Predictors of syrinx presentation and outcomes in pediatric Chiari malformation type I: a single institution experience of 218 consecutive syrinx patients.

PURPOSE: Chiari I malformation (CM-I) in pediatric patients can impose substantial neurologic and functional impairment. Additionally, the presence of syrinx is often a harbinger of clinical compromise, but little attention has been devoted to identifying features associated with syrinx development and the clinical impact of syrinx resolution. Therefore, this study aims to identify clinical and radiographic variables associated with preoperative syrinx presence and postoperative syrinx reduction in pediatric patients with CM-I and determine the relationship between postoperative syrinx reduction and clinical symptom improvement. METHODS: The authors performed a retrospective analysis of 435 consecutive pediatric patients who underwent surgical treatment of CM-I from 2001 to 2021 at a single tertiary pediatric medical center. All patients underwent pre- and postoperative MRI, and clinical and radiographic variables were recorded and subject to inferential analysis. RESULTS: Syrinx at presentation was independently associated with symptoms of spinal cord dysfunction at presentation (OR 2.17 (95% CI 1.05-4.48); p = 0.036), scoliosis (OR 5.33 (2.34-10.86); p = 0.001), and greater pB-C2 (posterior basion to C2 distance) measurement length (OR 1.14 (95% CI 1.01-1.30); p = 0.040). Syrinx at presentation was inversely associated with tussive headaches at presentation (OR 0.27 (95% CI 0.16-0.47); p = 0.001) and cranial nerve deficits at presentation (OR 0.49 (95% CI 0.26-0.92); p = 0.025). Postoperatively, patients with radiographic evidence of syrinx improvement had greater rates of symptom improvement (93.1% vs 82.1%; p = 0.049), better CCOS scores (15.4 vs 14.2; p = 0.001), and decreased rates of readmission (6.0% vs 25.0%, p = 0.002) and reoperation (0.5% vs 35.7%; p = 0.001). The difference in syrinx resolution was similar but not statistically significant (10.3% vs 16.7%; p = 0.251). AO joint anomaly (OR 0.20, 95% CI 0.04-0.95; p = 0.026) and foramen magnum diameter (OR 1.12, 95% CI 1.00-1.25; p = 0.049) were the only independent predictors of syrinx improvement, and surgical technique was the only predictor for syrinx resolution (OR 2.44, 95% CI 1.08-5.50; p = 0.031). Patients that underwent tonsil reduction surgery whose syrinx improved had a wider foramen magnum diameter than those whose did not improve (34.3 vs 31.7; p = 0.028). CONCLUSIONS: Radiographic syrinx improvement is associated with greater rates of symptom improvement and less readmissions and reoperations for CM-I. AO joint anomalies and narrower foramen magnums were independent risk factors for the lack of syrinx improvement. These novel insights will help guide preoperative patient counseling, pre- and intraoperative surgical decision-making, and postoperative clinical prognostication in the treatment of pediatric CM-I.

The Sensitivity of Limited-Sequence MRI in Identifying Pediatric Cervical Spine Injury: A Western Pediatric Surgery Research Consortium Multicenter Retrospective Cohort Study.

INTRODUCTION: Clinical clearance of a child's cervical spine after trauma is often challenging due to impaired mental status or an unreliable neurologic examination. Magnetic resonance imaging (MRI) is the gold standard for excluding ligamentous injury in children but is constrained by long image acquisition times and frequent need for anesthesia. Limited-sequence MRI (LSMRI) is used in evaluating the evolution of traumatic brain injury and may also be useful for cervical spine clearance while potentially avoiding the need for anesthesia. The purpose of this study was to assess the sensitivity and negative predictive value of LSMRI as compared to gold standard full-sequence MRI as a screening tool to rule out clinically significant ligamentous cervical spine injury. METHODS: We conducted a ten-center, five-year retrospective cohort study (2017-2021) of all children (0-18y) with a cervical spine MRI after blunt trauma. MRI images were re-reviewed by a study pediatric radiologist at each site to determine if the presence of an injury could be identified on limited sequences alone. Unstable cervical spine injury was determined by study neurosurgeon review at each site. RESULTS: We identified 2,663 children less than 18 years of age who underwent an MRI of the cervical spine with 1,008 injuries detected on full-sequence studies. The sensitivity and negative predictive value of LSMRI were both >99% for detecting any injury and 100% for detecting any unstable injury. Young children (age < 5 years) were more likely to be electively intubated or sedated for cervical spine MRI. CONCLUSION: LSMRI is reliably detects clinically significant ligamentous injury in children after blunt trauma. To decrease anesthesia use and minimize MRI time, trauma centers should develop LSMRI screening protocols for children without a reliable neurologic exam. LEVEL OF EVIDENCE: 2 (Diagnostic Tests or Criteria).

Management of cerebrospinal fluid pseudocysts in the laparoscopic age.

OBJECTIVE: Abdominal CSF pseudocysts are an uncommon but challenging complication of ventriculoperitoneal shunts. Pseudocysts consist of a loculated intraperitoneal compartment that inadequately absorbs CSF and may be infected or sterile at diagnosis. The treatment goal is to clear infection if present, reduce inflammation, and reestablish long-term function in an absorptive (intraperitoneal) space. This aim of this paper was to study the efficacy of primary laparoscopic repositioning of the distal shunt catheter for treatment of sterile abdominal CSF pseudocysts. METHODS: All patients treated for abdominal CSF pseudocysts at Dallas Children's Health from 1991 to 2021 were retrospectively reviewed. Patient history and pseudocyst characteristics were analyzed, with a primary outcome of pseudocyst recurrence at 1 year. RESULTS: Of 92 primary pseudocysts, 5 initial treatment strategies (groups) were used depending on culture status, clinical history, and surgeon preference: 1) shunt explant/external ventricular drain (EVD) placement (23/92), 2) distal tubing externalization (13/92), 3) laparoscopic repositioning (35/92), 4) open repositioning (4/92), and 5) other methods such as pseudocyst drainage or direct revision to another terminus (17/92). Seventy pseudocysts underwent shunt reimplantation in the peritoneal space. The 1-year peritoneal shunt survival for groups 1 and 2 combined was 90%, and 62% for group 3. In group 3, 1-year survival was better for those with normal systemic inflammatory markers (100%) than for those with high markers (47%) (p = 0.042). In a univariate Cox proportional hazards model, the risk of pseudocyst recurrence was increased if the most recent abdominal procedure was a nonshunt abdominal surgery (p = 0.012), and it approached statistical significance with male sex (p = 0.054) and elevated inflammatory markers (p = 0.056. Multivariate Cox analysis suggested increased recurrence risk with male sex (p = 0.05) and elevated inflammatory markers (p = 0.06), although the statistical significance threshold was not reached. The length of hospital stay was shorter for laparoscopic repositioning (6 days) than for explantation/EVD placement (21 days) (p < 0.0001). Ultimately, 62% of patients had a peritoneal terminus at the last follow-up, 33% (n = 30) had an extraperitoneal terminus (19 pleura, 8 right heart, and 3 gallbladder), and 5 patients were shunt free. CONCLUSIONS: Some sterile pseudocysts with normal systemic inflammatory markers can be effectively treated with laparoscopic repositioning, resulting in a significantly shorter hospitalization and modestly higher recurrence rate than shunt explantation.

Outcomes of permanent canines on the cleft side after secondary alveolar grafting using different materials in complete unilateral cleft lip and palate.

The prevalence of impaction of the permanent canine on the cleft side (PCCS) ranges from 12-35% after alveolar bone grafting (ABG). PCCSs usually develop above other permanent teeth in the alveolar process, gradually becoming vertical until they reach the occlusal plane. The type of cleft, hypodontia of lateral incisor on the cleft side, slower PCCS root development, and genetic factors are predictors of impaction and/or its ectopic eruption. To compare the behavior of PCCS in individuals with complete unilateral cleft lip and palate (UCLP) subjected to secondary alveolar grafting (SAG) with different materials. This retrospective longitudinal study analyzed 120 individuals undergoing SAG with iliac crest bone, rhBMP-2, and mandibular symphysis. The individuals were selected at a single center and equally divided into three groups. Panoramic radiographs were analyzed by the Dolphin Imaging 11.95 software to measure PCCS angulation and PCCS height from the occlusal plane at two different timepoints. No statistical significance was found between grafting materials (P=0.416). At T1, the PCCS height from the occlusal plane was greater for rhBMP-2 and mandibular symphysis compared to iliac crest bone. The lateral incisor on the cleft side was not related to success or lack of eruption of PCCS (P=0.870). Impaction rates of PCCS were similar for the materials studied. Absence of the lateral incisor on the cleft side did not prevent spontaneous eruption of PCCSs.

Clinical utility and interrater reliability of video urodynamics in children with isolated fibrolipoma of filum terminale.

INTRODUCTION: Children with an isolated fibrolipoma of filum terminale (IFFT) but otherwise normal spinal cord are often evaluated with video urodynamics (VUDS). VUDS interpretation is subjective and can be difficult in young children. These patients may undergo detethering surgery if there is concern for current or future symptomatic tethered cord. OBJECTIVE: We hypothesized that VUDS in children with IFFT would have limited clinical utility regarding decision for or against detethering surgery and VUDS interpretation would have poor interrater reliability. METHODS: Patients with IFFT who underwent VUDS for from 2009 to 2021 were retrospectively reviewed to evaluate clinical utility of VUDS. 6 pediatric urologists who were blinded to patient clinical characteristics reviewed the VUDS. Gwet's first order agreement coefficient (AC1) with 95% CI was used to assess interrater reliability. RESULTS: 47 patients (24F:23M) were identified. Median age at initial evaluation was 2.8yrs (IQR:1.5-6.8). 24 (51%) patients underwent detethering surgery (Table). VUDS at initial evaluation were interpreted by treating urologist as normal in 4 (8%), reassuring for normal in 39 (81%), or concerning for abnormal in 4 (9%). Based on neurosurgery clinic and operative notes for the 47 patients, VUDS made no change in management in 37 patients (79%), prompted detethering in 3 (6%), was given as reason for observation in 7 (15%), and was normal or reassuring for normal but not documented as a reason for observation in 16 (34%) (Table). Interrater reliability for VUDS interpretation had fair agreement (AC1 = 0.27) for overall categorization of VUDS and EMG interpretation (AC1 = 0.34). Moderate agreement was seen for detrusor overactivity interpretation (AC1 = 0.54) and bladder neck appearance (AC1 = 0.46). DISCUSSION: In our cohort, 90% of patients had a normal or reassuring for normal interpretation of VUDS. VUDS interpretation affected clinical course in a minority of patients. There was fair interrater reliability for overall VUDS interpretation and therefore clinical course regarding detethering surgery could vary depending upon interpreting urologist. This fair interrater variability appeared to be related to variability in EMG, bladder neck appearance, and detrusor overactivity interpretation. CONCLUSION: VUDS affected clinical management in about 20% of our cohort and supported the choice for observation in around 50% of patients. This suggests VUDS does have clinical utility in pediatric patients with IFFT. The overall VUDS interpretation had fair interrater reliability. This suggest VUDS interpretation has limitations in determining normal versus abnormal bladder function in children with IFFT. Neurosurgeons and urologists should be aware of VUDS limitations in this patient population.

Cerebellar tonsil reduction for surgical treatment of Chiari malformation type I in children.

OBJECTIVE: The goal of this study was to review the efficacy and safety of different surgical techniques used for treatment of Chiari malformation type I (CM-I) in children. METHODS: The authors retrospectively reviewed 437 consecutive children surgically treated for CM-I. Procedures were classified into four groups: bone decompression (posterior fossa decompression [PFD]) and duraplasty (PFD with duraplasty [PFDD]), PFDD with arachnoid dissection (PFDD+AD), PFDD with tonsil coagulation of at least one cerebellar tonsil (PFDD+TC), and PFDD with subpial tonsil resection of at least one tonsil (PFDD+TR). Efficacy was measured as a greater than 50% reduction in the syrinx by length or anteroposterior width, patient-reported improvement in symptoms, and rate of reoperation. Safety was measured as the rate of postoperative complications. RESULTS: The mean patient age was 8.4 years (range 3 months to 18 years). In total, 221 (50.6%) patients had syringomyelia. The mean follow-up was 31.1 months (range 3-199 months), and there was no statistically significant difference between groups (p = 0.474). Preoperatively, univariate analysis showed that non-Chiari headache, hydrocephalus, tonsil length, and distance from the opisthion to brainstem were associated with the surgical technique used. Multivariate analysis demonstrated that hydrocephalus was independently associated with PFD+AD (p = 0.028), tonsil length was independently associated with PFD+TC (p = 0.001) and PFD+TR (p = 0.044), and non-Chiari headache was inversely associated with PFD+TR (p = 0.001). In the treatment groups postoperatively, symptoms improved in 57/69 (82.6%) PFDD patients, 20/21 (95.2%) PFDD+AD patients, 79/90 (87.8%) PFDD+TC patients, and 231/257 (89.9%) PFDD+TR patients, and differences between groups were not statistically significant. Similarly, there was no statistically significant difference in postoperative Chicago Chiari Outcome Scale scores between groups (p = 0.174). Syringomyelia improved in 79.8% of PFDD+TC/TR patients versus only 58.7% of PFDD+AD patients (p = 0.003). PFDD+TC/TR remained independently associated with improved syrinx outcomes (p = 0.005) after controlling for which surgeon performed the operation. For those patients whose syrinx did not resolve, no statistically significant differences between surgery groups were observed in the length of follow-up or time to reoperation. Overall, there was no statistically significant difference between groups in postoperative complication rates, including aseptic meningitis and CSF- and wound-related issues, or reoperation rates. CONCLUSIONS: In this single-center retrospective series, cerebellar tonsil reduction, by either coagulation or subpial resection, resulted in superior reduction of syringomyelia in pediatric CM-I patients, without increased complications.

Risk factors for clinical and radiological worsening following Chiari malformation type I surgery in the pediatric population.

OBJECTIVE: Foramen magnum (FM) decompression with or without duraplasty is considered a common treatment strategy for Chiari malformation type I (CM-I). The authors' objective was to determine a predictive model of risk factors for clinical and radiological worsening after CM-I surgery. METHODS: A retrospective review of electronic health records was conducted at an academic tertiary care hospital from 2001 to 2019. A multivariable Cox proportional hazards regression model was used to determine the risk factors. The Kaplan-Meier estimate was plotted to delineate outcomes based on FM size. FM was measured as the preoperative distance between the basion and opisthion and dichotomized into < 34 mm and ≥ 34 mm. Syrinx was measured preoperatively and postoperatively in the craniocaudal and anteroposterior directions using a T2-weighted MRI sequence. RESULTS: A total of 454 patients (231 females [50.9%]) with a median (range) age of 8.0 (0-18) years were included in the study. The median duration of follow-up was 21.0 months (range 3.0-144.0 years). The model suggested that patients with symptoms consisting of occipital/tussive headache (HR 4.05, 95% CI 1.34-12.17, p = 0.01), cranial nerve symptoms (HR 3.46, 95% CI 1.16-10.2, p = 0.02), and brainstem/spinal cord symptoms (HR 3.25, 95% CI 1.01-11.49, p = 0.05) had higher risk, whereas those who underwent arachnoid dissection/adhesion lysis had 75% lower likelihood (HR 0.25, 95% CI 0.10-0.64, p = 0.004) of clinical worsening postoperatively. Similarly, patients with evidence of brainstem/spinal cord symptoms (HR 7.9, 95% CI 2.84-9.50, p = 0.03), scoliosis (HR 1.04, 95% CI 1.01-2.80, p = 0.04), and preoperative syrinx (HR 16.1, 95% CI 1.95-132.7, p = 0.03) had significantly higher likelihood of postoperative worsening of syrinx. Patients with symptoms consisting of occipital/tussive headache (HR 5.44, 95% CI 1.86-15.9, p = 0.002), cranial nerve symptoms (HR 2.80, 95% CI 1.02-7.68, p = 0.04), and nonspecific symptoms (HR 6.70, 95% CI 1.99-22.6, p = 0.002) had significantly higher likelihood, whereas patients with FM ≥ 34 mm and those who underwent arachnoid dissection/adhesion lysis had 73% (HR 0.27, 95% CI 0.08-0.89, p = 0.03) and 70% (HR 0.30, 95% CI 0.12-0.73, p = 0.008) lower likelihood of reoperation, respectively. The Kaplan-Meier curve showed that patients with FM size ≥ 34 mm had significantly better clinical (p = 0.02) and syrinx (p = 0.03) improvement postoperatively when the tonsils were resected. CONCLUSIONS: These results showed that preoperative and intraoperative factors may help to provide better clinical decision-making for CM-I surgery. Patients with FM size ≥ 34 mm may have better outcomes when the tonsils are resected.

Outcomes of permanent canines on the cleft side after secondary alveolar grafting using different materials in complete unilateral cleft lip and palate

Abstract The prevalence of impaction of the permanent canine on the cleft side (PCCS) ranges from 12-35% after alveolar bone grafting (ABG). PCCSs usually develop above other permanent teeth in the alveolar process, gradually becoming vertical until they reach the occlusal plane. The type of cleft, hypodontia of lateral incisor on the cleft side, slower PCCS root development, and genetic factors are predictors of impaction and/or its ectopic eruption. Objective: To compare the behavior of PCCS in individuals with complete unilateral cleft lip and palate (UCLP) subjected to secondary alveolar grafting (SAG) with different materials. Methodology: This retrospective longitudinal study analyzed 120 individuals undergoing SAG with iliac crest bone, rhBMP-2, and mandibular symphysis. The individuals were selected at a single center and equally divided into three groups. Panoramic radiographs were analyzed by the Dolphin Imaging 11.95 software to measure PCCS angulation and PCCS height from the occlusal plane at two different timepoints. Results: No statistical significance was found between grafting materials (P=0.416). At T1, the PCCS height from the occlusal plane was greater for rhBMP-2 and mandibular symphysis compared to iliac crest bone. The lateral incisor on the cleft side was not related to success or lack of eruption of PCCS (P=0.870). Conclusion: Impaction rates of PCCS were similar for the materials studied. Absence of the lateral incisor on the cleft side did not prevent spontaneous eruption of PCCSs.

Osteonecrosis of the Intermediate Cuneiform: A Case Report.

Osteonecrosis is a disease that rarely affects the bones of the foot. When present, it is more common in the talus and in the navicular. Cases of osteonecrosis of the intermediate cuneiform are extremely rare, and after a thorough bibliographic review, we found only five reports in the literature, all of them in pediatric patients. Below, we present the case of an adult patient with osteonecrosis of the intermediate cuneiform that was resistant to conservative treatment. Thus, we proposed a surgical approach with good results. Level of Evidence V; Therapeutic Studies; Expert Opinion .

Osteonecrosis of the Intermediate Cuneiform: A Case Report / Osteonecrose do cuneiforme intermédio: Relato de caso

Abstract Osteonecrosis is a disease that rarely affects the bones of the foot. When present, it is more common in the talus and in the navicular. Cases of osteonecrosis of the intermediate cuneiform are extremely rare, and after a thorough bibliographic review, we found only five reports in the literature, all of them in pediatric patients. Below, we present the case of an adult patient with osteonecrosis of the intermediate cuneiform that was resistant to conservative treatment. Thus, we proposed a surgical approach with good results. Level of Evidence V; Therapeutic Studies; Expert Opinion.

Resumo A osteonecrose é uma doença que raramente afeta os ossos do pé. Quando presente, ela é mais comum no tálus e no navicular. Casos de osteonecrose do cuneiforme intermédio são extremamente raros, e após uma revisão bibliográfica minuciosa encontramos apenas cinco relatos na literatura, sendo todos eles em pacientes pediátricos. A seguir, apresentamos o caso de um paciente adulto com osteonecrose do cuneiforme intermédio resistente ao tratamento conservador. Portanto, propusemos uma abordagem cirúrgica com bom resultado. Nível de Evidência V; Estudos Terapêuticos; Opinião de Especialista.

Development of best practices in the utilization and implementation of pediatric cervical spine traction: a modified Delphi study.

OBJECTIVE: Cervical traction in pediatric patients is an uncommon but invaluable technique in the management of cervical trauma and deformity. Despite its utility, little empirical evidence exists to guide its implementation, with most practitioners employing custom or modified adult protocols. Expert-based best practices may improve the care of children undergoing cervical traction. In this study, the authors aimed to build consensus and establish best practices for the use of pediatric cervical traction in order to enhance its utilization, safety, and efficacy. METHODS: A modified Delphi method was employed to try to identify areas of consensus regarding the utilization and implementation of pediatric cervical spine traction. A literature review of pediatric cervical traction was distributed electronically along with a survey of current practices to a group of 20 board-certified pediatric neurosurgeons and orthopedic surgeons with expertise in the pediatric cervical spine. Sixty statements were then formulated and distributed to the group. The results of the second survey were discussed during an in-person meeting leading to further consensus. Consensus was defined as ≥ 80% agreement on a 4-point Likert scale (strongly agree, agree, disagree, strongly disagree). RESULTS: After the initial round, consensus was achieved with 40 statements regarding the following topics: goals, indications, and contraindications of traction (12), pretraction imaging (6), practical application and initiation of various traction techniques (8), protocols in trauma and deformity patients (8), and management of traction-related complications (6). Following the second round, an additional 9 statements reached consensus related to goals/indications/contraindications of traction (4), related to initiation of traction (4), and related to complication management (1). All participants were willing to incorporate the consensus statements into their practice. CONCLUSIONS: In an attempt to improve and standardize the use of cervical traction in pediatric patients, the authors have identified 49 best-practice recommendations, which were generated by reaching consensus among a multidisciplinary group of pediatric spine experts using a modified Delphi technique. Further study is required to determine if implementation of these practices can lead to reduced complications and improved outcomes for children.

NOD Mice Recapitulate the Cardiac Disturbances Observed in Type 1 Diabetes.

This work aimed at testing the hypothesis that NOD/ShiLtJ mice (NOD) recapitulate the cardiac disturbances observed on type 1 diabetes (T1D). NOD mice were studied 4 weeks after the onset of hyperglycemia, and NOR/Lt mice matched as control. Cardiac function was evaluated by echocardiography and electrocardiography (ECG). Action potentials (AP) and Ca2+ transients were evaluated at whole heart level. Heart mitochondrial function was evaluated by high-resolution respirometry and H2O2 release. NOD mice presented a reduction in hearth weight. Mitochondrial oxygen fluxes and H2O2 release were similar between NOD and NOR mice. ECG revealed a QJ interval prolongation in NOD mice. Furthermore, AP duration at 30% of repolarization was increased, and it depicted slower Ca2+ transient kinetics. NOD mice presented greater number/severity of ventricular arrhythmias both in vivo and in vitro. In conclusion, NOD mice evoked cardiac electrical and calcium handling disturbances similar to the observed in T1D. Graphical Abstract .

Dynamic compression in vertebral artery dissection in children: apropos of a new protocol.

PURPOSE: Our goals are (1) to report a consecutive prospective series of children who had posterior circulation stroke caused by vertebral artery dissection at the V3 segment; (2) to describe a configuration of the vertebral artery that may predispose to rotational compression; and (3) to recommend a new protocol for evaluation and treatment of vertebral artery dissection at V3. METHODS: All children diagnosed with vertebral artery dissection at the V3 segment from September 2014 to July 2020 at our institution were included in the study. Demographic, clinical, surgical, and radiological data were collected. RESULTS: Sixteen children were found to have dissection at a specific segment of the vertebral artery. Fourteen patients were male. Eleven were found to have compression on rotation during a provocative angiogram. All eleven underwent C1C2 posterior fusion as part of their treatment. Their mean age was 6.44 years (range 18 months-15 years). Mean blood loss was 57.7 mL. One minor complication occurred: a superficial wound infection treated with oral antibiotics only. There were no vascular or neurologic injuries. There have been no recurrent ischemic events after diagnosis and/or treatment. Mean follow-up was 33.3 months (range 2-59 months). We designed a new protocol to manage V3 dissections in children. CONCLUSION: Posterior C1C2 fusion is a safe and effective option for treatment of dynamic compression in vertebral artery dissection in children. Institution of and compliance with a strict diagnostic and treatment protocol for V3 segment dissections seem to prevent recurrent stroke.

Hyperglycemia in a type 1 Diabetes Mellitus model causes a shift in mitochondria coupled-glucose phosphorylation and redox metabolism in rat brain.

Hyperglycemia associated with Diabetes Mellitus type 1 (DM1) comorbidity may cause severe complications in several tissues that lead to premature death. These dysfunctions are related, among others, to redox imbalances caused by the uncontrolled cellular levels of reactive oxygen species (ROS). Brain is potentially prone to develop diabetes complications because of its great susceptibility to oxidative stress. In addition to antioxidant enzymes, mitochondria-coupled hexokinase (mt-HK) plays an essential role in maintaining high flux of oxygen and glucose to control the mitochondrial membrane and redox potential in brain. This redox control is critical for healthy conditions in brain and in the pathophysiological progression of DM1. The mitochondrial and mt-HK contribution in this process is essential to understand the relationship between DM1 complications and the management of the cellular redox balance. Using a rat model of one month of hyperglycemia induced by a single administration intraperitoneally of streptozotocin, we showed in the present work that, in rat brain mitochondria, there is a specifically reduction of the mitochondrial complex I (CI) activity and an increase in the activity of the antioxidant enzyme thioredoxin reductase, which are related to decreased hydrogen peroxide generation, oxygen consumption and mt-HK coupled-to-OxPhos activity via mitochondrial CI. Surprisingly, DM1 increases respiratory parameters and mt-HK activity via mitochondrial complex II (CII). This way, for the first time, we provide evidence that early progression of hyperglycemia, in brain tissue, changes the coupling of glucose phosphorylation at the level of mitochondria by rearranging the oxidative machinery of brain mitochondria towards CII dependent electron harvest. In addition, DM1 increased the production of H2O2 by α-ketoglutarate dehydrogenase without causing oxidative stress. Finally, DM1 increased the oxidation status of PTEN and decreased the activation of NF-kB in DM1. These results indicate that this reorganization of glucose-oxygen-ROS axis in mitochondria may impact turnover of glucose, brain amino acids, redox and inflammatory signaling. In addition, this reorganization may be involved in early protection mechanisms against the development of cognitive degeneration and neurodegenerative disease, widely associated to mitochondrial CI deficits.

Margin-Free Fractionated Stereotactic Radiation Therapy for Pediatric Brain Tumors.

PURPOSE: Conventional radiation therapy (RT) to pediatric brain tumors exposes a large volume of normal brain to unwarranted radiation causing late toxicity. We hypothesized that in well demarcated pediatric tumors lacking microscopic extensions, fractionated stereotactic RT (SRT), without target volume expansions, can reduce high dose normal tissue irradiation without affecting local control. METHODS AND MATERIALS: Between 2008 and 2017, 52 pediatric patients with brain tumors were treated using the CyberKnife (CK) with SRT in 180 to 200 cGy per fraction. Thirty representative cases were retrospectively planned for intensity modulated RT (IMRT) with 4-mm PTV expansion. We calculated the volume of normal tissue within the high or intermediate dose region adjacent to the target. Plan quality and radiation dose-volume dosimetry parameters were compared between CK and IMRT plans. We also reported overall survival, progression-free survival (PFS), and local control. RESULTS: Tumors included low-grade gliomas (n = 28), craniopharyngiomas (n = 16), and ependymomas (n = 8). The volumes of normal tissue receiving high (≥80% of prescription dose or ≥40 Gy) or intermediate (80% > dose ≥50% of the prescription dose or 40 Gy > dose ≥25 Gy) dose were significantly smaller with CK versus IMRT plans (P < .0001 for all comparisons). With a median follow-up of 3.7 years (range, 0.1-9.0), 3-year local control was 92% for all patients. Eight failures occurred: 1 craniopharyngioma (marginal), 2 ependymomas (both in-field), and 5 low-grade gliomas (2 in-field, 1 marginal, and 2 distant). CONCLUSIONS: Fractionated SRT using CK without target volume expansion appears to reduce the volume of irradiated tissue without majorly compromising local control in pediatric demarcated brain tumors. These results are hypothesis generating and should be tested and validated in prospective studies.

Fluoroscopy only for the placement of long iliac screws: A study on 14 patients.

BACKGROUND: Iliac screw placement is challenging due to the particular anatomy of the ilium. Most series have reported the use of relatively short (≤90 mm in length) screws despite a long iliac buttress, which has an average length of 129 mm in females and 141 mm in males. This study describes a series of 14 patients who underwent placement of long iliac screws (≥100 mm in length) as part of a spinopelvic fusion utilizing fluoroscopy alone. METHODS: All patients who received at least one long iliac screw were included in this study. Placement accuracy, the average distance from the screw tip to the anterior inferior iliac spine (AIIS), neurovascular injuries, acetabulum and/or sciatic notch violations, and screw prominence were all measured. RESULTS: Fourteen patients received 38 iliac screws, with 31 screws being ≥100 mm in length. The accuracy rate was 87.1% (27/31) for the long iliac screws. The average shortest distance from the iliac screw tip to the AIIS was 15.5 mm for the right-sided and 17.1 mm for the left-sided ilia. There were no neurovascular injuries, acetabulum, or sciatic notch violations, and no screws loosened or fractured. Of interest, only one patient required off-set connectors to link the rods to the iliac screws. CONCLUSIONS: Placement of long iliac screws under intraoperative fluoroscopy only was shown to be feasible, with a high accuracy rate and few complications, in this series of patients.

Growth and alignment of the pediatric subaxial cervical spine following rigid instrumentation and fusion: a multicenter study of the Pediatric Craniocervical Society.

OBJECTIVE The long-term effects of surgical fusion on the growing subaxial cervical spine are largely unknown. Recent cross-sectional studies have demonstrated that there is continued growth of the cervical spine through the teenage years. The purpose of this multicenter study was to determine the effects of rigid instrumentation and fusion on the growing subaxial cervical spine by investigating vertical growth, cervical alignment, cervical curvature, and adjacent-segment instability over time. METHODS A total of 15 centers participated in this multi-institutional retrospective study. Cases involving children less than 16 years of age who underwent rigid instrumentation and fusion of the subaxial cervical spine (C-2 and T-1 inclusive) with at least 1 year of clinical and radiographic follow-up were investigated. Charts were reviewed for clinical data. Postoperative and most recent radiographs, CT, and MR images were used to measure vertical growth and assess alignment and stability. RESULTS Eighty-one patients were included in the study, with a mean follow-up of 33 months. Ninety-five percent of patients had complete clinical resolution or significant improvement in symptoms. Postoperative cervical kyphosis was seen in only 4 patients (5%), and none developed a swan-neck deformity, unintended adjacent-level fusion, or instability. Of patients with at least 2 years of follow-up, 62% demonstrated growth across the fusion construct. On average, vertical growth was 79% (4-level constructs), 83% (3-level constructs), or 100% (2-level constructs) of expected growth. When comparing the group with continued vertical growth to the one without growth, there were no statistically significant differences in terms of age, sex, underlying etiology, surgical approach, or number of levels fused. CONCLUSIONS Continued vertical growth of the subaxial spine occurs in nearly two-thirds of children after rigid instrumentation and fusion of the subaxial spine. Failure of continued vertical growth is not associated with the patient's age, sex, underlying etiology, number of levels fused, or surgical approach. Further studies are needed to understand this dichotomy and determine the long-term biomechanical effects of surgery on the growing pediatric cervical spine.

Craniectomy and Traumatic Brain Injury in Children on Extracorporeal Membrane Oxygenation Support.

Severe trauma may cause refractory life-threatening respiratory failure requiring extracorporeal membrane oxygenation (ECMO). Concurrent traumatic brain injury, however, complicates the use of ECMO because of the major risk of intracranial bleeding with systemic anticoagulation. Craniotomy and/or craniectomy for hematoma evacuation during ECMO are extremely high-risk procedures secondary to ongoing anticoagulation, and there are only a few such case reports in the literature. We present the case of a child with multiple thoracic injuries and life-threatening respiratory failure supported on ECMO. She developed an intracranial hemorrhage while systemically heparinized that required emergent decannulation and bedside craniectomy for hematoma extraction. She survived with an excellent neurologic outcome. We also review the relevant literature regarding the use of ECMO in patients with polytrauma and the occurrence of craniectomy on extracorporeal support, with a focus on pediatric publications. Patients with polytrauma with brain injury can be supported on ECMO, but extreme precaution must be taken regarding anticoagulation. The intracranial complications of ECMO in this population are not infrequent, but our case report and review of the literature suggest that neurosurgical intervention should be considered in life-threatening conditions when no other alternatives are available.

Long iliac screw fixation in a case of isthmic spondyloptosis.

BACKGROUND: We report the case of a patient with a spondyloptosis who presented with progressive deformity and worsening neurological deficits. The patient had two previous lumbosacral instrumented fusions. CASE DESCRIPTION: A salvage revision surgery was performed, in which long iliac screws along with anterior column support at L5-S1 were used to immobilize the lumbosacral junction. Two years after the procedure a solid fusion is seen along with marked neurological improvement. CONCLUSIONS: Pelvic fixation using long iliac screws is a very useful technique that can be employed when revision surgery for high-grade spondylolisthesis is needed.