Tracheostomy for COVID-19 Respiratory Failure: Multidisciplinary, Multicenter Data on Timing, Technique, and Outcomes.

OBJECTIVE: The aim of this study was to assess the outcomes of tracheostomy in patients with COVID-19 respiratory failure. SUMMARY BACKGROUND DATA: Tracheostomy has an essential role in managing COVID-19 patients with respiratory failure who require prolonged mechanical ventilation. However, limited data are available on how tracheostomy affects COVID-19 outcomes, and uncertainty surrounding risk of infectious transmission has led to divergent recommendations and practices. METHODS: It is a multicenter, retrospective study; data were collected on all tracheostomies performed in COVID-19 patients at 7 hospitals in 5 tertiary academic medical systems from February 1, 2020 to September 4, 2020. RESULT: Tracheotomy was performed in 118 patients with median time from intubation to tracheostomy of 22 days (Q1-Q3: 18-25). All tracheostomies were performed employing measures to minimize aerosol generation, 78.0% by percutaneous technique, and 95.8% at bedside in negative pressure rooms. Seventy-eight (66.1%) patients were weaned from the ventilator and 18 (15.3%) patients died from causes unrelated to tracheostomy. No major procedural complications occurred. Early tracheostomy (≤14 days) was associated with decreased ventilator days; median ventilator days (Q1-Q3) among patients weaned from the ventilator in the early, middle and late groups were 21 (21-31), 34 (26.5-42), and 37 (32-41) days, respectively with P = 0.030. Compared to surgical tracheostomy, percutaneous technique was associated with faster weaning for patients weaned off the ventilator [median (Q1-Q3): 34 (29-39) vs 39 (34-51) days, P = 0.038]; decreased ventilator-associated pneumonia (58.7% vs 80.8%, P = 0.039); and among patients who were discharged, shorter intensive care unit duration [median (Q1-Q3): 33 (27-42) vs 47 (33-64) days, P = 0.009]; and shorter hospital length of stay [median (Q1-Q3): 46 (33-59) vs 59.5 (48-80) days, P = 0.001]. CONCLUSION: Early, percutaneous tracheostomy was associated with improved outcomes compared to surgical tracheostomy in a multi-institutional series of ventilated patients with COVID-19.

Prey exclusion combined with simulated fire increases subsequent prey-capture potential in the pale pitcher plant, Sarracenia alata.

PREMISE: The association of carnivory (an adaptation to nutrient-poor soils) with fire has been described as a paradox, given increases in nutrient availability that often accompany fire. The nutrients that increase in availability following fire, however, may not be the same as those provided by prey and may not reduce nutrient limitation if accompanied by even greater increases in light. METHODS: Using a factorial experiment in the field, we examined how simulated fire (clipping plus nitrogen-free fertilizer addition) and prey-derived nutrient availability (prey exclusion) interacted to influence carnivorous potential in Sarracenia alata and belowground competition with its neighbors (manipulated via trenching). We hypothesized that simulated fire combined with prey exclusion would (1) increase the potential for prey capture relative to shade avoidance, hereafter, relative prey-capture potential (RPCP), and/or (2) increase belowground competition with neighboring plants. RESULTS: Sarracenia alata increased RPCP in response to the combination of simulated fire and prey exclusion, despite increases in phosphorus and other nutrients associated with the simulated fire treatment, suggesting that prey capture potential increases in response to increased nitrogen limitation resulting from increases in light and/or phosphorus after fire. We found no evidence of belowground competition. CONCLUSIONS: The potential importance of carnivory in Sarracenia alata increases following fire. This result helps to explain the paradoxical association of carnivorous plants with fire by demonstrating the potential for prey-derived nutrient limitation to increase rather than decrease in response to increases in light and nutrients other than nitrogen following fire.

Minimal Overlap in Language Control Across Production And Comprehension: Evidence from Read-Aloud Versus Eye-Tracking Tasks.

Bilinguals are remarkable at language control-switching between languages only when they want. However, language control in production can involve switch costs. That is, switching to another language takes longer than staying in the same language. Moreover, bilinguals sometimes produce language intrusion errors, mistakenly producing words in an unintended language (e.g., Spanish-English bilinguals saying "pero" instead of "but"). Switch costs are also found in comprehension. For example, reading times are longer when bilinguals read sentences with language switches compared to sentences with no language switches. Given that both production and comprehension involve switch costs, some language-control mechanisms might be shared across modalities. To test this, we compared language switch costs found in eye-movement measures during silent sentence reading (comprehension) and intrusion errors produced when reading aloud switched words in mixed-language paragraphs (production). Bilinguals who made more intrusion errors during the read-aloud task did not show different switch cost patterns in most measures in the silent-reading task, except on skipping rates. We suggest that language switching is mostly controlled by separate, modality-specific processes in production and comprehension, although some points of overlap might indicate the role of domain general control and how it can influence individual differences in bilingual language control.

Intraobserver and Interobserver Reliability of Radiographic Analysis of Proximal Humerus Fractures in Adolescents.

BACKGROUND: Multiple studies have shown low intrarater and interrater agreement of radiographic classification systems for proximal humerus fractures (PHFs) in adults. There is no standardized method of measuring angulation of pediatric PHFs, nor is there consensus as to the amount of angulation and displacement that require operative fixation of adolescent PHFs. We propose a new standardized method to measure fracture angulation that is similar to the method used to measure the epiphyseal-shaft angle for slipped capital femoral epiphysis. The primary purpose of this study was to evaluate the intraobserver and interobserver reliability of our proposed method compared with a nonstandardized method. The secondary purpose was to evaluate the intrarater and interrater agreement of the Neer and Horowitz (NH), and Salter-Harris (SH) classification systems. METHODS: Seven raters evaluated 26 deidentified anteroposterior shoulder radiographs of patients 10 to 16 years of age with PHFs. Raters classified each fracture using the NH and SH systems, and used their own method to measure fracture angulation. This process was repeated 2 weeks later. During the second round, raters also measured fracture angulation using our proposed standardized method. Two weeks after the second round, raters reevaluated the radiographs using the standardized method. Intraclass correlation coefficients were calculated. RESULTS: Excellent intraobserver and interobserver agreement was achieved for the standardized method of measuring fracture angulation. All of the raters had an intrarater reliability classified as excellent (>0.80) using the standardized method. Good intrarater and excellent interrater agreement was achieved when raters used their own fracture angulation measurement method but wide confidence intervals suggested that the results were less precise. Fair to moderate intrarater and interrater reliability was seen for the NH and SH classifications. CONCLUSIONS: Our standardized method for measuring angulation in adolescent PHFs demonstrated excellent intrarater and interrater reliability. We propose that this technique may be a more precise method of measuring fracture angulation and this method should be used in future studies that evaluate indications for operative management of adolescent PHFs. LEVEL OF EVIDENCE: Level III-diagnostic.

Complications After Plate Fixation of Displaced Pediatric Midshaft Clavicle Fractures.

BACKGROUND: Operative treatment of displaced pediatric midshaft clavicle fractures has become increasingly popular, despite lack of evidence that surgical management leads to superior outcomes. Complications, such as plate irritation necessitating removal and wound infection, have been reported in adults. The purpose of this study was to evaluate complications after plate fixation of midshaft clavicle fractures in the pediatric population. METHODS: We retrospectively identified patients 10 to 18 years old who had undergone plate fixation of a displaced midshaft clavicle fracture between 2009 and 2014. Patients who had surgery for a malunion or nonunion, and patients with <6 months of follow-up were excluded. Demographic data, radiographic union, time to return to activity, and complications were recorded. Any complication that led to unplanned surgery was considered a major complication. RESULTS: We analyzed 36 patients (25 males, 11 females) with 37 fractures. The average age at surgery was 14.5±1.7 years and mean follow-up was 1.3±1.0 years. All of the fractures healed and average time to return to activity was 58±28 days. The overall postoperative complication rate was 86% (32/37): 59% (22/37) implant prominence or irritation, 16% (6/37) anterior chest wall numbness, 5% (2/37) superficial wound dehiscence or infection, 3% (1/37) refracture adjacent to the plate, and 3% (1/37) refracture after implant removal. The major complication rate was 43% (16/37). Fifteen patients underwent a second surgery for implant removal secondary to prominence or pain. One patient underwent revision open reduction and internal fixation after he sustained a refracture at the distal aspect of the plate that resulted in a painful nonunion. Only 1 patient had a refracture after implant removal and this was treated nonoperatively. CONCLUSIONS: Implant prominence or irritation is common after plate fixation of displaced pediatric midshaft clavicle fractures. A second surgery for implant removal may be necessary. Patients should be appropriately counseled regarding complications before plate fixation of midshaft clavicle fractures. LEVEL OF EVIDENCE: Level IV-therapeutic.

A High Preoperative Pain and Symptom Profile Predicts Worse Pain Outcomes for Children After Spine Fusion Surgery.

BACKGROUND: Preoperative pain predicts persistent pain after spine fusion, yet little is understood about the nature of that pain, related symptoms, and how these symptoms relate to postoperative pain outcomes. This prospective study examined children's baseline pain and symptom profiles and the association between a high symptom profile and postoperative outcomes. METHODS: Seventy children (aged 10-17 years) scheduled for correction of idiopathic scoliosis completed pain and symptom surveys during their preoperative visit (ie, pain intensity [0-10 numeric rating scores], a pediatric version of the 2011 fibromyalgia survey criteria [including pain locations and symptom severity scale], neuropathic pain symptoms [painDETECT], and Patient-Reported Outcome Measurement System measures of fatigue, depression, function, pain interference, and pain catastrophizing). Pain intensity and total analgesic use were recorded daily postoperatively and for 2 weeks after discharge. A 2-step cluster analysis differentiated a high and low pain and symptom profile at baseline, and a multivariate main effects regression model examined the association between pain profile and posthospital discharge pain and analgesic outcomes. RESULTS: The cluster analysis differentiated 2 groups of children well characterized by their baseline symptom reporting. Thirty percent (95% confidence interval [CI], 20.2%-41.8%) had a high symptom profile with higher depression, fatigue, pain interference, a pediatric version of the fibromyalgia survey criteria symptoms, neuropathic pain, and catastrophizing. Girls were more likely than boys to be clustered in the high symptom profile (odds ratio [OR], 5.76 [95% CI, 1.20-27.58]; P = .022) as were those with preoperative pain lasting >3 months (OR, 3.42 [95% CI, 1.21-9.70]; P = .018). Adjusting for sex, age, and total in-hospital opioid consumption, high cluster membership was independently associated with higher self-reported pain after discharge (mean difference +1.13 point [97.5% CI, 0.09-2.17]; P = .015). Children in the high symptom cluster were more likely to report ongoing opioid use at 2 weeks compared with the low symptom group (87% vs 50%; OR, 6.5 [95% CI, 1.30-33.03]; P = .015). At 6 months, high symptom cluster membership was associated with higher pain intensity, higher pain interference, and ongoing analgesic use (P ≤ .018). CONCLUSIONS: A behavioral pain vulnerable profile was present preoperatively in 30% of children with idiopathic scoliosis and was independently associated with poorer and potentially long-lasting pain outcomes after spine fusion in this setting. This high symptom profile is similar to that described in children and adults with chronic and centralized pain disorders and was more prevalent in girls and those with long-standing pain. Further study is needed to elucidate the potential mechanisms behind our observations.

Comparison of submuscular and open plating of pediatric femur fractures: a retrospective review.

BACKGROUND: Plate osteosynthesis is an accepted method of treatment of pediatric femur fractures. Historically, open plating has been used. Submuscular bridge plating has gained recent popularity due to the theoretical advantages of decreased operative time, decreased blood loss, and decreased risk for infection. The purpose of this study was to compare submuscular bridge plating to open plating of pediatric femur fractures. METHODS: We retrospectively reviewed 79 patients (80 treated femur fractures) between 1999 and 2011 that underwent either open plating (58 femur fractures) or submuscular bridge plating (22 femur fractures). The outcome measures evaluated were operative time, estimated blood loss, malunion, leg length discrepancy, time to union, infection, unplanned return to the operating room, and length of hospital stay after surgery. RESULTS: Among our outcome measures, there was no difference between the 2 groups in terms of operative time, leg length discrepancy, time to union, infection, or length of hospital stay after surgery. There was greater estimated blood loss in the open plating group (P≤0.0001) and greater rotational asymmetry in the submuscular bridge plating group (P=0.005). There was a trend of increased unplanned return to the operating room in the open plating group (5/58 vs. 0/22) although not statistically significant (P=0.32). CONCLUSIONS: Submuscular bridge plating and open plating seem to be equally viable options for the management of pediatric diaphyseal femur fractures. In this study, open plating had an increase in estimated blood loss and a trend of more unplanned returns to the operating room, whereas submuscular bridge plating had an increase in asymptomatic rotational asymmetry. Further larger, prospective, randomized studies are necessary to further evaluate these operative techniques. LEVEL OF EVIDENCE: Therapeutic Level III.

A genome-wide approach for identification and characterisation of metabolite-inducible systems.

Inducible gene expression systems are vital tools for the advancement of synthetic biology. Their application as genetically encoded biosensors has the potential to contribute to diagnostics and to revolutionise the field of microbial cell factory development. Currently, the number of compounds of biological interest by far exceeds the number of available biosensors. Here, we address this limitation by developing a generic genome-wide approach to identify transcription factor-based inducible gene expression systems. We construct and validate 15 functional biosensors, provide a characterisation workflow to facilitate forward engineering efforts, exemplify their broad-host-range applicability, and demonstrate their utility in enzyme screening. Previously uncharacterised interactions between sensors and compounds of biological relevance are identified by employing the largest reported library of metabolite-responsive biosensors in an automated high-throughput screen. With the rapidly growing genomic data these innovative capabilities offer a platform to vastly increase the number of biologically detectable molecules.

Superelectrophilic chemistry of imidazoles.

The mechanistic and synthetic chemistry of imidazole-based superelectrophiles has been studied. The protonated imidazole ring, or imidazolium group, is shown to enhance the electrophilic reactivity of an adjacent carboxonium group (compared to a related monocationic species). This leads to efficient condensation reactions between imidazole aldehydes and ketone with arenes in the Brønsted superacid CF3SO3H. The imidazole-based superelectrophiles are shown to be useful in other reactions leading to functionalized heterocycles. The imidazolium group may also trigger charge migration reactions in dicationic species.

Prolonged Field Care in Support of Operation Inherent Resolve, 2016.

The authors present their experience in emergency and longterm medical care by Special Operations Forces (SOF) medical providers in an austere environment. In this case, a Special Forces Operational Detachment-Alpha (SFOD-A) was deployed in support of Operation Inherent Resolve, partnered with indigenous combat forces.

Intrathecal Morphine and Oral Analgesics Provide Safe and Effective Pain Control After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Retrospective comparative study. OBJECTIVE: The aim of this study was to demonstrate that intrathecal morphine (ITM) and oral analgesics provide effective pain control after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS), and this protocol has a low complication rate so patients can be admitted to a general care floor. SUMMARY OF BACKGROUND DATA: Previous studies have shown that ITM combined with intravenous patient-controlled analgesia or epidural infusion (EPI) provides effective pain control after PSF for AIS. Owing to concerns for respiratory depression, ITM patients were routinely admitted to the intensive care unit (ICU) postoperatively. There are little data on ITM combined with oral analgesics. METHODS: We identified AIS patients aged 10 to 17 years who had undergone PSF. Twenty-eight patients who received ITM were matched to 28 patients who received a hydromorphone EPI. The ITM group received oral oxycodone starting at 16 hours postinjection. The EPI group received oxycodone after the epidural catheter was removed on postoperative day 2. Pain scores, adverse events, and length of stay were recorded. RESULTS: A higher number of EPI patients received fentanyl (11 vs. 3, P = 0.014) in the post-anesthesia care unit (PACU). The ITM group had lower pain scores between PACU discharge and midnight (mean 2.9 vs. 4.2, P = 0.034). Pain scores were similar during the remaining postoperative periods. All ITM patients transitioned to oxycodone without intravenous opioids. Time to ambulation (19.9 vs. 26.5 hours, P = 0.010) and Foley catheter removal (21.3 vs. 41.9 hours, P < 0.001) were earlier in the ITM patients. Length of hospital stay was shorter in the ITM group (3.1 vs. 3.5 days, P = 0.043). Adverse events occurred at similar rates in both groups. CONCLUSION: ITM and oral analgesics provide safe and effective pain control after PSF for AIS. Routine postoperative admission to the ICU is not necessary. LEVEL OF EVIDENCE: 3.

Paper #35: Comparison of EOSQ-24 and SRS-22 scores in Congenital Scoliosis.

EOSQ-24 has been validated in early onset scoliosis (EOS), including congenital scoliosis (CS), and is completed by the caregiver. SRS-22 has been validated in idiopathic scoliosis and is completed by the patient. This study demonstrated a strong correlation between EOSQ-24 and SRS-22 for patients with CS who completed both questionnaires. It may be appropriate for cognitively normal children with EOS due to CS to complete SRS-22.

Ectopic HOXA5 expression results in abnormal differentiation, migration and p53-independent cell death of superficial dorsal horn neurons.

Previously, we reported a line of mice (Hoxa5SV2) that ectopically expresses HOXA5 in the developing cervical and brachial dorsal spinal cord. Animals from this line exhibited a clear loss of cells in the outer lamina of the mature dorsal horn that coincided with an adult phenotype of sensory and motor defects of the forelimb. In this report, we examined the etiology of lost dorsal horn cells. Cells normally fated to populate the outer laminae I-III of the dorsal horn migrated inappropriately, as the percentage of laterally positioned cells in the dorsal horn was significantly reduced in Hoxa5SV2 transgenics. Apoptosis was a major cause of cell loss while proliferation of neurons was not affected in Hoxa5SV2 animals. Although Hoxa5 has been shown in vitro to regulate p53 expression and cause p53-dependent apoptosis, p53 was not required in vivo for the inappropriate apoptosis seen in Hoxa5SV2 mice, or for the normal death of motor neurons. Normal apoptosis is not dependent on Hoxa5, as the level of ventral horn motor neuron apoptosis was not changed in Hoxa5 null animals. As a possible cause of aberrant migration and/or apoptosis of dorsal neurons, misexpression of cell type markers was demonstrated. Further, the expression pattern of laminar markers was altered and sensory fibers aberrantly penetrated the outer lamina of mutants. Our evidence suggests that the loss of dorsal horn neurons in Hoxa5SV2 mutants was due to misexpression of dorsal horn neuronal markers, aberrant migration, and inappropriate apoptosis.

Purple pitcher plant (Sarracenia rosea) Dieback and partial community disassembly following experimental storm surge in a coastal pitcher plant bog.

Sea-level rise and frequent intense hurricanes associated with climate change will result in recurrent flooding of inland systems such as Gulf Coastal pitcher plant bogs by storm surges. These surges can transport salt water and sediment to freshwater bogs, greatly affecting their biological integrity. Purple pitcher plants (Sarracenia rosea) are Gulf Coast pitcher plant bog inhabitants that could be at a disadvantage under this scenario because their pitcher morphology may leave them prone to collection of saline water and sediment after a surge. We investigated the effects of storm surge water salinity and sediment type on S. rosea vitality, plant community structure, and bog soil-water conductivity. Plots (containing ≥1 ramet of S. rosea) were experimentally flooded with fresh or saline water crossed with one of three sediment types (local, foreign, or no sediment). There were no treatment effects on soil-water conductivity; nevertheless, direct exposure to saline water resulted in significantly lower S. rosea cover until the following season when a prescribed fire and regional drought contributed to the decline of all the S. rosea to near zero percent cover. There were also significant differences in plant community structure between treatments over time, reflecting how numerous species increased in abundance and a few species decreased in abundance. However, in contrast to S. rosea, most of the other species in the community appeared resilient to the effects of storm surge. Thus, although the community may be somewhat affected by storm surge, those few species that are particularly sensitive to the storm surge disturbance will likely drop out of the community and be replaced by more resilient species. Depending on the longevity of these biological legacies, Gulf Coastal pitcher plant bogs may be incapable of fully recovering if they become exposed to storm surge more frequently due to climate change.

Skipping syntactically illegal the previews: The role of predictability.

Readers tend to skip words, particularly when they are short, frequent, or predictable. Angele and Rayner (2013) recently reported that readers are often unable to detect syntactic anomalies in parafoveal vision. In the present study, we manipulated target word predictability to assess whether contextual constraint modulates the-skipping behavior. The results provide further evidence that readers frequently skip the article the when infelicitous in context. Readers skipped predictable words more often than unpredictable words, even when the, which was syntactically illegal and unpredictable from the prior context, was presented as a parafoveal preview. The results of the experiment were simulated using E-Z Reader 10 by assuming that cloze probability can be dissociated from parafoveal visual input. It appears that when a short word is predictable in context, a decision to skip it can be made even if the information available parafoveally conflicts both visually and syntactically with those predictions.

Transgenic mice ectopically expressing HOXA5 in the dorsal spinal cord show structural defects of the cervical spinal cord along with sensory and motor defects of the forelimb.

Mutation of murine Hoxa5 has shown that HOXA5 controls lung, gastrointestinal tract and vertebrae development. Hoxa5 is also expressed in the spinal cord, yet no central nervous system phenotype has been described in Hoxa5 knockouts. To identify the role of Hoxa5 in spinal cord development, we developed transgenic mice that express HOXA5 in the dorsal spinal cord in the brachial region. Using HOXA5-specific antibodies, we show this expression pattern is ectopic as the endogenous protein is expressed only in the ventral spinal cord at this anterio-posterior level. This transgenic line (Hoxa5SV2) also displays forelimb-specific motor and sensory defects. Hoxa5SV2 transgenic mice cannot support their body weight in a forelimb hang, and forelimb strength is decreased. However, Rotarod performance was not impaired in Hoxa5SV2 mice. Hoxa5SV2 mice also show a delayed forelimb response to noxious heat, although hindlimb response time was normal. Administration of an analgesic significantly reduced the hang test defect and decreased the transgene effect on forelimb strength, indicating that pain pathways may be affected. The morphology of transgenic cervical (but not lumbar) spinal cord is highly aberrant. Nissl staining indicates superficial laminae of the dorsal horn are severely disrupted. The distribution of cells and axons immunoreactive for substance P, neurokinin-B, and their primary receptors were aberrant only in transgenic cervical spinal cord. Further, we see increased levels of apoptosis in transgenic spinal cord at embryonic day 13.5. Our evidence suggests apoptosis due to HOXA5 misexpression is a major cause of loss of superficial lamina cells in Hoxa5SV2 mice.

Gartland type III supracondylar humerus fractures: outcome and complications as related to operative timing and pin configuration.

PURPOSE: Supracondylar fractures of the humerus are the most common fracture of the elbow in children. The purpose of this study was to evaluate, in terms of outcomes and complications, Gartland type III pediatric supracondylar humerus fractures treated at a pediatric level-one trauma center over a 7-year period, specifically addressing the impact of time to surgery on the incidence of complications and conversion to open reduction. METHODS: We retrospectively reviewed 297 pediatric patients that sustained a closed Gartland type III supracondylar humerus fracture treated between December 2004 and December 2011. The time to the operating room was calculated from the medical records for each patient. The outcome measures evaluated were operative time, conversion to open procedure, and perioperative and postoperative complications. RESULTS: In our study, there were 30 complications in 25 children (8.4%). Conversion to open reduction occurred in 28 children (9.4%). The time from the emergency department to the operating room was not significantly correlated with increased complications, increased operative time, or conversion to open reduction (p > 0.05). Crossed pinning resulted in an increased risk of overall complications [odds ratio (OR) = 2.6] and iatrogenic nerve injuries (OR = 9.3). Complications also occurred more commonly in boys (OR = 3.3) and in older patients (p = 0.0069) CONCLUSIONS: We found no significant correlation between the time to surgery and complications, operative time, or need for open reduction. These findings support the trend of treating Gartland type III supracondylar humerus fractures in a less urgent manner. In addition, our study supports the concept that cross pinning leads to more complications than lateral pinning, including an 8-fold increase in iatrogenic nerve injury.

SUPERACID-PROMOTED HYDROXYALKYLATION OF 1,2-INDANDIONES.

1,2-Indandione reacts efficiently with arenes to give 2,2-diaryl-1-indanones by the hydroxyalkylation reaction. The Brønsted superacid CF3SO3H (triflic acid) is an effective catalyst for these condensation reactions. The requisite 1,2-indandiones were prepared from the 1-indanones.

Magnetic resonance imaging of obstetrical brachial plexus injuries.

OBJECTIVE: We reviewed MR imaging in infants with Erb's palsy. The goal was to determine the effectiveness of MR imaging in predicting operative findings for these infants. METHODS: Fifteen patients (mean age: 14.5 months) underwent surgical exploration of the brachial plexus. Preoperative MR imaging was acquired in all patients with a GE (Milwaukee, WI, USA) 1.5-Tesla MRI and correlated with the surgical findings as outlined in the children's operative notes. RESULTS: Through imaging, the presence of at least one pseudomeningocele was found in 8 of the 15 patients (53.3%) while 3 of the 15 patients (20%) had multiple pseudomeningoceles. Posterior shoulder subluxation was seen in 11 patients (73.3%). Fourteen children(93.3%) had imaging abnormalities consistent with either a reparative neuroma or scar tissue investing plexus elements. We were unable to differentiate between the two with MR imaging. At surgery, scar tissue was found entrapping the C5-C6 roots, upper trunk, and/or lateral and posterior cords in 11 patients (73.3%)while 4 patients had reparative neuromas. Two patients had both entrapment by scar tissue and a reparative neuroma. Either entrapment by scar tissue or neuroma was found in all 15 patients (100%). CONCLUSIONS: MR imaging is an effective tool for demonstrating lesions of the brachial plexus worthy of surgical exploration.