Here is a selection of some of the
Publications by Gavin Davis.
Please click on any of the titles below to view the available abstract.
Consensus Statement On Concussion In Sport – The 5th International Conference On Concussion In Sport Held In Berlin, October 2016.
- Consensus Statement On Concussion In Sport – The 5th International Conference On Concussion In Sport Held In Berlin, October 2016. Paul McCrory, Willem Meeuwisse, Jiri Dvorak, Mark Aubry, Julien Bailes, Steve Broglio, Bob Cantu, David Cassidy, Rudi Castellani, Gavin Davis, Ruben Echemendia, Rich Ellenbogen, Carolyn Emery, Lars Engebretsen, Nina Feddermann-Demont, Christopher Giza, Kevin Guskewicz, Stanley Herring, Grant Iverson, Karen Johnston, James Kissick, Jeffrey Kutcher, John Leddy, David Maddocks, Michael Makdissi, Geoff Manly, Mike McCrea, William Meehan, Shinji Nagahiro, Jon Patricios, Margot Putukian, Martin Raftery, Kathryn Schneider, Allen Sills, Charles Tator, Michael Turner, Pieter Vos. British J Sports Medicine. 2017 doi:10.1136/ bjsports-2017-097699
The Child Sport Concussion Assessment Tool 5th Edition (Child SCAT5). Gavin A. Davis, Laura Purcell, Kathryn Schneider, Keith Owen Yeates, Gerard Gioia, Vicki Anderson, Richard G. Ellenbogen, Ruben Echemendia, Michael Makdissi, Allen Sills, Grant L. Iverson, Jiri Dvorak, Paul McCrory, Willem Meeuwisse, Jon Patricios, Christopher C. Giza, Jeffrey S. Kutcher. British J Sports Medicine. 2017
This article presents the Child Sport Concussion Assessment Tool 5th Edition (Child SCAT5). The Sport Concussion Assessment Tool was introduced in 2004, following the 2nd International Conference on Concussion in Sport in Prague, Czech Republic. Following the 4th International Consensus Conference, held in Zurich, Switzerland, in 2012, the SCAT 3rd edition (Child SCAT3) was developed for children aged between 5 and12 years. Research to date was reviewed and synthesised for the 5th International Consensus Conference on Concussion in Sport in Berlin, Germany, leading to the current revision of the test, the Child SCAT5. This article describes the development of the Child SCAT5.
The Sport Concussion Assessment Tool 5th Edition (SCAT5). Ruben J. Echemendia,Willem Meeuwisse, Paul McCrory, Gavin A. Davis, Margot Putukian, John Leddy, Michael Makdissi, John Sullivan, Steven P. Broglio, Martin Raftery, Kathryn Schneider, James Kissick, Michael McCrea, Jiri Dvorak, Allen K. Sills, Mark Aubry, Lars Engebretsen, Mike Lossemore, Gordon Fuller, Jeffrey Kutcher, Richard Ellenbogen, Kevin Guskiewicz, Jon Patricios, Stanley Herring. British J Sports Medicine. 2017
This paper presents the Sport Concussion Assessment Tool 5th Edition (SCAT5), which is the most recent revision of a sport concussion evaluation tool for use by healthcare professionals in the acute evaluation of suspected concussion. The revision of the SCAT3 (first published in 2013) culminated in the SCAT5. The revision was based on a systematic review and synthesis of current research, public input and expert panel review as part of the 5th International Consensus Conference on Concussion in Sport held in Berlin in 2016. The SCAT5 is intended for use in those who are 13 years of age or older. The Child SCAT5 is a tool for those aged 5–12 years, which is discussed elsewhere.
The Concussion Recognition Tool 5th Edition (CRT5). Ruben J. Echemendia,Willem Meeuwisse, Paul McCrory, Gavin A. Davis, Margot Putukian, John Leddy, Michael Makdissi, John Sullivan, Steven P. Broglio, Martin Raftery, Kathryn Schneider, James Kissick, Michael McCrea, Jiri Dvorak, Allen K. Sills, Mark Aubry, Lars Engebretsen, Mike Lossemore, Gordon Fuller, Jeffrey Kutcher, Richard Ellenbogen, Kevin Guskiewicz, Jon Patricios, Stanley Herring. British J Sports Medicine. 2017
The Concussion Recognition Tool 5 (CRT5) is the most recent revision of the Pocket Sport Concussion Assessment Tool 2 that was initially introduced by the Concussion in Sport Group in 2005. The CRT5 is designed to assist non-medically trained individuals to recognise the signs and symptoms of possible sport- related concussion and provides guidance for removing an athlete from play/sport and to seek medical attention. This paper presents the development of the CRT5 and highlights the differences between the CRT5 and prior versions of the instrument.
What is the difference in concussion management in children as compared to adults? A systematic review. Gavin A. Davis, Vicki Anderson, Franz E Babl, Gerry Gioia, Christopher C. Giza, William Meehan, Rosemarie Scolaro Moser, Laura Purcell, Philip Schatz, Kathryn Schneider, Michael Takagi, Keith Owen Yeates, Roger Zemek. British J Sports Medicine. 2017
What tests and measures should be added to the SCAT3 and related tests to improve their reliability, sensitivity and/or specificity in sideline concussion diagnosis? Ruben J. Echemendia, Steven Broglio, Gavin Davis, Kevin Guskiewicz, Alix Hayden, John Leddy, William Meehan, Paul McCrory, Margot Putukian, John Sullivan. British J Sports Medicine. 2017
Ulnar Nerve Submuscular Transposition. Mark Ehlers, Gavin Davis, and Amgad Hanna. In Neurosurgical Operative Atlas: Spine and Peripheral Nerves, 3rd edition (eds. Wolfla, Resnick), Thieme (New York). 2017.
Validation of a score to determine time to post-concussive recovery. Stephen Hearps, Michael Takagi, Franz Babl, Silvia Bressan, Katherine Truss, Gavin Davis, Celia Godfrey, Cathriona Clarke, Melissa Doyle, Vanessa Rausa, Kevin Dunne, Vicki Anderson. Pediatrics. DOI: 10.1542/peds.2016-2003
METHODS: The current study was a prospective, longitudinal observational study conducted between July 2013 and November of 2015 at a statewide tertiary pediatric hospital. Participants were 120 children (5–18 years of age) presenting to the emergency department with a concussion within 48 hours of injury. PCS were assessed by using the Postconcussion Symptom Inventory (PCSI), acutely, 1 to 4 days postinjury and 2 weeks postinjury. Using comprehensive clinical assessment as gold standard, we assessed the clinical cutoff discrimination ability of PCSI at 2 weeks postinjury by using published approaches, and then varying each approach to optimize their discrimination ability.
RESULTS: Existing and potential clinical cutoff scores were explored in predicting delayed recovery. Receiver operating characteristic curve results returned acceptable discrimination and sensitivity when PCSI items increased in severity from preinjury by 1 or more. Compared with a published cutoff score being 3+ items with increased severity, the current study suggests a more stringent cutoff requirement of 2+ is better able to accurately classify symptomatic children.
CONCLUSIONS: This study provides the first validated index (2+ items, 1+ severity) of concussion recovery for children and youth. Further stud
Using video analysis for concussion surveillance in Australian football. Michael Makdissi and Gavin Davis. Journal of Science and Medicine in Sport. DOI 10.1016/j.jsams.2016.02.014. (2016)
The objectives of the study were to assess the relationship between various player and game factors and risk of concussion; and to assess the reliability of video analysis for mechanistic assessment of concussion in Australian football.
Prospective cohort study.
All impacts and collisions resulting in concussion were identified during the 2011 Australian Football League season. An extensive list of factors for assessment was created based upon previous analysis of concussion in Australian Football League and expert opinions. The authors independently reviewed the video clips and correlation for each factor was examined.
A total of 82 concussions were reported in 194 games (rate: 8.7 concussions per 1000 match hours; 95% confidence interval: 6.9–10.5). Player demographics and game variables such as venue, timing of the game (day, night or twilight), quarter, travel status (home or interstate) or score margin did not demonstrate a significant relationship with risk of concussion; although a higher percentage of concussions occurred in the first 5 min of game time of the quarter (36.6%), when compared to the last 5 min (20.7%). Variables with good inter-rater agreement included position on the ground, circumstances of the injury and cause of the impact. The remainder of the variables assessed had fair-poor inter-rater agreement. Common problems included insufficient or poor quality video and interpretation issues related to the definitions used.
Clear definitions and good quality video from multiple camera angles are required to improve the utility of video analysis for concussion surveillance in Australian football.
The reliability and validity of video analysis for the assessment of clinical signs of concussion in Australian football. Michael Makdissi and Gavin Davis. Journal of Science and Medicine in Sport. DOI 10.1016/j.jsams.2016.02.015. (2016)
The objective of this study was to determine the reliability and validity of identifying clinical signs of concussion using video analysis in Australian football.
Prospective cohort study.
All impacts and collisions potentially resulting in a concussion were identified during 2012 and 2013 Australian Football League seasons. Consensus definitions were developed for clinical signs associated with concussion. For intra- and inter-rater reliability analysis, two experienced clinicians independently assessed 102 randomly selected videos on two occasions. Sensitivity, specificity, positive and negative predictive values were calculated based on the diagnosis provided by team medical staff.
212 incidents resulting in possible concussion were identified in 414 Australian Football League games. The intra-rater reliability of the video-based identification of signs associated with concussion was good to excellent. Inter-rater reliability was good to excellent for impact seizure, slow to get up, motor incoordination, ragdoll appearance (2 of 4 analyses), clutching at head and facial injury. Inter-rater reliability for loss of responsiveness and blank and vacant look was only fair and did not reach statistical significance. The feature with the highest sensitivity was slow to get up (87%), but this sign had a low specificity (19%). Other video signs had a high specificity but low sensitivity. Blank and vacant look (100%) and motor incoordination (81%) had the highest positive predictive value.
Video analysis may be a useful adjunct to the side-line assessment of a possible concussion. Video analysis however should not replace the need for a thorough multimodal clinical assessment.
Use of video to facilitate sideline concussion diagnosis and management decision-making. Gavin Davis and Michael Makdissi. Journal of Science and Medicine in Sport. DOI 10.1016/j.jsams.2016.02.005 (2016)
Video analysis can provide critical information to improve diagnostic accuracy and speed of clinical decision-making in potential cases of concussion. The objective of this study was to validate a hierarchical flowchart for the assessment of video signs of concussion, and to determine whether its implementation could improve the process of game day video assessment.
Prospective cohort study
All impacts and collisions potentially resulting in a concussion were identified during 2012 and 2013 Australian Football League (AFL) seasons. Consensus definitions were developed for clinical signs associated with concussion. A hierarchical flowchart was developed based on the reliability and validity of the video signs of concussion. Ninety videos were assessed, with 45 incidents of clinically confirmed concussion, and 45 cases where no concussion was sustained. Each video was examined using the hierarchical flowchart, and a single response was given for each video based on the highest-ranking element in the flowchart.
No protective action, impact seizure, motor incoordination, or blank/vacant look were the highest ranked video signs in almost half of the clinically confirmed concussions, but in only 8.8% of non-concussed individuals. The presence of facial injury, clutching at the head and slow to get up were the highest ranked sign in 77.7% of non-concussed individuals.
This study suggests that the implementation of a flowchart model could improve timely assessment of concussion, and it identifies the video signs that should trigger automatic removal from play.
Protocol for a prospective,longitudinal,cohort study of post-concussive symptoms in children:the TakeC.A.Re (Concussion Assessment and Recovery Research) study.Silvia Bressan, Michael Takagi, Franz E Babl, Gavin A Davis, Ed Oakley, Kevin Dunne, Cathriona Clarke, Melissa Doyle, Stephen Hearps, Vera Ignjatovic, Marc Seal, Vicki Anderson. BMJ Open. 2016;doi:10.1136/bmjopen-2015-009427
Introduction: A substantial minority of children who sustain a concussion suffer prolonged postconcussive symptoms. These symptoms can persist for more than 1 month postinjury and include physical, cognitive, behavioural and emotional changes. Those
affected can develop significant disability, diminishing their quality of life. The precise prevalence of postconcussive symptoms following child concussion is unclear, with heterogeneous and at times conflicting results published regarding factors that predict children at risk for developing long-lasting postconcussive symptoms. The aim of the Take C.A.Re (Concussion Assessment and Recovery Research) study is to provide an in-depth multidimensional description
of the postconcussive recovery trajectories from a physical, neurocognitive and psychosocial
perspective in the 3 months following concussion, with a focus on the early postconcussive period, and identification of factors associated with prolonged recovery.
Methods and analysis: Take C.A.Re is a prospective, longitudinal study at a tertiary children’s hospital, recruiting and assessing patients aged 5– <18 years who present to the emergency department with a concussion and following them at 1–4 days,
2 weeks, 1 month and 3 months postinjury. Multiple domains are assessed: postconcussive symptoms, balance and coordination, neurocognition, behaviour, quality of life, fatigue, post-traumatic stress symptoms, parental distress and family burden. ‘Delayed recovery’ is operationalised as the presence of ≥3 symptoms on the Post Concussive Symptoms Inventory rated as worse compared with baseline. Main analyses comprise analysis of variance (recovery trajectories, delayed vs normal recovery groups) and regression analyses of predictors of recovery (preinjury, acute and family factors).
Ethics and dissemination: Ethical approval has been obtained through the Royal Children’s Hospital Melbourne Human Research Ethics Committee (33122). We aim to disseminate the findings through international conferences, international peer-reviewed journals and social media.
Trial registration number: ACTRN12615000316505.
Cognitive and physical symptoms of concussive injury in children: a detailed longitudinal recovery study. Louise Crowe, Alex Collie, Stephen Hearps, Julian Dooley, Helen Clausen, David Maddocks, Paul McCrory, Gavin Davis, Vicki Anderson. Br J Sports Med doi:10.1136/bjsports- 2015-094663
HeadCheck - a concussion app. Gavin A Davis, Sarva Thurairatnam, Paula Feleggakis, Vicki Anderson, Silvia Bressan, Franz E Babl. Journal of Paediatrics and Child Health. 51 (2015) 830–831.
In a collaboration of child concussion experts at the Murdoch Childrens Research Institute (MCRI), the Royal Children’s Hospital and the University of Melbourne, along with Curve Tomorrow, a software development and design company with expertise in the child health sector, a smartphone app, HeadCheck, was developed to help adults recognise the signs and symptoms of concussion in children. Although the primary focus of the app was for use in school-aged children and adolescents, the app is sufficiently robust for use in adult players as well. HeadCheck dynamically guides users through a series of concise questions to quickly assist in recognising symptoms of concussion (Figure 1). The HeadCheck algorithm prioritises the information the user needs to understand, ensuring logical steps are followed in a potentially stressful situation. Depending on the severity of the individual’s symptoms, the app may automatically re-direct the user to call the Australian emergency services phone number, ‘000’.
Neurodegeneration and Sport. Gavin A. Davis, Rudolph J. Castellani, Paul McCrory. Neurosurgery. 76: 643-656, 2015
The recent interest in concussion in sport has resulted in significant media focus about chronic traumatic encephalopathy (CTE), although a direct causative link(s) between concussion and CTE is not established. Typically, sport-related CTE occurs in a retired athlete with or without a history of concussion(s) who presents with a constellation of cognitive, mood, and/or behavioral symptoms and who has postmortem findings of tau deposition within the brain. There are many confounding variables, however, that can account for brain tau deposition, including genetic mutations, drugs, normal aging, environmental factors, postmortem brain processing, and toxins. To understand the roles of such factors in neurodegenerative diseases that may occur in athletes, this article reviews some neurodegenerative diseases that may present with similar findings in nonathletes. The article also reviews pathological changes identified with normal aging, and reviews the pathological findings of CTE in light of all these factors. While many of these athletes have a history of exposure to head impacts as a part of contact sport, there is insufficient evidence to establish causation between sports concussion and CTE. It is likely that many of the cases with neuropathological findings represent the normal aging process, the effects of opiate abuse, or a variant of frontotemporal lobar degeneration. Whether particular genetic causes may place athletes at greater risk of neurodegenerative disease is yet to be determined.
Developmental trajectory of information processing skills in children: computer-based assessment. Jacqueline Williams, Louise M. Crowe, Julian Dooley, Alex Collie, Gavin Davis, Paul McCrory, Helen Clausen, David Maddocks, & Vicki Anderson. Applied Neuropsychology: Child. DOI: 10.1080/21622965.2014.939271, 2015
There are significant merits to a comprehensive cognitive assessment but they are also time consuming, costly, susceptible to practice effects and may not detect change in the context of medical interventions or minor brain disruptions. Brief computer-based assessments focused on ‘fluid’ cognitive domains (e.g., information processing skills), which are vulnerable to disruption as a result of a brain injury, may provide an alternative assessment option. This study sought to: i) examine the utility of a well-established, adult-based, computerized tool, CogSport for Kids (CogState®), for evaluating information processing skills in children and adolescents; and ii) to report normative data for healthy children and adolescents. The study was a cross-sectional, community based observational study of typically developing children aged 9-17 years (N=832). Participants completed the CogSport for Kids test battery, which comprises six brief computerized tasks that assess cognitive functions including processing speed, attention and working memory. Results showed an improvement with age for response speed and accuracy. Greatest change occurred between 9 and 12 years with performance stabilizing at 15 years. This brief screening tool is appropriate for clinical and research use in children from 9 years of age, and may be used to track cognitive development from childhood into adulthood, and to identify children who deviate from normal expectations.
Translating guidelines for the diagnosis and management of sports-related concussion into practice. Alex Donaldson, Joshua Newton, Paul McCrory, Peta White, Gavin Davis, Michael Makdissi, Caroline F Finch. Am J Lifestyle Med. doi: 10.1177/1559827614538751
Sports injuries are a significant clinical and public health concern. There is a growing call to improve the translation of available evidence-based and expert- informed sports injury prevention interventions into sustained use in practice by physicians and others (eg, athletic trainers, coaches, and parents) who care for injured athletes. This article provides a brief overview of the current sport injury prevention implementation literature before focusing specifically on the translation of guidelines (including consensus and position statements) developed to assist physicians and others diagnose and manage athletes with sport-related concussion and the associated return-to-play decisions. The outcomes of more than 20 published studies indicate that physician, athletic trainer, coach, parent, and athlete knowledge, use of, and compliance with sport-related concussion guidelines are limited. More concerted, coordinated, and theory-informed efforts are required to facilitate the widespread dissemination, translation, and implementation of such guidelines. An example is provided of how implementation drivers could be used to inform the development of a comprehensive, multilevel implementation strategy targeting the individual, organizational, and system-level changes necessary to support the translation of available sport-related concussion guidelines in both the clinical and sports settings.
Updated guidelines for the management of sports-related concussion in general practice. Michael Makdissi, Gavin Davis, Paul McCrory. Australian Family Physician. 2014; 43(3):94-99.
Concussion is common in many sports and recreational activities. It is thought to reflect a functional rather than structural injury to the brain. The clinical features are typically short-lived and usually resolve spontaneously. Complications, however, can occur and may include prolonged symptoms and/or cognitive deficits in the short term, as well as depression and cumulative deterioration in brain function in the longer term.
This article will provide an updated clinical review of concussion in sport, with an emphasis on assessment and management in general practice.
The critical issues in the clinical management of concussion in sport include making a diagnosis, differentiating between concussion and other pathologies (particularly structural head injury), recognising the presence of any modifying factors (which may increase the risk of complications) and determining when the patient can safely return to competition. The key components of safe return-to-play decisions include rest, neuropsychological testing and a graded program of exertion before return to sport.
Intention to use sport concussion guidelines among community-level coaches and sports trainers. Joshua D. Newton, Peta E. White, Michael T. Ewing, Michael Makdissi, Gavin A. Davis, Alex Donaldson, S. John Sullivan, Hugh Seward, & Caroline F. Finch. Journal of Science and Medicine in Sport. 2014; 17: 469-473.
Sporting bodies have developed guidelines for managing community-level players with suspected concussion in response to international consensus statements on concussion in sport. The purpose of this study was to examine the factors that influence the intended use of concussion guidelines among community-level coaches and sports trainers from two popular football codes in Australia: Australian football and rugby league.
The survey, based on an extended theory of planned behaviour model, was completed by 183 Australian football coaches, 121 Australian football sports trainers, 171 rugby league coaches, and 142 rugby league sports trainers.
Personal norms and self-efficacy were significant predictors of intention to use concussion guidelines, although the relationship between self-efficacy and intention was stronger among Australian football coaches than rugby league coaches. Analysis of the salient beliefs that underpin self-efficacy found that coaches, irrespective of football code, felt less familiar (χ2 = 25.70, p < 0.001) and less experienced (χ2 = 31.56, p < 0.001) than sports trainers in using the concussion guidelines. At the same time, Australian football personnel, irrespective of their team role, felt that they had insufficient time (χ2 = 8.04, p < 0.01) and resources (χ2 = 12.31, p < 0.001) to implement the concussion guidelines relative to rugby league personnel.
Programmes aimed at increasing the intended use of sport concussion guidelines should focus on enhancing self-efficacy and leveraging personal norms. Increasing coaches’ familiarity and experience in using the concussion guidelines would also be warranted, as would finding ways to overcome the perceived time and resource constraints identified among Australian football personnel.
Knowledge about sports-related concussion: Is the message getting through to coaches and trainers? Br J Sports Med doi:10.1136/bjsports-2013-092785 Peta E White, Joshua D. Newton, Michael Makdissi, S. John Sullivan, Gavin Davis, Paul McCrory, Alex Donaldson, Michael T. Ewing, Caroline F Finch
Aim The need for accurate diagnosis and appropriate return-to-play decisions following a concussion in sports has prompted the dissemination of guidelines to assist managing this condition. This study aimed to assess whether key messages within these guidelines are reflected in the knowledge of coaches and sports trainers involved in community sport.
Methods An online knowledge survey was widely promoted across Australia in May–August 2012 targeting community Australian Football (AF) and Rugby League (RL) coaches and sports trainers. 260 AF coaches, 161 AF sports trainers, 267 RL coaches and 228 RL sports trainers completed the survey. Knowledge scores were constructed from Likert scales and compared across football codes and respondent groups.
Results General concussion knowledge did not differ across codes but sports trainers had higher levels than did coaches. There were no significant differences in either concussion symptoms or concussion management knowledge across codes or team roles. Over 90% of respondents correctly identified five of the eight key signs or symptoms of concussion. Fewer than 50% recognised the increased risk of another concussion following an initial concussion. Most incorrectly believed or were uncertain that scans typically show damage to the brain after a concussion occurs. Fewer than 25% recognised, and >40% were uncertain that younger players typically take longer to recover from concussion than adults.
Conclusions The key messages from published concussion management guidelines have not reached community sports coaches and sports trainers. This needs to be redressed to maximise the safety of all of those involved in community sport.
Prevalence of adjacent segment disc degeneration in patients undergoing anterior cervical discectomy and fusion based on pre-operative MRI findings. KM Lundine, G Davis, M Rogers, M Staples, G Quan. J Clin Neurosci 2014 Jan;21(1):82-5
The evaluation and management of acute concussion differs in young children. Gavin A Davis, Laura K Purcell. British Journal of Sports Medicine. ￼￼2014;48:98–101.
Evidence-based approach to revising the SCAT2: introducing the SCAT3 Kevin M Guskiewicz, Johna Register-Mihalik, Paul McCrory, Michael McCrea, Karen Johnston, Michael Makdissi, Jiří Dvořák, Gavin Davis, Willem Meeuwisse. Br J Sports Med 2013;47:289–293.
The Sport Concussion Assessment Tool 2 (SCAT2), which evolved from the 2008 Concussion in Sport Group (CISG) Consensus meeting, has been widely used internationally for the past 4 years. Although the instrument is considered very practical and moderately effective for use by clinicians who manage concussion, the utility and sensitivity of a 100-point scoring system for the SCAT2 has been questioned. The 2012 CISG Consensus Meeting provided an opportunity for several of the world’s leading concussion researchers and clinicians to present data and to share experiences using the SCAT2. The purpose of this report is to consider recommendations by the CISG, and to review the current literature to identify the most sensitive and reliable concussion assessment components for inclusion in a revised version—the SCAT3. Through this process, it was determined that important clinical information can be ascertained in a streamlined manner through the use of a multimodal instrument such as the SCAT3. This test battery should include an initial assessment of injury severity using the Glasgow Coma Scale, immediately followed by observing and documenting concussion signs. Once this is complete, symptom endorsement and symptom severity, neurocognitive function and balance function should be assessed in any athlete suspected of sustaining a concussion. There is no evidence to support the use of a composite/total score; however, there is good evidence to support the use of each component (scored independently) in a revised assessment tool.
What evidence exists for new strategies or technologies in the diagnosis of sports concussion and assessment of recovery? Jeffrey Scott Kutcher, Paul McCrory, Gavin Davis, Alain Ptito, Willem H Meeuwisse, Steven P Broglio. Br J Sports Med 2013;47:299–303.
Revisiting the modifiers: how should the evaluation and management of acute concussions differ in specific groups? Michael Makdissi, Gavin Davis, Barry Jordan, Jon Patricios, Laura Purcell, Margot Putukian. Br J Sports Med 2013;47: 314–320.
Consensus statement on concussion in sport: the 4th International Conference on Concussion in Sport held in Zurich, November 2012 - Br J Sports Med 2013;47:250–258.
Paul McCrory, Willem H Meeuwisse, Mark Aubry, Bob Cantu, Jiří Dvořák, Ruben J Echemendia, Lars Engebretsen, Karen Johnston, Jeffrey S Kutcher, Martin Raftery, Allen Sills, Brian W Benson, Gavin A Davis, Richard G Ellenbogen, Kevin Guskiewicz, Stanley A Herring, Grant L Iverson, Barry D Jordan, James Kissick, Michael McCrea, Andrew S McIntosh, David Maddocks, Michael Makdissi, Laura Purcell, Margot Putukian, Kathryn Schneider, Charles H Tator, Michael Turner
Br J Sports Med 2013;47:250–258.
To view the statement in full, click here
Practical Management of Head and Neck Injury (Published 2012)
Practical Management of Head and Neck Injury is a unique textbook which comprehensively covers the patient journey from injury to the rehabilitation phase. It includes diagnosis and management of head and neck injury with additional chapters on prognosis and special conditions including head injury in sport, the elderly, children, pregnant women, penetrating head injury, spine and spinal cord injury and brain death. It describes an integrated approach to care from all the relevant specialties with Australian, UK and US experts contributing to many chapters.
Table of Contents
Chapter 1: Epidemiology
Chapter 2: Anatomy
Chapter 3: Pathophysiology of traumatic brain injury
Chapter 4: Pre-hospital management
Chapter 5: Emergency room management
Chapter 6: Spine injury
Chapter 7: Vascular injury
Chapter 8: Operative surgery
Chapter 9: Intensive care management of head injury
Chapter 10: Ward care of the head-injured patient
Chapter 11: Rehabilitation of head injury patients: issues in rehabilitation following traumatic brain injury
Chapter 12: Head injury in children
Chapter 13: Head injury in the elderly
Chapter 14: Head injury in sport - Gavin A Davis, Michael Makdissi, Paul McCrory
Chapter 15: Pentrating head injury
Chapter 16: Bleeding diathesis and anticoagulants
Chapter 17: Neurotrauma in pregnancy
Chapter 18: Brain death
Chapter 19: Prolonged post coma unresponsiveness (the persistent vegetative state) and minimally responsive state post head injury
Chapter 20: Prediction of outcome and the prognosis of head injury
Chapter 21: Prevention of head injury and trauma systems
Appendices, including evidence-based guidelines
Mild Traumatic Brain Injury in Children and Adolescents From Basic Science to Clinical Management Edited by Michael W. Kirkwood and Keith Owen Yeates (published 2012)
A cutting-edge synthesis of science and practice, this book covers everything from sports-related concussions to less common types of mild traumatic brain injury (mTBI) and related complications. Preeminent authorities review what is known about mTBI in childhood and adolescence—including its biomechanics, pathophysiology, and neurological and neurobehavioral outcomes—and showcase evidence-based clinical evaluation tools and management strategies. Challenging areas such as evaluating complicated mTBI and treating persistent problems after injury are discussed in detail. Also addressed are forensic issues, injury in very early childhood, and other special-interest topics.
Table of Contents:
1. History, Diagnostic Considerations, and Controversies, Elisabeth A. Wilde, Stephen R. McCauley, Gerri Hanten, Gunes Avci, Alyssa P. Ibarra, and Harvey S. Levin
2. Epidemiology and Prevention, R. Dawn Comstock and Kelsey Logan
3. Biomechanics of Sports Concussion, Jason P. Mihalik
4. Animal Models, Andre Obenaus, Lei Huang, Jacqueline S. Coats, Richard Hartman, Jerome Badaut, and Stephen Ashwal
II. Evidence-Based Outcomes
5. Pathophysiological Outcomes, Talin Babikian, John DiFiori, and Christopher C. Giza
6. Neurological Outcomes, Gavin A. Davis
7. Neurobehavioral Outcomes, Keith Owen Yeates and H. Gerry Taylor
III. Clinical Evaluation
8. Biochemical Markers, Rachel P. Berger and Noel Zuckerbraun
9. Neuroimaging, Stephen Ashwal, Karen A. Tong, Brenda Bartnik-Olson, and Barbara A. Holshouser
10. Physical and Neurological Exam, Joseph A. Grubenhoff and Aaron Provance
11. Balance Testing, Tamara C. Valovich McLeod and Kevin M. Guskiewicz
12. Postconcussion Symptom Assessment, Jennifer A. Janusz, Maegan D. Sady, and Gerard A. Gioia
13. Cognitive Screening and Neuropsychological Assessment, Doug Bodin and Nicole Shay
IV. Clinical Intervention
14. Active Rehabilitation for Slow-to-Recover Children, Grant L. Iverson, Isabelle Gagnon, and Grace S. Griesbach
15. Medical and Pain Management, Pamela E. Wilson and Gerald H. Clayton
16. School-Based Management, John W. Kirk, Beth Slomine, and Jeanne E. Dise-Lewis
V. Topics of Special Interest
17. Sport-Related Concussion, Michael W. Kirkwood, Christopher Randolph, Michael McCrea, James P. Kelly, and Keith Owen Yeates
18. Injury in Preschool-Age Children, Audrey McKinlay
19. Forensic Considerations, Jacobus Donders
Brukner & Khan's Clinical Sports Medicine 4th Edition (published 2012)
The bible of sports medicine. It covers all aspects of diagnosis and management of sports related injuries
Brukner and Khan's Clinical Sports Medicine is the bible of sports medicine. The text explores all aspects of diagnosis and management of sports-related injuries and physical activity such as the fundamental principles of sports medicine, diagnosis and treatment of sports injuries, enhancement of sports performance and dealing with special groups of participants. Each chapter has been comprehensively reviewed and updated and there are 12 new chapters which cover topics such as military medicine, prevention of sudden cardiac death and the integration of evidence into clinical practice. The contributing authors are renowned experts in their field and are based all around the world.
Chapter 17 - Sports Concussion
Paul McCrory, Gavin Davis, Michael Makdissi and Michael Turner
Second Impact Syndrome or Cerebral Swelling after Sporting Head Injury. Paul McCrory, Gavin Davis, and Michael Makdissi. Current Sports Medicine Reports. 11(1) January/February 2012; 21-23
Second impact syndrome is believed to be the catastrophic consequence of repeated head injury in sport. The scientific evidence to support this concept is nonexistent, and belief in the syndrome is based upon the interpretation of anecdotal cases more often than not, lacking sufficient clinical detail to make definitive statements. The fear of this condition has driven many of the current return-to-play guidelines following concussion. Diffuse cerebral swelling (DCS) following a head injury is a well-recognized condition, more common in children than in adults, and usually has a poor outcome.
Concussion in Sport. Makidissi M, Davis G, McCrory P. MedicineToday 2011; 12(7): 75-82
Head trauma is a common occurrence in many sports and recreational pursuits. Recent figures from the USA estimate approximately 1.6 to 3.8 million cases of sports- and recreation-related head injury each year. In Australia, common participation sports such as Australian rules football, rugby league and rugby union have high rates of head injury. The reported incidence of concussion in these sports is in excess of five concussive injuries per 1000 player hours, which equates to over five concussions per team per season. Over the past eight years, three conferences have been held in which the world leading experts have addressed key issues in the understanding and management of concussion in sport. Following each of these meetings, a summary and agreement statement have been published with an aim to ‘improve the safety and health of athletes who suffer concussive injuries during participation in sport’. The most recent conference was held in Zurich, Switzerland, in November 2008. The consensus statement produced from this meeting provides the most up-to-date knowledge on concussion in sport, and outlines the current best practice management guidelines. This article aims to provide an overview of the key concepts arising from the conferences on concussion in sport, including an understanding of the injury, an outline of potential risks and an overview of current management guidelines.
Tibial intraneural ganglia at the ankle and knee: incorporating the unified (articular) theory in adults and children. Davis GA, Cox IH. Journal of Neurosurgery. 2010 April; DOI: 10.3171/2010.3.JNS10427
OBJECT: The etiology of intraneural ganglia has been debated for centuries, and only recently a unifying theory has been proposed. The incidence of tibial nerve intraneural ganglia is restricted to the occasional case report, and there are no reported cases of these lesions in children. While evidence of the unifying theory for intraneural ganglia of the common peroneal nerve is strong, there are only a few reports describing the application of the theory in the tibial nerve. In this report the authors examine tibial nerve intraneural ganglia at the ankle and knee in an adult and a child, respectively, and describe the clinical utility of incorporating the unifying (articular) theory in the management of tibial intraneural ganglia in adults and children.
METHODS: Cases of tibial intraneural ganglion cysts were examined clinically, radiologically, operatively, and histologically to demonstrate the application of the unified (articular) theory for the development of these cysts in adults and children.
RESULTS: Two patients with intraneural ganglion cysts of the tibial nerve were identified: an adult with an intraneural ganglion cyst of the tibial nerve at the tarsal tunnel and a child with an intraneural ganglion cyst of the tibial nerve at the knee. In each case, preoperative MR imaging demonstrated the intraneural cyst and its connection to the adjacent joint via the articular branch to the subtalar joint and superior tibiofibular joint. At surgery the articular branch was identified and resected, thus disconnecting the tibial nerve intraneural cyst from the joint of origin.
CONCLUSIONS: These cases detail the important features of intraneural ganglion cysts of the tibial nerve and document the clinical utility of incorporating the unifying (articular) theory for the surgical management of tibial intraneural ganglia in adults and children.
Consensus Statement on Concussion in Sport – the 3rd International Conference on Concussion in Sport held in Zurich, November 2008. British J Sports Medicine. 2009;43;i76-i84
Sphenoid Wing Lesion. Journal of Clinical Neuroscience. Lam K, Davis GA, Fitt G, Kalnins R. :2010 May;17(5):606, 677.
Sphenoid wing lesion.
Lam K, Fitt G, Kalnins R, Davis G.
Department of Neurosurgery, Austin Hospital, 145 Studley Road, Heidelberg, Victoria 3084, Australia.
Contributions of Neuroimaging, Balance Testing, Electrophysiology, and Blood Markers to the Assessment of Sport-Related Concussion. Davis GA, Iverson GL, Guskiewicz KM, Ptito A, Johnston KM. British J Sports Medicine. 2009; 43 (Suppl_1): i36-i45.
Objective: To review the diagnostic tests and investigations used in the management of sports concussion, in the adult and paediatric populations, to (a) monitor the severity of symptoms and deficits, (b) track recovery and (c) advance knowledge relating to the natural history and neurobiology of the injury.
Design: Qualitative literature review of the neuroimaging, balance testing, electrophysiology, blood marker and concussion literature.
Intervention: PubMed and Medline databases were reviewed for investigations used in the management of adult and paediatric concussion, including structural imaging (computerised tomography, magnetic resonance imaging, diffusion tensor imaging), functional imaging (single photon emission computerised tomography, positron emission tomography, functional magnetic resonance imaging), spectroscopy (magnetic resonance spectroscopy, near infrared spectroscopy), balance testing (Balance Error Scoring System, Sensory Organization Test, gait testing, virtual reality), electrophysiological tests (electroencephalography, evoked potentials, event related potentials, magnetoencephalography, heart rate variability), genetics (apolipoprotein E4, channelopathies) and blood markers (S100, neuron-specific enolase, cleaved Tau protein, glutamate).
Results: For the adult and paediatric populations, each test has been classified as being: (1) clinically useful, (2) a research tool only or (3) not useful in sports-related concussion.
Conclusions: The current status of the diagnostic tests and investigations is analysed, and potential directions for future research are provided. Currently, all tests and investigations, with the exception of clinical balance testing, remain experimental. There is accumulating research, however, that shows promise for the future clinical application of functional magnetic resonance imaging in sport concussion assessment and management.
Clinics in Neurology and Neurosurgery of Sport - Asymptomatic cervical canal stenosis and transient quadraparesis. Davis G, Ugokwe K, Roger E, Benzel E, Cantu R, Rogers M, Dvorak J, McCrory P. British Journal of Sports Medicine. 2009; 43:1154-1158.
The cervical spine is a relatively mobile structure commencing at the base of the skull and finishing at the relatively immobile thoracic spine. The cervical spinal cord and the paired vertebral arteries are critical occupants of the cervical spine, and injury to these structures results in catastrophic quadriplegia (spinal cord injury) or stroke (vertebral artery injury). Trauma to the neck is not uncommon in sport, but only rarely results in neurovascular injury or significant spinal instability. Every physician or trainer entrusted with the care of athletes’ fears that the next neck injury seen may be a catastrophic one and endeavours to seek every opportunity possible to prevent such disaster. The question is: which athletes are at risk? Is asymptomatic spinal canal stenosis a risk factor for spinal cord injury and does an episode of transient quadriparesis predispose an athlete to the development of catastrophic spinal cord injury?
Case study: patient 1
A 26-year-old male footballer sustains a concussion with loss of consciousness lasting 30 seconds. He makes a full recovery, but as a precaution is taken to the local hospital emergency department. He is examined and found to be neurologically intact. A CT scan of the brain is reported as normal. Plain radiographs of the cervical spine suggest narrowing of the spinal canal with a Torg–Pavlov ratio of 0.76 (normal >0.8) measured at C3 ( fig 1 ). Flexion extension radiography of the cervical spine is performed, with no evidence of instability. The managing team physician refers the patient to you for expert opinion.
What recommendations do you make, based on the following considerations?
1. Given that the patient is asymptomatic with respect to the cervical spine and based on these findings, will you allow him to return …
Clinics in Neurology and Neurosurgery of Sport - Benign Brain Tumors. Davis G, Marion D, George B, Le Roux P, Laws E, McCrory P. British Journal of Sports Medicine. 2009; 43:619-622
When athletes are investigated for acute neurological symptoms a brain scan may reveal a tumour or mass lesion. Occasionally, these are incidental findings. The location of the tumour in the brain will critically affect its clinical presentation. A tumour compressing the optic nerve will result in visual loss, a tumour obstructing the cerebral aqueduct will cause hydrocephalus, and a tumour in the hippocampus may cause epilepsy.
The biology of the tumour determines its growth propensity and aggressiveness. Although tectal plate glioma and glioblastoma multiforme are both classified as astrocytomas, the behaviour of each is completely different. A tectal plate i glioma is a very slow-growing, indolent lesion, often remaining stable for many years without the requirement for any treatment, whereas a glioblastoma multiforme is aggressive and invasive, and can grow rapidly within a few weeks. Similarly, the classification of meningiomas includes tumours with a broad spectrum of clinical behaviour. A benign convexity meningioma grows very slowly and is cured with complete resection, whereas a skull base meningioma can invade bone, brain, vascular and neural structures. Tumour biology also affects the brain’s reaction to the tumour, such as the development of cerebral oedema surrounding the lesion.
Treatment of tumours takes these and other factors into account, including patient age and functional level, comorbidity, neurological deficits and seizures. Depending on the tumour type, location and clinical presentation, treatment options include any combination of surgical resection, radiosurgery, radiotherapy, chemotherapy, and treatment of associated phenomena such as hydrocephalus and seizures.
The athlete with a high-grade aggressive tumour with pronounced neurological deficit is unlikely to return to elite sport, but a sportsman with an incidental benign brain tumour will probably want to return and may be able to do so. This forum is inappropriate for a detailed discussion of the management of all brain tumours, …
Clinics in Neurology and Neurosurgery of Sport - Cervical Disc Prolapse. Davis G, Dvorak J, Hamlyn P, Sears W, McCrory P. British Journal of Sports Medicine. 2009; 43:455-459.
A cervical intervertebral disc can prolapse (hernia or rupture) asymptomatically or may produce neck pain, nerve root compression (radiculopathy) or spinal cord compression (myelopathy). Surgery is indicated in cases of cervical myelopathy. In cases of symptomatic cervical radiculopathy, surgery is indicated in cases that fail to respond to conservative treatment. Surgical approaches to the cervical spine are usually anterior or posterior. Currently, anterior cervical discectomy is the most common procedure used. This may be performed alone or with the addition of fusion (insertion of a bone graft) and with or without instrumentation (an intervertebral prosthesis or use of plates or screws). An alternative to fusion (arthrodesis) is a disc replacement (arthroplasty). There is extensive debate among spinal surgeons as to the most appropriate technique, and as the literature lacks absolute clarity regarding the superiority of one technique over another, most spinal surgeons use the technique that works well in their hands.
CASE STUDY: POSTACCIDENT SURGERY FOR SINGLE LEVEL DISC
A 25-year-old professional soccer player is involved in a motor vehicle crash, sustaining an acute C6–7 disc prolapse with radiculopathy ( figs 1 and 2 ). He undergoes C6–7 anterior cervical discectomy and fusion. Postoperatively he is neurologically intact. Three months have now passed and you are asked to provide your expert opinion. What recommendations do you make, based on the following considerations?
1. Can the patient return to play?
2. If so, when? Do you place any restrictions on him and is there any further follow-up that you require?
3. If you determine that he may not return to play, please explain your reasons for this) If you review him 12 months after surgery and plain x-ray of the cervical spine shows solid fusion, with stable flexion extension x-rays of the cervical spine, would this alter your decision? Are there any other factors that would alter your decision?
Clinics in Neurology and Neurosurgery of Sport - Traumatic cerebral contusion. Davis G, Marion D, George B, Hamel O, Turner M, McCrory P. British Journal of Sports Medicine. 2009; 43:451-454.
This case highlights the difficulties encountered in managing a sports player with traumatic brain injury. Fortunately, most head injuries in sport are minor and recover completely. Although the consensus definition 1 of sports concussion emphasizes the lack of structural brain injury, this is not the case with more severe injuries.
The presence of acute abnormalities (eg, contusion, haemorrhage) on CT or MRI scans in such patients inherently pushes the nature and consequences of the injury higher up the spectrum of traumatic brain injury and standard sports concussion management guidelines may no longer apply.
The case described is one of mild TBI and not simple concussion. However, many elements of the management are common to both conditions, and for the sake of simplicity, we will accept, as have the faculty, that this is a case of concussion with a cerebral contusion.
CASE STUDIES: FRONTAL CONTUSION
A 26 year-old professional ice hockey player was celebrating his team’s victory at a local nightclub. He was hit over the head with a beer bottle and lost consciousness for 3 minutes. In the emergency department, he had neurologically fully recovered. His scalp laceration was sutured and a CT scan of the brain was performed, revealing a small frontal contusion. There was no associated skull fracture and the CT scan was otherwise unremarkable. He was advised to rest for 6 weeks and then underwent formal neurological and neuropsychological testing, which were normal. Repeat CT scan of the brain showed complete resolution of the contusion ( fig 1 ). What recommendations do you make, based on the following considerations?
(1) Can he return to ice hockey?
1. If so, when?
2. Are there any extra precautions you would take when he returns to competition?
3. If he sustains a …
Clinics in Neurology and Neurosurgery of Sport - Extradural and subdural haematoma. Davis G, Marion DW, Le Roux P, Laws E, McCrory P. British Journal of Sports Medicine. Jun 2008; doi:10.1136/bjsm.2008.048215
Although concussion is the most common type of brain injury seen in athletes, there is always the possibility that head impact may cause a more severe structural brain injury. This is a complication that is feared by all sports physicians and others involved in athletic care.
Acute subdural haematoma (ASDH) results from traumatic laceration to the brain, from bleeding from the cortical vessels into the subdural space or from acceleration–deceleration injury to the head that causes tearing of the bridging veins, resulting in clot formation in the subdural space between the arachnoid and dural meningeal layers. A subdural haematoma is often associated with some underlying parenchymal (brain) injury, including diffuse axonal injury. In contrast, extradural haematoma usually results from a skull fracture causing damage to a meningeal artery, which is situated between the dura and the skull. Classically, there is no significant parenchymal injury in extradural haematoma.
Subdural and extradural haematomas are distinct clinical entities that share some common elements in sports medicine yet also have certain individual peculiarities that are important in return-to-sports decision making.
Case 1: subdural haematoma
A 31-year-old professional boxer has won all 26 fights he has contested. He sustained a small subdural haematoma in a fight he won ( fig 1 ). There was mild mass effect from the subdural haematoma, and it was observed with serial CT scans, without the requirement for surgical drainage. Spontaneous resolution of the subdural collection was noted on a repeat CT scan at 6 weeks. It is now 1 year later, and he has a normal neurological examination and formal neuropsychological testing is normal. The result of his brain MRI scan is also normal (including magnetic resonance venogram (MRV) and magnetic resonance angiogram (MRA) sequences).
What are …
Clinics in Neurology and Neurosurgery of Sport - Lumbar spine - sequestrated disc prolapse and disc bulge. Davis G, Johnson E, McCormick P, Roger E, Ugokwe K, Benzel E, Sears W, McCrory P. British Journal of Sports Medicine. 2009; 43:796-801.
Focal degenerative disc disease in the lumbar spine is broadly categorized into three clinical types: (1) asymptomatic disc degeneration, (2) degenerative disc disease resulting in low back pain (LBP) and (3) focal disc prolapse resulting in compression of the spinal nerve root producing the clinical picture of radiculopathy or sciatica. Whenever possible, non-surgical management is the favoured option, but when persistent nerve root compression does not respond to conservative measures, surgical decompression of the nerve root is required. A variety of operative procedures and approaches exists to deal with focal disc prolapse. Such procedures include open discectomy, microdiscectomy and endoscopic percutaneous discectomy. In some situations, in addition to discectomy, a vertebral fusion procedure is also required.
Although the fine details of surgical technique are beyond the scope of this paper, two cases have been selected for discussion because they represent common clinical scenarios encountered by the spinal surgeon, but there is limited published information specific to the athlete with such an injury. We have therefore addressed the issues specific to return to sport rather than focus on the myriad surgical procedures that can be performed on the lumbar spine.
Case study: patient 1. Lumbar: sequestrated disc prolapse
A 29-year-old American footballer was tackled to the ground and instantly felt a “twinge” in his lower back. He got up from his fall, and over the next few hours the pain intensified and then radiated into his right thigh, calf and foot. Treatment over the following 4 weeks included physiotherapy, acupuncture, non-steroidal anti-inflammatory medication, and hydrotherapy. The leg pain intensified and MRI of the lumbar spine showed a right L5–S1 sequestrated disc prolapse ( figs 1 and 2 ). A microdiscectomy was performed, with complete resolution of pain. He was discharged from hospital the day after surgery and has remained free of pain. You review him 6 weeks postoperatively and he is …
Clinics in Neurology and Neurosurgery of Sport - Mass lesions: Cavernoma. Davis G, Fabinyi G, Le Roux P, McCrory P. British Journal of Sports Medicine. 2009; 43:866-868.
The advent of widespread access to MR scanning has meant that a wide spectrum of incidental findings are now detected and referred for advice and management. Although cavernous haemangiomas (or cavernomas) are one of the most common types of benign vascular malformations, their precise incidence is unknown. They can occur as single or multiple lesions and provide a real dilemma for an athlete who wishes to participate in contact sports. Before the advent of modern neuroimaging techniques, such lesions would typically present as haemorrhage or seizures rather than as incidental findings on brain scans. In this patient, their risks and suggested management is discussed.
Case study: cavernoma
A footballer is involved in a motor vehicle accident. The patient incurs a head injury and loses consciousness for 30 seconds. The patient attends the emergency department, where is found to be asymptomatic, with normal systemic and neurological examination findings. A CT scan of the brain is performed, which shows a lesion in the anterior right frontal lobe. And MRI scan of the brain confirms this as a solitary cavernous haemangioma (cavernoma) ( fig 1 ). The treating clinicians order formal neuropsychology assessment and EEG, which are both normal. One week later, the patient attends your office seeking medical clearance to resume playing professional rugby. What recommendations do you make, based on the following considerations?
1. Does the presence of the cavernoma preclude the patient from returning to rugby or other contact sports?
2. Would you recommend any other treatment (eg, gamma knife) in order to allow him to return to sport?
3. If you permit him to play, is there any benefit from wearing a helmet and if so, does …
Clinics in Neurology and Neurosurgery of Sport - Peripheral Nerve Injury. Davis G, Kline D, Spinner R, Zager E, Garberina M, Williams G, McCrory P. British Journal of Sports Medicine. 2009; 43:537-540.
Peripheral nerve injuries are not uncommon in sports. Typically, these are associated with orthopaedic injury (eg, axillary nerve injury with glenohumeral joint dislocation) rather than the transection or gunshot-type injuries often seen in emergency departments.
The classification of nerve injuries is complex, 1 2 but the underlying principle is that the simplest of nerve injuries is a physiological loss only (neurapraxia) and the most severe form is complete anatomical transection of the nerve and its coverings (neurotmesis). Between these two extremes are varying degrees of injury to the axon and its covering sheath.
With all degrees of nerve injury, the greater the degree of preservation of anatomical structures, the greater the chance of neurological recovery. Thus a neurapraxic injury will recover spontaneously, whereas a neurotmetic injury will not recover without surgical intervention. Between these two ends of the spectrum is a large group of nerve injuries in which the capacity for spontaneous recovery cannot be accurately assessed clinically and may require surgical exploration with or without nerve repair.
On the sports field, the most common mechanism of nerve injury is a stretch or traction type of injury. In the first few weeks following a stretch injury, clinical observation is required. and after sufficient time has elapsed for Wallerian degeneration to occur (at least 2 weeks), then nerve conduction studies (NCS) and electromyography (EMG) can be performed. Over the following 6–8 weeks, a nerve injury is then followed by clinical examination and repeat NCS/EMG, with the objective being to determine whether spontaneous recovery will occur. If there is failure of neurological recovery at 3 months after the injury, then surgical intervention is required to facilitate recovery before irreversible fibrosis in the denervated muscle results.
The principles used by the peripheral nerve surgeon include neurolysis, intraoperative nerve action potentials (NAP), primary repair, …
Pancoast Tumors. Davis GA, Knight SR. Neurosurgery Clinics of North America. 19:545-557, October 2008.
Pancoast tumors (superior sulcus tumors or apical lung tumors) typically invade structures at the thoracic outlet, including the inferior elements of the brachial plexus (C8, T1 nerve roots and lower trunk). Historically, these tumors are rapidly fatal, but newer treatment with induction chemotherapy and radiotherapy, followed by surgical resection of the tumor has resulted in improved patient survival. To accomplish oncologic excision, resection of the involved brachial plexus elements is still standard practice in most centers, resulting in loss of hand function and/or development of neuropathic pain. We present a modification of this protocol that incorporates induction chemoradiation, surgical resection of the lung tumor by a thoracic surgeon, and neurolysis and preservation of the brachial plexus by a neurosurgeon. Improved survival outcome, especially in patients demonstrating a pathologic complete response, with preservation of hand function, supports our hypothesis that involved brachial plexus does not need resection in these patients.
Granular Cell Tumour - A rare tumour of the ulnar nerve. Davis G. Neurosurgical Focus. 22(6):E25, June 2007.
Granular cell tumors of the ulnar nerve are extremely rare, with only two cases previously reported in the English literature. The author presents a case of granular cell tumor of the ulnar nerve, in which the tumor was resected and the nerve was repaired with a nerve graft. The histopathological characteristics, imaging findings, and clinical data regarding these tumors are reviewed, and based on all the available evidence, a new treatment paradigm is proposed, which differs from that used in the earlier reported cases and takes into account the reported rate of tumor recurrence after incomplete resection.
Pancoast tumour resection with preservation of brachial plexus and hand function. Davis GA, Knight S. Neurosurgical Focus. 22(6):E15, June 2007.
OBJECT: Pancoast tumors are aggressive bronchogenic lesions of the lung apex that are rapidly fatal if untreated. Modern treatment includes induction chemotherapy and radiotherapy prior to resection, but many authors also resect the T-1 nerve root (with or without the C-8 nerve root and the lower trunk of the brachial plexus) as part of the therapy, causing significant loss of hand function in many patients. The current authors determined whether a different approach allowing preservation of the brachial plexus and hand function could be adopted without compromising patient survival. An extensive historical review of Pancoast tumors is presented as a baseline for clinical comparison.
METHODS: Five patients harboring Pancoast tumors with brachial plexus involvement underwent surgery performed by both a neurosurgeon and thoracic surgeon. In all cases the tumor was resected from the brachial plexus using neurolysis while preserving the C-8 and T-1 nerve roots and lower trunk of the brachial plexus.
RESULTS: One patient died 3 years posttreatment; the other four patients remain alive and well 2 to 5 years postoperatively. Hand function improved or remained normal in all four survivors, with postoperative intrinsic hand muscle function being Louisiana State University Medical Center Grade 5 in each patient. These results (2-year survival rate of 100%) compare favorably with the Southwest Oncology Group Data (overall 2-year survival rate of 55%; 70% in patients who had undergone complete resection). With a minimum 2-year follow-up, 80% of patients remained alive and well, with normal hand function.
CONCLUSIONS: Although this patient series is small, the findings are extremely encouraging and suggest that the described treatment paradigm preserves survival as well as hand function in patients with Pancoast tumors.
Ulnar Nerve Volar to Medial Epicondyle – An important anatomical variation. (Case Illustration) Davis GA. Journal of Neurosurgery. 104: 625, 2006.
Long-term seizure outcome following surgery for dysembryoplastic neuroepithelial tumour. Chan CHP, Bittar RG, Kalnins RM, Davis GA, Fabinyi GCA. Journal of Neurosurgery. 104: 62-69, 2006.
OBJECT: Resection of dysembryoplastic neuroepithelial tumor (DNET) is thought to result in favorable seizure outcome, but long-term follow-up data are scarce. The authors present a review of 18 patients who underwent surgical removal of a DNET: 12 via temporal lobectomy and six via lesionectomy.
METHODS: The mean long-term follow up was 10.8 years (median 10.4 years, range 7.8 to 14.8 years), and results obtained during this time period were compared with previously reported short-term (mean 2.7 years) seizure outcome data. In the current study, 66.7% patients had an Engel Class I outcome and 55.6% had an Engel Class IA outcome compared with 77.8% and 55.6%, respectively. Temporal lobectomy (Engel Class I, 83.3%; Engel Class IA, 66.7%) led to a better seizure outcome than lesionectomy (Engel Classes I and IA, 33.3%). Two patients (11.1%) required repeated operation and both had an incomplete lesionectomy initially.
CONCLUSIONS: Results indicated that complete resection of a DNET leads to a favorable seizure outcome, with epilepsy cure in those who had experienced early postoperative seizure relief. Long-term seizure outcome after surgery is predictable based on the result of short-term follow up.
Value of neuropsychological testing after head injuries in football. McCrory P, Makdissi M, Davis G, Collie A. British J Sports Medicine. 39(Supp 1):i58-i63, 2005.
Can we manage sport-related concussion in children the same as in adults? McCrory P, Collie A, Anderson V, Davis G. British J Sports Medicine. 38:516-519, 2004.
Can we manage sport related concussion in children the same as in adults?
P McCrory, A Collie, V Anderson, and G Davis
Centre for Health, Exercise and Sports Medicine and the Brain Research Institute, University of Melbourne, Parkville, Victoria 3010, Australia.
Submuscular Transposition of the ulnar nerve : review of safety, efficacy and correlation with neurophysiological outcome. Davis GA and Bulluss KJ. Journal of Clinical Neuroscience. 12(5): 524-528, 2005.
The surgical management of ulnar nerve entrapment at the elbow is a controversial topic, with each surgeon believing his/her technique to be the best. The authors routinely perform submuscular transposition (SMT) of the ulnar nerve to treat entrapment neuropathy at the elbow. The aims of this review are (1) to review the results of SMT with respect to safety and complications, (2) to compare the efficacy of SMT with other studies previously published, and (3) to compare the clinical results with the neurophysiological outcome.
A retrospective review of patients who underwent SMT for ulnar nerve entrapment between April 2000 and May 2003 was performed. Forty-five ulnar nerves in 44 patients were operated, of which 40 nerves were first time operation (primary group), and 5 nerves had previously undergone a simple decompressive procedure elsewhere (redo group). All patients were graded using the Louisiana State University Medical Centre (LSUMC) system for grading of ulnar nerve entrapment. Pre- and post-operative nerve conduction studies were performed, and these results compared to clinical recovery post-operatively.
For the primary group, function improved by one grade in 32.5%, two grades in 37.5% and three grades in 12.5% of patients. There was no change in 17.5%, and no patient deteriorated post-operatively.
In the redo group there was improvement of at least one grade in 60% of patients. When clinical improvement was compared with electrophysiological improvement, no clear correlation was demonstrated.
Submuscular transposition of the ulnar nerve is a safe, effective treatment for ulnar nerve entrapment at the elbow. When performed by trained peripheral nerve surgeons, good results are achievable for both primary and redo surgery.
Keywords: anterior transposition; cubital tunnel syndrome; ulnar nerve
Brachial Plexus Surgery and Apical Lung Tumours. Davis GA, Knight S. Cancer Forum. 28 (1): 11-12, 2004.
Cerebral Metastases in a Patient with Malignant Mesothelioma : Mah E, Bittar RG, Davis GA. Journal of Clinical Neuroscience. 11:917-918, 2004.
Malignant mesothelioma is an uncommon tumour with an inevitably poor outcome. Statistics from the US National Cancer Institute reveal a steady rise in its incidence over the past 25 years. It typically arises from the pleura, but can also originate in the peritoneum, pericardium, genital tracts and tunica vaginalis. Previously considered a local disease with low incidence of metastasis, there is increasing evidence suggesting otherwise. Reported cases of cerebral metastasis are rare and the vast majority are postmortem findings. This report documents a patient with symptomatic cerebral metastasis from malignant mesothelioma, who underwent craniotomy and excision of two cerebral lesions. It is one of a handful of case reports in the literature in which histological confirmation has been obtained ante-mortem and where surgical treatment of the intracranial mesothelioma was undertaken.
Increased perivascular spaces mimicking frontal lobe tumour. Davis GA, Fitt GJ, Kalnins RM and Mitchell LA. Journal of Neurosurgery. 97:723, 2002.
Increased perivascular spaces mimicking frontal lobe tumor.
Davis G, Fitt GJ, Kalnins RM, Mitchell LA.
Department of Neurosurgery, Austin and Repatriation Medical Centre, Heidelberg, Victoria, Australia.
Acute onset non-traumatic paraplegia in childhood: Fibrocartilagenous embolism or acute myelitis? Davis GA, Klug GL. Child's Nervous System. 16( 9), 551-554, 2000.
Fibrocartilaginous embolus causing acute spinal cord infarction is a rare cause of acute-onset paraplegia or quadriplegia. Few cases of survivors have been reported in the neurosurgical literature, with most reports involving postmortem or biopsy findings. There is little information on MRI findings in such patients. We present the youngest patient ever reported, and discuss the important differences between fibrocartilaginous embolus and acute myelitis of childhood. A 6-year-old girl with a history of back pain presented with sudden-onset nontraumatic paraplegia, with a clinical anterior spinal artery syndrome. Initial MRI scan revealed intervertebral disc disease at L1-2 and an incidental thoracic syrinx, but no cause for her acute-onset paraplegia was identified. Cerebrospinal fluid and other investigations were all negative. Sequential MRI scans revealed development of spinal cord expansion from T10 to the conus medullaris, with increased cord signal in the anterior aspect of the spinal cord. The intervertebral disc disease was unchanged. The imaging and clinical findings were caused by fibrocartilaginous embolus, which meant there was no need for spinal cord biopsy. The report describes the clinical and imaging criteria for diagnosis of fibrocartilaginous embolus, highlighting the case for avoiding an unnecessary biopsy. The clinical pattern in the paediatric group is discussed, with features differentiating it from acute myelitis of childhood.
Delayed presentation of transorbital intracranial pen. Davis GA, Holmes AD, Klug GL. Journal of Clinical Neuroscience. 7(6):545-548, 2000.
A 13 year old Fijian boy sustained a stab wound to the left orbit 3 years ago. It was not appreciated by the treating physicians in Fiji that the plastic pen had crossed from the left orbit, through the nose, right orbit and right optic nerve, into the right middle cranial fossa and lodged in the right temporal lobe and that the pen remained in situ for the past 3 years. The boy presented to Australia with a discharge from the entry wound in his left lower eyelid. The retained foreign body was not detected on computed tomography imaging, but was detected on subsequent magnetic resonance image. A combined neurosurgery/plastic surgery craniofacial approach was undertaken with successful complete removal of the retained pen, and preservation of vision in his only seeing eye.
Dysembryoplastic Neuroepithelial Tumour and Mixed DNET-Ganglioglioma - Seizure Outcome Following Surgery. Davis GA, Kalnins RM, Fabinyi GCA. Journal of Clinical Neuroscience 4(4):451-457,1997.
Dysembryoplastic neuroepithelial tumour (DNET) is a recently recognized tumour occurring in patients with epilepsy of early onset. Long-term seizure outcome following resection is not well known. A review of 18 patients with DNET is presented. There were 13 temporal lobe, 3 frontal lobe and 2 parietal lobe DNETs. Of the 13 temporal lobe tumours, there were 3 mixed DNET-gangliogliomas. Resection in all 18 patients produced an overall class 1 seizure outcome of 78%. Class 1 outcomes for the subgroups of mixed DNET-ganglioglioma and anterior temporal lobe DNETs were 100% each. Although the number of patients is statistically small, comparison with other reported series is made.
Concurrent Adjacent Meningioma and Astrocytoma - A report of three cases and review of the literature. Davis GA, Fabinyi GCA, Kalnins RM, Brazenor GA, Rogers MA. Neurosurgery 36:599-605,1995.
Three patients presenting with an adjacent meningioma and astrocytoma are described. A review of the literature discusses several modes of neuroimaging and the difficulties in diagnosing simultaneous adjacent tumors. Aspects of the pathology and etiology of these tumors are also reviewed.