapeutic algorithm of an idiopathic mononeuritis.