G. Carl Huber (1865-1934): A Michigan Pioneer in Peripheral Nerve Injury and Regeneration.

The treatment of peripheral nerve injuries has seen tremendous innovations over the past century. Dr Gotthelf Carl Huber, an American immigrant and early experimental pioneer in the field of peripheral nerve injury, created a foundation of scientific knowledge for these advancements. At the beginning of his career, Huber published novel work in peripheral nerve injury, supporting the concept of Wallerian degeneration and demonstrating the use of nerve grafting for repair. As his scientific career evolved into other research areas at the University of Michigan, Huber's impact extended far beyond just the study of peripheral nerve injury. Because of the external forces of the First World War, Dr Huber's focus returned to translational projects concentrated on the treatment of neuromas and war time peripheral nerve injuries. Huber's scientific impact in the field of peripheral nerve injury and repair came as a result of his incredible work ethic, mentorship, and tremendous leadership qualities; through this, his work still influences clinical practice today, a century later.

Quantifying Patient-Initiated Upper Extremity Movement After Surgical Reconstruction for Adult Pan-Brachial Plexus Injury.

BACKGROUND AND OBJECTIVES: Determining functional recovery in adult patients with traumatic pan-brachial plexus injury (pBPI) is hampered by the fact that most outcome measures are collected in the clinical setting and may not reflect arm use in the real world. This study's objectives were to demonstrate the feasibility of using wearable motion sensor technology to quantify spontaneous arm movement in adult patients with pBPI after surgical reconstruction and report the time and intensity with which the affected arm was used. METHODS: Twenty-nine patients with pBPI who underwent surgical reconstruction at least 2 years prior were included in this study. Study participants wore an accelerometer on bilateral arms for 7 days. The vector time (VT) and magnitude with which each arm moved were collected and divided by the same values collected from the uninjured arm to generate a ratio (VT and vector magnitude [VM], respectively) to quantify differences between the arms. Correlations between VT, VM, and patient demographic and physician-elicited clinical measures were calculated. Patients were enrolled at Chang Gung Memorial Hospital, Linkou Medical Center, Taiwan, and data analysis was performed at the University of Michigan. RESULTS: Twelve patients had pan-avulsion injuries, and 17 patients had C5 rupture with C6-T1 avulsion injuries. All underwent nerve reconstruction with contralateral C7 or ipsilateral C5 nerve roots as donors. At mean 7.3 years after surgery, the mean VT ratio was 0.54 ± 0.13 and the mean VM ratio was 0.30 ± 0.13. Both VT and VM ratios were significantly correlated with patient employment and movements at the elbow and forearm. CONCLUSION: Wearable motion detection technology can capture spontaneous, real-world movements of the arm in patients who have undergone surgical reconstruction for pBPI. Despite severe injuries, these patients are able to use their affected arm 50% of the time and with 30% of the intensity of their unaffected arm, which is positively correlated with return to work after injury. These data support the use of surgical reconstruction for pBPI.

Supraclavicular approach for neonatal brachial plexus palsy.

Neonatal brachial plexus palsy describes injury to the brachial plexus in the perinatal period, resulting in motor and sensory deficits of the upper arm. Nerve reconstruction, including graft repair and nerve transfers, can be used to restore function in patients whose injury does not respond to conservative management. Despite the availability of these techniques, 30%-40% of children have lifelong disability, reflecting a 10-fold underutilization of surgery. Here, the authors demonstrate a supraclavicular approach for brachial plexus exploration, as well as a spinal accessory to suprascapular nerve transfer for restoration of shoulder abduction and external rotation. The video can be found here: https://stream.cadmore.media/r10.3171/2022.10.FOCVID22109.

Defining postoperative C5 palsy and recovery: a systematic review.

OBJECTIVE: Postoperative C5 palsy (C5P) is a well-recognized and often-delayed complication of cervical spine surgery. Most patients recover within 6 months of onset, but the prognosis of severe cases is poor. The clinical significance and natural history of mild versus severe C5P appear to differ substantially, but palsy severity and recovery have been poorly characterized in the literature. METHODS: Owing to the varying prognoses and expanding treatment options such as nerve transfer surgery to reconstruct the C5 myotome, this systematic review attempted to describe how C5P severity is classified and how C5P and its recovery are defined, with the aim of proposing a postoperative C5P scale to support clinical decision-making. PubMed was searched for articles in English published since 2000 that offer a clear definition of postoperative C5P or its recovery. Only articles reporting exclusively on C5 palsy for patients undergoing surgery for degenerative disease were included. A single reviewer screened titles and abstracts and reviewed the full text of relevant articles, with consultation as needed from a second reviewer. Data collected included postoperative C5P definitions, classification of C5P severity, and definition and/or classification of C5P recovery. Qualitative analysis was performed. RESULTS: Full-text reviews were conducted of 98 of 272 articles identified and screened, and 43 met the inclusion criteria. Postoperative C5P was most commonly defined as a reduction in deltoid muscle strength by ≥ 1 grade using manual muscle testing (MMT), with potential biceps involvement also noted by some studies. The few studies that stratified C5P on the basis of severity unanimously characterized severe C5P as MMT grade ≤ 2. Nine studies reported on C5P recovery. Deltoid muscle strength improvement of MMT grade 5 commonly defined complete recovery, with no MMT improvement considered partial recovery. CONCLUSIONS: This review identified clear discrepancies in the definitions of C5P and its recovery, leading to heterogeneity in its evaluation and management. With the emergence of therapeutic procedures for severe C5P, standardization of the definitions of C5P and its recovery is critical. The authors propose MMT grades of 4, 3, and ≤ 2 to classify C5P as mild, moderate, and severe, respectively, and grades of 5, 4, and 3 to classify recovery as complete, sufficient, and useful, respectively.

Acute Flaccid Myelitis: Review of Clinical Features, Diagnosis, and Management with Nerve Transfers.

BACKGROUND: Acute flaccid myelitis (AFM) is a devastating neurologic condition in children, manifesting as acute limb weakness and/or paralysis. Despite increased awareness of AFM following initiation of U.S. surveillance in 2014, no treatment consensus exists. The purpose of this systematic review was to summarize the most current knowledge regarding AFM epidemiology, cause, clinical features, diagnosis, and supportive and operative management, including nerve transfer. METHODS: The authors systematically reviewed the literature based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using multiple databases to search the keywords ("acute flaccid myelitis"), ('acute flaccid myelitis'/exp OR 'acute flaccid myelitis'), and (Acute AND flaccid AND myelitis). Included articles reported on (1) AFM diagnosis and (2) patient-specific data regarding epidemiology, cause, clinical features, diagnostic features, or management of AFM. RESULTS: Ninety-nine articles were included in this review. The precise cause and pathophysiologic mechanism of AFM remain undetermined, but AFM is strongly associated with nonpolio enterovirus infections. Clinical presentation typically comprises preceding viral prodrome, pleocytosis, spinal cord lesions on T2-weighted magnetic resonance imaging, and acute onset of flaccid weakness/paralysis with hyporeflexia in at least one extremity. Supportive care includes medical therapy and rehabilitation. Early studies of nerve transfer for AFM have shown favorable outcomes for patients with persistent weakness. CONCLUSIONS: Supportive care and physical therapy are the foundation of a multidisciplinary approach to managing AFM. For patients with persistent limb weakness, nerve transfer has shown promise for improving function in distal muscle groups. Surgeons must consider potential spontaneous recovery, patient selection, donor nerve availability, recipient nerve appropriateness, and procedure timing.

Quantifying real-world upper limb activity via patient-initiated spontaneous movement in neonatal brachial plexus palsy.

BACKGROUND: Neonatal brachial plexus palsy (NBPP) results in muscle weakness and impaired somatosensory function of the arm. Current functional assessment is primarily based on clinician-elicited measurements including muscle strength and range of motion. To what extent these measures are representative of real-world arm movement is unclear. OBJECTIVE: To determine the feasibility of using body-worn accelerometers to remotely assess arm movements in children with NBPP. DESIGN: Prospective criterion validity study of accelerometry versus clinician assessment. SETTING: Academic medical center. PARTICIPANTS: Nine adolescents with NBPP and nine age- and gender-matched control adolescents participated in the study. All were enrolled in school and participated in community activities. INTERVENTIONS: Not applicable. METHODS: Standard clinician-elicited measurements were collected. For assessing spontaneous arm movements, participants wore activity monitors during all waking hours for 7 days. Results were expressed as ratios of affected to unaffected arm motion for duration and magnitude and correlated with traditional clinic-based assessments. Spearman correlations were used to determine relationships between accelerometry results and traditional assessments. A p value <.05 was considered statistically significant. MAIN OUTCOME MEASUREMENTS: Accelerometry measurements of arm motion and traditional clinical assessments. RESULTS: Compared to control ratios, duration of arm movement and magnitude ratios were reduced in the NBPP group, particularly for arm magnitude due to reduced affected arm movement and an increase in unaffected arm movement. Ratios were highly correlated with shoulder function and, to a lesser extent, with elbow function. CONCLUSION: Real-world arm use is an appropriate outcome measure that reflects functional recovery. This study demonstrates the feasibility of wearable technology to quantify duration and intensity of spontaneous arm movement in children with NBPP. Accelerometry also allows for the association between traditional clinician-elicited assessment measures and spontaneous arm movements, demonstrating the importance of the shoulder as a focus of treatment in NBPP.

The injured sciatic nerve atlas (iSNAT), insights into the cellular and molecular basis of neural tissue degeneration and regeneration.

Upon trauma, the adult murine peripheral nervous system (PNS) displays a remarkable degree of spontaneous anatomical and functional regeneration. To explore extrinsic mechanisms of neural repair, we carried out single-cell analysis of naïve mouse sciatic nerve, peripheral blood mononuclear cells, and crushed sciatic nerves at 1 day, 3 days, and 7 days following injury. During the first week, monocytes and macrophages (Mo/Mac) rapidly accumulate in the injured nerve and undergo extensive metabolic reprogramming. Proinflammatory Mo/Mac with a high glycolytic flux dominate the early injury response and rapidly give way to inflammation resolving Mac, programmed toward oxidative phosphorylation. Nerve crush injury causes partial leakiness of the blood-nerve barrier, proliferation of endoneurial and perineurial stromal cells, and entry of opsonizing serum proteins. Micro-dissection of the nerve injury site and distal nerve, followed by single-cell RNA-sequencing, identified distinct immune compartments, triggered by mechanical nerve wounding and Wallerian degeneration, respectively. This finding was independently confirmed with Sarm1-/- mice, in which Wallerian degeneration is greatly delayed. Experiments with chimeric mice showed that wildtype immune cells readily enter the injury site in Sarm1-/- mice, but are sparse in the distal nerve, except for Mo. We used CellChat to explore intercellular communications in the naïve and injured PNS and report on hundreds of ligand-receptor interactions. Our longitudinal analysis represents a new resource for neural tissue regeneration, reveals location- specific immune microenvironments, and reports on large intercellular communication networks. To facilitate mining of scRNAseq datasets, we generated the injured sciatic nerve atlas (iSNAT): https://cdb-rshiny.med.umich.edu/Giger_iSNAT/.

Implications of median sensory study to the thumb and deltoid/biceps motor unit recruitment on identifying C6 root avulsion in upper neonatal brachial plexus palsy.

INTRODUCTION/AIMS: Anatomic representation suggests that a median sensory nerve conduction study recording the thumb (median D1 NCS) may effectively assess upper neonatal brachial plexus palsy (NBPP). We sought to determine the feasibility of technique, establish reference data, and assess its ability to: (a) identify focal upper plexus lesions; and (b) identify C6 root avulsion. In a secondary analysis, we explored the association between absence/presence of motor unit action potentials (MUAPs) during needle electromyography (EMG) of the deltoid and biceps brachii muscles and C6 avulsion status. METHODS: A retrospective chart review was performed of surgical patients with severe upper NBPP who ultimately underwent surgical reconstruction (between 2017 and 2020). Median D1 sensory nerve action potential (SNAP) amplitude ranges were determined in affected and contralateral limbs and analyzed by C6 root avulsion status. Also, presence/absence of MUAPs during EMG of the deltoid and biceps brachii was compared between C6 avulsion patients and controls. RESULTS: Thirty-eight patients were included in our analysis. A median D1 NCS study was readily performed, showing a contralateral limb mean amplitude of 27.42 µV (range, 3.8-54.7 µV). Most patients had a low ipsilateral median D1 SNAP amplitude, regardless of C6 avulsion status. Detectable MUAPs in either deltoid or biceps brachii on EMG were atypical in C6 root avulsion. DISCUSSION: The median D1 NCS identifies upper NBPP, but does not distinguish C6 avulsions from post-ganglionic lesions, likely due to the frequent co-occurrence of post-ganglionic axonal disruption. The presence of MUAPs on deltoid/biceps brachii EMG suggests C6 avulsion is unlikely.

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

OBJECTIVE: Cervical nerve 5 palsy can occur following surgery for cervical spine pathology. The prognosis of C5 palsy is generally favorable, and most patients recover useful function. However, some patients do not recover useful strength. Nerve transfers are a potential effective treatment of postoperative severe C5 palsy. This study aimed to further delineate the natural history of recovery from postoperative C5 palsy, determine whether lack of recovery at specific time points predicts poor recovery prognosis, and thereby determine a reasonable time point for referral to a complex peripheral nerve specialist. METHODS: The authors conducted a retrospective review of 72 patients who underwent surgery for cervical spondylosis and stenosis complicated by C5 palsy. Medical Research Council (MRC) motor strength grades were recorded preoperatively; immediately postoperatively; at discharge; and at 2 weeks, 3 months, 6 months, and 12 months postoperatively. Univariate and multivariate logistic regression models were used to identify demographic and clinical risk factors associated with recovery of useful strength after severe C5 palsy. RESULTS: The mean patient age was 62.5 years, and 36.1% of patients were female. Thirty patients (41.7%) experienced severe C5 palsy with less than antigravity strength (MRC grade 2 or less) at discharge. Twenty-one (70%) of these patients recovered useful strength (MRC grade 3 or greater) at 12 months postoperatively, and 9 patients (30%) did not recover useful strength at 12 months. Of those patients with persistent severe C5 palsy at 3 months postoperatively, 50% recovered useful strength at 12 months. Of those patients with persistent severe C5 palsy at 6 months postoperatively, 25% recovered useful strength at 12 months. No patient with MRC grade 0 or 1 strength at 6 months postoperatively recovered useful strength. A history of diabetes was associated with the occurrence of severe C5 palsy. On multivariate analysis, female sex was associated with recovery of useful strength. CONCLUSIONS: Most patients with severe C5 palsy recover useful strength in their C5 myotome within 12 months of onset. However, at 3 months postoperatively, patients with persistent severe C5 palsy had only a 50% chance of recovering useful strength by 12 months. Lack of recovery of useful strength at 3 months postoperatively is a reasonable time point for referral to a complex peripheral nerve center to establish care and to determine candidacy for nerve transfer surgery if severe C5 palsy persists.

Quantifying long-term upper-limb activity using wearable motion sensors after nerve reconstruction for neonatal brachial plexus palsy.

OBJECTIVE: Standard, physician-elicited clinical assessment tools for the evaluation of function after nerve reconstruction for neonatal brachial plexus palsy (NBPP) do not accurately reflect real-world arm function. Wearable activity monitors allow for the evaluation of patient-initiated, spontaneous arm movement during activities of daily living. In this pilot study, the authors demonstrate the feasibility of using body-worn sensor technology to quantify spontaneous arm movement in children with NBPP 10 years after nerve reconstruction and report the timing and magnitude of recovered arm movement. METHODS: Eight children with NBPP who underwent brachial plexus reconstruction approximately 10 years prior were recruited to take part in this single-institution prospective pilot study. Per the treatment protocol of the authors' institution, operated patients had severe, nonrecovering nerve function at the time of surgery. The patients were fitted with an activity monitoring device on each of the affected and unaffected arms, which were worn for 7 consecutive days. The duration (VT) and power (VM) with which each arm moved during the patient's normal daily activities were extracted from the accelerometry data and ratios comparing the affected and unaffected arms were calculated. Demographic data and standard physician-elicited clinical measures of upper-extremity function were also collected. RESULTS: Three children underwent nerve grafting and transfer and 5 children underwent graft repair only. The mean (± SD) active range of motion was 98° ± 53° for shoulder abduction, 130° ± 24° for elbow flexion, and 39° ± 34° for shoulder external rotation. The median Medical Research Council grade was at least 2.5 for all muscle groups. The median Mallet grade was at least 2 for all categories, and 13.5 total. The VT ratio was 0.82 ± 0.08 and the VM ratio was 0.53 ± 0.12. CONCLUSIONS: Wearable activity monitors such as accelerometers can be used to quantify spontaneous arm movement in children who underwent nerve reconstruction for NBPP at long-term follow-up. These data more accurately reflect complex, goal-oriented movement needed to perform activities of daily living. Notably, despite severe, nonrecovering nerve function early in life, postsurgical NBPP patients use their affected arms more than 80% of the time that they use their unaffected arms, paralleling results in patients with NBPP who recovered spontaneously. These data represent the first long-term, real-world evidence to support brachial plexus reconstruction for patients with NBPP.

Optimizing nerve transfer surgery in tetraplegia: clinical decision making based on innervation patterns in spinal cord injury.

OBJECTIVE: Nerve transfers are increasingly being utilized in the treatment of chronic tetraplegia, with increasing literature describing significant improvements in sensorimotor function up to years after injury. However, despite technical advances, clinical outcomes remain heterogenous. Preoperative electrodiagnostic testing is the most direct measure of nerve health and may provide prognostic information that can optimize preoperative patient selection. The objective of this study in patients with spinal cord injury (SCI) was to determine various zones of injury (ZOIs) via electrodiagnostic assessment (EDX) to predict motor outcomes after nerve transfers in tetraplegia. METHODS: This retrospective review of prospectively collected data included all patients with tetraplegia from cervical SCI who underwent nerve transfer at the authors' institution between 2013 and 2020. Preoperative demographic data, results of EDX, operative details, and postoperative motor outcomes were extracted. EDX was standardized into grades that describe donor and recipient nerves. Five zones of SCI were defined. Motor outcomes were then compared based on various zones of innervation. RESULTS: Nineteen tetraplegic patients were identified who underwent 52 nerve transfers targeting hand function, and 75% of these nerve transfers were performed more than 1 year postinjury, with a median interval to surgery following SCI of 24 (range 8-142) months. Normal recipient compound muscle action potential and isolated upper motor neuron injury on electromyography (EMG) were associated with greater motor recovery. When nerve transfers were stratified based on donor EMG, greater motor gains were associated with normal than with abnormal donor EMG motor unit recruitment patterns. When nerve transfers were separated based on donor and recipient nerves, normal flexor donors were more crucial than normal extensor donors in powering their respective flexor recipients. CONCLUSIONS: This study elucidates the relationship of the preoperative innervation zones in SCI patients to final motor outcomes. EDX studies can be used to tailor surgical therapies for nerve transfers in patients with tetraplegia. The authors propose an algorithm for optimizing nerve transfer strategies in tetraplegia, whereby understanding the ZOI and grade of the donor/recipient nerve is critical to predicting motor outcomes.

Neonatal brachial plexus palsy: associated birth injury outcomes, hospital length of stay and costs.

OBJECTIVE: To compare the birth injury outcomes and hospital length of stay and costs among newborns delivered at 34-42 weeks with neonatal brachial plexus palsy (NBPP) versus those without. STUDY DESIGN: We conducted a retrospective, cross-sectional study using data from the National Inpatient Sample to identify all newborns hospitalizations that occurred in the U.S. between 2016 and 2017. We included non-anomalous single liveborn delivered in-hospital at 34-42 weeks. The newborns with NBPP were identified by International Classification of Diseases, 10th Revision, Clinical Modification codes. Birth injury outcomes, and hospital length of stay and hospital costs were examined. A multivariable Poisson regression model with robust error variance was used to examine the association between NBPP and birth injury outcomes. A multivariable generalized linear regression model was used to examine the association between NBPP and hospital length of stay and hospital costs. RESULTS: Of 7,019,722 non-anomalous single liveborn delivered at 34-42 weeks in the U.S. from 2016 to 2017, the rate of NBPP (n = 6695) was 0.95 per 1000 newborn hospitalizations. After multivariable regression adjustment, compared to newborns without NBPP, the risk of the composite birth injury outcome was 2.91 (95% CI 2.61-3.25) times higher in those with NBPP. Similar results of an increased risk among newborns with NBPP were observed in all individual birth injury outcomes. Compared to newborns without NBPP, after adjustment, the hospital length of stay was 1.48 (95% IC 1.38-1.59) times higher and the hospital costs were 2.21 (95% CI 1.97-2.48) times higher in those with NBPP. CONCLUSIONS: Among newborns delivered at 34-42 weeks, the risk of associated birth injuries, hospital length of stay and costs, were significantly higher in newborns with NBPP than those without.

Knowledge of neonatal brachial plexus palsy among medical professionals in North America.

PURPOSE: Early referral of neonatal brachial plexus palsy (NBPP) patients to multidisciplinary clinics is critical for timely diagnosis, treatment, and improved functional outcomes. In Saudi Arabia, inadequate knowledge regarding NBPP is a reason for delayed referral. We aimed to evaluate the knowledge of North American healthcare providers (HCPs) regarding the diagnosis, management, and prognosis of NBPP. METHODS: A 12-question survey regarding NBPP was distributed via electronic and paper formats to North American providers from various referring and treating specialties. NBPP knowledge was compared between Saudi Arabian vs. North American providers, referring vs. treating specialties, academic vs. community hospitals, and providers with self-reported confidence vs. nonconfidence in NBPP knowledge. RESULTS: Of the 273 surveys collected, 45% were from referring providers and 55% were from treating providers. Saudi Arabian and North American HCPs demonstrated similar NBPP knowledge except for potential etiologies for NBPP and surgery timing. In North America, referring and treating providers had similar overall knowledge of NBPP but lacked familiarity with its natural history. A knowledge gap existed between academic and community hospitals regarding timing of referral/initiation of physical/occupational therapy (PT/OT) and Horner's syndrome. Providers with self-reported confidence in treating NBPP had greater knowledge of types of NBPP and timing for PT/OT initiation. CONCLUSIONS: Overall, North American providers demonstrated adequate knowledge of NBPP. However, both eastern and western physicians remain overly optimistic in believing that most infants recover spontaneously. This study revealed a unique and universal knowledge gap in NBPP diagnosis, referral, and management worldwide. Continuous efforts to increase NBPP knowledge are indicated.

Assessment of variability in motor grading and patient-reported outcome reporting: a multi-specialty, multi-national survey.

BACKGROUND: The goal of this survey-based study was to evaluate the current practice patterns of clinicians who assess patients with peripheral nerve pathologies and to assess variance in motor grading on the Medical Research Council (MRC) scale using example case vignettes. METHODS: An electronic survey was distributed to clinicians who regularly assess patients with peripheral nerve pathology. Survey sections included (1) demographic data, (2) vignettes where respondents were asked to assess on the MRC scale, and (3) assessment of practice patterns regarding the use of patient-reported outcome measures. Inter-rater reliability statistics were calculated for the application of the MRC scale on example vignettes. RESULTS: There were 109 respondents. There was significant dispersion in motor grading seen on the example vignettes. For the raw responses grading the example vignettes on the MRC scale, Krippendorff's alpha was 0.788 (95% CI 0.604, 0.991); Gwet's AC2 was 0.808 (95% CI 0.683, 0.932); Fleiss' kappa was 0.416 (95% CI 0.413, 0.419). Most respondents reported not utilizing any patient-reported outcome measures across peripheral nerve pathologies. DISCUSSION: Our data show that there is significant disagreement among providers when applying the MRC scale. It is important for us to reassess our current tools for patient evaluation in order to improve upon both clinical evaluation and outcomes reporting. Consensus guidelines for outcomes reporting are needed, and domains outside of manual muscle testing should be included.

MRI evaluation of nerve root avulsion in neonatal brachial plexus palsy: understanding the presence of isolated dorsal/ventral rootlet disruption.

OBJECTIVE: The evaluation, treatment, and prognosis of neonatal brachial plexus palsy (NBPP) continues to have many areas of debate, including the use of ancillary testing. Given the continued improvement in imaging, it is important to revisit its utility. Nerve root avulsions have historically been identified by the presence of pseudomeningoceles or visible ruptures. This "all-or-none" definition of nerve root avulsions has many implications for the understanding and management of NBPP, especially as characterization of the proximal nerve root as a potential donor remains critical. This study examined the ability of high-resolution MRI to more specifically define the anatomy of nerve root avulsions by individually examining the ventral and dorsal rootlets as they exit the spinal cord. METHODS: This is a retrospective review of patients who had undergone brachial plexus protocol MRI for clinical evaluation of NBPP at a single institution. Each MR image was independently reviewed by a board-certified neuroradiologist, who was blinded to both established diagnosis/surgical findings and laterality. Each dorsal and ventral nerve rootlet bilaterally from C5 to T1 was evaluated from the spinal cord to its exit in the neuroforamen. Each rootlet was classified as avulsed, intact, or undeterminable. RESULTS: Sixty infants underwent brachial plexus protocol MRI from 2010 to 2018. All infants were included in this study. Six hundred individual rootlets were analyzed. There were 49 avulsed nerve rootlets in this cohort. Twenty-nine (59%) combined dorsal/ventral avulsions involved both the ventral and dorsal rootlets, and 20 (41%) were either isolated ventral or isolated dorsal rootlet avulsions. Of the isolated avulsion injuries, 13 (65%) were dorsal only, meaning that the motor rootlets were intact. CONCLUSIONS: A closer look at nerve root avulsions with MRI demonstrates a significant prevalence (approximately 41%) of isolated dorsal or ventral nerve rootlet disruptions. This finding implies that nerve roots previously labeled as "avulsed" but with only isolated dorsal (sensory) rootlet avulsion can yet provide donor fascicles in reconstruction strategies. A majority (99%) of the rootlets can be clearly visualized with MRI. These findings may significantly impact the clinical understanding of neonatal brachial plexus injury and its treatment.

Analysis of the effect of intraoperative neuromonitoring during resection of benign nerve sheath tumors on gross-total resection and neurological complications.

OBJECTIVE: The aim of this study was to examine the role of intraoperative neuromonitoring (IONM) during resection of benign peripheral nerve sheath tumors in achieving gross-total resection (GTR) and in reducing postoperative neurological complications. METHODS: Data from consecutive adult patients who underwent resection of a benign peripheral nerve sheath tumor at 7 participating institutions were combined. Propensity score matching was used to balance covariates. The primary outcomes of interest were the association between IONM and GTR and the association of IONM and the development of a permanent postoperative neurological complication. The secondary outcomes of interest were the association between IONM and GTR and the association between IONM and the development of a permanent postoperative neurological complication in the subgroup of patients with tumors involving a motor or mixed nerve. Univariate and multivariate logistic regression were then performed on the propensity score-matched samples to assess the ability of the independent variables to predict the outcomes of interest. RESULTS: A total of 337 patients who underwent resection of benign nerve sheath tumors were included. In multivariate analysis, the use of IONM (OR 0.460, 95% CI 0.199-0.978; p = 0.047) was a significant negative predictor of GTR, whereas none of the variables, including IONM, were associated with the occurrence of a permanent postoperative neurological complication. Within the subgroup of motor/mixed nerve tumors, in the multivariate analysis, IONM (OR 0.263, 95% CI 0.096-0.723; p = 0.010) was a significant negative predictor of a GTR, whereas IONM (OR 3.800, 95% CI 1.925-7.502; p < 0.001) was a significant positive predictor of a permanent postoperative motor deficit. CONCLUSIONS: Overall, 12% of the cohort had a permanent neurological complication, with new or worsened paresthesias most common, followed by pain and then weakness. The authors found that formal IONM was associated with a reduced likelihood of GTR and had no association with neurological complications. The authors believe that these data argue against IONM being considered standard of care but do not believe that these data should be used to universally argue against IONM during resection of benign nerve sheath tumors.

Nerve graft versus nerve transfer for neonatal brachial plexus: shoulder outcomes.

OBJECTIVE: The decision-making in neonatal brachial plexus palsy (NBPP) treatment continues to have many areas in need of clarification. Graft repair was the gold standard until the introduction of nerve transfer strategies. Currently, there is conflicting evidence regarding outcomes in patients with nerve grafts versus nerve transfers in relation to shoulder function. The objective of this study was to further define the outcomes for reconstruction strategies in NBPP with a specific focus on the shoulder. METHODS: A cohort of patients with NBPP and surgical repairs from a single center were reviewed. Demographic and standard clinical data, including imaging and electrodiagnostics, were gathered from a clinical database. Clinical data from physical therapy evaluations, including active and passive range of motion, were examined. Statistical analysis was performed on the available data. RESULTS: Forty-five patients met the inclusion criteria for this study, 19 with graft repair and 26 with nerve transfers. There were no significant differences in demographics between the two groups. Understandably, there were no patients in the nerve grafting group with preganglionic lesions, resulting in a difference in lesion type between the cohorts. There were no differences in preoperative shoulder function between the cohorts. Both groups reached statistically significant improvements in shoulder flexion and shoulder abduction. The nerve transfer group experienced a significant improvement in shoulder external rotation, from -78° to -28° (p = 0.0001), whereas a significant difference was not reached in the graft group. When compared between groups, there appeared to be a trend favoring nerve transfer in shoulder external rotation, with the graft patients improving by 17° and the transfer patients improving by 49° (p = 0.07). CONCLUSIONS: In NBPP, patients with shoulder weakness experience statistically significant improvements in shoulder flexion and abduction after graft repair or nerve transfer, and patients with nerve transfers additionally experience significant improvement in external rotation. With regard to shoulder external rotation, there appear to be some data supporting the use of nerve transfers.

Persistence and Extent of Neonatal Brachial Plexus Palsy: Association with Number of Maneuvers and Duration of Shoulder Dystocia.

Objective The main objective of this article is to determine if persistence of neonatal brachial plexus palsy (NBPP) following shoulder dystocia was associated with maneuvers used or duration of impacted shoulder. Study Design Retrospective review of children with NBPP and documented shoulder dystocia. Student t -tests and chi-squared tests were used to compare outcomes when shoulder dystocia resolved with > 3 versus ≤ 3 maneuvers or duration > versus ≤ 120 seconds. Relative risk (RR) with 95% confidence intervals (CI) was calculated. Results Among 46 children with NBPP and shoulder dystocia, incidence of persistence was significantly higher at 2 years of age when > 3 versus ≤ 3 maneuvers were used (100 vs. 62%; RR: 1.6, 95% CI: 1.2-2.2). When resolution of impacted shoulder lasted >120 versus ≤ 120 seconds, NBPP at 2 years was significantly more likely (100 vs. 63%; RR: 1.6, 95% CI: 1.1-2.2). Injury to all five nerves of the brachial plexus was more likely if standard deviation lasted > 120 versus ≤ 120 seconds (RR: 2.2; 95% CI: 1.03-4.6). Conclusion Though the number of maneuvers used and duration of shoulder dystocia are associated with persistence of NBPP, the retrospective nature of the study of a selective cohort precludes recommendations changing the current management of shoulder dystocia.

CSF flow jet: novel CT myelogram finding of CSF leak through dural tear in traumatic pseudomeningocele.

Determining the exact location of dural violation after traumatic pre-ganglionic (avulsion) injury of the brachial plexus with associated progressively enlarging pseudomeningocele is critical for treatment, but current imaging by MR and CT myelogram remains inadequate as there are often only indirect imaging features. We present a case of a 25-year-old man with history of motorcycle accident and left brachial plexus injury, who was found to have an extensive anterior epidural CSF collection, resulting in the contralateral neurologic deficit. Surgical treatment relies upon the identification of the site of the dural violation. On dynamic CT myelogram images, a thin hyperdense line of contrast was seen, representing "CSF flow jet" extravasating into the pseudomeningocele. Subsequent laminectomy and foraminotomy revealed a left avulsed nerve root and a dural tear at the site localized on the CT myelogram. To our knowledge, this is the first case of using dynamic CT myelography to visualize "CSF flow jet," revealing the exact location of dural violation resulting in the expanding pseudomeningocele, providing crucial information for perioperative planning.