Acute Osmotic Central Pontine Demyelination in an Alcoholic Patient With Normal Sodium Levels and a Vitamin B6 Deficiency.

We report a Native American male in his 50s with a complex medical history including alcohol use disorder and seizure disorder who presented with complaints of generalized weakness and multiple falls. The patient was admitted for altered mental status, community acquired pneumonia, sepsis, and bacteremia. On hospital day 23, the patient reported a sudden onset of sensation of food stuck in his upper chest. Brain MRI confirmed osmotic demyelination syndrome (ODS) within the central pons. Further workup revealed this finding was likely due to malnutrition, alcoholism, hypoalbuminemia, and vitamin B6 deficiency. However, the patient presented with normonatremia throughout his entire hospital stay. After acute onset of ODS, the patient was transferred to the ICU where he continued to decline. After 68 days from initial presentation, the patient died in hospice care from myelinolysis complications. This case demonstrates a case of ODS of the central pons in a patient with normonatremia, hypoalbuminemia, and severe vitamin B6 deficiency.

Gluten Ataxia and mGluR1 Autoimmune Encephalitis Presenting as Acute Cerebellar Ataxia: A Case Report.

A Caucasian male in his 60s presented with acute onset of dizziness, dysarthria, and gait ataxia. Upon extensive workup, positive findings were cerebrospinal fluid (CSF) showing lymphocytic pleocytosis with oligoclonal bands, positive celiac disease autoantibodies in blood, a duodenal biopsy indicating lymphocytic infiltration, and positive anti-mGluR1 antibody titers in CSF. The patient was started on a strict gluten-free diet and intravenous immunoglobulin therapy for 5 days and showed mild consecutive improvements each day of treatment. He was discharged after 22 days, and was encouraged to continue gluten adherence, physical and speech therapy, and follow up with neuroimmunology. This report demonstrates that autoimmune encephalitis due to anti-mGluR1antibodies and gluten ataxia are both immune-mediated disorders that should be considered in acute cerebellar ataxia cases. By broadening the differential diagnosis and a comprehensive CSF analysis, identification of gluten ataxia and autoimmune encephalitis were beneficial in the management of this particular patient.

Neurotoxicity assessment of the herbicide pethoxamid in zebrafish (Danio rerio) embryos/larvae.

Pethoxamid, a member of the chloroacetamide herbicide family, is a recently approved chemical for pre- or post-emergence weed control; however, toxicity data for sublethal effects in aquatic organisms exposed to pethoxamid are non-existent in literature. To address this, we treated zebrafish embryos/larvae to pethoxamid over a 7-day period post-fertilization and evaluated several toxicological endpoints associated with oxidative stress and neurotoxicity. Continuous pethoxamid exposure did not affect survival nor hatch success in embryos/larvae for 7 days up to 1000 µg L-1. Exposure to pethoxamid did not affect embryonic ATP-linked respiration, but it did reduce non-mitochondrial respiration at the highest concentration tested. We also noted a significant increase in both apoptosis and levels of reactive oxygen species (ROS) in larvae zebrafish following exposure to pethoxamid. Increases in apoptosis and ROS, however, were not correlated with any altered gene expression pattern for apoptotic and oxidative damage response transcripts. To assess neurotoxicity potential, we measured behavior and several transcripts implicated in neural processes in the central nervous system. While locomotor activity of larval zebrafish was affected by pethoxamid exposure (hyperactivity was observed at concentrations below 1 µg L-1, and hypoactivity was noted at higher exposures to 10 and 100 µg L-1 pethoxamid), there were no effects on steady state mRNA abundance for neurotoxicity-related transcripts tested. This data contributes to knowledge regarding exposure risks for chloroacetamide-based herbicides and is the first study investigating sublethal toxicity for this newly registered herbicide.

A Population-Based Approach to the Argument on Brain-First and Body-First Pathogenesis of Lewy Body Disease.

OBJECTIVE: To explore the clinical progression of the brain-/body-first categories within Lewy body disease (LBD): Parkinson's disease (PD), dementia with Lewy bodies (DLB), and PD dementia. METHODS: We used of the Rochester Epidemiology Project to establish a population-based cohort of clinically diagnosed LBD. We used two definitions for differentiating between brain- and body-first LBD: a previously hypothesized body-first presentation in patients with rapid eye movement sleep behavior onset before motor symptoms onset; and an expanded definition of body-first LBD when a patient had at least 2 premotor symptoms between constipation, erectile dysfunction, rapid eye movement sleep behavior, anosmia, or neurogenic bladder. RESULTS: Brain-first patients were more likely to be diagnosed with PD (RR = 1.43, p = 0.003), whereas body-first patients were more likely to be diagnosed with DLB (RR = 3.15, p < 0.001). Under the expanded definition, there was no difference in LBD diagnosis between brain-first and body-first patients (PD: RR = 1.03, p = 0.10; DLB: RR = 0.88, p = 0.58) There were no patterns between brain- or body-first presentation, PD dementia under either definition (original: p = 0.09, expanded: p = 0.97), and no significant difference in motor symptoms between brain-first and body-first. INTERPRETATION: Our findings do not support the dichotomous classification of body-first and brain-first LBD with the currently proposed definition. Biological exposures resulting in PD and DLB are unlikely to converge on a binary classification of top-down or bottom-up synuclein pathology. ANN NEUROL 2024.

Cognitive function in adolescence and the risk of early-onset stroke.

BACKGROUND: Stroke is increasingly prevalent at younger ages but the risk factors are uncertain. We examined the association between adolescent cognitive function and early-onset stroke. METHODS: This was a nationwide population-based cohort study of 1 741 345 Israeli adolescents (42% women) who underwent comprehensive cognitive function tests at age 16-20 years, before mandatory military service, during 1987-2012. Cognitive function (range: 1-9) was categorised as low (1-3, corresponding to IQ score below 89), medium (4-7, IQ score range: 89-118), or high (8-9, IQ score above 118). Participant data were linked to the Israeli National Stroke Registry. Cox proportional hazard models were used to estimate risks for the first occurrence of ischaemic stroke during 2014-2018. RESULTS: During 8 689 329 person-years of follow-up, up to a maximum age of 50 years, 908 first stroke events occurred (767 ischaemic and 141 haemorrhagic). Compared with a reference group of people with high cognitive function, body mass index-adjusted and sociodemographic-adjusted HRs (95% CIs) for early-onset stroke were 1.78 (1.33-2.38) in medium and 2.68 (1.96-3.67) in low cognitive function groups. There was evidence of a dose-response relationship (P for trend <0.0001) such that one-unit of lower cognitive function z-score was associated with a 33% increased risk of stroke (1.33; 1.23-1.42). These associations were similar for ischaemic stroke but lower for haemorrhagic stroke; persisted in sensitivity analyses that accounted for diabetes status and hypertension; and were evident before age 40 years. CONCLUSIONS: Alongside adolescent obesity and hypertension, lower cognitive function may be a risk factor for early-onset stroke.

Emergence of the natural history of Myhre syndrome: 47 patients evaluated in the Massachusetts General Hospital Myhre Syndrome Clinic (2016-2023).

Myhre syndrome is an increasingly diagnosed ultrarare condition caused by recurrent germline autosomal dominant de novo variants in SMAD4. Detailed multispecialty evaluations performed at the Massachusetts General Hospital (MGH) Myhre Syndrome Clinic (2016-2023) and by collaborating specialists have facilitated deep phenotyping, genotyping and natural history analysis. Of 47 patients (four previously reported), most (81%) patients returned to MGH at least once. For patients followed for at least 5 years, symptom progression was observed in all. 55% were female and 9% were older than 18 years at diagnosis. Pathogenic variants in SMAD4 involved protein residues p.Ile500Val (49%), p.Ile500Thr (11%), p.Ile500Leu (2%), and p.Arg496Cys (38%). Individuals with the SMAD4 variant p.Arg496Cys were less likely to have hearing loss, growth restriction, and aortic hypoplasia than the other variant groups. Those with the p.Ile500Thr variant had moderate/severe aortic hypoplasia in three patients (60%), however, the small number (n = 5) prevented statistical comparison with the other variants. Two deaths reported in this cohort involved complex cardiovascular disease and airway stenosis, respectively. We provide a foundation for ongoing natural history studies and emphasize the need for evidence-based guidelines in anticipation of disease-specific therapies.

Simulation of Hydrogen Adsorption in Hierarchical Silicalite: Role of Electrostatics and Surface Chemistry.

Adsorption in nanoporous materials is one strategy that can be used to store hydrogen at conditions of temperature and pressure that are economically viable. Adsorption capacity of nanoporous materials depends on surface area which can be enhanced by incorporating a hierarchical pore structure. We report grand canonical Monte Carlo (GCMC) simulation results on the adsorption of hydrogen in hierarchical models of silicalite that incorporate 4 nm wide mesopores in addition to the 0.5 nm wide micropores at 298 K, using different force fields to model hydrogen. Our results suggest that incorporating mesopores in silicalite can enhance adsorption by at least 20 % if electrostatic interactions are not included and up to 100 % otherwise. Incorporating electrostatic interactions results in higher adsorption by close to 100 % at lower pressures for hierarchical silicalite whereas for unmodified silicalite, it is less significant at all pressures. Hydroxylating the mesopore surface in hierarchical silicalite results in an enhancement in adsorption at pressures below 1 atm and suppression by up to 20 % at higher pressures. Temperature dependence at selected pressures exhibits expected decrease in adsorption amounts at higher temperatures. These findings can be useful in the engineering, selection, and optimization of nanoporous materials for hydrogen storage.

Navigating the Impact of the Dobbs Decision: Perspectives from Pediatric Surgeons on Reproductive Health Care.

SUMMARY: Nationwide abortion restrictions resulting from the Dobbs v. Jackson Women's Health Organization (2022) decision have generated confusion and uncertainty among healthcare professionals, with concerns for liability impacting clinical decision-making and outcomes. The impact on pediatric surgery can be seen in prenatal counseling for fetal anomaly cases, counseling for fetal intervention, and recommendations for pregnant children and adolescents who seek termination. It is essential that all physicians and healthcare team members understand the legal implications on their clinical practices, engage with resources and organizations which can help navigate these circumstances, and consider advocating for patients and themselves. Pediatric surgeons must consider the impact of these changing laws on their ability to provide comprehensive and ethical care and counseling to all patients.

Waterborne exposure to the antineoplastic 5-fluorouracil alters lipid composition in larval zebrafish (Danio rerio).

Antineoplastic medications are present in aquatic environments and are measured at relatively high concentrations in hospital sewage effluent. Thus, it is important to characterize risk associated with waterborne exposures to anticancer drugs. The drug 5-fluorouracil (5-FU) is used to treat several types of cancers, acting to inhibit cell division and cellular metabolism. The objectives of this study were to determine the effects of 5-FU on developmental endpoints and lipid composition in zebrafish. 5-FU did not negatively affect development nor survival in developing zebrafish at concentrations up to 1000 µg/L. However, 5-FU increased neutral lipid content in zebrafish larvae, indicating potential for lipid dysregulation. To further discern effects on lipids, lipidomics was conducted and a total of 164 lipids belonging to 14 lipid classes were identified. Significant changes (false discovery rate < 0.05) in abundance were detected for 19 lipids including some ceramides, ether-linked phosphatidylethanolamines, and sphingomyelins among others. We also measured the expression levels of 14 lipid-related enzymes and transporters (e.g., acox3, dgat1, fads2, fasn, elovl2) using real-time PCR; however, mRNA abundance levels were not affected, suggesting transcriptional changes may not be a primary mechanism underlying lipid dysregulation. Locomotor activity was measured in zebrafish as lipids are needed for swimming activity in larvae. Exposure to 5-FU did not affect locomotor activity up to 1000 µg/L. We conclude that lipids accumulate in larval zebrafish with exposure to 5-FU, which can subsequently affect lipid composition. These data reveal potential lipid signatures of 5-FU exposure and contribute to risk assessments for antineoplastic exposure in aquatic environments.

Exposure to the antineoplastic ifosfamide alters molecular pathways related to cardiovascular function, increases heart rate, and induces hyperactivity in zebrafish (Danio rerio).

Ifosfamide is an alkylating antineoplastic drug used in chemotherapy, but it is also detected in wastewater. Here, the objectives were to (1) determine teratogenic, cardiotoxic, and mitochondrial toxicity potential of ifosfamide exposure; (2) elucidate mechanisms of toxicity; (3) characterize exposure effects on larval behavior. Survival rate, hatch rate, and morphological deformity incidence were not different amongst treatments following exposure levels up to 1000 µg/L ifosfamide over 7 days. RNA-seq reveled 231 and 93 differentially expressed transcripts in larvae exposed to 1 µg/L and 100 µg/L ifosfamide, respectively. Several gene networks related to vascular resistance, cardiovascular response, and heart rate were affected, consistent with tachycardia observed in exposed embryonic fish. Hyperactivity in larval zebrafish was observed with ifosfamide exposure, potentially associated with dopamine-related gene networks. This study improves ecological risk assessment of antineoplastics by elucidating molecular mechanisms related to ifosfamide toxicity, and to alkylating agents in general.

Thoracoabdominal aneurysm repair using the Unitary Manifold Device.

OBJECTIVE: To present a single-center prospective study of 126 consecutively treated patients who underwent endovascular repair of a thoracoabdominal aortic aneurysm with the physician-modified, nonanatomic-based Unitary Manifold (UM) device. METHODS: Data were collected from 126 consecutive all-comer patients treated with the physician-modified, nonanatomic-based UM from 2015 to 2023. Treatment was performed at a single center by a single physician under a Physician Sponsored Investigation Exemption G140207. RESULTS: The UM was indicated for repair of all Crawford extents including juxtarenal, pararenal, and short-neck infrarenal aneurysms (<10 mm) in 126 consecutive patients. Patients were not excluded from the study based on presentation, extent of aneurysm or dissection, or history of a spinal cord event. Patients with a thoracoabdominal aortic aneurysm were categorized by Crawford classification: types I and V (3.3%, n = 4), type II (3.3%, n = 4), type III (1%, n = 1), and type IV (93.3%, n = 117). The type IV classification patients were further categorized with 33 (28.2%) true type IV, 68 (58.1%) pararenal or infrarenal, and 16 (13.7%) with dissection. Technical success was 99.2% (n = 125). The most common major adverse event within both 30 days and 365 days of all patients was respiratory failure (11.9%, n = 15, and 13.5%, n = 17, respectively). One patient (0.8%) experienced persistent paraplegia at 365 days. Reintervention for patients at 365 days was 5.6% (n = 7). Of the 444 branches stented, the primary patency rate was remarkably high as only three patients (2.4%) required reintervention due to loss of limb patency within 365 days. Aneurysm enlargement (≥5 mm) occurred in 1.6% (n = 2) patients, and no patients experienced aneurysm rupture. No patients underwent conversion to open repair. The aneurysm-related mortality at 365 days for all patients was 4.0% (n = 5), whereas all-cause mortality was 16.7% (n = 21). Physician-modified endograft device integrity failure was not observed in any patient. CONCLUSIONS: The UM device demonstrated remarkable technical surgical success, treatment success, and device patency rates with very reasonable major adverse events and reintervention rates. This study is the most representative example of the general population in comparison with other studies of off-the-shelf devices, with 126 consecutive all-comer patients with diverse pathologies.

Improving Breath Detection From Pulsed-Flow Oxygen Sources Using a New Nasal Interface.

BACKGROUND: Patients with COPD and other lung diseases are treated with long-term oxygen therapy (LTOT). Portable oxygen sources are required to administer LTOT while maintaining patient autonomy. Existing portable oxygen equipment has limitations that can hinder patient mobility. A novel nasal interface is presented in this study, aiming to enhance breath detection and triggering efficiency of portable pulsed-flow oxygen devices, thereby improving patient mobility and independence. METHOD: To examine the effectiveness of the new interface, 8 respiratory therapists participated in trials using different oxygen sources (tank with oxygen-conserving device, SimplyGo Mini portable oxygen concentrator [POC], and OxyGo NEXT POC) and breathing types (nasal and oral) while using either the new nasal interface or a standard cannula. Each trial was video recorded so participant breaths could be retroactively matched with a pulse/no-pulse response, and triggering success rates were calculated by dividing the number of oxygen pulses by the number of breaths in each trial. After each trial, volunteers were asked to rate their perceived breathing resistance. RESULTS: Nasal breathing consistently resulted in higher triggering success rates compared to oral breathing for pulsed-flow oxygen devices. POCs exhibited higher triggering success rates than did the oxygen tanks with conserving device. However, there were no significant differences in triggering success rates between the two POC models. The new nasal interface demonstrated improved triggering success rates compared to the standard cannula. Whereas the new nasal interface was associated with a slight increase in perceived breathing resistance during nasal breathing trials, participants reported manageable resistance levels when using the interface. CONCLUSIONS: This study demonstrates that the new nasal interface can improve triggering success rates of pulsed-flow oxygen devices during both nasal and oral breathing scenarios. Further research involving patient trials is recommended to understand the clinical implications of improved pulse triggering.

BIPOC experiences of (anti-)racist patient engagement in adolescent and young adult oncology research: an electronic Delphi study.

Aims: To characterize Black, Indigenous and People of Color (BIPOC) adolescent and young adult (AYA) cancer patients' experiences of patient engagement in AYA oncology and derive best practices that are co-developed by BIPOC AYAs and oncology professionals. Materials & methods: Following a previous call to action from AYA oncology professionals, a panel of experts composed exclusively of BIPOC AYA cancer patients (n = 32) participated in an electronic Delphi study. Results: Emergent themes described BIPOC AYA cancer patients' direct experiences and consensus opinion on recommendations to advance antiracist patient engagement from BIPOC AYA cancer patients and oncology professionals. Conclusion: The findings reveal high-priority practices across all phases of research and are instructional for advancing health equity.

Cyfip2 controls the acoustic startle threshold through FMRP, actin polymerization, and GABAB receptor function.

Animals process a constant stream of sensory input, and to survive they must detect and respond to dangerous stimuli while ignoring innocuous or irrelevant ones. Behavioral responses are elicited when certain properties of a stimulus such as its intensity or size reach a critical value, and such behavioral thresholds can be a simple and effective mechanism to filter sensory information. For example, the acoustic startle response is a conserved and stereotyped defensive behavior induced by sudden loud sounds, but dysregulation of the threshold to initiate this behavior can result in startle hypersensitivity that is associated with sensory processing disorders including schizophrenia and autism. Through a previous forward genetic screen for regulators of the startle threshold a nonsense mutation in Cytoplasmic Fragile X Messenger Ribonucleoprotein (FMRP)-interacting protein 2 (cyfip2) was found that causes startle hypersensitivity in zebrafish larvae, but the molecular mechanisms by which Cyfip2 establishes the acoustic startle threshold are unknown. Here we used conditional transgenic rescue and CRISPR/Cas9 to determine that Cyfip2 acts though both Rac1 and FMRP pathways, but not the closely related FXR1 or FXR2, to establish the acoustic startle threshold during early neurodevelopment. To identify proteins and pathways that may be downstream effectors of Rac1 and FMRP, we performed a candidate-based drug screen that indicated that Cyfip2 can also act acutely to maintain the startle threshold branched actin polymerization and N-methyl D-aspartate receptors (NMDARs). To complement this approach, we used unbiased discovery proteomics to determine that loss of Cyfip2 alters cytoskeletal and extracellular matrix components while also disrupting oxidative phosphorylation and GABA receptor signaling. Finally, we functionally validated our proteomics findings by showing that activating GABAB receptors, which like NMDARs are also FMRP targets, restores normal startle sensitivity in cyfip2 mutants. Together, these data reveal multiple mechanisms by which Cyfip2 regulates excitatory/inhibitory balance in the startle circuit to control the processing of acoustic information.

hnRNP A1 dysfunction alters RNA splicing and drives neurodegeneration in multiple sclerosis (MS).

Neurodegeneration is the primary driver of disease progression in multiple sclerosis (MS) resulting in permanent disability, creating an urgent need to discover its underlying mechanisms. Herein, we establish that dysfunction of the RNA binding protein heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) results in differential of binding to RNA targets causing alternative RNA splicing, which contributes to neurodegeneration in MS and its models. Using RNAseq of MS brains, we discovered differential expression and aberrant splicing of hnRNP A1 target RNAs involved in neuronal function and RNA homeostasis. We confirmed this in vivo in experimental autoimmune encephalomyelitis employing CLIPseq specific for hnRNP A1, where hnRNP A1 differentially binds and regulates RNA, including aberrantly spliced targets identified in human samples. Additionally, dysfunctional hnRNP A1 expression in neurons caused neurite loss and identical changes in splicing, corroborating hnRNP A1 dysfunction as a cause of neurodegeneration. Collectively, these data indicate hnRNP A1 dysfunction causes altered neuronal RNA splicing, resulting in neurodegeneration in MS.

Relationships Between Schistosoma mansoni Infection Intensity and Nutritional Status and Anemia Among Preschool-aged Children in Uganda.

In a cross-sectional analysis of 354 Ugandan children (age 12-48 months) infected with Schistosoma mansoni, we assessed relationships between infection intensity and nutritional morbidities. Higher intensity was associated with an increased risk for anemia (RR = 1.05, 95% confidence interval [CI] 1.01-1.10) yet not associated with risk for underweight, stunting, or wasting.

Risk of hospitalization in synucleinopathies and impact of psychosis.

Background: Few studies have investigated the risk of hospitalization among patients with synucleinopathies (Parkinson disease, Dementia with Lewy Bodies, Parkinson disease dementia, Multiple System Atrophy) with associated psychosis and the impact of antipsychotic treatments on hospital admissions and duration of the stay. Objective: To determine the risk of hospitalization among patients with synucleinopathies and in patients with associated psychosis. To evaluate the impact of antipsychotic treatments on hospital admission of patients with synucleinopathies and psychosis in an incident cohort study in Olmsted County, Minnesota (MN). Methods: We used the Rochester Epidemiology Project (REP) to define an incident cohort of patients with clinically diagnosed synucleinopathies (1991-2010) in Olmsted County, MN. A movement disorder specialist reviewed all medical records to confirm the clinical diagnosis of synucleinopathies using the NINDS/NIMH unified diagnostic criteria. Results: We included 416 incident cases of clinically diagnosed synucleinopathies from 2,669 hospitalizations. 409 patients (98.3%) were admitted to the hospital at least once for any cause after the onset of parkinsonism. The median number of hospitalizations for a single patient was 5. In total, 195 (46.9%) patients met the criteria for psychosis: patients with psychosis had a 49% (HR = 1.49, p < 0.01) increased risk of hospitalization compared to patients without psychosis. Among patients with psychosis, 76 (39%) received antipsychotic medication. Treatment with antipsychotic medications did not affect the risk of hospitalization (HR = 0.93, p = 0.65). The median length of hospitalization among the entire cohort was 1 (IQR 0-4) day. There was no difference between hospitalization length for patients with no psychosis and patients with active psychosis (RR = 1.08, p = 0.43) or patients with resolved psychosis (RR = 0.79, p = 0.24). Conclusion: Psychosis increases the risk of hospitalization in patients with clinically defined synucleinopathies; however, it does not affect the length of hospital stays in our cohort. Antipsychotic treatment does not affect the risk of hospitalization in our study.

Chronic Nerve Root Injury in Pediatric Patients With Chronic Lumbar Stress Fractures: A Retrospective Review.

INTRODUCTION: Many orthopedic providers currently treat chronic spondylolysis as self-limited fractures. While the condition has previously been associated with back pain in pediatrics, there has been little attention on the risk of neurologic harm. Electromyography (EMG) is a common study used to evaluate nerve injury, but it has not been previously reported for testing pediatric patients with stress fractures. In this study, pediatric patients with chronic pars fractures and muscle extremity weakness who underwent EMG testing were reviewed to analyze their risk of chronic nerve injury. METHODS: 120 pediatric patients who underwent EMG testing between 2015 and 2021 were analyzed, and 41(21F,20M) patients with a mean age of 16(13-20) met criteria of chronic lumbar pediatric spondylolysis with weakness on ankle dorsiflexion or plantarflexion. No exclusions were made. Initial EMG testing was indicated for the extremity weakness; pain was not the major concern. All exams were completed by JWM. Thin-cut lumbar CT studies were done at the same institution, and EMGs were completed by one of three physiatrists. EMGs were determined as normal, abnormal but not meeting chronic nerve injury threshold, or abnormal and meeting threshold for chronic nerve injury. RESULTS: Of the 41 patients, 33 had bilateral and 8 had unilateral fractures with 95% (39/41) of them located at L4 or L5. 55% (18/33) of the bilateral fractures had abnormal EMGs and demonstrated chronic nerve injury; 1 had an abnormal EMG but did meet chronic injury threshold. 75% (6/8) of the unilateral fractures had abnormal EMGs and demonstrated chronic nerve injury; 1 had an abnormal EMG but did meet chronic injury threshold. Overall, 36% (15/41) had normal EMGs, 5% (2/41) had abnormal results but did not reach chronic injury threshold, and 59% (24/41) met threshold for chronic nerve injury. CONCLUSION: Chronic pars fractures have historically been treated as a benign and self-limited sports injury. However, our analysis showed that 59% of adolescent patients presenting with chronic pars fractures and dorsiflexion or plantarflexion weakness have developed a chronic nerve injury. This study is the first to demonstrate the risk of neurologic harm in unhealed pediatric lumbar stress fractures, and it indicates the importance of EMG testing in young patients presenting with chronic spondylolysis and extremity weakness.