CoChat
Sign Up
Cited by 663Traumatic Brain Injury ResearchSports injuries and preventionLong-Term Effects of COVID-19

A systematic review of potential long-term effects of sport-related concussion.

Open access
Manley, Geoff, Gardner, Andrew J, Schneider, Kathryn J, Guskiewicz, Kevin M, Bailes, Julian, Cantu, Robert C, Castellani, Rudolph J, Turner, Michael +7 more·2017·British Journal of Sports Medicine
DOI 10.1136/bjsports-2017-097791PMC PMC5466926
Open this paper in CoChat — free accountOpen PDF

Abstract

Objective: Systematic review of possible long-term effects of sports-related concussion in retired athletes. Data sources: Ten electronic databases. Study selection: Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as>10 years after the injury. Data extraction: Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors. Results: Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes. Conclusion: Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1136/bjsports-2017-097791

Cites

22 of 22 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 52

  1. [1]Martland HS Punch drunk. J Am Med Assoc 1928; 91: 1103– 7. 10.1001/jama.1928.02700150029009 · DOI · Paper page
  2. [2]Parker HL Traumatic encephalopathy (`punch drunk') of professional pugilists. J Neurol Psychopathol 1934; 15: 20– 8. 10.1136/jnnp.s1-15.57.20 21610785 PMC1039021 · DOI
  3. [3]Millspaugh JA Dementia pugilistica. U.S. Naval Medicine Bulletin 1937; 35: 297– 303.
  4. [5]Critchley M Medical aspects of boxing, particularly from a neurological standpoint. Br Med J 1957; 1: 357– 62. 10.1136/bmj.1.5015.357 13396257 PMC1974382 · DOI
  5. [7]Randolph C, Karantzoulis S, Guskiewicz K Prevalence and characterization of mild cognitive impairment in retired national football league players. J Int Neuropsychol Soc 2013; 19: 873– 80. 10.1017/S1355617713000805 23902607 · DOI · Paper page
  6. [9]Strain J, Didehbani N, Cullum CM, et al Depressive symptoms and white matter dysfunction in retired NFL players with concussion history. Neurology 2013; 81: 25– 32. 10.1212/WNL.0b013e318299ccf8 23709590 PMC3770203 · DOI · Paper page
  7. [10]Koerte IK, Lin AP, Muehlmann M, et al Altered neurochemistry in former professional soccer players without a history of concussion. J Neurotrauma 2015; 32: 1287– 93. 10.1089/neu.2014.3715 25843317 PMC4545372 · DOI
  8. [11]McKee AC, Stern RA, Nowinski CJ, et al The spectrum of disease in chronic traumatic encephalopathy. Brain 2013; 136: 43– 64. 10.1093/brain/aws307 23208308 PMC3624697 · DOI · Paper page
  9. [13]Howick J, Chalmers I, Glasziou P, et al The Oxford 2011 levels of evidence: oxford centre for Evidence-Based medicine, pps. OCEBM Levels of Evidence Working Group* 2011.
  10. [14]Bailes JE, Petraglia AL, Omalu BI, et al Role of subconcussion in repetitive mild traumatic brain injury. J Neurosurg 2013; 119: 1235– 45. 10.3171/2013.7.JNS121822 23971952 · DOI
  11. [15]Belanger HG, Vanderploeg RD, McAllister T Subconcussive blows to the head: a formative review of short-term clinical outcomes. J Head Trauma Rehabil 2016; 31: 159– 66. 10.1097/HTR.0000000000000138 25931186 · DOI
  12. [16]Montenigro PH, Alosco ML, Martin BM, et al Cumulative head impact exposure predicts later-life depression, apathy, executive dysfunction, and cognitive impairment in former high school and college football players. J Neurotrauma 2017; 34: 328– 40. 10.1089/neu.2016.4413 27029716 PMC5220530 · DOI
  13. [17]Lin AP, Ramadan S, Stern RA, et al Changes in the neurochemistry of Athletes with repetitive brain trauma: preliminary results using localized correlated spectroscopy. Alzheimers Res Ther 2015; 7: 13 10.1186/s13195-015-0094-5 25780390 PMC4361214 · DOI
  14. [18]Koerte IK, Mayinger M, Muehlmann M, et al Cortical thinning in former professional soccer players. Brain Imaging Behav 2016; 10: 792– 8. 10.1007/s11682-015-9442-0 26286826 · DOI
  15. [19]Vann Jones SA, Breakey RW, Evans PJ Heading in football, long-term cognitive decline and dementia: evidence from screening retired professional footballers. Br J Sports Med 2014; 48: 159– 61. 10.1136/bjsports-2013-092758 24026299 · DOI
  16. [20]Meehan WP, Taylor AM, Berkner P, et al Division III collision sports are not associated with neurobehavioral quality of life. J Neurotrauma 2016; 33: 254– 9. 10.1089/neu.2015.3930 26193380 PMC4722573 · DOI
  17. [21]Koerte IK, Hufschmidt J, Muehlmann M, et al Cavum septi pellucidi in symptomatic former professional football players. J Neurotrauma 2016; 33: 346– 53. 10.1089/neu.2015.3880 26414478 PMC4761807 · DOI
  18. [22]Gardner RC, Hess CP, Brus-Ramer M, et al Cavum septum pellucidum in retired American pro-football players. J Neurotrauma 2016; 33: 157– 61. 10.1089/neu.2014.3805 25970145 PMC4696427 · DOI
  19. [23]Goswami R, Dufort P, Tartaglia MC, et al Frontotemporal correlates of impulsivity and machine learning in retired professional Athletes with a history of multiple concussions. Brain Struct Funct 2016; 221: 1911– 25. 10.1007/s00429-015-1012-0 25721800 PMC4853456 · DOI
  20. [24]Strain JF, Womack KB, Didehbani N, et al Imaging correlates of memory and concussion history in retired national football league athletes. JAMA Neurol 2015; 72: 773– 80. 10.1001/jamaneurol.2015.0206 25985094 PMC6761828 · DOI
  21. [26]Wilde EA, Hunter JV, Li X, et al Chronic effects of boxing: diffusion tensor imaging and cognitive findings. J Neurotrauma 2016; 33: 672– 80. 10.1089/neu.2015.4035 26414735 PMC4827316 · DOI
  22. [27]Multani N, Goswami R, Khodadadi M, et al The association between white-matter tract abnormalities, and neuropsychiatric and cognitive symptoms in retired professional football players with multiple concussions. J Neurol 2016; 263: 1332– 41. 10.1007/s00415-016-8141-0 27142715 · DOI
  23. [28]Small GW, Kepe V, Siddarth P, et al PET scanning of brain tau in retired national football league players: preliminary findings. Am J Geriatr Psychiatry 2013; 21: 138– 44. 10.1016/j.jagp.2012.11.019 23343487 · DOI
  24. [30]Kerr ZY, DeFreese JD, Marshall SW Current physical and mental health of former collegiate athletes. Orthop J Sports Med 2014; 2: 2325967114544107 10.1177/2325967114544107 26535354 PMC4555572 · DOI
  25. [34]Murelius O, Haglund Y Does Swedish amateur boxing lead to chronic brain damage? 4. A retrospective neuropsychological study. Acta Neurol Scand 1991; 83: 9– 13. 10.1111/j.1600-0404.1991.tb03952.x 2011947 · DOI
  26. [35]Didehbani N, Munro Cullum C, Mansinghani S, et al Depressive symptoms and concussions in aging Retired NFL players. Arch Clin Neuropsychol 2013; 28: 418– 24. 10.1093/arclin/act028 23644673 PMC4007104 · DOI · Paper page
  27. [36]Stamm JM, Bourlas AP, Baugh CM, et al Age of first exposure to football and later-life cognitive impairment in former NFL players. Neurology 2015; 84: 1114– 20. 10.1212/WNL.0000000000001358 25632088 PMC4371403 · DOI
  28. [37]Hume PA, Theadom A, Lewis GN, et al A comparison of cognitive function in former rugby union players compared with former non-contact-sport players and the impact of concussion history. Sports Med 2016 10.1007/s40279-016-0608-8 27558141 · DOI
  29. [38]Lolekha P, Phanthumchinda K, Bhidayasiri R Prevalence and risk factors of Parkinson's disease in retired Thai traditional boxers. Mov Disord 2010; 25: 1895– 901. 10.1002/mds.23210 20669292 · DOI
  30. [40]Kerr ZY, Marshall SW, Guskiewicz KM Reliability of concussion history in former professional football players. Med Sci Sports Exerc 2012; 44: 377– 82. 10.1249/MSS.0b013e31823240f2 21857370 · DOI
  31. [42]Baron SL, Hein MJ, Lehman E, et al Body mass index, playing position, race, and the cardiovascular mortality of retired professional football players. Am J Cardiol 2012; 109: 889– 96. 10.1016/j.amjcard.2011.10.050 22284915 · DOI
  32. [43]Lehman EJ, Hein MJ, Baron SL, et al Neurodegenerative causes of death among retired national football league players. Neurology 2012; 79: 1970– 4. 10.1212/WNL.0b013e31826daf50 22955124 PMC4098841 · DOI · Paper page
  33. [44]Savica R, Parisi JE, Wold LE, et al High school football and risk of neurodegeneration: a community-based study. Mayo Clin Proc 2012; 87: 335– 40. 10.1016/j.mayocp.2011.12.016 22469346 PMC3538465 · DOI
  34. [45]Janssen PH, Mandrekar J, Mielke MM, et al High school football and Late-Life risk of neurodegenerative syndromes, 1956-1970. Mayo Clin Proc 2017; 92: 66– 71. 10.1016/j.mayocp.2016.09.004 27979411 PMC5452974 · DOI
  35. [46]Baugh CM, Stamm JM, Riley DO, et al Chronic traumatic encephalopathy: neurodegeneration following repetitive concussive and subconcussive brain trauma. Brain Imaging Behav 2012; 6: 244– 54. 10.1007/s11682-012-9164-5 22552850 · DOI · Paper page
  36. [48]McKee AC, Cantu RC, Nowinski CJ, et al Chronic traumatic encephalopathy in athletes: progressive tauopathy after repetitive head injury. J Neuropathol Exp Neurol 2009; 68: 709– 35. 10.1097/NEN.0b013e3181a9d503 19535999 PMC2945234 · DOI · Paper page
  37. [49]McKee AC, Gavett BE, Stern RA, et al TDP-43 proteinopathy and motor neuron disease in chronic traumatic encephalopathy. J Neuropathol Exp Neurol 2010; 69: 918– 29. 10.1097/NEN.0b013e3181ee7d85 20720505 PMC2951281 · DOI · Paper page
  38. [53]Ling H, Holton JL, Shaw K, et al Histological evidence of chronic traumatic encephalopathy in a large series of neurodegenerative diseases. Acta Neuropathol 2015; 130: 891– 3. 10.1007/s00401-015-1496-y 26497674 · DOI · Paper page
  39. [55]Koga S, Dickson DW, Bieniek KF Chronic traumatic encephalopathy pathology in multiple system atrophy. J Neuropathol Exp Neurol 2016; 75: 963– 70. 10.1093/jnen/nlw073 27543120 PMC5029441 · DOI · Paper page
  40. [56]Roberts GW, Allsop D, Bruton C The occult aftermath of boxing. J Neurol Neurosurg Psychiatry 1990; 53: 373– 8. 10.1136/jnnp.53.5.373 2191084 PMC488051 · DOI · Paper page
  41. [58]Johnson J Organic psychosyndromes due to boxing. Br J Psychiatry 1969; 115: 45– 53. 10.1192/bjp.115.518.45 5305282 · DOI · Paper page
  42. [59]Jordan BD The clinical spectrum of sport-related traumatic brain injury. Nat Rev Neurol 2013; 9: 222– 30. 10.1038/nrneurol.2013.33 23478462 · DOI · Paper page
  43. [62]Casson IR, Viano DC, Haacke EM, et al Is there chronic brain damage in retired NFL players? neuroradiology, neuropsychology, and neurology examinations of 45 retired players. Sports Health 2014; 6: 384– 95. 10.1177/1941738114540270 25177413 PMC4137679 · DOI
  44. [64]Schwenk TL, Gorenflo DW, Dopp RR, et al Depression and pain in retired professional football players. Med Sci Sports Exerc 2007; 39: 599– 605. 10.1249/mss.0b013e31802fa679 17414796 · DOI
  45. [65]González HM, Tarraf W, Whitfield KE, et al The epidemiology of Major depression and ethnicity in the United States. J Psychiatr Res 2010; 44: 1043– 51. 10.1016/j.jpsychires.2010.03.017 20537350 PMC2963677 · DOI
  46. [66]Cottler LB, Ben Abdallah A, Cummings SM, et al Injury, pain, and prescription opioid use among former National Football League (NFL) players. Drug Alcohol Depend 2011; 116: 188– 94. 10.1016/j.drugalcdep.2010.12.003 21277121 PMC3095672 · DOI
  47. [67]Crary JF, Trojanowski JQ, Schneider JA, et al Primary age-related tauopathy (PART): a common pathology associated with human aging. Acta Neuropathol 2014; 128: 755– 66. 10.1007/s00401-014-1349-0 25348064 PMC4257842 · DOI · Paper page
  48. [69]Elobeid A, Libard S, Leino M, et al Altered proteins in the aging brain. J Neuropathol Exp Neurol 2016; 75: 316– 25. 10.1093/jnen/nlw002 26979082 PMC4793886 · DOI · Paper page
  49. [70]Hinton PS, Johnstone B, Blaine E, et al Effects of current exercise and diet on late-life cognitive health of former college football players. Phys Sportsmed 2011; 39: 11– 22. 10.3810/psm.2011.09.1916 22030936 · DOI
  50. [73]Wortzel HS, Brenner LA, Arciniegas DB Traumatic brain injury and chronic traumatic encephalopathy: a forensic neuropsychiatric perspective. Behav Sci Law 2013; 31: 721– 38. 10.1002/bsl.2079 24019038 · DOI
  51. [75]Seichepine DR, Stamm JM, Daneshvar DH, et al Profile of self-reported problems with executive functioning in college and professional football players. J Neurotrauma 2013; 30: 1299– 304. 10.1089/neu.2012.2690 23421745 PMC3713446 · DOI
  52. [76]Corsellis JA, Bruton CJ, Freeman-Browne D The aftermath of boxing. Psychol Med 1973; 3: 270– 303. 10.1017/S0033291700049588 4729191 · DOI · Paper page

Cited by

Sorted by citations

Authors
Manley, G., 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., Hayden, K. A., Tator, C. H., McCrory, P., & Iverson, G. L.
Affiliations
  • John Hunter Hospital (AU)
  • University of Calgary (CA)
  • University of North Carolina at Chapel Hill (US)
  • Endeavor Health (US)
  • Boston University (US)
  • Western Michigan University (US)
  • The International Concussion and Head Injury Research Foundation Limited (GB)
  • Burke Rehabilitation Hospital (US)
  • Loyola University Medical Center (US)
  • University of Zurich (CH)
  • University of Toronto (CA)
  • Florey Institute of Neuroscience and Mental Health (AU)
  • Harvard University (US)
ORCID
Venue
British Journal of Sports Medicine
Publisher
BMJ
Published
2017-04-28
Volume
51
Issue
12
Pages
969-977
ISSN
  • 0306-3674 (ISSN-L)
  • 1473-0480
DOI
10.1136/bjsports-2017-097791
PMC
PMC5466926
OpenAlex
W2608826008
Cited by
663
References
22
Citations by year
2026: 32 · 2025: 55 · 2024: 81 · 2023: 89 · 2022: 78 · 2021: 102 · 2020: 101 · 2019: 63 · 2018: 51 · 2017: 8 · 2014: 1
FWCI
8.08
Type
journal article
Language
en
Open access
Licence
cc-by-nc
Locations
  • British Journal of Sports Medicine (publishedVersion, cc-by-nc)
  • Europe PMC (PubMed Central) (publishedVersion, cc-by-nc)
  • PubMed Central (publishedVersion, cc-by-nc)
  • PubMed (publishedVersion)
  • Minerva Access (University of Melbourne) (submittedVersion, cc-by-nc)
  • Digital Access to Scholarship at Harvard (DASH) (Harvard University) (submittedVersion, cc-by)
  • eScholarship (California Digital Library) (submittedVersion)
  • eScholarship (California Digital Library) (submittedVersion, cc-by-nc)
  • Figshare (submittedVersion, cc-by-nc)
  • HighWire Press Open Archive (submittedVersion)
  • NOVA (University of Newcastle Australia) (submittedVersion, cc-by-nc)
Topics
  • Health Sciences › Medicine › Epidemiology › Traumatic Brain Injury Research
  • Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports injuries and prevention
  • Health Sciences › Medicine › Neurology › Long-Term Effects of COVID-19
Keywords
sports-related concussion, long-term effects, former athletes, chronic traumatic encephalopathy, neurodegenerative diseases, cognitive impairment, depression, suicide risk, multiple concussions, American football, neuroimaging, neuropathology
MeSH terms
Athletic Injuries, Brain, Brain Concussion, Cognition Disorders, Depression, Football, Humans, Risk Factors, Incidence, Post-Concussion Syndrome, Athletes, Neuroimaging

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review