Treatment of brachial plexus injury

Brachial Plexus Injury Influences Efferent Transmission on More than Just the Symptomatic Side, as Verified with Clinical Neurophysiology Methods Using Magnetic and Electrical Stimulation

The variety of sources of brachial plexus injuries (BPIs) and the severity and similarity of their clinical symptoms with those of other injuries make their differential diagnosis difficult. Enriching their diagnosis with objective high-sensitivity diagnostics such as clinical neurophysiology may lead to satisfactory treatment results, and magnetic stimulation (MEP) might be an advantageous addition to the diagnostic standard of electrical stimulation used in electroneurography (ENG). The asymptomatic side in BPI cases sometimes shows only subclinical neurological deficits; this study aimed to clarify the validity and utility of using MEP vs. ENG to detect neural conduction abnormalities. Twenty patients with a BPI and twenty healthy volunteers with matching demographic and anthropometric characteristics were stimulated at their Erb's point in order to record the potentials evoked using magnetic and electrical stimuli to evaluate their peripheral motor neural transmission in their axillar, musculocutaneous, radial, and ulnar nerves. MEP was also used to verify the neural transmission in participants' cervical roots following transvertebral stimulations, checking the compatibility and repeatability of the evoked potential recordings. The clinical assessment resulted in an average muscle strength of 3-1 (with a mean of 2.2), analgesia that mainly manifested in the C5-C7 spinal dermatomes, and a pain evaluation of 6-4 (mean of 5.4) on the symptomatic side using the Visual Analog Scale, with no pathological symptoms on the contralateral side. A comparison of the recorded potentials evoked with magnetic versus electrical stimuli revealed that the MEP amplitudes were usually higher, at p = 0.04-0.03, in most of the healthy volunteers' recorded muscles than in those of the group of BPI patients, whose recordings showed that their CMAP and MEP amplitude values were lower on their more symptomatic than asymptomatic sides, at p = 0.04-0.009. In recordings following musculocutaneous and radial nerve electrical stimulation and ulnar nerve magnetic stimulation at Erb's point, the values of the latencies were also longer on the patient's asymptomatic side compared to those in the control group. The above outcomes prove the mixed axonal and demyelination natures of brachial plexus injuries. They indicate that different types of traumatic BPIs also involve the clinically asymptomatic side. Cases with predominantly median nerve lesions were detected in sensory nerve conduction studies (SNCSs). In 16 patients, electromyography revealed neurogenic damage to the deltoid and biceps muscles, with an active denervation process at work. The predominance of C5 and C6 brachial plexus injuries in the cervical root and upper/middle trunk of patients with BPI has been confirmed. A probable explanation for the bilateral symptoms of dysfunction detected via clinical neurophysiology methods in the examined BPI patients, who showed primarily unilateral damage, maybe the reaction of their internal neural spinal center's organization. Even when subclinical, this may explain the poor BPI treatment outcomes that sometimes occur following long-term physical therapy or surgical treatment.

Sarm1 is not necessary for activation of neuron-intrinsic growth programs yet required for the Schwann cell repair response and peripheral nerve regeneration

Upon peripheral nervous system (PNS) injury, severed axons undergo rapid SARM1-dependent Wallerian degeneration (WD). In mammals, the role of SARM1 in PNS regeneration, however, is unknown. Here we demonstrate that Sarm1 is not required for axotomy induced activation of neuron-intrinsic growth programs and axonal growth into a nerve crush site. However, in the distal nerve, Sarm1 is necessary for the timely induction of the Schwann cell (SC) repair response, nerve inflammation, myelin clearance, and regeneration of sensory and motor axons. In Sarm1-/- mice, regenerated fibers exhibit reduced axon caliber, defective nerve conduction, and recovery of motor function is delayed. The growth hostile environment of Sarm1-/- distal nerve tissue was demonstrated by grafting of Sarm1-/- nerve into WT recipients. SC lineage tracing in injured WT and Sarm1-/- mice revealed morphological differences. In the Sarm1-/- distal nerve, the appearance of p75NTR+, c-Jun+ SCs is significantly delayed. Ex vivo, p75NTR and c-Jun upregulation in Sarm1-/- nerves can be rescued by pharmacological inhibition of ErbB kinase. Together, our studies show that Sarm1 is not necessary for the activation of neuron intrinsic growth programs but in the distal nerve is required for the orchestration of cellular programs that underlie rapid axon extension.

Educational quality of YouTube content on brachial plexus injury and treatment

INTRODUCTION

While surgical literature exists on birth-related brachial plexus injury (BPI), there are not validated sources of information on BPI for patients, which can impact patient autonomy and decision-making. With YouTube as a popular source for patients to research diagnoses, this study aims to evaluate the quality of information regarding BPI and its treatment available on the platform.

MATERIALS AND METHODS

BPI YouTube videos were screened independently by two reviewers. Videos were categorized by source: (1) academic, government, and non-profit organizations; (2) private practices, companies, and for-profit organizations; (3) independent users. Each video was evaluated for reliability, credibility, and quality using the modified DISCERN criteria (scale, 0-5), Journal of the American Medical Association (JAMA) criteria (scale, 0-4), and Global Quality Scale (GQS; scale, 1-5). Surgical treatment videos were analyzed by the senior author using a modified "treatment" DISCERN criteria (scale, 8-40). Non-English videos were excluded from this study. Analysis of variance tests were used to compare means.

RESULTS

One hundred and fifteen videos were selected for final analysis. The mean modified DISCERN score was 3.26; JAMA was 2.31; GQS was 3.48. Videos were subdivided according to source. Group 1, 2, and 3 had 45, 24, and 46 videos, respectively. Modified DISCERN score was greater for Group 1 than Group 2 (3.58 vs. 3.04, p < .001) and Group 3 (3.58 vs. 3.07, p < .001). JAMA score was greater for Group 1 than Group 2 (2.63 vs 2.15, p = .041) and Group 3 (2.63 vs. 2.08, p = .002). GQS score was greater for Group 1 than Group 2 (3.93 vs. 3.31, p = .031) and Group 3 (3.93 vs. 3.13, p < .001). Of the 34 videos (44.7%) that mentioned treatment, the DISCERN score was 14.32.

CONCLUSION

The videos analyzed were found to have moderate reliability, credibility, and quality. The reliability of information regarding treatments for BPI was poor. Healthcare providers should supply additional information on treatment of BPI.

Treatment of Complete Brachial Plexus Injuries Using Double Free Muscle Transfer

PURPOSE

The purpose of this study was to examine the surgical outcomes of double free muscle transfer (DFMT) performed in patients with complete brachial plexus injury (BPI).

METHODS

We retrospectively analyzed the outcomes of DFMT for 12 patients with complete BPI who were followed up for more than 2 years after the final muscle transplantation. Their mean age was 29 years (range, 18-41). Three patients underwent contralateral C7 nerve root transfer before the DFMT. The range of motion (ROM) of the shoulder, elbow, and fingers was measured. Patient-reported outcome measures, including Disability of the Shoulder, Arm, and Hand (DASH) scores and visual analog scale (VAS) scores for pain, were also examined.

RESULTS

The mean shoulder ROM against gravity was 22° ± 8° in abduction and 33° ± 5° in flexion. Seven patients underwent phrenic nerve (PhN) transfer to the suprascapular nerves, and five exhibited asymptomatic lung impairment on spirography more than 2 years after PhN transfer. The mean elbow ROM against gravity was 111° ± 9° in flexion and -32° ± 7° in extension. All patients obtained elbow flexion >90° against a 0.5-kg weight. All patients obtained touch sensation and two recognized warm and cold sensations in the affected palm. The mean total active motion of the affected fingers was 44° ± 11°. All patients exhibited hook function of the hands. The mean preoperative and postoperative DASH scores were 70.3 ± 13.4 and 51.8 ± 15.9, respectively. The mean pain VAS score was 28 ± 31 at the final follow-up.

CONCLUSIONS

Double free muscle transfer provided patients with complete brachial plexus palsy with good elbow flexion and hand hook functions.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Towards comprehensive evaluation of the FLEXotendon glove-III: a case series evaluation in pediatric clinical cases and able-bodied adults

Injuries involving the nervous system, such as a brachial plexus palsy or traumatic brain injury, can lead to impairment in the functionality of the hand. Assistive robotics have been proposed as a possible method to improve patient outcomes in rehabilitation. The work presented here evaluates the FLEXotendon Glove-III, a 5 degree-of-freedom, voice-controlled, tendon-driven soft robotic hand exoskeleton, with two human subjects with hand impairments and four able-bodied subjects. The FLEXotendon Glove-III was evaluated on four unimpaired subjects, in conjunction with EMG sensor data, to determine the quantitative performance of the glove in applied pinch force, perturbation resistance, and exertion reduction. The exoskeleton system was also evaluated on two subjects with hand impairments, using two standardized hand function tests, the Jebsen-Taylor Hand Function Test and the Toronto Rehabilitation Institute Hand Function Test. The subjects were also presented with three qualitative questionnaires, the Capabilities of Upper Extremities Questionnaire, the Quebec User Evaluation of Satisfaction with Assistive Technology, and the Orthotics Prosthetics User Survey-Satisfaction module. From the previous design, minor design changes were made to the exoskeleton. The quick connect system was redesigned for improved performance, the number of motors was reduced to decrease overall footprint, and the entire system was placed into a compact acrylic case that can be placed into a backpack for increased portability.

Time to surgery and myo-d expression in biceps muscle of adult brachial plexus injury: a preliminary study

BACKGROUND

Brachial Plexus Injury (BPI) is one of the peripheral nerve injuries which causes severe functional impairment and disability. Without prompt treatment, prolonged denervation will cause severe muscle atrophy. MyoD, which is expressed by satellite cells, is one of the parameters that relate to the regeneration process in post-injury muscle and it is presumed to determine the clinical outcome following neurotization procedure. This study aims to understand the correlation between time to surgery (TTS) and MyoD expression in satellite cells in the biceps muscle of adult brachial plexus injury patients.

METHODS

Analytic observational study with a cross-sectional design was conducted at Dr. Soetomo General Hospital. All patients with BPI who underwent surgery between May 2013 and December 2015 were included. Muscle biopsy was taken and stained using immunohistochemistry for MyoD expression. Pearson correlation test was used to assess the correlation between MyoD expression with TTS and with age.

RESULTS

Twenty-two biceps muscle samples were examined. Most patients are males (81.8%) with an average age of 25.5 years. MyoD expression was found to be highest at TTS of 4 months and then dropped significantly (and plateau) from 9 to 36 months. MyoD expression is significantly correlated with TTS (r=-0.895; p = 0.00) but not with age (r=-0.294; p = 0.184).

CONCLUSION

Our study found, from the cellular point of view, that treatment of BPI needs to be done as early as possible before the regenerative potential - as indicated by MyoD expression - declined.

Age correlation in upper brachial plexus injury patients undergoing nerve transfer surgeries

•A patient's age can be a critical factor influencing the outcome following upper brachial plexus injury (BPI) reconstruction.•The favorable factor being younger patients with short denervation period.•In older patients early and more aggressive management for an optimal outcome.•This study supports the various correlation of age with the outcomes of upper brachial plexus reconstruction surgery.

Risk prediction model for unsuccessful elbow flexion recovery after nerve transfer surgery in patients with brachial plexus injury

OBJECTIVE

Nerve transfer surgery has been a mainstay treatment of brachial plexus injury, with varying success rates. Patients undergoing unsuccessful surgery are left with a useless limb for at least 2 years. Preoperative prediction has become a topic of interest to avoid an unsuccessful nerve transfer surgery. This study aimed to find strong predictive factors and develop a prediction model for unsuccessful functional elbow flexion recovery 2 years after a nerve transfer surgery in patients with brachial plexus injury.

METHODS

This retrospective study reviewed the medical records of 987 patients with traumatic brachial plexus injury who underwent brachial plexus surgery by five hand and microsurgery surgeons at a single tertiary care referral center from December 2001 to July 2018. Four hundred thirty-three patients were eligible for analysis. Patient demographic data, injury factors, surgical details, and postoperative factors were collected. Multivariable logistic regression was used to identify strong prognostic factors for unsuccessful nerve transfer surgery for elbow flexion. A simplified model was developed by rounding the coefficient to the nearest 0.5 score or an integer. Both original and simplified models were validated using the Hosmer-Lemeshow goodness-of-fit test and bootstrapping.

RESULTS

A full, original prognostic model from a stepwise backward logistic regression consisted of a BMI ≥ 23 kg/m2 (p = 0.015), smoking (p = 0.046), total arm-type injury (p = 0.033), donor nerve (p < 0.001), associated upper-extremity fracture (p = 0.013), and associated ipsilateral vascular injury (p = 0.095). The areas under the receiver operating characteristic curve of the original and simplified models were 0.765 and 0.766, respectively. The Hosmer-Lemeshow test showed good agreement of predicted and observed probability of the original (p = 0.49) and simplified (p = 0.19) models. Bootstrapping estimated an average optimism (1.9%) in the original model and minimal optimism (0.1%) in the simplified model.

CONCLUSIONS

The prediction model for failed elbow flexion recovery after nerve transfer surgery in traumatic brachial plexus injury was developed with good predictive value and internal validity. An alternative treatment, i.e., primary free functioning muscle transfer, should be offered in preoperative counseling in cases of a very high risk of failure.

Comparison of Anterior vs. Dorsal Approach for Spinal Accessory to Suprascapular Nerve Transfer in Patients With a Brachial Plexus Injury and Its Outcome on Shoulder Function

Background

Brachial plexus injuries are frequently encountered in the domain of plastic surgery, mostly secondary to road traffic accidents, gunshot injuries, or falls from a height. Many modalities have been described in the management, depending on the level and duration of the injury. C5, C6 and C5, C6, C7 are two common patterns in which nerve repair and transfers are described. At our center, we practice spinal accessory to suprascapular nerve transfer in all patients with upper trunk brachial plexus injury. There are two described approaches for the spinal accessory nerve to suprascapular nerve transfer, i.e. anterior or dorsal. The rationale for doing the posterior approach is that this approach avoids damaging the suprascapular nerve at its entrance in the suprascapular notch under the suprascapular ligament during exploration due to traction.

Materials and methods

This is a retrospective study with a consecutive sampling of 23 patients presenting at Liaquat National Hospital, Karachi, with upper trunk brachial plexus injuries during the time period from January 2016 to December 2017, i.e. two years. We divided these 23 patients into two groups, one with the anterior approach and the other with a dorsal approach for spinal accessory to suprascapular nerve transfer for shoulder abduction. The mean duration of post-surgical follow-up was from 18 to 24 months and recovery and functional outcomes were assessed.

Results

Out of the 23 patients that were included, 10 patients were operated on with an anterior approach and 13 with a posterior approach. Fifty percent (50%) of patients operated with the anterior approach and 84% of patients with the posterior showed the best motor grade recovery of M4, respectively, with better performance in patients with the posterior approach as compared to the anterior approach.

Conclusion

We advocate taking a posterior approach for spinal accessory to suprascapular nerve transfer for shoulder abduction, as it has shown better results with reliable outcomes concerning shoulder abduction, angle of abduction, and range of motion.

Virtual Reality combined with Robotic facilitated movements for pain management and sensory stimulation of the upper limb following a Brachial Plexus injury: A case study

Brachial Plexus injuries are complex in nature caused in large by high impact traffic accidents which can lead to additional complications such as Complex Regional Pain Syndrome and even lead to amputation or the need for further surgical intervention. Treatment options to help repair the brachial plexus initially involve surgical intervention and post-surgery rehabilitation with medication to help with ongoing pain. Pain treatments used for these types of injuries are limited and differ in effectiveness. Paradigms utilising multimodal systems such as the one described in this paper based on virtual reality and robotics could yield results that are non-invasive and provide better rehabilitation outcomes for the sufferers. In this paper we present a single case study exploring whether Virtual Reality plus Haptic feedback have any practical potential for reducing upper limb pain and improving function in patients with brachial plexus injuries. The case study is presented with long standing complex combination of phantom limb and neuropathic pain. A decrease in perceived levels of pain was reported which amounts to a 50% reduction in pain from baseline and an improved range of motion. An examination of the sensory phantom map on the stump seems to indicate an early establishment of the thumb representation on the stump close to the area being stimulated with potential implications for prosthesis use.

Case Report: Plasticity in Central Sensory Finger Representation and Touch Perception After Microsurgical Reconstruction of Infraclavicular Brachial Plexus Injury

After brachial plexus injury (BPI), early microsurgery aims at facilitating reconnection of the severed peripheral nerves with their orphan muscles and sensory receptors and thereby reestablishing communication with the brain. In order to investigate this sensory recovery, here we combined functional magnetic resonance imaging (fMRI) and tactile psychophysics in a patient who suffered a sharp, incomplete amputation of the dominant hand at the axilla level. To determine somatosensory detection and discomfort thresholds as well as sensory accuracy for fingers of both the intact and affected hand, we used electrotactile stimulation in the framework of a mislocalization test. Additionally, tactile stimulation was performed in the MRI scanner in order to determine the cortical organization of the possibly affected primary somatosensory cortex. The patient was able to detect electrotactile stimulation in 4 of the 5 fingertips (D1, D2, D4, D5), and in the middle phalanx in D3 indicating some innervation. The detection and discomfort threshold were considerably higher at the affected side than at the intact side, with higher detection and discomfort thresholds for the affected side. The discrimination accuracy was rather low at the affected side, with stimulation of D1/D2/D3/D4/D5 eliciting most commonly a sensation at D4/D1/D3/D2/D5, respectively. The neuroimaging data showed a mediolateral succession from D2 to D5 to D1 to D4 (no activation was observed for D3). These results indicate a successful regrowth of the peripheral nerve fibers from the axilla to four fingertips. The data suggest that some of the fibers have switched location in the process and there is a beginning of cortical reorganization in the primary somatosensory cortex, possibly resulting from a re-education of the brain due to conflicting information (touch vs. vision).

Optimal Donor Nerve to Restore Elbow Flexion After Traumatic Brachial Plexus Injury: A Systematic Review and Meta-Analysis

BACKGROUND

Traumatic brachial plexus injuries (BPIs) often lead to devastating upper extremity deficits. Treatment frequently prioritizes restoring elbow flexion through transfer of various donor nerves; however, no consensus identifies optimal donor nerve sources.

OBJECTIVE

To complete a meta-analysis to assess donor nerves for restoring elbow flexion after partial and total BPI (TBPI).

METHODS

Original English language articles on nerve transfers to restore elbow flexion after BPI were included. Using a random-effects model, we calculated pooled, weighted effect size of the patients achieving a composite motor score of ≥M3, with subgroup analyses for patients achieving M4 strength and with TBPI. Meta-regression was performed to assess comparative efficacy of each donor nerve for these outcomes.

RESULTS

Comparison of the overall effect size of the 61 included articles demonstrated that intercostal nerves and phrenic nerves were statistically superior to contralateral C7 (cC7; P = .025, <.001, respectively) in achieving ≥M3 strength. After stratification by TBPI, the phrenic nerve was still superior to cC7 in achieving ≥M3 strength (P = .009). There were no statistical differences among ulnar, double fascicle, or medial pectoral nerves in achieving ≥M3 strength. Regarding M4 strength, the phrenic nerve was superior to cC7 (P = .01) in patients with TBPI and the ulnar nerve was superior to the medial pectoral nerve (P = .036) for partial BPI.

CONCLUSION

Neurotization of partial BPI or TBPI through the intercostal nerve or phrenic nerve may result in functional advantage over cC7. In patients with upper trunk injuries, neurotization using ulnar, median, or double fascicle nerve transfers has similarly excellent functional recovery.

The role of neurotization in autologous breast reconstruction: Can reconstruction restore breast sensation?

As the sophistication of microsurgical breast reconstruction continues to evolve, plastic surgeons are focusing on techniques to improve functional and psychosocial outcomes for patients, including breast sensation. Interest in neurotization of breast flaps, among both patients and surgeons, has grown significantly in recent years. This study aimed to review the outcomes of neurotization across autologous flap reconstructions, to provide a comprehensive analysis of the efficacy of this technique in improving postoperative sensory recovery.

Functional outcome predictors after spinal accessory nerve to suprascapular nerve transfer for restoration of shoulder abduction in traumatic brachial plexus injuries in adults: the effect of time from injury to surgery

BACKGROUND

Shoulder abduction is crucial for daily activities, and its restoration is one of the surgical priorities. We evaluated the predictive factors of shoulder abduction functional outcome after spinal accessory nerve (SAN) to suprascapular nerve (SSN) transfer, with special emphasis on the effect of time from injury to the surgery, in the treatment of traumatic brachial plexus injuries.

METHOD

This cohort included adult patients who underwent SAN-to-SSN transfer with a preoperative Medical Research Council strength grade 0 and a follow-up of minimum 18 months. The primary outcome was shoulder abduction function (bad, < 30°; good, 30°-60°; or excellent, > 60°). Demographics, trauma characteristics, time lapse between injury and surgery, concomitant axillary nerve reconstruction, and surgery duration were registered. Ordinal logistic regression was used to identify predictors of functional outcomes.

RESULTS

The records of 83 patients (86.7% men, mean age 28.8 ± 9.8 years) were analysed. Mean body mass index was 24.1 ± 3.7 kg/m², and 43.1% were overweight/obese. Motorcycle crashes were the most common trauma mechanism (88.0%). Excellent, good, and bad outcomes were achieved by 20.4%, 38.6%, and 41.0%, respectively. Older patients tended to have worse outcomes (p = 0.074), as well as left-sided lesions (p = 0.015) or those contralateral to manual dominance (p = 0.057). The longer the interval between injury and surgery the worse the outcome: excellent, 5.5 (4.3-7.1); good, 6.9 (5.9-8.7); and bad, 8.2 (5.7-10.1) months (p = 0.018). After multivariable analysis, longer time interval predicted lower odds of better outcomes (OR 0.823, 95% CI 0.699-0.970, p = 0.020; 17.7% lower odds of good or excellent outcome for each additional month). The odd of good or excellent outcomes was also associated with axillary nerve reconstruction (OR 2.767, 95% CI 1.016-7.536, p = 0.046), but not with age or lesion laterality.

CONCLUSIONS

Excellent or good functional outcomes for shoulder abduction were achieved by almost sixty percent of adults who underwent SAN-to-SSN transfer for reconstruction of traumatic brachial plexus injuries, associated or not with axillary nerve reconstruction strategies. Longer delays from injury to surgery predicted worse outcomes, and the best time frame seemed to be less than 6 months.

Obesity status is a risk factor for secondary surgery after neurolysis, direct nerve repair or nerve grafting in traumatic brachial plexus injury: a retrospective cohort study

Background

The objective of the study was to investigate the association between obesity and the presence of secondary surgery following neurolysis, direct nerve repair, or nerve grafting in patients with traumatic brachial plexus injury.

Methods

In this retrospective chart review spanning two Level I medical centers in a single metropolitan area, 57 patients who underwent neurolysis, direct nerve repair, or nerve grafting for brachial plexus injuries between 2002 and 2015 were identified. Risk regression analysis was used to evaluate the association between obesity status and secondary surgery.

Results

After controlling for the confounding variables of age, high energy injury, associated shoulder dislocation and associated clavicle fracture using multivariate regression (risk regression), the risk ratio of secondary surgery in obese patients compared to non-obese patients was 6.99 (P = 0.028). The most common secondary surgery was tendon or local muscle transfer.

Conclusions

There is an increased risk of secondary surgery in obese patients compared to non-obese patients of the same age and with the same severity of injury. The increased risk may be due to challenges related to powering a heavier upper extremity. A weight reduction program might be considered as part of the preoperative strategy.

Brachial Plexus Injuries in Sport Medicine: Clinical Evaluation, Diagnostic Approaches, Treatment Options, and Rehabilitative Interventions

The brachial plexus represents a complex anatomical structure in the upper limb. This "network" of peripheral nerves permits the rearrangement of motor efferent fibers, coming from different spinal nerves, in several terminal branches directed to upper limb muscles. Moreover, afferent information coming from different cutaneous regions in upper limb are sorted in different spinal nerves through the brachial plexus. Severe brachial plexus injuries are a rare clinical condition in the general population and in sport medicine, but with dramatic consequences on the motor and sensory functions of the upper limb. In some sports, like martial arts, milder injuries of the brachial plexus can occur, with transient symptoms and with a full recovery. Clinical evaluation represents the cornerstone in the assessment of the athletes with brachial plexus injuries. Electrodiagnostic studies and imaging techniques, like magnetic resonance and high-frequency ultrasound, could be useful to localize the lesion and to define an appropriate treatment and a functional prognosis. Several conservative and surgical techniques could be applied, and multidisciplinary rehabilitative programs could be performed to guide the athlete toward the recovery of the highest functional level, according to the type of injury.

EPIDEMIOLOGICAL STUDY OF TRAUMATIC BRACHIAL PLEXUS INJURIES

OBJECTIVE

To conduct an epidemiological study on brachial plexus injuries, through data collection of patients treated in the Hospital São Paulo, which is the referral center for high complexity in this region.

METHODS

We conducted a retrospective study with a review of the electronic medical records of the Hospital, from August 2008 to June 2013.

RESULTS

We estimated an 1.88/100,000 annual incidence, considering that the Hospital is the only referral center for brachial plexus injuries. The mean time between injury and the first visit to the reference hospital was 8.25 months. The mean time interval between injury and surgery was 11.25 months. The percentage of total injuries was 33%, while the upper and middle trunk injuries were 33% and 28%, respectively.

CONCLUSION

We observed many aspects in common with those reported by other centers of excellence in Brazil such as: sex, age and mechanism of injury. However, some findings were different from most other epidemiological studies, namely: level of injury, time between the accident and the first appointment and the time between injury and surgery. Level of evidence IV, case series.

Cost-Effectiveness Analysis of Combined Dual Motor Nerve Transfers versus Alternative Surgical and Nonsurgical Management Strategies to Restore Shoulder Function Following Upper Brachial Plexus Injury

BACKGROUND

Restoration of shoulder function is an important treatment goal in upper brachial plexus injury (UBPI). Combined dual motor nerve transfer (CDNT) of spinal accessory to suprascapular and radial to axillary nerves demonstrates good functional recovery with minimal risk of perioperative complications.

OBJECTIVE

To evaluate the cost-effectiveness of CDNT vs alternative operative and nonoperative treatments for UBPI.

METHODS

A decision model was constructed to evaluate costs ($, third-party payer) and effectiveness (quality-adjusted life years [QALYs]) of CDNT compared to glenohumeral arthrodesis (GA), conservative management, and nontreatment strategies. Estimates for branch probabilities, costs, and QALYs were derived from published studies. Incremental cost-effectiveness ratios (ICER, $/QALY) were calculated to compare the competing strategies. One-way, 2-way, and probabilistic sensitivity analyses with 100 000 iterations were performed to account for effects of uncertainty in model inputs.

RESULTS

Base case model demonstrated CDNT effectiveness, yielding an expected 21.04 lifetime QALYs, compared to 20.89 QALYs with GA, 19.68 QALYs with conservative management, and 19.15 QALYs with no treatment. The ICERs for CDNT, GA, and conservative management vs nontreatment were $5776.73/QALY, $10 483.52/QALY, and $882.47/QALY, respectively. Adjusting for potential income associated with increased likelihood of returning to work after clinical recovery demonstrated CDNT as the dominant strategy, with ICER = -$56 459.54/QALY relative to nontreatment. Probabilistic sensitivity analysis showed CDNT cost-effectiveness at a willingness-to-pay threshold of $50 000/QALY in 78.47% and 81.97% of trials with and without income adjustment, respectively. Conservative management dominated in <1% of iterations.

CONCLUSION

CDNT and GA are cost-effective interventions to restore shoulder function in patients with UBPI.

Timing of surgery in traumatic brachial plexus injury: a systematic review

OBJECTIVE

Ideal timeframes for operating on traumatic stretch and blunt brachial plexus injuries remain a topic of debate. Whereas on the one hand spontaneous recovery might occur, on the other hand, long delays are believed to result in poorer functional outcomes. The goal of this review is to assess the optimal timeframe for surgical intervention for traumatic brachial plexus injuries.

METHODS

A systematic search was performed in January 2017 in PubMed and Embase databases according to the PRISMA guidelines. Search terms related to "brachial plexus injury" and "timing" were used. Obstetric plexus palsies were excluded. Qualitative synthesis was performed on all studies. Timing of operation and motor outcome were collected from individual patient data. Patients were categorized into 5 delay groups (0-3, 3-6, 6-9, 9-12, and > 12 months). Median delays were calculated for Medical Research Council (MRC) muscle grade ≥ 3 and ≥ 4 recoveries.

RESULTS

Forty-three studies were included after full-text screening. Most articles showed significantly better motor outcome with delays to surgery less than 6 months, with some studies specifying even shorter delays. Pain and quality of life scores were also significantly better with shorter delays. Nerve reconstructions performed after long time intervals, even more than 12 months, can still be useful. All papers reporting individual-level patient data described a combined total of 569 patients; 65.5% of all patients underwent operations within 6 months and 27.4% within 3 months. The highest percentage of ≥ MRC grade 3 (89.7%) was observed in the group operated on within 3 months. These percentages decreased with longer delays, with only 35.7% ≥ MRC grade 3 with delays > 12 months. A median delay of 4 months (IQR 3-6 months) was observed for a recovery of ≥ MRC grade 3, compared with a median delay of 7 months (IQR 5-11 months) for ≤ MRC grade 3 recovery.

CONCLUSIONS

The results of this systematic review show that in stretch and blunt injury of the brachial plexus, the optimal time to surgery is shorter than 6 months. In general, a 3-month delay appears to be appropriate because while recovery is better in those operated on earlier, this must be considered given the potential for spontaneous recovery.

Outcomes of Elbow Flexion Reconstruction in Patients Older than 50 with Traumatic Brachial Plexus Injury

BACKGROUND

There is controversy regarding the effectiveness of brachial plexus reconstruction for elbow function in older patients, as reported outcomes are generally poor. The purpose of this study was to evaluate elbow function outcomes in patients older than 50.

METHODS

Fifty-eight patients older than 50 years underwent nerve grafting, transfers, or free functioning muscle transfer to improve elbow function after traumatic brachial plexus injury. Patients were evaluated preoperatively and postoperatively for elbow flexion strength and range of motion; Disabilities of the Arm, Shoulder and Hand scores; pain; concomitant trauma; severity of trauma; and type of reconstruction.

RESULTS

The average age of the patients was 57.8 years, and the average follow-up was 24.0 months. The average modified British Medical Research Council elbow flexion grade improved significantly from 0.26 to 2.63. Thirty-three patients (60 percent) achieved functional flexion greater than or equal to M3 postoperatively, compared to zero patients preoperatively. There was no correlation between age and modified British Medical Research Council grade. Active elbow range of motion improved significantly postoperatively, with no effect of age on flexion motion. More patients achieved greater than or equal to M3 flexion with nerve transfers (69 percent) compared to free functioning muscle transfer (43 percent). Patients had worse outcomes with high-energy injuries. The mean Disabilities of the Arm, Shoulder and Hand score decreased from 51.5 to 49.6 postoperatively, and the average pain score decreased from 5.0 to 4.3.

CONCLUSION

Brachial plexus reconstruction for elbow function in patients older than 50 can yield useful flexion.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Spinal cord injury transiently alters Meissner's corpuscle density in the digit pads of macaque monkeys

Meissner's corpuscles (MCs) are cutaneous mechanoreceptors found in glabrous skin and are exquisitely sensitive to light touch. Along with other receptors, they provide continuous sensory feedback that informs the execution of fine manual behaviors. Following cervical spinal deafferentation injuries, hand use can be initially severely impaired, but substantial recovery occurs over many weeks, even when ~95% of the original input is permanently lost. While most SCI research focuses on central neural pathway responses, little is known about the role of peripheral receptors in facilitating recovery. We begin to address this by asking the following: (1) What is the normal pattern of MCs in the distal pads of all five digits in the macaque monkey (with hands similar to humans)? (2) What happens to these receptors 4-5 months following either a dorsal column lesion (DCL) or a combined dorsal root/dorsal column lesion (DRL/DCL), when functional recovery is largely complete? (3) What happens chronically, 12-14 months later? Our findings show that in normal monkeys, MCs are densest in the distal pads of the opposing thumb and index finger, with the greatest concentration on the thumb. This reflects a close functional relationship between receptor density and precision grip. At 4-5 months post-injury, there was a (~30%) loss of MCs on the deafferented digits of the injured hand compared with the contralateral side. However, 12-14 months after a DRL/DCL, receptor densities had returned to normal levels. Our findings indicate a complex peripheral response and highlight the importance of the periphery in shaping central changes.

Brachioradialis to flexor digitorum profundus tendon transfer to restore finger flexion

Introduction:

The main deformity following an adult lower brachial plexus injury is the loss of finger flexion. Distal nerve transfers have been used to restore finger and thumb flexion followed by tendon transfers for intrinsic replacement for opening of the fingers. When patients present beyond 6 months, only tendon transfers are applicable. Since the brachioradialis (BR) is always spared in such injuries, it is the ideal muscle to provide finger flexion. Wrist extensor power may not be normal for the use of the radial wrist extensor to serve as donor. BR to FDP transfer provides reasonable flexion range and an acceptable hand function to permit activities of daily living, when associated with ancillary procedures like opponensplasty, PIPJ arthrodesis.

Materials and Methods:

Eleven patients underwent a BR to FDP tendon transfer between January 2013 and January 2017 of which eight patients came for follow-up.

Results:

Four of the eight patients got a functionally useful hand to carry out activities of daily living with hook grip, span grasp, key pinch, chuck grip and pulp pinch. These patients also underwent simultaneous or secondary ancillary procedures. Four of the patients need secondary procedures to further improve functionality of the hand inspite of having a flexion range.

Conclusion:

The BR is an effective donor in providing adequate range and power of finger flexion in lower plexus injuries.

Nerve transfer versus muscle transfer to restore elbow flexion after pan-brachial plexus injury: a cost-effectiveness analysis

OBJECTIVE Pan-brachial plexus injury (PBPI), involving C5-T1, disproportionately affects young males, causing lifelong disability and decreased quality of life. The restoration of elbow flexion remains a surgical priority for these patients. Within the first 6 months of injury, transfer of spinal accessory nerve (SAN) fascicles via a sural nerve graft or intercostal nerve (ICN) fascicles to the musculocutaneous nerve can restore elbow flexion. Beyond 1 year, free-functioning muscle transplantation (FFMT) of the gracilis muscle can be used to restore elbow flexion. The authors present the first cost-effectiveness model to directly compare the different treatment strategies available to a patient with PBPI. This model assesses the quality of life impact, surgical costs, and possible income recovered through restoration of elbow flexion. METHODS A Markov model was constructed to simulate a 25-year-old man with PBPI without signs of recovery 4.5 months after injury. The management options available to the patient were SAN transfer, ICN transfer, delayed FFMT, or no treatment. Probabilities of surgical success rates, quality of life measurements, and disability were derived from the published literature. Cost-effectiveness was defined using incremental cost-effectiveness ratios (ICERs) defined by the ratio between costs of a treatment strategy and quality-adjusted life years (QALYs) gained. A strategy was considered cost-effective if it yielded an ICER less than a willingness-to-pay of $50,000/QALY gained. Probabilistic sensitivity analysis (PSA) was performed to address parameter uncertainty. RESULTS The base case model demonstrated a lifetime QALYs of 22.45 in the SAN group, 22.0 in the ICN group, 22.3 in the FFMT group, and 21.3 in the no-treatment group. The lifetime costs of income lost through disability and interventional/rehabilitation costs were $683,400 in the SAN group, $727,400 in the ICN group, $704,900 in the FFMT group, and $783,700 in the no-treatment group. Each of the interventional modalities was able to dramatically improve quality of life and decrease lifelong costs. A Monte Carlo PSA demonstrated that at a willingness-to-pay of $50,000/QALY gained, SAN transfer dominated in 88.5% of iterations, FFMT dominated in 7.5% of iterations, ICN dominated in 3.5% of iterations, and no treatment dominated in 0.5% of iterations. CONCLUSIONS This model demonstrates that nerve transfer surgery and muscle transplantation are cost-effective strategies in the management of PBPI. These reconstructive neurosurgical modalities can improve quality of life and lifelong earnings through decreasing disability.

Magnetic resonance imaging for detecting root avulsions in traumatic adult brachial plexus injuries: protocol for a systematic review of diagnostic accuracy

BACKGROUND

Adult brachial plexus injuries (BPI) are becoming more common. The reconstruction and prognosis of pre-ganglionic injuries (root avulsions) are different to other types of BPI injury. Preoperative magnetic resonance imaging (MRI) is being used to identify root avulsions, but the evidence from studies of its diagnostic accuracy are conflicting. Therefore, a systematic review is needed to address uncertainty about the accuracy of MRI and to guide future research.

METHODS

We will conduct a systematic search of electronic databases alongside reference tracking. We will include studies of adults with traumatic BPI which report the accuracy of preoperative MRI (index test) against surgical exploration of the roots of the brachial plexus (reference standard) for detecting either of the two target conditions (any root avulsion or any pseudomeningocoele as a surrogate marker of root avulsion). We will exclude case reports, articles considering bilateral injuries and studies where the number of true positives, false positives, false negatives and true negatives cannot be derived. The methodological quality of the included studies will be assessed using a tailored version of the QUADAS-2 tool. Where possible, a bivariate model will be used for meta-analysis to obtain summary sensitivities and specificities for both target conditions. We will investigate heterogeneity in the performance of MRI according to field strength and the risk of bias if data permits.

DISCUSSION

This review will summarise the current diagnostic accuracy of MRI for adult BPI, identify shortcomings and gaps in the literature and so help to guide future research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016049702 .

USE OF MAGNETIC RESONANCE IMAGING TO DIAGNOSE BRACHIAL PLEXUS INJURIES

Objective:

To compare magnetic resonance imaging and intraoperative findings in patients diagnosed with traumatic injury to the brachial plexus.

Methods:

Patients with a diagnosis of traumatic injury to the brachial plexus admitted to the hand and microsurgery outpatient consult of the Hospital das Clínicas at the University of São Paulo were selected during December 2016. A total of three adult patients with up to six months of injury who underwent surgical treatment were included in the study. A diffusion-weighted sequence magnetic resonance protocol and fluid-sensitive volumetric reformatting sequence were applied. The magnetic resonance results were compared with the diagnoses obtained from the injuries observed during the surgery. The study was double-blind (surgeon and radiologist).

Results:

A descriptive correlation was found between the magnetic resonance imaging results and the diagnostic findings from the surgeries, for both pre- and post-ganglionic injuries.

Conclusion:

Magnetic resonance imaging has shown to be a promising diagnostic method in preoperative assessment of brachial plexus lesions; it is less invasive than other common methods, showing not only avulsion lesions but also localized postganglionic lesions in the supra- and infraclavicular region. Level of Evidence III; Diagnostic studies - Investigating a diagnostic test.

Symptomatic Neuroma Following Initial Amputation for Traumatic Digital Amputation

PURPOSE

We tested the null hypothesis that no factors are independently associated with the development of symptomatic neuroma after traumatic digital amputation.

METHODS

We performed a retrospective review of 1,083 patients who underwent revision amputation for traumatic digital amputation; we excluded those undergoing replantation or revascularization. Patients who developed a painful neuroma during follow-up were identified with a minimum follow-up of 1 week and a median of 3.3 months. We calculated the rate of developing a painful neuroma as a proportion of the total number of patients and performed multivariable logistic regression analysis to identify factors independently associated with its development.

RESULTS

Of 1,083 patients, 71 (6.6%) developed a symptomatic neuroma. Mean time to diagnosis was 6.4 months. A total of 47 patients (66%) underwent surgery for painful neuroma. Mean time to surgical intervention was 11 months. Index finger injury and avulsion injury mechanism were significantly associated with a higher risk for symptomatic neuroma.

CONCLUSIONS

Approximately 1 in 15 patients will develop a symptomatic neuroma after traumatic digital amputation and more than half of these patients will undergo revision surgery for neuroma, with a mean time to operative intervention of 11 months.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic II.

The phrenic nerve transfer in the treatment of a septuagenarian with brachial plexus avulsion injury: a case report

Phrenic nerve transfer has been a well-established procedure for restoring elbow flexion function in patients with brachial plexus avulsion injury. Concerning about probably detrimental respiratory effects brought by the operation, however, stirred up quite a bit of controversy. We present a case report of the successful application of phrenic nerve as donor to reinnervate the biceps in a septuagenarian with brachial plexus avulsion injury, not accompanied with significant clinical respiratory problem.

Bioabsorbable nerve conduits coated with induced pluripotent stem cell-derived neurospheres enhance axonal regeneration in sciatic nerve defects in aged mice

Aging influences peripheral nerve regeneration. Nevertheless, most basic research of bioabsorbable nerve conduits including commercial products have been performed in very young animals. Results from these studies may not provide information about axonal regeneration in aged tissue, because young nerve tissue holds sufficient endogenous potential for axonal regeneration. The clinical target age for nerve conduit application is most likely going to increase with a rapidly growing elderly population. In the present study, we examined axonal regeneration after sciatic nerve defects in aged and young mice. 5-mm sciatic nerve defects in young (6 weeks old) and aged (92 weeks old) mice were reconstructed using nerve conduits (composed of a poly lactide and caprolactone) or autografts. In addition, in aged mice, sciatic nerve defects were reconstructed using nerve conduits coated with mouse induced pluripotent stem cell (iPSc)-derived neurospheres. Using electrophysiological and histological techniques, we demonstrated axonal regeneration was significantly less effective in aged than in young mice both for nerve conduits and for nerve autografts. However, despite the low regenerative capacity of the peripheral nerve in aged mice, axonal regeneration significantly increased when nerve conduits coated with iPSc-derived neurospheres, rather than nerve conduits alone, were used. The present study shows that aging negatively affects peripheral nerve regeneration based on nerve conduits in mice. However, axonal regeneration using nerve conduits was improved when supportive iPSc-derived neurospheres were added in the aged mice. We propose that tissue-engineered bioabsorbable nerve conduits in combination with iPSc-derived neurospheres hold therapeutic potential both in young and elderly patients. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1752-1758, 2018.

Brachial plexus injuries

Brachial Plexus Injuries result from a variety of causative mechanisms. They often present in a polytraumatic setting, and as such there is often a delay in their diagnosis and treatment. An understanding of the anatomy of the Brachial Plexus, and associated clinical pictures associated with injury, allows for early diagnosis and treatment. This review will consider the specific features of Brachial Plexus injuries relating to incidence, anatomy, mechanisms of injury, clinical presentation, and diagnostic evaluation.

Analyzing cost-effectiveness of ulnar and median nerve transfers to regain forearm flexion

OBJECTIVE Peripheral nerve transfers to regain elbow flexion via the ulnar nerve (Oberlin nerve transfer) and median nerves are surgical options that benefit patients. Prior studies have assessed the comparative effectiveness of ulnar and median nerve transfers for upper trunk brachial plexus injury, yet no study has examined the cost-effectiveness of this surgery to improve quality-adjusted life years (QALYs). The authors present a cost-effectiveness model of the Oberlin nerve transfer and median nerve transfer to restore elbow flexion in the adult population with upper brachial plexus injury. METHODS Using a Markov model, the authors simulated ulnar and median nerve transfers and conservative measures in terms of neurological recovery and improvements in quality of life (QOL) for patients with upper brachial plexus injury. Transition probabilities were collected from previous studies that assessed the surgical efficacy of ulnar and median nerve transfers, complication rates associated with comparable surgical interventions, and the natural history of conservative measures. Incremental cost-effectiveness ratios (ICERs), defined as cost in dollars per QALY, were calculated. Incremental cost-effectiveness ratios less than $50,000/QALY were considered cost-effective. One-way and 2-way sensitivity analyses were used to assess parameter uncertainty. Probabilistic sampling was used to assess ranges of outcomes across 100,000 trials. RESULTS The authors' base-case model demonstrated that ulnar and median nerve transfers, with an estimated cost of $5066.19, improved effectiveness by 0.79 QALY over a lifetime compared with conservative management. Without modeling the indirect cost due to loss of income over lifetime associated with elbow function loss, surgical treatment had an ICER of $6453.41/QALY gained. Factoring in the loss of income as indirect cost, surgical treatment had an ICER of -$96,755.42/QALY gained, demonstrating an overall lifetime cost savings due to increased probability of returning to work. One-way sensitivity analysis demonstrated that the model was most sensitive to assumptions about cost of surgery, probability of good surgical outcome, and spontaneous recovery of neurological function with conservative treatment. Two-way sensitivity analysis demonstrated that surgical intervention was cost-effective with an ICER of $18,828.06/QALY even with the authors' most conservative parameters with surgical costs at $50,000 and probability of success of 50% when considering the potential income recovered through returning to work. Probabilistic sampling demonstrated that surgical intervention was cost-effective in 76% of cases at a willingness-to-pay threshold of $50,000/QALY gained. CONCLUSIONS The authors' model demonstrates that ulnar and median nerve transfers for upper brachial plexus injury improves QALY in a cost-effective manner.

Impaired regeneration in aged nerves: Clearing out the old to make way for the new

Although many observational studies have shown that peripheral nerve regeneration is impaired with aging, underlying cellular and molecular mechanisms have remained obscure until recently. A series of recent genetic, live imaging and heterochronic parabiosis experiments are providing new insights into the underlying mechanisms of reduced regenerative capacity with aging. These studies show that Schwann cells pose a primary impediment to axon regeneration in older animals as they fail to support regenerating axons, while the contribution from macrophages remains an unresolved issue. Neurons do not appear to have an intrinsic defect of axonal elongation with aging but are impaired when they encounter an inhibitory environment, suggesting that therapeutic approaches to improve intrinsic neuronal regeneration capacity across inhibitory environments, as it is being done in central nervous system regeneration, can improve peripheral nerve regeneration as well. As in many aspects of neuroscience therapeutics development, a combinatorial approach may yield the best outcomes for nerve regeneration in aged individuals.

An attenuated immune response by Schwann cells and macrophages inhibits nerve regeneration in aged rats

Although peripheral nerves are capable of regeneration, advanced age decreases the potential for functional recovery after injury. The cellular mechanisms for this are not currently understood. Here, we performed sciatic nerve grafting with young (2 months old) and aged (18 months old) Brown-Norway male rats, in which 1 cm nerve grafts from young or aged rats were sutured into nerves of young or aged rats. Axons were allowed to regenerate until the nerve grafts and distal nerves were harvested at 1, 3, and 7 days and 2 and 6 weeks. At 6 weeks, our data suggested that young nerve grafts supported regeneration better than aged nerve grafts. In addition, myelin debris clearance was inhibited in young nerves when grafted into aged rats, but clearance was faster when aged nerves were grafted into young rats. Further analysis revealed that aged macrophages have delayed migration into injured nerve, and macrophages and Schwann cells from aged rats were less phagocytic for myelin debris in vitro. To understand these impairments, expression levels of pro- and anti-inflammatory cytokines were analyzed at 1 day after injury. Based on these levels, there was not a clear polarization to either an M1 or M2 phenotype; however, expression levels of IL-6, IL-10, CCL2 (MCP1), and Arg-1 were decreased in aged nerves. Taken together, both macrophages and Schwann cells had attenuated responses to nerve injury in aged rats, leading to inefficient clearance of debris and impaired axonal regeneration.

Nerve transfer helps repair brachial plexus injury by increasing cerebral cortical plasticity

In the treatment of brachial plexus injury, nerves that are functionally less important are transferred onto the distal ends of damaged crucial nerves to help recover neuromuscular function in the target region. For example, intercostal nerves are transferred onto axillary nerves, and accessory nerves are transferred onto suprascapular nerves, the phrenic nerve is transferred onto the musculocutaneous nerves, and the contralateral C₇ nerve is transferred onto the median or radial nerves. Nerve transfer has become a major method for reconstructing the brachial plexus after avulsion injury. Many experiments have shown that nerve transfers for treatment of brachial plexus injury can help reconstruct cerebral cortical function and increase cortical plasticity. In this review article, we summarize the recent progress in the use of diverse nerve transfer methods for the repair of brachial plexus injury, and we discuss the impact of nerve transfer on cerebral cortical plasticity after brachial plexus injury.

Radial to axillary nerve neurotization for brachial plexus injury in children: a combined case series

OBJECT

Axillary nerve palsy, isolated or as part of a more complex brachial plexus injury, can have profound effects on upper-extremity function. Radial to axillary nerve neurotization is a useful technique for regaining shoulder abduction with little compromise of other neurological function. A combined experience of this procedure used in children is reviewed.

METHODS

A retrospective review of the authors' experience across 3 tertiary care centers with brachial plexus and peripheral nerve injury in children (younger than 18 years) revealed 7 cases involving patients with axillary nerve injury as part of an overall brachial plexus injury with persistent shoulder abduction deficits. Two surgical approaches to the region were used.

RESULTS

Four infants (ages 0.6, 0.8, 0.8, and 0.6 years) and 3 older children (ages 8, 15, and 17 years) underwent surgical intervention. No patient had significant shoulder abduction past 15° preoperatively. In 3 cases, additional neurotization was performed in conjunction with the procedure of interest. Two surgical approaches were used: posterior and transaxillary. All patients displayed improvement in shoulder abduction. All were able to activate their deltoid muscle to raise their arm against gravity and 4 of 7 were able to abduct against resistance. The median duration of follow-up was 15 months (range 8 months to 5.9 years).

CONCLUSIONS

Radial to axillary nerve neurotization improved shoulder abduction in this series of patients treated at 3 institutions. While rarely used in children, this neurotization procedure is an excellent option to restore deltoid function in children with brachial plexus injury due to birth or accidental trauma.

Diminished Schwann cell repair responses underlie age-associated impaired axonal regeneration

The regenerative capacity of the peripheral nervous system declines with age. Why this occurs, however, is unknown. We demonstrate that 24-month-old mice exhibit an impairment of functional recovery after nerve injury compared to 2-month-old animals. We find no difference in the intrinsic growth capacity between aged and young sensory neurons in vitro or in their ability to activate growth-associated transcriptional programs after injury. Instead, using age-mismatched nerve transplants in vivo, we show that the extent of functional recovery depends on the age of the nerve graft, and not the age of the host. Molecular interrogation of the sciatic nerve reveals that aged Schwann cells (SCs) fail to rapidly activate a transcriptional repair program after injury. Functionally, aged SCs exhibit impaired dedifferentiation, myelin clearance, and macrophage recruitment. These results suggest that the age-associated decline in axonal regeneration results from diminished Schwann cell plasticity, leading to slower myelin clearance.

Treatment options for brachial plexus injuries

The incidence of brachial plexus injuries is rapidly growing due to the increasing number of high-speed motor-vehicle accidents. These are devastating injuries leading to significant functional impairment of the patients. The purpose of this review paper is to present the available options for conservative and operative treatment and discuss the correct timing of intervention. Reported outcomes of current management and future prospects are also analysed.

Local injection of autologous bone marrow cells to regenerate muscle in patients with traumatic brachial plexus injury: a pilot study

Objectives

Traumatic brachial plexus injury causes severe functional impairment of the arm. Elbow flexion is often affected. Nerve surgery or tendon transfers provide the only means to obtain improved elbow flexion. Unfortunately, the functionality of the arm often remains insufficient. Stem cell therapy could potentially improve muscle strength and avoid muscle-tendon transfer. This pilot study assesses the safety and regenerative potential of autologous bone marrow-derived mononuclear cell injection in partially denervated biceps.

Methods

Nine brachial plexus patients with insufficient elbow flexion (i.e., partial denervation) received intramuscular escalating doses of autologous bone marrow-derived mononuclear cells, combined with tendon transfers. Effect parameters included biceps biopsies, motor unit analysis on needle electromyography and computerised muscle tomography, before and after cell therapy.

Results

No adverse effects in vital signs, bone marrow aspiration sites, injection sites, or surgical wound were seen. After cell therapy there was a 52% decrease in muscle fibrosis (p = 0.01), an 80% increase in myofibre diameter (p = 0.007), a 50% increase in satellite cells (p = 0.045) and an 83% increase in capillary-to-myofibre ratio (p < 0.001) was shown. CT analysis demonstrated a 48% decrease in mean muscle density (p = 0.009). Motor unit analysis showed a mean increase of 36% in motor unit amplitude (p = 0.045), 22% increase in duration (p = 0.005) and 29% increase in number of phases (p = 0.002).

Conclusions

Mononuclear cell injection in partly denervated muscle of brachial plexus patients is safe. The results suggest enhanced muscle reinnervation and regeneration.

Cite this article: Bone Joint Res 2014;3:38–47.

Magnetic resonance imaging in brachial plexus injury

Brachial plexus injury represents the most severe nerve injury of the extremities. While obstetric brachial plexus injury has showed a reduction in the number of cases due to the improvements in obstetric care, brachial plexus injury in the adult is an increasingly common clinical problem. The therapeutic measures depend on the pathologic condition and the location of the injury: Preganglionic avulsions are usually not amenable to surgical repair; function of some denervated muscles can be restored with nerve transfers from intercostals or accessory nerves and contralateral C7 transfer. Postganglionic avulsions are repaired with excision of the damaged segment and nerve autograft between nerve ends or followed up conservatively. Magnetic resonance imaging is the modality of choice for depicting the anatomy and pathology of the brachial plexus: It demonstrates the location of the nerve damage (crucial for optimal treatment planning), depicts the nerve continuity (with or without neuroma formation), or may show a completely disrupted/avulsed nerve, thereby aiding in nerve-injury grading for preoperative planning. Computed tomography myelography has the advantage of a higher spatial resolution in demonstration of nerve roots compared with MR myelography; however, it is invasive and shows some difficulties in the depiction of some pseudomeningoceles with little or no communication with the dural sac.

Pictorial essay: Role of magnetic resonance imaging in evaluation of brachial plexus pathologies

Brachial plexopathies, traumatic and nontraumatic, often present with vague symptoms. Clinical examination and electrophysiological studies are useful but may not localize the lesion accurately. Magnetic resonance imaging (MRI) with its multiplanar imaging capability and soft tissue contrast resolution plays an important role in evaluation of the abnormal brachial plexus.

Shoulder abduction and external rotation restoration with nerve transfer

INTRODUCTION

In upper brachial plexus palsy patients, loss of shoulder function and elbow flexion is obvious as the result of paralysed muscles innervated by the suprascapular, axillary and musculocutaneus nerve. Shoulder stabilisation, restoration of abduction and external rotation are important as more distal functions will be affected by the shoulder situation.

PATIENTS AND METHODS

Between 2005 and 2011, eleven patients with upper type brachial plexus palsy were operated on with triceps nerve branch transfer to anterior axillary nerve branch and spinal accessory nerve transfer to the suprascapular nerve for shoulder abduction and external rotation restoration. Nine patients met the inclusion criteria for the study. All patients were men with ages ranged from 21 to 35 years (average, 27.4 years). The interval between injury and surgery ranged from 4 to 11 months (average, 7.2 months). Atrophy of the supraspinatus, infraspinatus and deltoid muscle and subluxation at the glenohumeral joint was obvious in all patients preoperatively. During the pre-op examination all patients had at least muscle grading 4 on the triceps muscle.

RESULTS

The mean post-operative value of shoulder abduction was 112.2° (range: 60-170°) while preoperatively none of the patients was able for abduction (p<0.001). The mean post-operative value of shoulder external rotation was 66° (range: 35-110°) while preoperatively none of them was able for external rotation (p<0.001). Postoperative values of shoulder abduction were significantly better that those of external rotation (p=0.0004). The postoperative average muscle grading for shoulder abduction according the MRC scale was 3.6±0.5 and for the shoulder external rotation was 3.2±0.4.

CONCLUSIONS

Combined nerve transfer by using the spinal accessory nerve for suprascapular nerve neurotisation and one of the triceps nerve branches for axillary nerve and teres minor branch neurotisation is an excellent choice for shoulder abduction and external rotation restoration.

Long-term observation of respiratory function after unilateral phrenic nerve and multiple intercostal nerve transfer for avulsed brachial plexus injury

BACKGROUND

Phrenic nerve transfer (PNT) or multiple intercostal nerve transfer (MIT) alone are reported to have no significant impact on pulmonary function in the short or medium term, but it has rarely been reported whether the combination of PNT-MIT could influence respiratory function in the long term.

OBJECTIVE

Respiratory function was evaluated after PNT and PNT-MIT 7 to 19 years (mean, 10 years) postoperatively.

METHODS

Twenty-three adult patients with brachial plexus avulsion injuries who underwent PNT-MIT were compared with 19 corresponding patients who underwent PNT. Pulmonary function testings, phrenic nerve conduction study, and chest fluoroscopy were performed. In the PNT-MIT group, further investigation was performed on the effect of the number of transferred intercostal nerves and the timing of MIT.

RESULTS

In the PNT-MIT group, forced vital capacity, forced expiratory volume in one second, and total lung capacity were 73.69%, 72.04%, and 74.81% of predicted values without significant differences from the PNT group. Diaphragmatic paralysis permanently existed with 1 to 1.5 intercostal spaces (ICSs) elevation and near 1 ICS reduced excursion. There was no statistical difference between the PNT and PNT-MIT groups. Furthermore, 3 and 4 intercostal nerves transferred resulted in no further decrease in pulmonary function test results than 2 intercostal nerves. No significant difference was found when PNT and MIT were performed at the same stage or with an interval.

CONCLUSION

PNT-MIT did not result in additional impairment in respiratory function in adult patients compared with PNT alone. It is safe to transfer 2 to 4 intercostal nerves at 1 to 2 months delay after PNT.

Cardiovascular responses to static muscle contraction in patients with brachial plexus injury treated with intercostal nerve transfer

Pressor response is carried in afferent fibers of somatic nerves to increase blood pressure (BP) and heart rate (HR) during static exercise in humans. However, there is no information that peripheral responses restore muscle contraction with nerve transfer operation. In this study, we aimed to assess isometric exercise-induced pressor responses in patients with brachial plexus injury (BPI) after intercostal nerve transfer (ICNT) to restore elbow flexor muscles. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and HR during 2-min sustained isometric muscle contraction of elbow flexors at 20% and 35% of maximal voluntary contraction (MVC) on the unaffected side and the ICNT side, were measured in seven subjects with BPI treated with ICNT. SBP, DBP, and HR during 2-min sustained isometric muscle contraction of elbow flexors at 20% of MVC on the unaffected side were similar to those recorded before and after the exercise. However, the same variables increased significantly (p<0.001) during a similar type of exercise at 35% MVC on the unaffected side. On the ICNT side, no significant differences were noted in elbow flexors at 20% and 35% MVC. Isometric static exercise at 35% of MVC did not induce pressor and HR changes on the ICNT side. The difference in the responses between the two sides could have been caused by incomplete recovery of afferent nerve function following nerve repair, despite the restoration of efferent nerve function. Alternatively, the HR and BP responses to static contraction may depend upon the active muscle mass.

Brain reorganization in patients with brachial plexus injury: a longitudinal functional MRI study

The aim of this study is to assess plastic changes of the sensorimotor cortex (SMC) in patients with traumatic brachial plexus injury (BPI) using functional magnetic resonance imaging (fMRI). Twenty patients with traumatic BPI underwent fMRI using blood oxygen level-dependent technique with echo-planar imaging before the operation. Sixteen patients underwent their second fMRI at approximately one year after injury. The subjects performed two tasks: a flexion-extension task of the affected elbow and a task of the unaffected elbow. After activation, maps were generated, the number of significantly activated voxels in SMC contralateral to the elbow movement in the affected elbow task study (N_af) and that in the unaffected task study (N_unaf) were counted. An asymmetry index (AI) was calculated, where AI = (N_af − N_unaf)/(N_af + N_unaf). Ten healthy volunteers were also included in this fMRI study. The AI of the first fMRI of the patients with BPI was significantly lower than that of the healthy subjects (P = 0.035). The AI of the second fMRI significantly decreased compared with that of the first fMRI (P = 0.045). Brain reorganization associates with peripheral nervous changes after BPI and after operation for functional reconstruction.