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Corrado C, Willer BS, McPherson JI, Storey EP, Sisto SA, Master CL, Wiebe DJ, Grady MF, Mannix RC, Meehan WP, Leddy JJ, Haider MN. Adolescents With More Oculomotor and Vestibular Signs of Sport-Related Concussion Benefit from Aerobic Exercise: An Exploratory Analysis. J Neurotrauma 2023; 40:1718-1729. [PMID: 36884297 DOI: 10.1089/neu.2022.0225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023] Open
Abstract
Abstract Early targeted heart rate (HR) aerobic exercise has been shown to reduce the duration of recovery from sport-related concussion (SRC) as well as the incidence of persistent post-concussive symptoms (PPCS). It is not known, however, if more severe oculomotor and vestibular presentations of SRC benefit from a prescription of aerobic exercise. The current study is an exploratory analysis of two published randomized controlled trials that compared aerobic exercise within 10 days of injury with a placebo-like stretching intervention. Combining the two studies yielded a larger sample size to stratify severity of concussion based on the number of abnormal physical examination signs present at the initial office evaluation, which were confirmed with self-reported symptoms and recovery outcomes. The most discriminant cut-off was between those who had ≤3 oculomotor and vestibular signs and those who had >3 signs. Aerobic exercise (hazard ratio = 0.621 [0.412, 0.936], p = 0.023) reduced recovery times even when controlling for site (hazard ratio = 0.461 [0.303, 0.701], p < 0.001), severity (hazard ratio = 0.528 [0.325, 0.858], p = 0.010) and the interaction term of intervention and severity (hazard ratio = 0.972 [0.495, 1.909], p = 0.935). Adolescents who presented with >3 signs and were assigned to the placebo-like stretching group had a PPCS incidence of 38%, which was the highest of all subgroups (aerobic exercise and ≤3 findings: 8%; stretching and ≤3 findings: 11%; aerobic exercise and >3 findings: 21%). This exploratory study provides pilot evidence that prescribed sub-symptom threshold aerobic exercise treatment early after SRC may be effective for adolescents with more oculomotor and vestibular physical examination signs and should be validated in future adequately powered trials.
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Affiliation(s)
- Cathlyn Corrado
- Department of Orthopedics and Sports Medicine, State University of New York at Buffalo, Buffalo, New York, USA
| | - Barry S Willer
- Department of Psychiatry, State University of New York at Buffalo, Buffalo, New York, USA
| | - Jacob I McPherson
- Department of Rehabilitation Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Eileen P Storey
- Christiana Care, Medicine-Pediatrics Residency Program, Newark, Delaware, USA
| | - Sue Ann Sisto
- Department of Rehabilitation Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Christina L Master
- Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Douglas J Wiebe
- University of Michigan Injury Prevention Center, University of Michigan, Ann Arbor, Michigan, USA
| | - Mathew F Grady
- Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rebekah C Mannix
- Brain Injury Center, Boston Children's Hospital, Boston, Massachusetts, USA
- Division of Emergency Medicine, Boston, Massachusetts, USA
| | - William P Meehan
- Brain Injury Center, Boston Children's Hospital, Boston, Massachusetts, USA
| | - John J Leddy
- Department of Orthopedics and Sports Medicine, State University of New York at Buffalo, Buffalo, New York, USA
| | - Mohammad N Haider
- Department of Orthopedics and Sports Medicine, State University of New York at Buffalo, Buffalo, New York, USA
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Vernau BT, Haider MN, Fleming A, Leddy JJ, Willer BS, Storey EP, Grady MF, Mannix R, Meehan W, Master CL. Exercise-Induced Vision Dysfunction Early After Sport-Related Concussion Is Associated With Persistent Postconcussive Symptoms. Clin J Sport Med 2023:00042752-990000000-00111. [PMID: 37015066 DOI: 10.1097/jsm.0000000000001145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
OBJECTIVE The purpose of this study was to determine if exercise-induced vision dysfunction [reduced performance and/or symptom exacerbation on a post-exercise King-Devick (KD) test] in adolescents early after sport-related concussion was associated with increased risk of persistent post-concussive symptoms (PPCS, recovery >28 days). We used exercise as a provocative maneuver before the KD test, hypothesizing that concussed adolescents with exercise-induced vision dysfunction would be more likely to develop PPCS. DESIGN Secondary analysis of data from a multi-center, randomized clinical trial comparing KD test performance before and after the Buffalo Concussion Treadmill Test in adolescents within 10 days of sport-related concussion who were randomized to aerobic exercise or placebo stretching program. SETTING Three university-associated sports medicine clinical programs. PARTICIPANTS Ninety-nine adolescents with sport-related concussion (exercise group: n = 50, 15.3 ± 1 years, 60% M, 22% with PPCS; stretching group: n = 49, 15.9 ± 1 years, 65% M, 35% with PPCS) tested a mean of 6 ± 2 days from injury. INDEPENDENT VARIABLE King-Devick test performed immediately before and 2 minutes after Buffalo Concussion Treadmill Test. MAIN OUTCOME MEASURE Persistent post-concussive symptoms. RESULTS Adolescents who demonstrated exercise-induced vision dysfunction upon initial evaluation developed PPCS at a significantly greater rate when compared with adolescents who did not (71% vs 34%, P < 0.001). Exercise-induced vision dysfunction corresponded to a relative risk of 3.13 for PPCS. CONCLUSIONS Adolescents with exercise-induced vision dysfunction had a 3-fold greater relative risk of developing PPCS than those without exercise-induced vision dysfunction.
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Affiliation(s)
- Brian T Vernau
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | | | | | | | - Barry S Willer
- Psychiatry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York
| | - Eileen P Storey
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Matthew F Grady
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Rebekah Mannix
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts; and
- Harvard Medical School, Boston, Massachusetts
| | - William Meehan
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts; and
- Harvard Medical School, Boston, Massachusetts
| | - Christina L Master
- Minds Matter Concussion Program, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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Roby PR, Metzger KB, Storey EP, Master CL, Arbogast KB. Influence of concussion history and age of first concussion on visio-vestibular function. J Sci Med Sport 2022; 25:715-719. [PMID: 35821211 PMCID: PMC9489638 DOI: 10.1016/j.jsams.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 06/16/2022] [Accepted: 06/18/2022] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To assess if abnormalities on visio-vestibular examination (VVE) are associated with concussion history (first vs. repeat) or age of first concussion in acutely concussed adolescents. DESIGN Cross-sectional. METHODS Data were queried from the Children's Hospital of Philadelphia Minds Matter concussion registry. Patients aged 14-18 years old presenting for their initial visit to the specialty care concussion program within 28 days of injury were included. Demographics, including age, sex, concussion history, and age of first concussion, were collected before the exam. The VVE consisted of 9 subtests: smooth pursuit, horizontal/vertical saccades and vestibulo-ocular reflex (VOR), binocular convergence, left/right monocular accommodation, and complex tandem gait. Primary outcomes included VVE subtests (normal/abnormal), and total VVE score (abnormal = 2+ abnormal subtests). RESULTS Among 1051 patients included (female = 604(57.5 %); age = 15.6 ± 1.2; median lifetime concussions = 1 [IQR = 1,3]), 518 had repeat concussion. Controlling for age and sex, first vs. repeat concussion was not associated with any VVE subtest or total score (Total VVE Score RR = 1.35, 99.5%CI = 0.70,2.61). Of those with repeat concussion, 190 had valid age of first concussion data. Controlling for age, sex, and number of lifetime concussions, age of first concussion was not significantly associated with any VVE subtest or total score (Total VVE Score RR = 1.11, 99.5%CI = 0.78,1.57). CONCLUSIONS Adolescents with concussion history present with similar visio-vestibular function to those with no concussion history. Additionally, clinical effects of early age of first concussion may not be evident in children. This study provides foundational data regarding potential cumulative effects of concussion in younger athletes.
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Affiliation(s)
- Patricia R Roby
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, United States of America
| | - Kristina B Metzger
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, United States of America
| | - Eileen P Storey
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, United States of America
| | - Christina L Master
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, United States of America; Perelman School of Medicine, University of Pennsylvania, United States of America; Sports Medicine Performance Center, The Children's Hospital of Philadelphia, United States of America
| | - Kristy B Arbogast
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, United States of America; Perelman School of Medicine, University of Pennsylvania, United States of America; Division of Emergency Medicine, The Children's Hospital of Philadelphia, United States of America.
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Leddy JJ, Master CL, Mannix R, Wiebe DJ, Grady MF, Meehan WP, Storey EP, Vernau BT, Brown NJ, Hunt D, Mohammed F, Mallon A, Rownd K, Arbogast KB, Cunningham A, Haider MN, Mayer AR, Willer BS. Early targeted heart rate aerobic exercise versus placebo stretching for sport-related concussion in adolescents: a randomised controlled trial. Lancet Child Adolesc Health 2021; 5:792-799. [PMID: 34600629 DOI: 10.1016/s2352-4642(21)00267-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/07/2021] [Accepted: 08/11/2021] [Indexed: 01/22/2023]
Abstract
BACKGROUND Sport-related concussion is a public health problem, particularly in adolescents. Quality of life is reduced in adolescents with persistent post-concussive symptoms (symptoms >28 days). We replicated a previous randomised controlled trial to validate the safety, efficacy, and generalisability of, and objective adherence to, prescribed early targeted heart rate subsymptom threshold aerobic exercise compared with placebo-like stretching exercise for adolescent recovery from sport-related concussion and for reducing the risk of persistent post-concussive symptoms. METHODS This randomised controlled trial was done at three community and hospital-affiliated sports medicine concussion centres in the USA. Male and female adolescent athletes (aged 13-18 years) presenting within 10 days of sport-related concussion were randomly assigned to individualised subsymptom threshold aerobic or stretching exercise at least 20 min daily, for up to 4 weeks after injury. Exercise adherence and intensity were measured by heart rate monitors. The primary outcome was clinical recovery (ie, return to baseline symptoms, normal exercise tolerance, and a normal physical examination) within the 4-week intervention period, and development of persistent post-concussive symptoms beyond 28 days after injury. This study is registered with ClinicalTrials.gov, NCT02959216. FINDINGS Between Aug 1, 2018, and March 31, 2020, 118 adolescents were recruited (61 were randomly assigned to the aerobic exercise group and 57 to the stretching exercise group) and included in the intention-to-treat analysis. On survival analysis, controlling for sex, site, and mean daily exercise time, patients assigned to aerobic exercise were more likely to recover within 4 weeks after injury compared with those assigned to stretching exercise, with a 48% reduced risk of persistent post-concussive symptoms (hazard ratio for stretching vs aerobic exercise of 0·52 [95% CI 0·28-0·97], p=0·039). No adverse events were reported. INTERPRETATION This multicentre study found that early treatment with subsymptom threshold aerobic exercise safely speeds recovery from sport-related concussion and reduces the risk for persistent post-concussive symptoms, an important result given the impact of delayed recovery on adolescent quality of life. Adherence was good and there were no adverse events from this non-pharmacological treatment. These results suggest that physicians should not only permit, but consider prescribing, early subsymptom threshold physical activity to adolescents as treatment for sport-related concussion and to reduce the risk of persistent post-concussive symptoms. FUNDING American Medical Society for Sports Medicine.
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Affiliation(s)
- John J Leddy
- UBMD Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA.
| | - Christina L Master
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Center for Injury Research and Prevention, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Rebekah Mannix
- Brain Injury Center, Boston Children's Hospital, Boston, MA, USA; Division of Emergency Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Douglas J Wiebe
- Department of Biostatistics and Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Matthew F Grady
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - William P Meehan
- Brain Injury Center, Boston Children's Hospital, Boston, MA, USA; Sports Concussion Clinic, Division of Sports Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Eileen P Storey
- Center for Injury Research and Prevention, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA; Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Brian T Vernau
- Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Naomi J Brown
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Danielle Hunt
- Sports Concussion Clinic, Division of Sports Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Fairuz Mohammed
- Center for Injury Research and Prevention, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Andrea Mallon
- Sports Medicine and Performance Center, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kate Rownd
- Center for Injury Research and Prevention, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Kristy B Arbogast
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Center for Injury Research and Prevention, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Adam Cunningham
- UBMD Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Mohammad N Haider
- UBMD Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
| | - Andrew R Mayer
- The Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Department of Neurology, and Department of Psychiatry, University of New Mexico School of Medicine, Albuquerque, NM, USA
| | - Barry S Willer
- Department of Psychiatry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, NY, USA
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Affiliation(s)
- Eileen P Storey
- ChristianaCare, Medicine-Pediatrics Residency Program, Newark, Delaware
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Haider MN, Patel KS, Willer BS, Videira V, Wilber CG, Mayer AR, Master CL, Mariotti BL, Wertz C, Storey EP, Arbogast KB, Park G, Oglesbee SJ, Bezherano I, Aguirre K, Fodero JG, Johnson BD, Mannix R, Miecznikowski JC, Leddy JJ. Symptoms upon postural change and orthostatic hypotension in adolescents with concussion. Brain Inj 2021; 35:226-232. [PMID: 33459038 DOI: 10.1080/02699052.2021.1871951] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Objective: Concussion is associated with dysautonomia, altered blood pressure (BP) control, and may cause Orthostatic Hypotension (OH). We measured prevalence of OH using the 1-minute supine-to-standing OH Test in adolescents with concussion and controls.Participants: Adolescents within 10 days of injury (Concussion Group, n = 297, 15.0 ± 1.7 years, 59% male) were compared with controls (Control Group, n = 214, 15.0 ± 1.5 years, 58% male).Methods: BP, heart rate (HR), and complaints of lightheadedness/dizziness were measured after 2-minute supine and 1-minute standing. Control Group was assessed once. Concussion Group was assessed twice; (1) initial visit (mean 6.0 ± 3 days-since-injury) and (2) after clinical recovery (mean 46.3 ± 42 days-since-injury).Results: Initial visit; Concussion Group reported feeling lightheaded/dizzy on postural change more often than the Control Group (37% vs 4%, p < .001) but did not differ in meeting standard OH criteria (3% vs 5%, p = .32). Experiencing symptoms did not correlate with meeting OH criteria, but correlated with abnormal vestibulo-ocular reflex. After clinical recovery; Concussion Group did not differ in experiencing lightheaded/dizziness on postural change than controls (4%, p = .65).Conclusion: Adolescents commonly experience orthostatic intolerance after concussion without meeting the standard criteria for OH.
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Affiliation(s)
- M Nadir Haider
- UBMD Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA.,Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Kush S Patel
- UBMD Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Barry S Willer
- Department of Psychiatry, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | | | - Charles G Wilber
- UBMD Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Andrew R Mayer
- The Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico, Unites States.,Departments of Neurology and Psychiatry, University of New Mexico School of Medicine, Albuquerque, New Mexico
| | - Christina L Master
- Sports Medicine and Performance Center, Division of Orthopedic Surgery, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA.,Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Brandon L Mariotti
- Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Christopher Wertz
- The Mind Research Network/Lovelace Biomedical and Environmental Research Institute, Albuquerque, New Mexico, Unites States
| | - Eileen P Storey
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Kristy B Arbogast
- Center for Injury Research and Prevention, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Grace Park
- Department of Emergency Medicine, University of New Mexico Hospital, Albuquerque, New Mexico
| | - Scott J Oglesbee
- Department of Emergency Medicine, University of New Mexico Hospital, Albuquerque, New Mexico
| | - Itai Bezherano
- UBMD Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Kenneth Aguirre
- UBMD Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Jesse G Fodero
- Department of Emergency Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
| | - Blair D Johnson
- Department of Exercise and Nutrition Sciences, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, New York, USA
| | - Rebekah Mannix
- Department of Emergency Medicine, Harvard Medical School, Boston, Massachusetts, USA
| | - Jeffrey C Miecznikowski
- Department of Biostatistics, School of Public Health and Health Professions, State University of New York at Buffalo, Buffalo, New York, USA
| | - John J Leddy
- UBMD Department of Orthopaedics and Sports Medicine, Jacobs School of Medicine and Biomedical Sciences, State University of New York at Buffalo, Buffalo, New York, USA
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Abstract
BACKGROUND Although there are several causes of unplanned return to the operating room (RTOR) following pediatric anterior cruciate ligament (ACL) reconstruction (ACLR), prior outcomes studies focus primarily on the risk of graft failure. We sought to comprehensively describe indications for RTOR in pediatric primary ACLR patients, estimate associated rates of RTOR, and assess the impact of concomitant meniscal procedures on these rates. METHODS This retrospective cohort study considered patients who underwent primary ACLR at an urban, pediatric tertiary care hospital between 2013 and 2015. Cohorts were defined based on the presence or absence of a concomitant surgical meniscal procedure with the index ACLR. The primary outcome was RTOR for an indication pertaining to ACLR or a potential predilection for knee injury. Cases of RTOR were cataloged and classified according to indication. Survival analyses were performed using the Kaplan-Meier estimation and competing-risks regression. Comparisons of any-cause RTOR rates were done using log-rank tests. RESULTS After exclusion criteria were applied, 419 subjects were analyzed. RTOR indications were organized into 5 categories. The overall rate for any RTOR by 3 years after surgery was 16.5%. Graft failure and contralateral ACL tear were the most common indications for RTOR, with predicted rates of 10.3% and 7.1%, respectively. ACL graft failure accounted for less than half of RTOR cases cataloged. Patients who had a concomitant meniscus procedure had lower rates of RTOR. CONCLUSIONS Approximately 1 in 6 pediatric ACLR patients underwent ≥1 repeat surgery within 3 postoperative years for indications ranging from wound breakdown to contralateral ACL rupture. While previous studies revealed high rates of complication after pediatric ACLR due primarily to graft failure, we found that re-tear is responsible for less than half of the 3-year RTOR risk. As almost half of re-tears in our sample occurred before clearance to return to full activities, we suspect that the high rate of complication is largely attributable to pediatric patients' high activity levels and difficulties adhering to postoperative restrictions. Early treatment of meniscus pathology may reduce rates of RTOR. LEVEL OF EVIDENCE Level III-therapeutic.
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Affiliation(s)
- Christopher J DeFrancesco
- Division of Orthopaedics, The Children's Hospital of Philadelphia
- The Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Eileen P Storey
- Division of Orthopaedics, The Children's Hospital of Philadelphia
| | - John M Flynn
- Division of Orthopaedics, The Children's Hospital of Philadelphia
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Master CL, P. Storey E. Assessment, Management, and Rehabilitation of Pediatric Concussions. Concussion 2020. [DOI: 10.1016/b978-0-323-65384-8.00012-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Storey EP, Wiebe DJ, DʼAlonzo BA, Nixon-Cave K, Jackson-Coty J, Goodman AM, Grady MF, Master CL. Vestibular Rehabilitation Is Associated With Visuovestibular Improvement in Pediatric Concussion. J Neurol Phys Ther 2019; 42:134-141. [PMID: 29912034 DOI: 10.1097/npt.0000000000000228] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND AND PURPOSE Vision and vestibular-related deficits are common after concussion and are associated with prolonged recovery times, substantially impacting the quality of life for children. The utility of targeted vestibular rehabilitation for these deficits in children after concussion is unknown. The purpose of this study was to determine whether active vestibular rehabilitation is associated with an improvement in visuovestibular signs and symptoms in children with concussion. METHODS A retrospective cohort study of children diagnosed with concussion and referred to vestibular rehabilitation between 2012 and 2014 was conducted. Patient-reported symptoms and visuovestibular performance measures were assessed in the medical practice and physical therapy settings. RESULTS One hundred nine children were included in the study with a mean age of 11.8 (3.4) years. Among this group, 59 (54%) were male and 48 (44%) had a sports-related concussion. Children presented to a pediatric sports medicine office and physical therapy a median of 24 (interquartile range [IQR], 14-42) and 55 (IQR, 39-94) days after injury, respectively. Concussion symptoms decreased from a median of 9 (IQR, 5-13) symptoms at initial evaluation to a median of 0 (IQR, 0-2) symptoms at final assessment. Performance on all visuovestibular tasks improved significantly over the course of therapy except for near point of convergence. For the 45 children who completed the Balance Error Scoring System at both initial and final therapy visits, there was a significant improvement in mean level of performance (P < 0.0001). Characteristics between those who completed a full versus partial course of physical therapy were similar. DISCUSSION AND CONCLUSIONS Vestibular rehabilitation in children with concussion is associated with improvement in symptoms as well as visuovestibular performance. This active intervention may benefit children with persistent symptoms after concussion. Future prospective studies are needed to determine the efficacy and optimal postinjury timing of vestibular rehabilitation.Video Abstract available for more insights from the authors (see Supplemental Digital Content 1, available at: http://links.lww.com/JNPT/A208).
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Affiliation(s)
- Eileen P Storey
- The Children's Hospital of Philadelphia, Division of Orthopaedics, Sports Medicine and Performance Center, Philadelphia, Pennsylvania (E.P.S., K.N-C., J.J-C., M.F.G., C.L.M.); Perelman School of Medicine, University of Pennsylvania, Philadelphia (M.F.G., C.L.M.); Saint Peter's Sports Medicine Institute, Somerset, New Jersey (A.M.G.); and Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia (D.J.W., B.D.)
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10
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Abstract
BACKGROUND Adolescent athletes who sustain an anterior cruciate ligament (ACL) tear have significantly reduced activity levels during recovery. Activity level is linked to body mass index (BMI); however, it is unclear how recovery from an ACL reconstruction (ACLR) affects relative BMI and whether these changes persist after return to activity. HYPOTHESIS Patients' BMI percentile will significantly increase after ACLR, but will trend toward baseline after return to activity. STUDY DESIGN Cross-sectional study. LEVEL OF EVIDENCE Level 3. METHODS A retrospective review of 666 pediatric and adolescent patients who underwent ACLR was performed. Body mass was assessed by evaluating change in BMI percentile at 8 standard-of-care time windows relative to BMI percentile at time of surgery. Linear regression and bivariate and multivariate analyses were used to assess the effect of time window and other demographic factors on the change in BMI percentile. These analyses were rerun after dividing patients by clinical obesity categorization (underweight, normal, overweight, or obese) at time of surgery to assess the effect of preinjury body mass levels. RESULTS BMI percentile of all BMI categories tended to increase postoperatively, peaking 6 to 9 months after surgery, with a median increase of 1.83 percentile points. After this peak, BMI approached baseline but remained elevated at 0.95 percentile points 2 years postoperatively. Beginning 3 months after surgery, the normal-weight group had significantly larger changes in BMI percentile at each time window, peaking at 4.15 points above baseline at 9 months. This BMI increase among normal-weight patients persisted in the second postoperative year, with a median percentile increase of 2.63 points. CONCLUSION Pediatric and adolescent patients, especially those with a normal BMI, undergo significant changes to their BMI during recovery from ACLR. CLINICAL RELEVANCE Patients' failure to return to their presurgical BMI percentile 2 years postoperatively suggests that ACLR may have long-reaching and often unappreciated effects on body mass.
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Affiliation(s)
- Elle M MacAlpine
- Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Divya Talwar
- Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Eileen P Storey
- Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - Scott M Doroshow
- Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
| | - J Todd R Lawrence
- Division of Orthopaedics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania
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Howell DR, Brilliant AN, Storey EP, Podolak OE, Meehan WP, Master CL. Objective Eye Tracking Deficits Following Concussion for Youth Seen in a Sports Medicine Setting. J Child Neurol 2018; 33:794-800. [PMID: 30088436 DOI: 10.1177/0883073818789320] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Quantification of visual deficits may help to identify dysfunction following concussion. We evaluated eye-tracking measurements among adolescents within 10 days of concussion and healthy control participants. Patients who reported to 2 tertiary care sport concussion clinics within 10 days of concussion completed an objective eye tracking assessment. Seventy-nine participants completed the study, 44 with concussion (mean age = 14.1 ± 2.2 years, 39% female) and 35 controls (mean age = 14.3 ± 2.4 years, 57% female). Right eye skew along the bottom of the screen was significantly higher for the concussion group compared to controls (median = 0.022 [interquartile range = -0.263, 0.482] vs 0.377 [interquartile range = -0.574, -0.031]; P = .002), but not the left eye. Among the variables investigated, right eye skew was altered for adolescents with a concussion. Visual function is an important component in the postconcussion evaluation, and identifying deficits soon after injury may allow for earlier specialist referral and intervention.
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Affiliation(s)
- David R Howell
- 1 Sports Medicine Center, Children's Hospital Colorado, Aurora, CO, USA.,2 Department of Orthopedics, University of Colorado School of Medicine, Aurora, CO, USA.,3 The Micheli Center for Sports Injury Prevention, Waltham, MA, USA
| | - Anna N Brilliant
- 3 The Micheli Center for Sports Injury Prevention, Waltham, MA, USA.,4 Department of Orthopaedics, Division of Sports Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Eileen P Storey
- 5 Sports Medicine and Performance Center, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Olivia E Podolak
- 5 Sports Medicine and Performance Center, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - William P Meehan
- 3 The Micheli Center for Sports Injury Prevention, Waltham, MA, USA.,4 Department of Orthopaedics, Division of Sports Medicine, Boston Children's Hospital, Boston, MA, USA.,6 Department of Pediatrics and Orthopaedic Surgery, Harvard Medical School, Boston, MA, USA
| | - Christina L Master
- 5 Sports Medicine and Performance Center, Division of Orthopedics, Children's Hospital of Philadelphia, Philadelphia, PA, USA.,7 University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
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Storey EP, Grady MF, Master CL. The Relationship Between Patient-Reported Visual Symptoms and Visual Deficits After Concussion. Med Sci Sports Exerc 2018. [DOI: 10.1249/01.mss.0000536656.45206.9a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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13
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Mayer AR, Wertz C, Ryman SG, Storey EP, Park G, Phillips J, Dodd AB, Oglesbee S, Campbell R, Yeo RA, Wasserott B, Shaff NA, Leddy JJ, Mannix R, Arbogast KB, Meier TB, Grady MF, Master CL. Neurosensory Deficits Vary as a Function of Point of Care in Pediatric Mild Traumatic Brain Injury. J Neurotrauma 2018; 35:1178-1184. [PMID: 29336197 DOI: 10.1089/neu.2017.5340] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Neurosensory abnormalities are frequently observed following pediatric mild traumatic brain injury (pmTBI) and may underlie the expression of several common concussion symptoms and delay recovery. Importantly, active evaluation of neurosensory functioning more closely approximates real-world (e.g., physical and academic) environments that provoke symptom worsening. The current study determined whether symptom provocation (i.e., during neurosensory examination) improved classification accuracy relative to pre-examination symptom levels and whether symptoms varied as a function of point of care. Eighty-one pmTBI were recruited from the pediatric emergency department (PED; n = 40) or outpatient concussion clinic (n = 41), along with matched (age, sex, and education) healthy controls (HC; n = 40). All participants completed a brief (∼ 12 min) standardized neurosensory examination and clinical questionnaires. The magnitude of symptom provocation upon neurosensory examination was significantly higher for concussion clinic than for PED patients. Symptom provocation significantly improved diagnostic classification accuracy relative to pre-examination symptom levels, although the magnitude of improvement was modest, and was greater in the concussion clinic. In contrast, PED patients exhibited worse performance on measures of balance, vision, and oculomotor functioning than the concussion clinic patients, with no differences observed between both samples and HC. Despite modest sample sizes, current findings suggest that point of care represents a critical but highly under-studied variable that may influence outcomes following pmTBI. Studies that rely on recruitment from a single point of care may not generalize to the entire pmTBI population in terms of how neurosensory deficits affect recovery.
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Affiliation(s)
- Andrew R Mayer
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico.,2 Neurology Department, University of New Mexico School of Medicine , Albuquerque, New Mexico.,3 Psychiatry Department, University of New Mexico School of Medicine , Albuquerque, New Mexico.,4 Psychology Department, University of New Mexico , Albuquerque, New Mexico
| | - Christopher Wertz
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico
| | - Sephira G Ryman
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico
| | - Eileen P Storey
- 5 Division of Orthopedic Surgery, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania
| | - Grace Park
- 6 Emergency Medicine, University of New Mexico Hospital , Albuquerque, New Mexico
| | - John Phillips
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico.,4 Psychology Department, University of New Mexico , Albuquerque, New Mexico
| | - Andrew B Dodd
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico
| | - Scott Oglesbee
- 6 Emergency Medicine, University of New Mexico Hospital , Albuquerque, New Mexico
| | - Richard Campbell
- 3 Psychiatry Department, University of New Mexico School of Medicine , Albuquerque, New Mexico
| | - Ronald A Yeo
- 4 Psychology Department, University of New Mexico , Albuquerque, New Mexico
| | - Benjamin Wasserott
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico
| | - Nicholas A Shaff
- 1 The Mind Research Network/Lovelace Biomedical and Environmental Research Institute , Pete & Nancy Domenici Hall, Albuquerque, New Mexico
| | - John J Leddy
- 7 Department of Orthopaedics, University at Buffalo , Buffalo, New York
| | - Rebekah Mannix
- 8 Division of Emergency Medicine, Boston Children's Hospital , Boston, Massachusetts
| | - Kristy B Arbogast
- 9 Center for Injury Research and Prevention, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania
| | - Timothy B Meier
- 10 Department of Neurosurgery, Medical College of Wisconsin , Milwaukee, Wisconsin.,11 Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Matthew F Grady
- 5 Division of Orthopedic Surgery, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania.,9 Center for Injury Research and Prevention, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania
| | - Christina L Master
- 5 Division of Orthopedic Surgery, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania.,9 Center for Injury Research and Prevention, The Children's Hospital of Philadelphia , Philadelphia, Pennsylvania
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DeFrancesco CJ, Storey EP, Shea KG, Kocher MS, Ganley TJ. Challenges in the Management of Anterior Cruciate Ligament Ruptures in Skeletally Immature Patients. Instr Course Lect 2018; 67:391-402. [PMID: 31411427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Although initially considered rare, anterior cruciate ligament (ACL) ruptures in pediatric patients recently have increased substantially as a result of greater awareness of the injury and increased participation in youth sports. Although pediatric patients with an ACL injury and a clinically stable joint may handle the injury well and return to sports activity without requiring surgical reconstruction, young, active patients with an ACL rupture and an unstable joint may be good candidates for ACL reconstruction to prevent ongoing instability and additional joint damage. ACL reconstruction techniques have been developed to prevent physeal injury in skeletally immature patients. The surgical treatment of skeletally immature patients with an ACL rupture may differ from that of adults with an ACL rupture and presents unique challenges with regard to reconstruction technique selection, graft preparation, rehabilitation, and return to sports activity. Orthopaedic surgeons should understand various physeal-sparing ACL reconstruction techniques and the general challenges associated with the surgical management of ACL ruptures in pediatric patients.
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Affiliation(s)
- Christopher J DeFrancesco
- Research Fellow, Department of Orthopaedics, The Children�s Hospital of Philadelphia, Philadelphia, Pennsylvania
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Gornitzky AL, Mistovich RJ, Atuahene B, Storey EP, Ganley TJ. Erratum to: Osteochondritis Dissecans Lesions in Family Members: Does a Positive Family History Impact Phenotypic Potency? Clin Orthop Relat Res 2017; 475:1751. [PMID: 27757802 PMCID: PMC5406331 DOI: 10.1007/s11999-016-5128-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Alex L. Gornitzky
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA ,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - R. Justin Mistovich
- Department of Orthopaedic Surgery, Case Western Reserve University School of Medicine, Cleveland, OH USA
| | - Brittany Atuahene
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA
| | - Eileen P. Storey
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA
| | - Theodore J. Ganley
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA
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Gornitzky AL, Mistovich RJ, Atuahuene B, Storey EP, Ganley TJ. Osteochondritis Dissecans Lesions in Family Members: Does a Positive Family History Impact Phenotypic Potency? Clin Orthop Relat Res 2017; 475:1573-1580. [PMID: 27600715 PMCID: PMC5406325 DOI: 10.1007/s11999-016-5059-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
BACKGROUND Although repetitive microtrauma and athletic overuse patterns are most commonly associated with osteochondritis dissecans (OCD), recent studies have identified a potential genetic predisposition for OCD. Several case series have documented family pedigrees that support autosomal-dominant inheritance, but the families in these studies were all selected as a result of unique histories that may not accurately represent OCD inheritance patterns at large. Because there has been little investigation beyond these case reports, we aimed to describe a broader, more representative pattern of OCD inheritance applicable to all affected patients. QUESTIONS/PURPOSES (1) What proportion of patients treated for OCD of the knee have one or more immediate and/or extended family members with a history of OCD lesions? (2) Do patients with more phenotypically potent lesions, which we defined as patients with bilateral OCD lesions or patients who have undergone multiple procedures for OCD, have a higher frequency of affected relatives than those with less potent lesions? METHODS This retrospective study queried patient databases, diagnosis codes (International Classification of Diseases, 9th Revision), and surgical logs at a regional, tertiary care children's hospital to identify all patients treated over a 10-year period (March 2004-March 2014) by the senior author for OCD of the knee. All patients aged 0-18 years at the time of diagnosis were included. At our institution, patients with intact lesions are treated with a trial of conservative therapy; conversely, patients with a break in the articular cartilage and/or loose fragments of bone/cartilage are treated surgically. There were no OCD-specific contraindications to surgery. This search identified 543 patients. After patient identification, a questionnaire was designed that asked for the number, age, and gender of all immediate family members and the history of OCD lesions in any family member (immediate or extended). For all positive family members, patients were further queried regarding relevant clinical details to affirm a history of OCD. Patients were contacted by mailed questionnaires and phone calls for survey completion. All 543 patients received the survey, of which 103 (19%) responded to it and were included here. Responders were approximately 1 year younger than nonresponders; there was no difference in gender distribution. A retrospective chart review was then conducted to collect demographic information, phenotypic disease severity, and treatment details. Of the 103 included patients, 20 patients (19%) with unilateral lesions were managed nonoperatively ("conservative" group), 50 patients (49%) had unilateral lesions advanced to surgery ("unilateral" group), 21 patients (20%) had bilateral lesions managed either conservatively or surgically ("bilateral" group), and 12 patients (12%) underwent multiple procedures for the same lesion ("multiple" group). Of those included, 75 patients (73%) were treated surgically. With the numbers available, there were no baseline differences among the groups in terms of gender, lesion laterality, lesion location, or number of secondary procedures at the time of the initial surgical intervention. RESULTS In total, 14 of 103 (14%) patients treated for OCD in this study had an immediate and/or extended family member with a history of OCD lesions. This included four of 20 (20%) patients in the conservative group, five of 50 (10%) in the unilateral group, four of 21 (19%) in the bilateral group, and one of 12 (8%) in the multiple group. With the numbers available, we did not identify a higher proportion of immediate and/or extended family members with a positive history of OCD in those patients with phenotypically potent lesions (bilateral and multiple) as compared with those with patients phenotypically less potent lesions (conservative and unilateral; five of 33 [15%] versus nine of 70 [13%]; odds ratio, 1.2; 95% confidence interval, 0.4-3.9; p = 0.751). CONCLUSIONS In this broad, heterogeneous cohort of pediatric patients with OCD, the proportion of patients with a positive family history of OCD was 14%, which appeared to be much higher than the reported prevalence of OCD in the general population according to prior research. Therefore, our data provide preliminary support for a familial inheritance pattern for OCD, suggesting that further clinical, biologic, and genomic investigation might help to improve our understanding of who is at highest risk for OCD and what moderating factors might influence their disease severity and risk of progression. Furthermore, our data suggest that expanded patient education and screening regarding inheritance patterns might enhance identification of potential familial disease burden and improve access to timely and appropriate treatment. LEVEL OF EVIDENCE Level IV, prognostic study.
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Affiliation(s)
- Alex L. Gornitzky
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA ,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - R. Justin Mistovich
- Department of Orthopaedic Surgery, Case Western Reserve University School of Medicine, Cleveland, OH USA
| | - Brittany Atuahuene
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA
| | - Eileen P. Storey
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA
| | - Theodore J. Ganley
- Division of Orthopaedics, The Children’s Hospital of Philadelphia, Philadelphia, PA USA
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Master CL, Storey EP, Wang L, Ayaz H, Podolak O, Grady MF. Head Injury - Soccer. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000516876.43868.eb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Storey EP, Ayaz H, Wang L, Podolak O, Grady MF, Master CL. The Use Of Functional Near-Infrared Spectroscopy (fNIRS) For Assessing Cognitive Workload During King-Devick Test After Concussion. Med Sci Sports Exerc 2017. [DOI: 10.1249/01.mss.0000518006.78218.6b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Storey EP, Boghozian R, Little JL, Lowman DW, Chakraborty R. Characterization of ‘Schizokinen’; a dihydroxamate-type siderophore produced by Rhizobium leguminosarum IARI 917. Biometals 2006; 19:637-49. [PMID: 16758117 DOI: 10.1007/s10534-006-9001-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2006] [Accepted: 02/07/2006] [Indexed: 11/29/2022]
Abstract
The Rhizobia comprise one of the most important groups of beneficial bacteria, which form nodules on the roots (rarely on the stems) of leguminous plants. They live within the nodules and reduce atmospheric nitrogen to ammonia, which is further assimilated by plants into required nitrogenous compounds. The Rhizobia in return obtain nutrition from the plant. Rhizobia are free-living soil bacteria and have to compete with other microorganisms for the limited available iron in the rhizosphere. In order to acquire iron Rhizobia have been shown to express siderophore-mediated iron transport systems. Rhizobium leguminosarum IARI 917 was investigated for its ability to produce siderophore. It was found to produce a dihydroxamate type siderophore under iron restricted conditions. The siderophore was purified and chemically characterized. The ESMS, MS/MS and NMR analysis indicate the dihydroxamate siderophore to be 'schizokinen', a siderophore reported to be produced by Bacillus megaterium that shares a similar structure to 'rhizobactin 1021' produced by Sinorhizobium meliloti 1021. This is the first report of production of schizokinen by a strain of R. leguminosarum, therefore it was carefully investigated to confirm that it is indeed 'schizokinen' and not a degradation product of 'rhizobactin 1021'. Since ferric-siderophore complexes are transported across the outer membrane (OM) into the periplasm via an OM receptor protein, R. leguminosarum IARI 917 was investigated for the presence of an OM receptor for 'ferric-schizokinen'. SDS PAGE analysis of whole cell pellet and extracted OM fractions indicate the presence of a possible iron-repressible OM receptor protein with the molecular weight (MW) of approximately 74 kDa.
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Affiliation(s)
- E P Storey
- Department of Health Sciences, College of Public and Allied Health, East Tennessee State University, 37614 Johnson City, TN, USA.
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