The Effectiveness of Serial Casting in the Treatment of Recurrent Equinovarus in Children With Arthrogryposis.

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is characterized by joint contractures in 2 or more body areas, often resulting in clubfoot deformities that are typically stiffer than those seen in idiopathic clubfoot deformities. While surgery is routinely used to treat clubfoot in AMC, it has a high rate of recurrence and complications. Current literature suggests serial casting (SC) could be useful in treating clubfoot in AMC, though evidence of its effectiveness is limited. METHODS: Passive range of motion (PROM), dynamic foot pressure, parent-reported Pediatric Outcomes Data Collection Instrument, brace tolerance, and the need for post-casting surgery were evaluated retrospectively in children with AMC treated with SC to address clubfoot deformities. Analysis of variance or paired t tests were used as appropriate on pre-casting, short-term (within 6 mo after SC) and/or longer-term (6 to 18 mo after SC) parameters to determine the effectiveness of SC. Brace tolerance before and after SC was analyzed using the Global Test for Symmetry, and medical records were reviewed to determine the need for surgery post-SC. RESULTS: Forty-six children (6.1±3.1 y old) were cast an average of 2.5±1.9 times, resulting in 206 SC episodes. PROM showed improvement in ankle dorsiflexion and forefoot abduction in the short term (P<0.05), returning to baseline measurements in the long term (P=0.09). Brace tolerance improved after casting (P<0.05). Only 15% of feet required surgery at follow-up at 10.3±5.5 years. There were no significant changes in dynamic foot pressure or Pediatric Outcomes Data Collection Instrument results after SC, except for an increase in the pain subtest (P<0.05). CONCLUSIONS: Serial casting in children with AMC can be effective in temporarily improving PROM and improving brace tolerance, but it does not impact dynamic barefoot position. Positive impact of conservative management in children with AMC can potentially delay or reduce the need for invasive surgical intervention by improving PROM and brace tolerance. LEVEL OF EVIDENCE: Level III, Retrospective Comparative Study.

Is Standing Function Improved After Orthopaedic Surgery in Children With Cerebral Palsy at GMFCS Levels III/IV?

BACKGROUND: Children with cerebral palsy (CP) at Gross Motor Function Classification System (GMFCS) levels III/IV are at risk for losses in standing function during adolescence and transition to adulthood. Multilevel surgery (MLS) is an effective treatment to improve gait, but its effects on standing function are not well documented. The objectives of our study were to describe standing function in children with CP classified as GMFCS levels III/IV and evaluate change after MLS. METHODS: This retrospective study included children with CP (GMFCS III/IV) ages 6 to 20 years who underwent instrumented gait analysis. A subset who underwent MLS were evaluated for change. Primary outcome measures were Gross Motor Function Measure dimension D, gait velocity, functional mobility scale, and the Pediatric Outcomes Data Collection Instrument (PODCI). Additional impairment level measures included foot pressure, knee extension during stance phase of gait, and knee extension passive range of motion. RESULTS: Four hundred thirty-seven instrumented gait analysis sessions from 321 children with CP (ages 13.7±4.8 y; GMFCS III-81%/IV-19%) were included. The GMFCS III group had higher Gross Motor Function Measure dimension D, gait velocity, PODCI scores, and better knee extension compared with the GMFCS IV group ( P <0.05); 94 MLS were evaluated for postoperative change 15.3±4.2 months after MLS. Children at GMFCS level III had improved PODCI scores ( P <0.05), better knee extension passive range of motion ( P <0.01), and improved coronal plane foot pressure ( P <0.05) post MLS. Maximum knee extension during stance and heel impulse improved significantly in both groups ( P <0.01). CONCLUSIONS: Standing function of children with CP at GMFCS IV was significantly more limited than at GMFCS III. After MLS, both groups (III/IV) showed improvement in impairment level outcomes (knee extension and foot position), whereas only those functioning at GMFCS III had improvement in activity/participation outcomes according to the PODCI. For children with CP at GMFCS levels IV, MLS may improve standing function, but appropriate goals related to assisted standing and measurement protocols sensitive to limited functional mobility should be adopted. LEVEL OF EVIDENCE: Level III-retrospective comparative study.

Can the Shriners Hospital Upper Extremity Evaluation (SHUEE) Detect Change in Dynamic Position and Spontaneous Function of the Upper Limb in People With Hemiplegic Cerebral Palsy?

BACKGROUND: The Shriners Hospital Upper Extremity Evaluation (SHUEE) is a video-based measure designed to assess upper extremity function in people with cerebral palsy (CP). The SHUEE completes both dynamic positional analysis (DPA; position during functional activities) and spontaneous functional analysis (spontaneous use of the involved limb). Although the SHUEE has been suggested as a measure for planning upper limb interventions and evaluating outcomes, limited evidence of its ability to detect change exists. Thus, this study aimed to describe responsiveness of the SHUEE to detect change after orthopaedic surgery. METHODS: In this Institutional Review Board-approved retrospective cohort study, we identified children with CP who were administered SHUEE on≥2 encounters. We formed pairs of initial and follow-up visits between temporally adjacent visits. Pairs were assigned to a surgery or non-surgery group based on intervening upper limb orthopaedic surgery. We compared differences in baseline SHUEE scores between groups and differences in temporally adjacent SHUEE scores within groups using Welch unequal variances t tests and paired t tests, respectively. RESULTS: Nineteen people (7 female) with hemiplegic CP had≥2 SHUEE assessments; Manual Ability Classification System levels I (3), II (8), III (7), IV (1); Gross Motor Function Classification System levels I (10), II (7), IV (2); mean age at baseline 11.9 (5.1 to 19.1) years; and follow-up at 13.4 (5.5 to 19.7) years. Six people had≥2 visits leading to 14 surgical pairs and 10 non-surgical pairs. At baseline, DPA of the wrist and forearm were significantly lower in the surgical group ( P <0.05). At follow-up, no significant difference between the groups existed in DPA measures ( P >0.05). After surgical intervention, there was a significant change in overall and wrist DPA ( P <0.05). CONCLUSIONS: The DPA measures demonstrated responsiveness to expected positional changes in the arm after orthopaedic surgery in people with CP. The SHUEE was useful in identifying abnormal segmental alignment pre-surgically and documenting changes in alignment postoperatively. As orthopaedic surgery does not address limb neglect or bimanual ability, spontaneous functional analysis scores were as expected-unchanged. LEVEL OF EVIDENCE: Level III, retrospective cohort study.

Walking activity after multilevel orthopedic surgery in children with cerebral palsy.

AIM: To determine how surgical burden and preoperative factors affect the recovery of walking activity after multilevel orthopedic surgery (MLS). METHOD: In this retrospective study, inclusion criteria were a diagnosis of cerebral palsy, MLS, and walking activity monitoring using a StepWatch device within 12 months pre-MLS and 24 months post-MLS. The outcome measure was total mean strides per day normalized to age and Gross Motor Function Classification System level. Pre- and postoperative walking activity were compared using unpaired t-tests; the effects of preoperative predictors and surgical burden on the recovery of walking activity were evaluated using regression analysis. RESULTS: Participants included 178 children (mean age 12 years 10 months [SD 8 years 7 months; range 4-20 years]; 91 males, 87 females). On average, children returned to baseline walking activity 3 months after low-burden surgery and 1 year 2 months after high-burden surgery. Postoperative walking activity was higher for children who had surgery at a younger age and those with a higher preoperative mobility function. INTERPRETATION: The burden of MLS was found to be inversely related to the time to recovery of postoperative walking activity. These findings provide evidence to help clinicians set expectations for return to function post-MLS. Further study is necessary to investigate the impact of postoperative factors on walking activity recovery. WHAT THIS PAPER ADDS: High-burden surgeries lead to longer recovery than low-burden surgeries. Younger children recover walking activity faster after multilevel orthopedic surgery. Children with high preoperative mobility function recover walking activity faster after surgery.

OBJETIVO: Determinar como a carga cirúrgica e os fatores pré-operatórios afetam a recuperação da atividade de caminhada após cirurgia ortopédica multinível (MLS). MÉTODOS: Neste estudo retrospectivo, os critérios de inclusão foram um diagnóstico de paralisia cerebral, MLS e monitoramento da atividade de caminhada usando um dispositivo Step Watch dentro de 12 meses pré-MLS e 24 meses pós-MLS. A medida de resultado foi o total de passos médios por dia normalizados para idade e nível do Sistema de Classificação da Função Motora Grossa. A atividade de caminhada pré e pós-operatória foi comparada usando testes t não pareados; os efeitos dos preditores pré-operatórios e da carga cirúrgica na recuperação da atividade de caminhada foram avaliados por meio de análise de regressão. RESULTADOS: Os participantes incluíram 178 crianças (idade média de 12 anos e 10 meses [DP 8 anos e 7 meses; intervalo de 4 a 20 anos]; 91 meninos, 87 meninas). Em média, as crianças retornaram à atividade de caminhada inicial 3 meses após a cirurgia de baixa carga e 1 ano e 2 meses após a cirurgia de alta carga. A atividade de caminhada pós-operatória foi maior para crianças que foram operadas em idade mais jovem e aquelas com maior função de mobilidade pré-operatória. INTERPRETAÇÃO: A carga de MLS foi inversamente relacionada ao tempo de recuperação da atividade de caminhada pós-operatória. Esses achados fornecem evidências objetivas para ajudar os médicos a definir as expectativas de retorno à função pós-MLS. Mais estudos são necessários para investigar o impacto dos fatores pós-operatórios na recuperação da atividade de caminhada.

Semaphorin 3A mediated brain tumor stem cell proliferation and invasion in EGFRviii mutant gliomas.

BACKGROUND: Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults, with a median survival of approximately 15 months. Semaphorin 3A (Sema3A), known for its axon guidance and antiangiogenic properties, has been implicated in GBM growth. We hypothesized that Sema3A directly inhibits brain tumor stem cell (BTSC) proliferation and drives invasion via Neuropilin 1 (Nrp1) and Plexin A1 (PlxnA1) receptors. METHODS: GBM BTSC cell lines were assayed by immunostaining and PCR for levels of Semaphorin 3A (Sema3A) and its receptors Nrp1 and PlxnA1. Quantitative BrdU, cell cycle and propidium iodide labeling assays were performed following exogenous Sema3A treatment. Quantitative functional 2-D and 3-D invasion assays along with shRNA lentiviral knockdown of Nrp1 and PlxnA1 are also shown. In vivo flank studies comparing tumor growth of knockdown versus control BTSCs were performed. Statistics were performed using GraphPad Prism v7. RESULTS: Immunostaining and PCR analysis revealed that BTSCs highly express Sema3A and its receptors Nrp1 and PlxnA1, with expression of Nrp1 in the CD133 positive BTSCs, and absence in differentiated tumor cells. Treatment with exogenous Sema3A in quantitative BrdU, cell cycle, and propidium iodide labeling assays demonstrated that Sema3A significantly inhibited BTSC proliferation without inducing cell death. Quantitative functional 2-D and 3-D invasion assays showed that treatment with Sema3A resulted in increased invasion. Using shRNA lentiviruses, knockdown of either NRP1 or PlxnA1 receptors abrogated Sema3A antiproliferative and pro-invasive effects. Interestingly, loss of the receptors mimicked Sema3A effects, inhibiting BTSC proliferation and driving invasion. Furthermore, in vivo studies comparing tumor growth of knockdown and control infected BTSCs implanted into the flanks of nude mice confirmed the decrease in proliferation with receptor KD. CONCLUSIONS: These findings demonstrate the importance of Sema3A signaling in GBM BTSC proliferation and invasion, and its potential as a therapeutic target.

The 5-Year Outcome of the Ponseti Method in Children With Idiopathic Clubfoot and Arthrogryposis.

BACKGROUND: The Ponseti method effectively treats idiopathic clubfoot, but its effectiveness in treating the stiffer clubfoot associated with arthrogryposis is less clear. The purpose of this study was to assess the comparative effectiveness of the Ponseti method in 5-year-old children with either idiopathic clubfoot or clubfoot due to arthrogryposis. METHODS: The outcomes of the Ponseti method were retrospectively evaluated in children with idiopathic clubfoot and clubfoot associated with arthrogryposis. The children with clubfoot were seen at our hospital between 2012 and 2019 and were 4.0 to 6.9 years old at the time of their evaluation. Outcomes of the 2 groups of children with clubfoot were assessed using passive range of motion, foot pressure analysis, the Gross Motor Function Measure Dimension-D, and parent report using the Pediatric Outcomes Data Collection Instrument. These results were also compared with the same measures from a group of typically developing children. Surgical and bracing history was also recorded. RESULTS: A total of 117 children were included (89 idiopathic clubfoot and 28 associated with arthrogryposis) with an average age of 4.8±0.8 years. The historical gait analyses of 72 typically developing children were used as a control, with an average age of 5.2±0.8 years. Significant residual equinovarus was seen in both children with idiopathic clubfoot and associated with arthrogryposis according to passive range of motion and foot pressure analysis when compared with normative data. Children with arthrogryposis demonstrated limited transfer and basic mobility, sports functioning, and global functioning while children with idiopathic clubfoot were significantly different from their typically developing peers in only transfer and basic mobility. CONCLUSIONS: Although children with idiopathic clubfoot continue with some level of residual deformity, the Ponseti method is effective in creating a pain-free, highly functional foot. In children with clubfoot associated with arthrogryposis, the Ponseti method is successful in creating a braceable foot that can delay the need for invasive surgical intervention. LEVEL OF EVIDENCE: Level III, Therapeutic Studies-Investigating the Results of Treatment.

Effectiveness of Granulocyte Colony-Stimulating Factor in Hospitalized Infants with Neutropenia.

Objective The objective of this study was to determine the time to hematologic recovery and the incidence of secondary sepsis and mortality among neutropenic infants treated or not treated with granulocyte colony-stimulating factor (G-CSF). Study Design We identified all neutropenic infants discharged from 348 neonatal intensive care units from 1997 to 2012. Neutropenia was defined as an absolute neutrophil count ≤ 1,500/µL for ≥ 1 day during the first 120 days of life. Incidence of secondary sepsis and mortality and number of days required to reach an absolute neutrophil count > 1,500/µL for infants exposed to G-CSF were compared with those of unexposed infants. Results We identified 30,705 neutropenic infants, including 2,142 infants (7%) treated with G-CSF. Treated infants had a shorter adjusted time to hematologic recovery (hazard ratio: 1.36, 95% confidence interval [CI]: 1.30-1.44) and higher adjusted odds of secondary sepsis (odds ratio [OR]: 1.50, 95% CI: 1.20-1.87), death (OR: 1.33, 95% CI: 1.05-1.68), and the combined outcome of sepsis or death (OR: 1.41, 95% CI: 1.19-1.67) at day 14 compared with untreated infants. These differences persisted at day 28. Conclusion G-CSF treatment decreased the time to hematologic recovery but was associated with increased odds of secondary sepsis and mortality in neutropenic infants. G-CSF should not routinely be used for infants with neutropenia.

Long-term Outcome of Internal Tibial Derotation Osteotomies in Children With Cerebral Palsy.

BACKGROUND: External tibial torsion (ETT) is a common bony deformity in children with cerebral palsy (CP). The current recommended treatment is tibial derotation osteotomy (TDO) to improve gait biomechanics. Satisfactory short-term results after TDO have been reported but long-term results have not been studied. The purpose of this study was to evaluate the long-term outcome following TDO to correct ETT in ambulatory children with CP. METHODS: Following IRB approval, gait kinematics and passive range of motion measurements were retrospectively evaluated in children with spastic CP who underwent TDO due to ETT comparing preoperative (E0), short-term postoperative (E1; 1 to 3 y post), and long-term postoperative (E2; >5 y post) results. Limbs were categorized as corrected, undercorrected, or overcorrected at both E1 and E2, by comparing mean tibial rotation (MTR) in gait to a group of typically developing children. Age at surgery, E0 MTR, E0 gait velocity, gross motor function classification system (GMFCS) score, and foot deformity were evaluated to determine their influence on long-term results. RESULTS: The study sample consisted of 43 legs (with E0 and E2) and 22 legs (with E0, E1, and E2). The mean age at surgery was 10.3±3.4 years (range, 6 to 19.2 y). In the group MTR trended toward improvement moving from -26±17 degrees (E0, external negative) to -16±16 degrees (E1) and relapsed to -23±17 degrees at the long term (P=0.071, E0/E1; P=0.589, E0/E2). Improvement was also seen in the transmalleolar axis (P=0.074), mean ankle rotation, and mean foot orientation (P<0.05, E0/E2). At the long-term evaluation, 16 legs (37%) were found to be in the kinematic corrected group, 25 legs (58%) in the kinematic undercorrected group, and 2 legs (5%) in the kinematic overcorrected group. There were no significant differences between the corrected and undercorrected groups of children with respect to age at surgery, GMFCS, E0 MTR, gait velocity, or foot deformity. CONCLUSIONS: Although internal TDO improves ETT in the short term, recurrence is frequent with an apparent developmental trend toward external rotation of the tibia. LEVELS OF EVIDENCE: Level IV-therapeutic study.

Long-term Outcome of External Tibial Derotation Osteotomies in Children With Cerebral Palsy.

BACKGROUND: Internal tibial torsion (ITT) is a common boney deformity in children with cerebral palsy (CP). The current recommended treatment is tibial derotation osteotomy (TDO) to improve gait biomechanics. Satisfactory short-term results after TDO have been reported but long-term results have not been studied. The purpose of this study was to evaluate the long-term outcome after external TDO performed to correct ITT in ambulatory children with CP. METHODS: Following IRB approval, gait kinematics and passive range of motion measurements were retrospectively evaluated in children with spastic CP who underwent TDO due to ITT comparing preoperative (E0), short-term postoperative (E1; 1 to 3 y post), and long-term postoperative (E2; >5 y post) results. Limbs were categorized as corrected, undercorrected, or overcorrected at both E1 and E2, by comparing the subjects mean tibial rotation (MTR) in gait to a group of typically developing children. Age at surgery, preop MTR (at E0), preop gait velocity (at E0), gross motor function classification system score, and foot deformity were evaluated to determine their influence on long-term results. RESULTS: The study sample consisted of 36 legs (with E0 and E2) and 17 legs (with E0, E1, and E2). The mean age at surgery was 7.4±2.8 (range, 4 to 16.6) years. Comparing the changes over time, kinematic MTR improved from 17±11 degrees initially (E0) to -10±14 degrees short term (E1) and progressed to -23±13 degrees long term (E2) (P<0.05 E0/E1/E2; internal rotation is positive). At E2, 16 legs (44%) were found to be in the kinematic corrected group and 20 legs (56%) in the kinematic overcorrected group. There were no significant differences between the corrected and overcorrected groups of children in respect to age of surgery, gross motor function classification system, E0 MTR, gait velocity, or foot deformity. CONCLUSIONS: Although external TDO is an accepted form of treatment in children with CP, in the long term a tendency to move into external tibial torsion is common. Therefore, caution is warranted with children who initially present with ITT to avoid overcorrection. LEVEL OF EVIDENCE: Level IV-therapeutic study.

Persistence and Recurrence Following Femoral Derotational Osteotomy in Ambulatory Children With Cerebral Palsy.

BACKGROUND: Excessive hip internal rotation is frequently seen in children with cerebral palsy (CP). Femoral derotational osteotomy (FDO) is effective in the short term, but factors associated with long-term correction remain unclear. The purposes of this study were to define the incidence of persistence and recurrence of hip internal rotation following FDO in ambulatory children with CP and to evaluate factors that influence outcome. METHODS: Following IRB approval, kinematic and passive range of motion (PROM) variables were retrospectively evaluated in children with spastic CP who had FDO to correct hip internal rotation as part of clinical care at a children's specialty hospital. Children included had a preoperative evaluation (Vpre), a short-term postoperative evaluation (Vshort, 1 to 3 y post), and, in some cases, a long-term postoperative evaluation (Vlong, ≥5 y post). Age at surgery, physical exam measures, and kinematics variables were evaluated as predictors for dynamic and static recurrence. RESULTS: Kinematic hip rotation improved from 14±12 degrees (Vpre; internal positive) to 4±13 degrees (Vshort) and relapsed to 9±15 degrees long term (P<0.05 Vpre/Vshort/Vlong; 99 limbs). Hip PROM midpoint improved from 23±9 degrees (Vpre) to 8±11 degrees (Vshort) and relapsed to 14±13 degrees (P<0.01 Vpre/Vshort/Vlong). Persistent hip internal rotation was noted in 41% (kinematics) and 18% (PROM) of limbs at Vshort (105 children, 178 limbs). Of limbs that showed initial improvement at Vshort (62 children, 95 limbs), recurrence was seen in 40% (kinematic hip rotation) and 39% (hip midpoint) at Vlong. Comparing children who had recurrent hip internal rotation and those who maintained long-term correction, we saw higher levels of spasticity and lower gait velocity in the recurrent group (P<0.05). CONCLUSIONS: Although FDO is an accepted treatment in children with CP, persistence and recurrence of hip internal rotation can occur. Recurrence is associated with spasticity and slower gait velocity. Predictor variables may be useful for surgeons during preoperative discussions of expected outcome with families of FDO candidates. LEVEL OF EVIDENCE: Level III.

Single-Leg Squat Performance in Active Adolescents Aged 8-17 Years.

Agresta, CE, Church, C, Henley, J, Duer, T, and O'Brien, K. Single-leg squat performance in active adolescents aged 8-17 years. J Strength Cond Res 31(5): 1187-1191, 2017-More than 30 million U.S. adolescents participate in sport and exercise. Lower extremity injury from sport participation accounts for up to 89% of injuries each year. The single-leg squat (SLS) is a simple clinical tool that assesses lower extremity mechanics often associated with injury risk. To date, there is limited information regarding SLS performance in healthy children. Such information could be useful when assessing youth athletes to determine if mechanics demonstrated are different than is to be expected and puts them at the risk for injury. Furthermore, maturity status is thought to influence motor performance. Currently, there is no information regarding the influence of maturity status on SLS performance in adolescents. The purpose of our study was to determine SLS performance in relation to age and maturity level in adolescents. Forty-five children aged 8-17 years were videotaped performing a series of 10 squats using a standardized protocol. Standing height, seated height, and leg length measures were collected. Investigators scored the SLS test using specific scoring criteria. Adolescents were categorized into 3 maturity levels using a peak height velocity calculation. Multiple linear regression analyses and analysis of variance were used to analyze the data. Chronological age was a significant predictor of SLS performance with younger children having poorer SLS scores. Coaches and trainers should consider the chronological age of the youth athlete when assessing SLS performance. Furthermore, tailored training programs by age may help to address faulty areas, like single-leg stability, and improve overall functional performance.

Second messengers and membrane trafficking direct and organize growth cone steering.

Graded distributions of extracellular cues guide developing axons toward their targets. A network of second messengers - Ca(2+) and cyclic nucleotides - shapes cue-derived information into either attractive or repulsive signals that steer growth cones bidirectionally. Emerging evidence suggests that such guidance signals create a localized imbalance between exocytosis and endocytosis, which in turn redirects membrane, adhesion and cytoskeletal components asymmetrically across the growth cone to bias the direction of axon extension. These recent advances allow us to propose a unifying model of how the growth cone translates shallow gradients of environmental information into polarized activity of the steering machinery for axon guidance.

Differential role of PTEN phosphatase in chemotactic growth cone guidance.

Negatively targeting the tumor suppressor and phosphoinositide phosphatase PTEN (phosphatase and tensin homologue) promotes axon regrowth after injury. How PTEN functions in axon guidance has remained unknown. Here we report the differential role of PTEN in chemotactic guidance of axonal growth cones. Down-regulating PTEN expression in Xenopus laevis spinal neurons selectively abolished growth cone chemorepulsion but permitted chemoattraction. These findings persisted during cAMP-dependent switching of turning behaviors. Live cell imaging using a GFP biosensor revealed rapid PTEN-dependent depression of phosphatidylinositol 3,4,5-trisphosphate levels in the growth cone induced by the repellent myelin-associated glycoprotein. Moreover, down-regulating PTEN expression blocked negative remodeling of ß1-integrin adhesions triggered by myelin-associated glycoprotein, yet permitted integrin clustering by a positive chemotropic treatment. Thus, PTEN negatively regulates growth cone phosphatidylinositol 3,4,5-trisphosphate levels and mediates chemorepulsion, whereas chemoattraction is PTEN-independent. Regenerative therapies targeting PTEN may therefore suppress growth cone repulsion to soluble cues while permitting attractive guidance, an essential feature for re-forming functional neural circuits.

Changes in foot posture evaluated with dynamic pedobarography over the course of childhood in ambulatory youth with cerebral palsy.

Purpose: Foot deformities are prevalent in children with cerebral palsy, but there is limited research on the progression of foot posture during growth. Our study aimed to evaluate the change in dynamic foot posture in children with cerebral palsy. Methods: Children with cerebral palsy, aged 17-40 months, were recruited to participate in this Institutional Review Board-approved prospective longitudinal study by having serial foot posture evaluations. The coronal plane index and foot segmental impulses were measured with dynamic pedobarography. Data were compared between children stratified by Gross Motor Function Classification System level and typically developing children using serial Welch's t-tests across time with Holm correction for multiple comparisons. Results: In total, 33 children (54 limbs) were included in the analysis (21 bilateral and 12 unilateral; Gross Motor Function Classification System: I-13, II-14, III-4, IV-2. Children completed 16.9 (± 4.4) evaluations (initial age 2.9 (± 0.7) and final age 18.6 (± 1.7) years)). Early valgus foot posture normalizes in children at Gross Motor Function Classification System levels I/II and persists in children at levels III/IV who do not have foot surgery. For most young children, foot posture development is variable. Conclusion: Foot posture in young children with cerebral palsy begins in valgus and tends to normalize in youth who walk without an assistive device. Conservative management of foot deformity is recommended in early childhood. Level of evidence: Level II, prognostic study.

Single vesicle imaging indicates distinct modes of rapid membrane retrieval during nerve growth.

BACKGROUND: During nerve growth, cytoplasmic vesicles add new membrane preferentially to the growth cone located at the distal tip of extending axons. Growth cone membrane is also retrieved locally, and asymmetric retrieval facilitates membrane remodeling during growth cone repulsion by a chemorepellent gradient. Moreover, growth inhibitory factors can stimulate bulk membrane retrieval and induce growth cone collapse. Despite these functional insights, the processes mediating local membrane remodeling during axon extension remain poorly defined. RESULTS: To investigate the spatial and temporal dynamics of membrane retrieval in actively extending growth cones, we have used a transient labeling and optical recording method that can resolve single vesicle events. Live-cell confocal imaging revealed rapid membrane retrieval by distinct endocytic modes based on spatial distribution in Xenopus spinal neuron growth cones. These modes include endocytic "hot-spots" triggered at the base of filopodia, at the lateral margins of lamellipodia, and along dorsal ridges of the growth cone. Additionally, waves of endocytosis were induced when individual filopodia detached from the substrate and fused with the growth cone dorsal surface or with other filopodia. Vesicle formation at sites of membrane remodeling by self-contact required F-actin polymerization. Moreover, bulk membrane retrieval by macroendocytosis correlated positively with the substrate-dependent rate of axon extension and required the function of Rho-family GTPases. CONCLUSIONS: This study provides insight into the dynamic membrane remodeling processes essential for nerve growth by identifying several distinct modes of rapid membrane retrieval in the growth cone during axon extension. We found that endocytic membrane retrieval is intensified at specific subdomains and may drive the dynamic membrane ruffling and re-absorption of filopodia and lamellipodia in actively extending growth cones. The findings offer a platform for determining the molecular mechanisms of distinct endocytic processes that may remodel the surface distribution of receptors, ion channels and other membrane-associated proteins locally to drive growth cone extension and chemotactic guidance.

The effect of medial only versus medial and lateral hamstring lengthening on transverse gait parameters in cerebral palsy.

Benefits of hamstring lengthening surgery on the sagittal plane in children with cerebral palsy have been previously demonstrated, but there is limited information on its effects on the transverse plane. This study compared the effects of medial hamstring lengthening (MHL) with those of medial and lateral hamstring lengthening (MLHL) procedures in the transverse plane. Children with gross motor function classification system (GMFCS) levels I-III who had MHL or MLHL were included. Baseline, short- (1-2 years), and long-term (3+ years) postoperative three-dimensional gait analysis outcomes were compared using analysis of variance. Children were excluded if they had concurrent osteotomies or tendon transfers. One hundred fifty children (235 limbs) were included, with 110 limbs in the MHL group (age 8.5 ± 4.1 years, GMFCS I-27%, II-52%, and III-21%) and 125 limbs in the MLHL group (age 10.0 ± 4.0 years, GMFCS I-23%, II-41%, and III-37%). Time between surgery and short- and long-term follow-up gait analysis was 1.5 ± 0.6 years and 6.6 ± 2.9 years, respectively. Transmalleolar axis became more external after MHL at both short and long terms ( P < 0.05), whereas there were only significant differences at long term in MLHL ( P < 0.05). Although hamstring lengthening has a positive impact on stance phase knee extension in children with cerebral palsy, intact lateral hamstrings after MHL likely contribute to increased tibial external rotation after surgery. Significant increases in external rotation at the knee in the long term are likely related to a trend present with growth in children with cerebral palsy rather than a direct result of surgical intervention.

Asymmetric PI(3,4,5)P3 and Akt signaling mediates chemotaxis of axonal growth cones.

The action of many extracellular guidance cues on axon pathfinding requires Ca2+ influx at the growth cone (Hong et al., 2000; Nishiyama et al., 2003; Henley and Poo, 2004), but how activation of guidance cue receptors leads to opening of plasmalemmal ion channels remains largely unknown. Analogous to the chemotaxis of amoeboid cells (Parent et al., 1998; Servant et al., 2000), we found that a gradient of chemoattractant triggered rapid asymmetric PI(3,4,5)P3 accumulation at the growth cone's leading edge, as detected by the translocation of a GFP-tagged binding domain of Akt in Xenopus laevis spinal neurons. Growth cone chemoattraction required PI(3,4,5)P3 production and Akt activation, and genetic perturbation of polarized Akt activity disrupted axon pathfinding in vitro and in vivo. Furthermore, patch-clamp recording from growth cones revealed that exogenous PI(3,4,5)P3 rapidly activated TRP (transient receptor potential) channels, and asymmetrically applied PI(3,4,5)P3 was sufficient to induce chemoattractive growth cone turning in a manner that required downstream Ca2+ signaling. Thus, asymmetric PI(3,4,5)P3 elevation and Akt activation are early events in growth cone chemotaxis that link receptor activation to TRP channel opening and Ca2+ signaling. Altogether, our findings reveal that PI(3,4,5)P3 elevation polarizes to the growth cone's leading edge and can serve as an early regulator during chemotactic guidance.

Extrathoracic metastases of thymic origin: a review of 35 cases.

Thymic tumors are categorized as types A, AB, B1, B2, B3, and thymic carcinoma under the World Health Organization (WHO) classification. Thymomas are typically slow growing tumors that predominantly involve the surrounding structures through direct invasion, while thymic carcinomas tend to be more aggressive. A significant number of patients are asymptomatic and can present with metastases as the first presentation. The exact incidence of extrathoracic metastases from thymoma is not known. This study describes a series of 35 cases of histologically documented metastatic thymomas and thymic carcinomas at extrathoracic sites. These cases were classified according to the current World Health Organization (WHO) classification criteria, and we present their clinical data as well as discuss the differential diagnoses of these lesions. Our study shows that all types of thymic tumors, regardless of histologic type, can be associated with invasion and metastases to thoracic and extrathoracic sites.

Bidirectional remodeling of ß1-integrin adhesions during chemotropic regulation of nerve growth.

BACKGROUND: Chemotropic factors in the extracellular microenvironment guide nerve growth by acting on the growth cone located at the tip of extending axons. Growth cone extension requires the coordination of cytoskeleton-dependent membrane protrusion and dynamic adhesion to the extracellular matrix, yet how chemotropic factors regulate these events remains an outstanding question. We demonstrated previously that the inhibitory factor myelin-associated glycoprotein (MAG) triggers endocytic removal of the adhesion receptor ß1-integrin from the growth cone surface membrane to negatively remodel substrate adhesions during chemorepulsion. Here, we tested how a neurotrophin might affect integrin adhesions. RESULTS: We report that brain-derived neurotropic factor (BDNF) positively regulates the formation of substrate adhesions in axonal growth cones during stimulated outgrowth and prevents removal of ß1-integrin adhesions by MAG. Treatment of Xenopus spinal neurons with BDNF rapidly triggered ß1-integrin clustering and induced the dynamic formation of nascent vinculin-containing adhesion complexes in the growth cone periphery. Both the formation of nascent ß1-integrin adhesions and the stimulation of axon extension by BDNF required cytoplasmic calcium ion signaling and integrin activation at the cell surface. Exposure to MAG decreased the number of ß1-integrin adhesions in the growth cone during inhibition of axon extension. In contrast, the BDNF-induced adhesions were resistant to negative remodeling by MAG, correlating with the ability of BDNF pretreatment to counteract MAG-inhibition of axon extension. Pre-exposure to MAG prevented the BDNF-induced formation of ß1-integrin adhesions and blocked the stimulation of axon extension by BDNF. CONCLUSIONS: Altogether, these findings demonstrate the neurotrophin-dependent formation of integrin-based adhesions in the growth cone and reveal how a positive regulator of substrate adhesions can block the negative remodeling and growth inhibitory effects of MAG. Such bidirectional remodeling may allow the growth cone to rapidly adjust adhesiveness to the extracellular matrix as a general mechanism for governing axon extension. Techniques for manipulating integrin internalization and activation state may be important for overcoming local inhibitory factors after traumatic injury or neurodegenerative disease to enhance regenerative nerve growth.