Explore This Lab

Overview

A sport-related concussion is a brain injury. The Centers for Disease Control and Prevention described sport-related concussion as an epidemic1. In an epidemiological study of high school athletes, concussion rates have increased steadily in the past decade2, possibly due to greater awareness among physicians, with recent estimates suggesting as many as 300,000 concussive injuries each year3. Student athletes who experience a concussion are at statistically increased risk for experiencing a future concussion.

There is tremendous interest and concern about sport-related concussion in youth athletes reflected by thousands of media stories and every state in the United States passing legislation relating to educational efforts, identification, and/or medical management of this injury. Massachusetts law mandates that school athletic personnel and medical professionals be responsible for education about concussion risk, management of injured athletes, and clearance of these athletes in order for them to return to play.

There is considerable concern regarding the long-term effects of this injury, especially in children and adolescents who suffer repetitive injuries. Whether or not there is a long-term effect of multiple concussions in high school athletes is not well understood. There are conflicting results in the medical and scientific literature.

There are some good resources available to health care professionals relating to the assessment, acute medical management, return to school, return to sports, and treatment and rehabilitation services for those who are slow to recover. However, a large amount of research is needed to better inform the medical community on how to manage this injury, and how to provide the most effective treatment and rehabilitation services for student athletes who are slow to recover.

Accelerate Knowledge/Improve Care

As one of the top hospitals in the country, Mass General epitomizes what makes an academic medical center special - translating research discoveries into better care for patients. We have a productive, diverse, and internationally recognized research program in sport-related concussion. We collaborate with clinicians and researchers locally, regionally, nationally, and internationally. Our research is designed to enhance knowledge and improve health care for student athletes who have sustained a concussion. We approach our research from a broad biopsychosocial perspective, and we use diverse technologies, biomarkers, and outcome measures such as microstructural neuroimaging (i.e., diffusion tensor imaging), cognitive testing, psychological assessment, and balance testing. We provide research training and experience to graduate students, medical residents, and post-doctoral fellows seeking careers in health service delivery or clinical research. Some of our priority areas of research are listed below.

  1. Understanding the Effects of Multiple Concussions: Athletes, parents, coaches, athletic trainers, physicians, scientists, and society as a whole are concerned about the possible effects of multiple concussions on adolescents and young adults. We are conducting a series of studies designed to address the questions below.

    1. Are high school athletes who have had prior concussions at increased risk for future concussions?

    2. Do athletes with multiple past concussions have worse effects of a future concussion than athletes who have no prior injuries?

    3. Are athletes with developmental problems, such as attention-deficit hyperactivity disorder (ADHD) or a learning disability, at increased risk for (a) sustaining a concussion, or (b) having worse outcome or slower recovery from this injury?

    4. Are multiple past concussions associated with current cognitive difficulties or symptoms (e.g., headaches) in adolescent student athletes?

  2. Improving the Methodology for Assessing Cognitive Impairment Following Concussion. Concussions can have an immediate and large adverse effect on cognitive functioning. This can interfere with an adolescent’s ability to function in daily life and school. We are conducting a series of studies that examine the reliability, accuracy, and clinical usefulness of computerized cognitive testing as a component of a sport concussion management program.

  3. Examining the Usefulness of Baseline, Preseason Testing. Few would doubt that a reliable, valid, and accurate assessment of a person’s pre-injury cognitive functioning would be useful for determining the nature and extent of post-injury cognitive deficits and the rate of recovery. There are multiple challenges and problems, however, associated with baseline testing. First, baseline computerized testing is often conducted in group settings, and one study illustrated that athletes tested in group settings perform more poorly than athletes tested individually10. As such, some authors have recommended individual baseline testing or testing in small, carefully monitored groups (e.g., 3-5 students)11. Second, baseline testing can be fairly expensive and labor intensive, depending on how it is done. Third, some tests used in concussion management programs have modest test-retest reliability12-14. Therefore, it can be difficult to accurately and precisely assess baseline and post-injury change scores. Finally, the value of baseline testing is largely assumed, and baseline testing is often encouraged in consensus15 or agreement16-17 statements—at least with some athletes. Few studies have examined this issue empirically, however.

    We believe that having an accurate measure of baseline cognitive functioning would be helpful for quantifying cognitive deficits following injury and for assessing recovery. This is especially true for athletes who have above average or below average cognitive functioning at baseline. Moreover, it can be helpful for athletes with developmental conditions, such as attention-deficit hyperactivity disorder or a learning disability. Students with self-reported ADHD, learning disabilities, or both perform more poorly on ImPACT® than students who do not have a developmental condition18. At present, however, there is insufficient evidence to conclude that having baseline test results is time- and cost-effective, or clearly superior to not having baseline test results. With our collaborators, we are pursuing studies relating to the advantages, disadvantages, and appropriate use of baseline testing.

  4. Improving Exertional Testing and Return to Play Protocols: Injured athletes are expected to undergo a progressive series of exercises and exertional tests, spanning several days, prior to be cleared to return to contact sports. It is important to understand and document the effects of exertional testing on athletes who are not injured so we have normative reference values to compare to athletes who are injured. We are examining the effects of exertional testing on cardiac physiology, balance, cognition, and subjective symptoms in both uninjured and injured athletes.

  5. Active Rehabilitation for Children and Adolescents Who are Slow to Recover from Concussion. There are no scientifically-established, evidence-based guidelines for providing treatment and rehabilitation services to student athletes who are slow to recover from concussion. An active rehabilitation treatment program for children and adolescents who are slow to recover following concussion has been offered at the Montreal Children’s Hospital Trauma Center since 2007. This group of clinicians and researchers is part of our research network. In addition, we are collaborating with clinicians from GF Strong Rehabilitation Hospital in Vancouver, Canada to do a small clinical trial on active rehabilitation with adolescents who are slow to recover. Through a series of studies conducted locally and with our Canadian collaborators, we will advance knowledge and refine treatment strategies for children and adolescents who have persistent symptoms and problems following their injuries.

References

  1. Injury Prevention and Control: Traumatic Brain Injury. http://www.cdc.gov/concussion/sports/facts.html. Accessed February 26, 2014.
  2. Lincoln AE, Caswell SV, Almquist JL, Dunn RE, Norris JB, Hinton RY. Trends in concussion incidence in high school sports: a prospective 11-year study. The American journal of sports medicine. 2011;39(5):958-963.
  3. Marar M, McIlvain NM, Fields SK, Comstock RD. Epidemiology of concussions among United States high school athletes in 20 sports. The American journal of sports medicine. 2012;40(4):747-755.
  4. Mannix R, Meehan WP, Mandeville J, Grant PE, Gray T, Berglass J, et al. Clinical correlates in an experimental model of repetitive mild brain injury. Annals of neurology. 2013;74(1):65-75.
  5. Meehan WP, 3rd, Zhang J, Mannix R, Whalen MJ. Increasing recovery time between injuries improves cognitive outcome after repetitive mild concussive brain injuries in mice. Neurosurgery. 2012;71(4):885-891.
  6. Guskiewicz KM, Marshall SW, Bailes J, McCrea M, Harding HP, Jr., Matthews A, et al. Recurrent concussion and risk of depression in retired professional football players. Medicine and science in sports and exercise. 2007;39(6):903-909.
  7. Kerr ZY, Marshall SW, Harding HP, Jr., Guskiewicz KM. Nine-year risk of depression diagnosis increases with increasing self-reported concussions in retired professional football players. The American journal of sports medicine. 2012;40(10):2206-2212.
  8. Schwenk TL, Gorenflo DW, Dopp RR, Hipple E. Depression and pain in retired professional football players. Medicine and science in sports and exercise. 2007;39(4):599-605.
  9. Guskiewicz KM, McCrea M, Marshall SW, Cantu RC, Randolph C, Barr W, et al. Cumulative effects associated with recurrent concussion in collegiate football players: the NCAA Concussion Study. JAMA: the journal of the American Medical Association. 2003;290(19):2549-2555.
  10. Moser RS, Schatz P, Neidzwski K, Ott SD. Group versus individual administration affects baseline neurocognitive test performance. Am J Sports Med 2011;39:2325-2330.
  11. Echemendia RJ, Iverson GL, McCrea M, Macciocchi SN, Gioia GA, Putukian M, Comper P. Advances in neuropsychological assessment of sport-related concussion. Br J Sports Med 2013;47:294-298.
  12. Mayers LB, Redick TS. Clinical utility of ImPACT assessment for postconcussion return-to-play counseling: psychometric issues. J Clin Exp Neuropsychol 2012;34:235-242.
  13. Broglio SP, Ferrara MS, Macciocchi SN, Baumgartner TA, Elliott R. Test-retest reliability of computerized concussion assessment programs. J Athl Train 2007;42:509-514.
  14. Resch J, Driscoll A, McCaffrey N, Brown C, Ferrara MS, Macciocchi S, Baumgartner T, Walpert K. ImPact test-retest reliability: reliably unreliable? J Athl Train 2013;48:506-511.
  15. McCrory P, Meeuwisse W, Johnston K, Dvorak J, Aubry M, Molloy M, Cantu R. Consensus statement on concussion in sport: the 3rd International Conference on Concussion in Sport held in Zurich, November 2008. J Athl Train 2009;44:434-448.
  16. Guskiewicz KM, Bruce SL, Cantu RC, Ferrara MS, Kelly JP, McCrea M, Putukian M, McLeod TC. Research based recommendations on management of sport related concussion: summary of the National Athletic Trainers' Association position statement. Br J Sports Med 2006;40:6-10.
  17. Moser RS, Iverson GL, Echemendia RJ, Lovell MR, Schatz P, Webbe FM, Ruff RM, Barth JT. Neuropsychological evaluation in the diagnosis and management of sports-related concussion. Arch Clin Neuropsychol 2007;22:909-916.
  18. Elbin RJ, Kontos AP, Kegel N, Johnson E, Burkhart S, Schatz P. Individual and combined effects of LD and ADHD on computerized neurocognitive concussion test performance: evidence for separate norms. Arch Clin Neuropsychol 2013;28:476-484.

Publications

Improving Assessment Methods: Cognition, Symptoms, and Balance

Kelshaw, P. M., Cook, N. E., Terry, D. P., Iverson, G. L., & Caswell, S. V. (2021). Child Sport Concussion Assessment Tool 5th Edition: Normative Reference Values in Demographically Diverse Youth.  Clinical Journal of Sport Medicine. See in PubMed

Iverson, G. L., Cook, N. E., Howell, D. R., Collings, L. J., Kusch, C., Sun, J., Virji-Babul, N., & Panenka, W. J. (2021). Preseason Vestibular Ocular Motor Screening in Children and Adolescents.  Clinical Journal of Sport Medicine31(4), e188–e192. See in PubMed

Iverson, G. L., Karr, J. E., Hong, Y., Yang, C. C., Maxwell, B., & Berkner, P. D. (2021). Baseline preseason ImPACT® testing in Mandarin with adolescent student-athletes in the United States. Applied Neuropsychology. Child, 1–11. Advance online publication. See in PubMed

Vartiainen, M. V., Peltonen, K., Holm, A., Koskinen, S., Iverson, G. L., & Hokkanen, L. (2021). Preliminary normative study of ImPACT® in Finnish professional male ice hockey players. Applied Neuropsychology. Adult28(1), 53–59. See in PubMed

Terry, D. P., Jurick, S. M., Huebschmann, N. A., Silverberg, N. D., Maxwell, B. A., Zafonte, R., Berkner, P. D., & Iverson, G. L. (2021). Sleep Insufficiency and Baseline Preseason Concussion-like Symptoms Reporting in Youth Athletes. Clinical Journal of Sport Medicine. See in PubMed

Caccese, J.B., Iverson, G.L., Hunzinger, K.J., Asken, B.M., Clugston, J.R., Cameron, K.L., Houston, M.N., Svoboda, S.J., Jackson, J.C., McGinty, G.T., Estevez, C.A., Susmarski, A.J., Enrique, A., Bryk, K., Broglio, S.P., McAllister, T.W., McCrea, M., Pasquina, P.F., & Buckley, T.A. (2021). CARE Consortium Investigators. Factors Associated with Symptom Reporting in U.S. Service Academy Cadets and NCAA Student Athletes without Concussion: Findings from the CARE Consortium. Sports Medicine; May;51(5):1087-1105. See in PubMed

Chung, J.P.Y., Lee, J.H., Howell, D.R., Iverson, G.L., & Gardner, A.J. (2020). Effects of Exercise on Sport Concussion Assessment Tool-Performance in Women. Clinical Journal of Sport Medicine, Jul;30(4):353-359. See in PubMed

Hänninen, T., Parkkari, J., Howell, D. R., Palola, V., Seppänen, A., Tuominen, M., Iverson, G. L., Luoto, T. M. (2020). Reliability of the Sport Concussion Assessment Tool 5 baseline testing: A 2-week test-retest study. Journal of Science and Medicine in Sport. [Epub ahead of print]. See in PubMed

Karr, J. E., Garcia-Barrera, M. A., Marsh, J. M., Maxwell, B., Berkner, P. D., Iverson, G. L. (2020). Preseason Baseline Neurocognitive Performances and Symptom Reporting on ImPACT: A Comparison of Adolescent Student-Athletes Tested in Spanish and English. Journal of Athletic Training. [Epub ahead of print]. See in PubMed

Cook, N. E., Sapigao, R. G., Silverberg, N. D., Maxwell, B. A., Zafonte, R., Berkner, P. D., & Iverson, G. L. (2020). Attention-Deficit/Hyperactivity Disorder Mimics the Post-concussion Syndrome in Adolescents. Frontiers in Pediatrics8, 2. Read PDF of Full Article

Karr, J. E., & Iverson, G. L. (2020). The structure of post-concussion symptoms in adolescent student athletes: confirmatory factor analysis and measurement invariance. The Clinical Neuropsychologist. [Epub ahead of print]. See in PubMed

Wallace, J., Schatz, P., Covassin, T., Iverson, G. L. (2020). Brief iPad-Based Assessment of Cognitive Functioning with ImPACT® Quick Test: Prevalence of Low Scores Using Multivariate Base Rates. Archives of Clinical Neuropsychology, 35(8):1276-1282. See in PubMed

Brett, B.L., Zuckerman, S.L., Terry, D.P., Solomon, G.S., Iverson, G.L. (2020). Normative Data for the Sway Balance System. Clinical Journal of Sport Medicine, 30(5):458-464. See in PubMed

Champigny, C., Rawana, J., Iverson, G.L., Maxwell, B., Berkner, P.D., & Wojtowicz, M. (2020). Influence of Anxiety on Baseline Cognitive Testing and Symptom Reporting in Adolescent Student Athletes. Journal of Neurotrauma, 37(24):2632-2638. See in PubMed

Chung Pin Yong, J. P., Lee, J. H., Howell, D. R., Meehan, W. P., 3rd, Iverson, G. L., & Gardner, A. J. (2020). Effects of Exercise on Sport Concussion Assessment Tool-Third Edition Performance in Women.  Clinical Journal of Sport Medicine30(4), 353–359. See in PubMed

Brett, B.L., Zuckerman, S.L., Terry, D.P., Solomon, G.S., Iverson, G.L. (2020). Normative Data for the Sway Balance System. Clinical Journal of Sport Medicine, Sep;30(5):458-464. See in PubMed

Terry, D.P., Reddi, P.J., Cook, N.E., Seifert, T., Maxwell, B.A., Zafonte, R.D., Berkner, P.D., & Iverson, G.L. (2019). Acute Effects of Concussion in Youth with Pre-Existing Migraines. Clinical Journal of Sports Medicine. Nov 26. [Epub ahead of print]. See in PubMed

Iverson, G.L., Schatz, P. (2019). Brief iPad-Based Assessment of Cognitive Functioning with ImPACT® Pediatric. Developmental Neuropsychology, 44(1), 43-49. See in PubMed

Cook, N. E., Kelshaw, P. M., Caswell, S. V., & Iverson, G. L. (2019). Children with Attention-Deficit/Hyperactivity Disorder Perform Differently on Pediatric Concussion Assessment. The Journal of Pediatrics214, 168-174. See in PubMed

Howell, D.R., Wilson, J.C., Brilliant, A.N., Gardner, A.J., Iverson, G.L., Meehan, W.P. 3rd. (2019). Objective clinical tests of dual-task dynamic postural control in youth athletes with concussion. Journal of Science and Medicine in Sport, May;22(5):521-525. See in PubMed

Howell, D.R., Kirkwood, M.W., Provance, A., Iverson, G.L., Meehan, W.P. 3rd. (2018). Using concurrent gait and cognitive assessments to identify impairments after concussion: a narrative review. Concussion, 3(1), CNC54. See in PubMed         

Schmidt, J.D., Terry, D.P., Ko, J., Newell, K.M., & Miller, L.S. (2018). Balance regularity among former high school football players with or without a history of concussion. Journal of Athletic Training, 53(2): 109-114. See in PubMed

Hänninen, T., Parkkari, J., Tuominen, M., Iverson, G.L., Öhman, J., Vartiainen, M., Luoto, T.M. (2017). Interpreting change on the SCAT3 in professional ice hockey players. Journal of Science and Medicine in Sport, 20(5): 424-431. See in PubMed

Cook, N.E., Huang, D.S., Silverberg, N.D., Brooks, B.L., Maxwell, B., Zafonte, R., Berkner, P.D., Iverson, G.L. (2017). Baseline cognitive test performance and concussion-like symptoms among adolescent athletes with ADHD: examining differences based on medication use. The Clinical Neuropsychologist, 31(8): 1341-1352. See in PubMed

Collings, L.J., Cook, N.E., Porter, S., Kusch, C., Sun, J., Virji-Babul, N., Iverson, G.L., & Panenka, W.J. (2017). Attention-Deficit/Hyperactivity Disorder is Associated with Baseline Child Sport Concussion Assessment Tool Third Edition Scores in Child Hockey Players. Brain Injury, 31(11): 1479-1485. See in PubMed

Lee, J.H., Howell, D.R., Meehan, W., Iverson, G.L., & Gardner, A.J. (2017). Effects of Exercise on Sports Concussion Assessment Tool-Third Edition Performance in Professional Athletes. The Orthopaedic Journal of Sports Medicine, 5(9). Read Study

Gerrard, P.B., Iverson, G.L., Atkins, J.E., Maxwell, B.A., Zafonte, R., Schatz, P., & Berkner, P.D. (2017). Factor Structure of ImPACT® in Adolescent Student Athletes. Archives of Clinical Neuropsychology, 32(1): 117-122. See in PubMed

Video Analysis of Injuries

Iverson, G. L., Van Patten, R., & Gardner, A. J. (2021). Examining Whether Onfield Motor Incoordination Is Associated With Worse Performance on the SCAT5 and Slower Clinical Recovery Following Concussion. Frontiers in Neurology. Read PDF of Full Article

Carey, L., Stanwell, P., Terry, D.P., McIntosh, A.S., Caswell, S.V., Iverson, G.L., Gardner, A.J. (2019). Verifying Head Impacts Recorded by a Wearable Sensor using Video Footage in Rugby League: a Preliminary Study. Sports Medicine Open. Mar 14;5(1):9. Read PDF of Full Article

Gardner, A.J., Howell, D.R., & Iverson, G.L. (2018). A video review of multiple concussion signs in National Rugby League match play. Sports Medicine - Open, 4(1): 5. Read Study

Gardner, A.J., Kohler, R.M.N., Levi, C.R., & Iverson, G.L. (2017). Usefulness of Video Review of Possible Concussions in National Youth Rugby League. International Journal of Sport, 38(1): 71-75. See in PubMed

Gardner, A.J., Levi, C.R., & Iverson, G.L. (2017). Observational review and analysis of concussion: A method for conducting a standardized video analysis of concussion in rugby league. Sports Medicine - Open, 3(1): 26. Read Study

Gardner, A.J., Wojtowicz, M., Terry, D., Levi, C.R., Zafonte, R., & Iverson, G.L. (2017).Video and clinical screening of Australian National Rugby League players suspected of sustaining concussion, Brain Injury., 31(13-14): 1918-1924. See in PubMed

Gardner, A.J., Howell, D.R., Levi, C.R., & Iverson, G.L. (2017). Evidence of Concussion Signs in National Rugby League Match Play: A Video Review and Validation Study. Sports Medicine - Open, 3(1): 29. Read Study

Davis, G.A., Purcell, L., Schneider, K., Yeates, K.O., Gioia, G., Anderson, V., Ellenbogen, R., Echemendia, R., Makdissi, M., Sills, A. Iverson, G.L., Dvorak, J., McCrory, P., and Meeuwisse, W. (2017). The Child Sport Concussion Assessment Tool 5th Edition (Child SCAT5). British Journal of Sports Medicine, 51(11): 859-861. See in PubMed

Predicting Clinical Outcome and Recovery Time

Cook, N. E., Iverson, G. L., Maxwell, B., Zafonte, R., & Berkner, P. D. (2021). Adolescents with ADHD Do Not Take Longer to Recover from Concussion. Frontiers in Pediatrics. Read Full Article

Büttner, F., Howell, D. R., Iverson, G. L., Doherty, C., Blake, C., Ryan, J., & Delahunt, E. (2021). Participation in pre-injury level sport one-year following sport-related concussion: A prospective, matched cohort study. Journal of science and medicine in sport24(6), 561–566. Read Full Article

Iverson, G. L., Williams, M. W., Gardner, A. J., & Terry, D. P. (2020). Systematic Review of Pre-Injury Mental Health Problems as a Vulnerability Factor for Worse Outcome Following Sport-Related Concussion. The Orthopaedic Journal of Sports Medicine. Read PDF of Full Article

Büttner, F., Terry, D.P., & Iverson, G.L. (2020). Using a Likelihood Heuristic to Summarize Conflicting Literature on Predictors of Clinical Outcome Following Sport-Related Concussion. Clinical Journal of Sport Medicine. [Epub ahead of print]. See in PubMed

Cook, N. E., Iaccarino, M. A., Karr, J. E., & Iverson, G. L. (2020). Attention Deficit/Hyperactivity Disorder and Outcome After Concussion: A systematic review. Journal of Developmental and Behavioral Pediatrics, 41(7):571-582. See in PubMed

Terry, D.P., Huebschmann, N.A., Maxwell, B.A., Cook, N.E., Mannix, R., Zafonte, R., Seifert, T., Berkner, P.D., Iverson, G.L. (2019). Preinjury Migraine History as a Risk Factor for Prolonged Return to School and Sports following Concussion. Journal of Neurotrauma, 36(1), 142-151 See in PubMed

Iaccarino, M. A., Fitzgerald, M., Pulli, A., Woodworth, K. Y., Spencer, T. J., Zafonte, R., & Biederman, J. (2018). Sport concussion and attention deficit hyperactivity disorder in student athletes: A cohort study. Neurology. Clinical practice8(5), 403–411. Read PDF of Full Article

Iverson, G.L., Gardner, A.J., Terry, D.P., Ponsford, J.L., Sills, A.K., Broshek, D.K., and Solomon, G.S. (2017). Predictors of Clinical Recovery from Concussion: A Systematic Review. British Journal of Sports Medicine, 51(12): 941-948. Read Study

Role of Rest and Active Rehabilitation

Silverberg, N.D., Iaccarino, M.A., Panenka, W.J., Iverson, G.L., McCulloch, K.L., Dams-O’Connor, K., Reed, N., McCrea, M.; American Congress of Rehabilitation Medicine Brain Injury Interdisciplinary Special Interest Group Mild TBI Task Force. (2020). Management of Concussion and Mild Traumatic Brain Injury: A Synthesis of Practice Guidelines. Archives of Physical Medicine and Rehabilitation, 101(2), 382-393. Read PDF of Full Article

Cook, N. E., Huebschmann, N. A., & Iverson, G. L. (2020). Safety and Tolerability of an Innovative Virtual Reality-Based Deep Breathing Exercise in Concussion Rehabilitation: A Pilot Study. Developmental Neurorehabilitation. [Epub ahead of print]. See in PubMed

Gauvin-Lepage, J., Friedman, D., Grilli, L., Sufrategui, M., De Matteo, C., Iverson, G.L., Gagnon, I. (2020). Effectiveness of an Exercise-Based Active Rehabilitation Intervention for Youth Who Are Slow to Recover After Concussion. Clinical Journal of Sport Medicine, 30(5):423-432. See in PubMed

Iaccarino, M. A., Philpotts, L. L., Zafonte, R., & Biederman, J. (2020). Stimulant Use in the Management of Mild Traumatic Brain Injury: A Qualitative Literature Review. Journal of Attention Disorders24(2), 309–317. See in PubMed

Reed, N., Silverberg, N.D., Iaccarino, M.A., McCrea, M., McCulloch, K.L., Panenka, W., Gregory, E., Dams-O'Connor, K., Iverson, G.L., Weyer Jamora, C., Belanger, H., McKinney, G., Cogan, A.M., Provvidenza, C. (2019). Returning to Activity After a Concussion. Archives of Physical Medicine and Rehabilitation, 100(4), 789-791. See in PubMed

Iverson G. L. (2019). Network Analysis and Precision Rehabilitation for the Post-concussion Syndrome. Frontiers in Neurology10, 489. Read PDF of Full Article

Sullivan, K. A., Hills, A. P., & Iverson, G. L. (2018). Graded Combined Aerobic Resistance Exercise (CARE) to Prevent or Treat the Persistent Post-concussion Syndrome. Current Neurology and Neuroscience Reports, 18(11): 75. See in PubMed

Zafonte, R. D., Shih, S. L., Iaccarino, M. A., & Tan, C. O. (2018). Neurologic benefits of sports and exercise. Handbook of Clinical Neurology158, 463–471. See in PubMed

Chan, C., Iverson, G. L., Purtzki, J., Wong, K., Kwan, V., Gagnon, I., & Silverberg, N. D. (2018). Safety of active rehabilitation for persistent symptoms after pediatric sport-related concussion: A randomized controlled trial. Archives of Physical Medicine and Rehabilitation., 99(2): 242-249. See in PubMed

Lamm, A.G., Babu, A., Zafonte, R., Iaccarino, M.A. (2018). Utilizing a Workshop Format for Physiatry Trainees in the Management of Acute Sports-Related Concussion. American Journal of Physical Medicine & Rehabilitation. [Epub ahead of print]. See in PubMed

Silverberg, N.D., & Iverson, G.L. Rest and Recovery from Concussion: How should rest be used in concussion management. In I Gagnon and A. Ptito (Eds.). Sport Concussion: A Complete Guide to Recovery and Management. Boca Raton, FL: CRC Press; 2017, 131-148.

Schneider, K.J., Leddy, J.J., Guskiewicz, K.M., Seifert, T., McCrea, M., Silverberg, N.D., Feddermann-Demont, N., Iverson, G.L., Hayden, K.A., and Makdissi, M. (2017). Rest and Treatment/Rehabilitation Following Sport-Related Concussion: A Systematic Review. British Journal of Sports Medicine, 51(12): 930-934. See in PubMed

Multiple Concussions

Cook, N. E., Karr, J. E., & Iverson, G. L. (2021). Children with ADHD Have a Greater Lifetime History of Concussion: Results from the ABCD Study. Journal of Neurotrauma. See in PubMed

Iverson, G. L., Cook, N. E., Gilman, I. G., Maxwell, B., Mannix, R., Zafonte, R., Berkner, P. D., Brooks, B. L. (2020). Multiple Past Concussions in High School Hockey Players: Examining Cognitive Functioning and Symptom Reporting. Clinical Journal of Sports Medicine. [Epub ahead of print]. See in PubMed

Iverson, G.L., Kelshaw, P.M., Cook, N.E., & Caswell, S.V. (2020). Middle School Children With Attention-Deficit/Hyperactivity Disorder Have a Greater Concussion History. Clinical Journal of Sport Medicine. Feb 6. [Epub ahead of print]. See in PubMed

Iverson, G.L., Wojtowicz, M., Brooks, B.L., Maxwell, B.A., Atkins, J.E., Zafonte, R., & Berkner, P.D. (2020). High School Athletes with ADHD and Learning Difficulties Have a Greater Lifetime Concussion History. Journal of Attention Disorders, 24(8), 1095-1101. See in PubMed

Terry, D. P., Wojtowicz, M., Cook, N. E., Maxwell, B., Zafonte, R., Seifert, T., Silverberg, N., Berkner, P., & Iverson, G. L. (2020). Factors associated with self-reported concussion history in middle school athletes. Clinical Journal of Sport Medicine, 30, S1:69-74. See in PubMed

Gardner, A.J., Howell, D.R., Iverson, G.L. (2020). The association between multiple prior concussions, cognitive test scores, and symptom reporting in youth rugby league players. Brain Injury, 34(2), 224-228. See in PubMed

Brooks, B.L., Silverberg, N., Maxwell, B., Mannix, R., Zafonte, R., Berkner, P.D., & Iverson, G.L., (2018). Investigating effects of sex differences and prior concussions on symptom reporting and cognition among adolescent soccer players. American Journal of Sports Medicine, 46(4): 961-968. See in PubMed

Wojtowicz, M., Iverson, G.L., Silverberg, N.D., Mannix, R., Zafonte, R.D., Maxwell, B., Berkner, P.D. (2017). Consistency of Self-reported Concussion History in Adolescent Athletes. Journal of Neurotrauma, 34(2): 322-327. See in PubMed

Age of First Exposure to Contact Sports and Brain Health

Iverson, G. L., Caccese, J. B., Merz, Z. C., Büttner, F., & Terry, D. P. (2021). Age of First Exposure to Football Is Not Associated With Later-in-Life Cognitive or Mental Health Problems. Frontiers in Neurology, 12:647314. Read PDF of Full Article

Iverson, G. L., Terry, D. P., Caccese, J. B., Büttner, F., & Merz, Z. C. (2020). Age of First Exposure to Football Is Not Associated with Midlife Brain Health Problems. Journal of Neurotrauma, [Epub ahead of print]. See in PubMed

Caccese, J.B., Houck, Z., Kaminski, T.W., Clugston, J.R., Iverson, G.L., Bryk, K., Oldham, J.R., Pasquina, P.F., Broglio, S.P., McAllister, T.W., McCrea, M., & Buckley, T.A. (2020). Estimated Age of First Exposure to American Football and Outcome from Concussion. Neurology, 95(21):e2935-e2944. See in PubMed

Caccese, J.B., Bodt, B.A., Iverson, G.L., Kaminski, T.W., Bryk, K., Oldham, J.R., Broglio, S.P., McCrea, M., McAllister, T.W., & Buckley, T.A. (2020). Estimated age of first exposure to contact sports and neurocognitive, psychological, and physical outcomes in healthy NCAA collegiate athletes: A cohort study. Sports Medicine. Jul;50(7):1377-1392. See in PubMed

Caccese, J.B., Iverson, G.L., Cameron, K.L., Houston, M.N., McGinty, G.T., Jackson, J.C., O'Donnell, P., Pasquina, P.F., Broglio, S.P., McCrea, M. and McAllister, T. & Buckley, T.A. (2020). Estimated Age of First Exposure to Contact Sports Is Not Associated with Greater Symptoms or Worse Cognitive Functioning in Male US Service Academy Athletes. Journal of Neurotrauma, 37(2), 334-339. Read PDF of Full Article

Brain Imaging and Biomarkers

Aaron, S. E., Hamner, J. W., Ozturk, E. D., Hunt, D. L., Iaccarino, M. A., Meehan, W. P., 3rd, Howell, D. R., & Tan, C. O. (2021). Cerebrovascular Neuroprotection after Acute Concussion in Adolescents. Annals of Neurology90(1), 43–51. See in PubMed

Cook, M. J., Gardner, A. J., Wojtowicz, M., Williams, W. H., Iverson, G. L., & Stanwell, P. (2020). Task-related functional magnetic resonance imaging activations in patients with acute and subacute mild traumatic brain injury: A coordinate-based meta-analysis. Neuroimage: clinical, 25, 102129. Read PDF of Full Article

Wright, D.K., Gardner, A.J., Wojtowicz, M., Iverson, G.L., O’Brien, T.J., Schultz, S.R., & Stanwell, P. (2020). White matter abnormalities in retired professional rugby league players. Journal of Neurotrauma. Apr 3. [Epub ahead of print] See in PubMed

Guell, X., Arnold Anteraper, S., Gardner, A.J., Whitfield-Gabrieli, S., Kay-Lambkin, F., Iverson, G.L., Gabrieli, J., & Stanwell, P. (2020). Functional Connectivity Changes in Retired Rugby League Players: A Data-Driven Functional Magnetic Resonance Imaging Study. Journal of Neurotrauma, 37(16):1788-1796. See in PubMed

Conley, A.C., Cooper, P.S., Karayanidis, F., Gardner, A.J., Levi, C.R., Stanwell, P., Gaetz, M.B., Iverson, G.L (2019). Resting State Electroencephalography and Sports-Related Concussion: A Systematic Review. Journal of Neurotrauma, 36(1), 1-13. See in PubMed

Terry, D.P., & Miller, L.S. (2018). Repeated mild traumatic brain injuries is not associated with volumetric differences in former high school football players. Brain Imaging and Behavior, 12(3): 631-639. See in PubMed

Wojtowicz, M., Gardner, A. J., Stanwell, P., Zafonte, R., Dickerson, B.C., & Iverson, G.L. (2018). Cortical thickness and subcortical brain volumes in professional rugby league players. Neuroimage Clinical, 18: 377-381. See in PubMed

Gardner, AJ, Iverson G.L., Wojtowicz, M., Levi, C.R., Kay-Lambkin, F., Schofield, P.W., Shultz, S.R., Zafonte, R.D., Lin, A.P., & Stanwell, P. (2017). MR Spectroscopy Findings in Retired Professional Rugby League Players. International Journal of Sports Medicine, 38(3): 241-252. See in PubMed

Consensus Statement

McCrory, P., Meeuwisse, W., Dvorak, J., Aubry, M., Bailes, J., Broglio, S., Cantu, R.C., Cassidy, D., Echemendia, R.J., Castellani, R.J., Davis, G.A., Ellenbogen, R., Emery, C., Engebretsen, L., Feddermann-Demont, N., Giza, C.C., Guskiewicz, K.M., Herring, S., Iverson, G.L., Johnston, K.M., Kissick, J., Kutcher, J., Leddy, J.J., Maddocks, D., Makdissi, M., Manley, G.T., McCrea, M., Meehan, W.P., Nagahiro, S., Patricios, J., Putukian, M., Schneider, K.J., Sills, A., Tator, C.H., Turner, M., Vos, P.E. (2017). Consensus statement on concussion in sport-the 5th international conference on concussion in sport held in Berlin, October 2016. British Journal of Sports Medicine, 51(11): 838-847. Read PDF of Full Article

Special Topics

Silverberg, N., D., Iverson, G. L.; ACRM Mild TBI Definition Expert Consensus Group and the ACRM Brain Injury Special Interest Group Mild TBI Task Force (2021). Expert Panel Survey to Update the American Congress of Rehabilitation Medicine Definition of Mild Traumatic Brain Injury. Archives of Physical Medicine and Rehabilitation, Jan;102(1):76-86. See in PubMed

Polich, G., Iaccarino, M. A., Kaptchuk, T. J., Morales-Quezada, L., & Zafonte, R. (2020). Nocebo Effects in Concussion: Is All That Is Told Beneficial? American Journal of Physical Medicine & Rehabilitation99(1), 71–80. See in PubMed

Rice, S., Iaccarino, M. A., Bhatnagar, S., Robidoux, G., Zafonte, R., & Kotler, D. H. (2020). Reporting of Concussion-Like Symptoms After Cycling Crashes: A Survey of Competitive and Recreational Cyclists. Journal of Athletic Training55(1), 11–16. Read PDF of Full Article

Gardner, A. J., Quarrie, K. L., & Iverson, G. L. (2019). The Epidemiology of Sport-Related Concussion: What the Rehabilitation Clinician Needs to Know. The Journal of Orthopaedic and Sports Physical Therapy49(11), 768–778. See in PubMed

Iverson, G. L., Jones, P. J., Karr, J. E., Maxwell, B. A., Zafonte, R., Berkner, P. D., & McNally, R. J. (2020). Network structure of physical, cognitive, and emotional symptoms at preseason baseline in student athletes with attention-deficit/hyperactivity disorder. Archives of Clinical Neuropsychology. Advance Online Publication. See in PubMed

Iverson, G. L., Jones, P. J., Karr, J. E., Maxwell, B. A., Zafonte, R., Berkner, P. D., & McNally, R. J. (2020). Architecture of physical, cognitive, and emotional symptoms at preseason baseline in adolescent student athletes with a history of mental health problems. Frontiers in Neurology, 11(175), 1-10. Read Full Article

Gardner, A. J., Howell, D. R., & Iverson, G. L. (2019). National Rugby League match scheduling and rate of concussion. Journal of Science and Medicine in Sport22(7), 780–783. See in PubMed

Possible Long-Term Effects and Later-in-Life Brain Health

Iverson, G. L., Merz, J. C., & Terry, D. P. (2021). High School Football and Midlife Brain Health Problems. Clinical Journal of Sport Medicine. Read Full Article

Iverson, G. L., Van Patten, R., Terry, D. P., Levi, C. R., & Gardner, A. J. (2021). Predictors and Correlates of Depression in Retired Elite Level Rugby League Players. Frontiers in Neurology12, 655746. Read PDF of Full Article

Iverson, G.L., Merz, Z.C., & Terry, D.P. (in press). Playing High School Football is Not Associated with Increased Risk for Suicidality in Early Adulthood. Clinical Journal of Sport Medicine.

Tenforde, A. S., Cortez, B., Coughlan-Gifford, E., Grashow, R., Baker, J., Baggish, A. L., Pascual-Leone, A., Nadler, L. M., Speizer, F. E., Taylor, H. A., Weisskopf, M. G., & Zafonte, R. (2021). Individual and cumulative health afflictions are associated with greater impairment in physical and mental function in former professional American style football players. PM&R: the journal of injury, function, and rehabilitation. See in PubMed

Roberts, A. L., Zafonte, R. D., Speizer, F. E., Baggish, A., Taylor, H. A., Nadler, L., & Weisskopf, M. G. (2021). Modifiable Risk Factors for Poor Cognitive Function in Former American-Style Football Players: Findings from the Harvard Football Players Health Study. Journal of Neurotrauma38(2), 189–195. Read PDF of Full Article

Iverson, G.L. (2020). Retired National Football League Players are Not at Greater Risk for Suicide. Archives of Clinical Neuropsychology, 35(3), 332-341. Read PDF of Full Article

Roberts, A. L., Taylor, H. A., Jr, Whittington, A. J., Zafonte, R. D., Speizer, F. E., Pascual-Leone, A., Baggish, A., & Weisskopf, M. G. (2020). Race in association with physical and mental health among former professional American-style football players: findings from the Football Players Health Study. Annals of Epidemiology51, 48–52.e2. Read PDF of Full Article

Plessow, F., Pascual-Leone, A., McCracken, C. M., Baker, J., Krishnan, S., Baggish, A., Connor, A., Courtney, T. K., Nadler, L. M., Speizer, F. E., Taylor, H. A., Weisskopf, M. G., Zafonte, R. D., & Meehan, W. P., III (2020). Self-Reported Cognitive Function and Mental Health Diagnoses among Former Professional American-Style Football Players. Journal of Neurotrauma37(8), 1021–1028. Read PDF of Full Article

Roberts, A. L., Pascual-Leone, A., Speizer, F. E., Zafonte, R. D., Baggish, A. L., Taylor, H., Jr, Nadler, L. M., Courtney, T. K., Connor, A., Grashow, R., Stillman, A. M., Marengi, D. A., & Weisskopf, M. G. (2019). Exposure to American Football and Neuropsychiatric Health in Former National Football League Players: Findings from the Football Players Health Study. The American Journal of Sports Medicine47(12), 2871–2880. Read PDF of Full Article

Nguyen, V. T., Zafonte, R. D., Chen, J. T., Kponee-Shovein, K. Z., Paganoni, S., Pascual-Leone, A., Speizer, F. E., Baggish, A. L., Taylor, H. A., Jr, Nadler, L. M., Courtney, T. K., Connor, A., & Weisskopf, M. G. (2019). Mortality Among Professional American-Style Football Players and Professional American Baseball Players. JAMA Network Open2(5), e194223. Read Full Article

Manley, G.T., Gardner, A.J., Schneider, K.J., Guskiewicz, K.M., Bailes, J., Cantu, R.C., Castellani, R.J., Turner, M., Jordan, B.D., Randolph, C., Dvořák, J., Tator, C.H., McCrory, P., & Iverson, G.L. (2017). A Systematic Review of Potential Long-Term Effects of Sport-Related Concussion. British Journal of Sports Medicine, 51(12): 969-977. Read Study

Chronic Traumatic Encephalopathy

Iverson, G. L., Merz, Z. C., & Terry, D. P. (2021). Examining the Research Criteria for Traumatic Encephalopathy Syndrome in Middle-Aged Men from the General Population Who Played Contact Sports in High School. Frontiers in Neurology12, 632618. Read PDF of Full Article

Iverson, G. L., & Gardner, A. J. (2021). Symptoms of traumatic encephalopathy syndrome are common in the US general population. Brain Communications3(1), fcab001. Read PDF of Full Article

Iverson, G. L., & Gardner, A. J. (2020). Risk for Misdiagnosing Chronic Traumatic Encephalopathy in Men With Anger Control Problems. Frontiers in Neurology, 11:739. Read PDF of Full Article

Grashow, R., Weisskopf, M. G., Baggish, A., Speizer, F. E., Whittington, A. J., Nadler, L., Connor, A., Keske, R., Taylor, H., Zafonte, R., & Pascual-Leone, A. (2020). Premortem Chronic Traumatic Encephalopathy Diagnoses in Professional Football. Annals of Neurology88(1), 106–112. Read PDF of Full Article

Iverson, G.L., & Gardner, A.J. (2020). Risk of misdiagnosing chronic traumatic encephalopathy in men with depression. The Journal of Neuropsychiatry and Clinical Neurosciences, 32(2), 139-146. See in PubMed

Iverson, G.L., Gardner, A.J., Shultz, S.R., Solomon, G.S., McCrory, P., Zafonte, R., Perry, G., Hazrati, L.N., Keene, C.D. & Castellani, R.J. (2019). Chronic traumatic encephalopathy neuropathology might not be inexorably progressive or unique to repetitive neurotrauma. Brain, 142(12), 3672-3693. Read PDF of Full Article

Iverson, G. L., Luoto, T. M., Karhunen, P. J., & Castellani, R. J. (2019). Mild chronic traumatic encephalopathy neuropathology in people with no known participation in contact sports or history of repetitive neurotrauma. Journal of Neuropathology & Experimental Neurology78(7), 615-625. Read PDF of Full Article

Iverson GL, Terry DP, Luz M, Zafonte R, McCrory P, Solomon GS, & Gardner AJ. (2019). Anger and Depression in Middle-Aged Men: Implications for a Clinical Diagnosis of Chronic Traumatic Encephalopathy, Journal of Neuropsychiatry and Clinical Neurosciences, 31(4), 328-336. See in PubMed

Iverson, G.L., Keene, C.D., Perry, G., & Castellani, R.J. (2018). The need to separate chronic traumatic encephalopathy neuropathology from clinical features. Journal of Alzheimer’s Disease, 61(1): 17-28. Read PDF of Full Article