{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T01:42:28Z","timestamp":1792806148164,"version":"4.5.0"},"reference-count":32,"publisher":"Journal of Neurosurgery Publishing Group (JNSPG)","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2020,12]]},"abstract":"\n OBJECTIVE<\/jats:title>\n Previous studies have shown that clinically asymptomatic high-acceleration head impacts (HHIs) may be associated with neuronal and axonal injury, as measured by advanced imaging and biomarkers. Unfortunately, these methods of measurement are time-consuming, invasive, and costly. A quick noninvasive measurement tool is needed to aid studies of head injury and its biological impact. Quantitative pupillometry is a potential objective, rapid, noninvasive measurement tool that may be used to assess the neurological effects of HHIs. In this study, the authors investigated the effect of HHIs on pupillary metrics, as measured using a pupillometer, in the absence of a diagnosed concussion.<\/jats:p>\n <\/jats:sec>\n \n METHODS<\/jats:title>\n \n A prospective observational cohort study involving 18 high school football athletes was performed. These athletes were monitored for both the frequency and magnitude of head impacts that they sustained throughout a playing season by using the Head Impact Telemetry System. An HHI was defined as an impact exceeding 95\n g<\/jats:italic>\n linear acceleration and 3760 rad\/sec\n 2<\/jats:sup>\n rotational acceleration. Pupillary assessments were performed at baseline, midseason, after occurrence of an HHI, and at the end of the season by using the NeurOptics NPi-200 pupillometer. The Sport Concussion Assessment Tool, 5th Edition (SCAT5), was also used at each time point. Comparisons of data obtained at the various time points were calculated using a repeated-measures analysis of variance and a t-test.\n <\/jats:p>\n <\/jats:sec>\n \n RESULTS<\/jats:title>\n Seven athletes sustained HHIs without a related diagnosed concussion. Following these HHIs, the athletes demonstrated decreases in pupil dilation velocity (mean difference 0.139 mm\/sec; p = 0.048), percent change in pupil diameter (mean difference 3.643%; p = 0.002), and maximum constriction velocity (mean difference 0.744 mm\/sec; p = 0.010), compared to measurements obtained at the athletes\u2019 own midseason evaluations. No significant changes occurred between the SCAT5 subtest scores calculated at midseason and those after a high impact, although the effect sizes (Cohen\u2019s d) on individual components ranged from 0.41 to 0.65.<\/jats:p>\n <\/jats:sec>\n \n CONCLUSIONS<\/jats:title>\n Measurable changes in pupil response were demonstrated following an HHI. These results suggest that clinically asymptomatic HHIs may affect brain reflex pathways, reflecting a biological injury previously seen when more invasive methods were applied.<\/jats:p>\n <\/jats:sec>","DOI":"10.3171\/2019.7.jns191272","type":"journal-article","created":{"date-parts":[[2019,12,13]],"date-time":"2019-12-13T20:44:19Z","timestamp":1576269859000},"page":"1886-1891","source":"Crossref","is-referenced-by-count":29,"title":["Pupillary changes after clinically asymptomatic high-acceleration head impacts in high school football athletes"],"prefix":"10.3171","volume":"133","author":[{"given":"Jacob R.","family":"Joseph","sequence":"first","affiliation":[{"name":"Department of Neurosurgery,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jennylee S.","family":"Swallow","sequence":"additional","affiliation":[{"name":"Michigan Concussion Center,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kylene","family":"Willsey","sequence":"additional","affiliation":[{"name":"Department of Pediatrics,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea A.","family":"Almeida","sequence":"additional","affiliation":[{"name":"NeuroSport, and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Matthew T.","family":"Lorincz","sequence":"additional","affiliation":[{"name":"NeuroSport, and"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Robert K.","family":"Fraumann","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark E.","family":"Oppenlander","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicholas J.","family":"Szerlip","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery,"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steven P.","family":"Broglio","sequence":"additional","affiliation":[{"name":"Michigan Concussion Center,"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1754","reference":[{"key":"b1","series-title":"Neurology","doi-asserted-by":"publisher","first-page":"e2133","DOI":"10.1212\/WNL.0000000000006617","article-title":"Concussion BASICS III: serum biomarker changes following sport-related concussion","volume":"91","author":"Asken BM","year":"2018","unstructured":"Asken BM, Bauer RM, DeKosky ST, Svingos AM, Hromas G, Boone JK, : Concussion BASICS III: serum biomarker changes following sport-related concussion. Neurology 91:e2133\u2013e2143, 20183040478610.1212\/WNL.0000000000006617"},{"key":"b2","series-title":"J Neurosurg","doi-asserted-by":"publisher","first-page":"1235","DOI":"10.3171\/2013.7.JNS121822","article-title":"Role of subconcussion in repetitive mild traumatic brain injury","volume":"119","author":"Bailes JE","year":"2013","unstructured":"Bailes JE, Petraglia AL, Omalu BI, Nauman E, Talavage T: Role of subconcussion in repetitive mild traumatic brain injury. J Neurosurg 119:1235\u20131245, 20132397195210.3171\/2013.7.JNS121822"},{"key":"b3","series-title":"Clin J Sport Med","article-title":"Eye tracking as a biomarker for concussion in children","author":"Bin Zahid A","unstructured":"Bin Zahid A, Hubbard ME, Lockyer J, Podolak O, Dammavalam VM, Grady M, : Eye tracking as a biomarker for concussion in children. Clin J Sport Med [epub ahead of print], 201830095503"},{"key":"b4","series-title":"J Athl Train","doi-asserted-by":"publisher","first-page":"160","DOI":"10.4085\/1062-6050-51.9.05","article-title":"If you\u2019re not measuring, you\u2019re guessing: the advent of objective concussion assessments","volume":"52","author":"Broglio SP","year":"2017","unstructured":"Broglio SP, Guskiewicz KM, Norwig J: If you\u2019re not measuring, you\u2019re guessing: the advent of objective concussion assessments. J Athl Train 52:160\u2013166, 201710.4085\/1062-6050-51.9.05"},{"key":"b5","series-title":"Med Sci Sports Exerc","doi-asserted-by":"publisher","first-page":"2064","DOI":"10.1249\/MSS.0b013e3181dd9156","article-title":"Biomechanical properties of concussions in high school football","volume":"42","author":"Broglio SP","year":"2010","unstructured":"Broglio SP, Schnebel B, Sosnoff JJ, Shin S, Fend X, He X, : Biomechanical properties of concussions in high school football. Med Sci Sports Exerc 42:2064\u20132071, 20102035159310.1249\/MSS.0b013e3181dd9156"},{"key":"b6","series-title":"J Athl Train","doi-asserted-by":"publisher","first-page":"511","DOI":"10.4085\/1062-6050-51.7.04","article-title":"Football players\u2019 head-impact exposure after limiting of full-contact practices","volume":"51","author":"Broglio SP","year":"2016","unstructured":"Broglio SP, Williams RM, O\u2019Connor KL, Goldstick J: Football players\u2019 head-impact exposure after limiting of full-contact practices. J Athl Train 51:511\u2013518, 201610.4085\/1062-6050-51.7.0427333460"},{"key":"b7","series-title":"J Spine","article-title":"Pupillary light reflex as an objective biomarker for early identification of blast-induced mTBI","author":"Cap\u00f3-Aponte JE","unstructured":"Cap\u00f3-Aponte JE, Urosevich TG, Walsh DV, Temme LA, Tarbett AK: Pupillary light reflex as an objective biomarker for early identification of blast-induced mTBI. J Spine [epub ahead of print], 2013"},{"key":"b8","series-title":"Crit Care","doi-asserted-by":"publisher","first-page":"99","DOI":"10.1186\/s13054-016-1239-z","article-title":"Reliability of standard pupillometry practice in neurocritical care: an observational, double-blinded study","volume":"20","author":"Couret D","year":"2016","unstructured":"Couret D, Boumaza D, Grisotto C, Triglia T, Pellegrini L, Ocquidant P, : Reliability of standard pupillometry practice in neurocritical care: an observational, double-blinded study. Crit Care 20:99, 20162707231010.1186\/s13054-016-1239-z"},{"key":"b9","series-title":"Br J Sports Med","first-page":"848","article-title":"The Sport Concussion Assessment Tool 5th Edition (SCAT5): background and rationale","volume":"51","author":"Echemendia RJ","year":"2017","unstructured":"Echemendia RJ, Meeuwisse W, McCrory P, Davis GA, Putukian M, Leddy J, : The Sport Concussion Assessment Tool 5th Edition (SCAT5): background and rationale. Br J Sports Med 51:848\u2013850, 201728446453"},{"key":"b10","series-title":"Br J Sports Med","doi-asserted-by":"publisher","first-page":"978","DOI":"10.1136\/bjsports-2016-097452","article-title":"What strategies can be used to effectively reduce the risk of concussion in sport? A systematic review","volume":"51","author":"Emery CA","year":"2017","unstructured":"Emery CA, Black AM, Kolstad A, Martinez G, Nettel-Aguirre A, Engebretsen L, : What strategies can be used to effectively reduce the risk of concussion in sport? A systematic review. Br J Sports Med 51:978\u2013984, 201710.1136\/bjsports-2016-097452"},{"issue":"CN Suppl 1","key":"b11","series-title":"Neurosurgery","doi-asserted-by":"publisher","first-page":"386","DOI":"10.1093\/neurosurgery\/12.CN_suppl_1.386","article-title":"Report of Ad Hoc Committee to Study Head Injury Nomenclature","volume":"12","author":"Gurdjian E","year":"1966","unstructured":"Gurdjian E, Volis H: Report of Ad Hoc Committee to Study Head Injury Nomenclature. Neurosurgery 12 (CN Suppl 1):386\u2013394, 196610.1093\/neurosurgery\/12.CN_suppl_1.386"},{"key":"b12","series-title":"World Neurosurg","doi-asserted-by":"publisher","first-page":"73","DOI":"10.1016\/j.wneu.2017.03.106","article-title":"Impact of increased football field width on player high-speed collision rate","volume":"103","author":"Joseph JR","year":"2017","unstructured":"Joseph JR, Khalsa SS, Smith BW, Park P: Impact of increased football field width on player high-speed collision rate. World Neurosurg 103:73\u201377, 20172837725210.1016\/j.wneu.2017.03.106"},{"key":"b13","series-title":"J Neurosurg","doi-asserted-by":"publisher","first-page":"1409","DOI":"10.3171\/2017.12.JNS172386","article-title":"Elevated markers of brain injury as a result of clinically asymptomatic high-acceleration head impacts in high-school football athletes","volume":"130","author":"Joseph JR","year":"2019","unstructured":"Joseph JR, Swallow JS, Willsey K, Lapointe AP, Khalatbari S, Korley FK, : Elevated markers of brain injury as a result of clinically asymptomatic high-acceleration head impacts in high-school football athletes. J Neurosurg 130:1409\u20131788, 201910.3171\/2017.12.JNS172386"},{"key":"b14","series-title":"Soc Sci Med","doi-asserted-by":"publisher","first-page":"66","DOI":"10.1016\/j.socscimed.2015.04.011","article-title":"Concussion under-reporting and pressure from coaches, teammates, fans, and parents","volume":"134","author":"Kroshus E","year":"2015","unstructured":"Kroshus E, Garnett B, Hawrilenko M, Baugh CM, Calzo JP: Concussion under-reporting and pressure from coaches, teammates, fans, and parents. Soc Sci Med 134:66\u201375, 201510.1016\/j.socscimed.2015.04.01125917137"},{"key":"b15","series-title":"Clin J Sport Med","doi-asserted-by":"publisher","first-page":"542","DOI":"10.1097\/JSM.0000000000000409","article-title":"Disparities in athletic trainer staffing in secondary school sport: implications for concussion identification","volume":"27","author":"Kroshus E","year":"2017","unstructured":"Kroshus E, Rivara FP, Whitlock KB, Herring SA, Chrisman SPD: Disparities in athletic trainer staffing in secondary school sport: implications for concussion identification. Clin J Sport Med 27:542\u2013547, 20172874260410.1097\/JSM.0000000000000409"},{"key":"b16","series-title":"Crit Care","doi-asserted-by":"publisher","first-page":"161","DOI":"10.1186\/s13054-016-1349-7","article-title":"Portable infrared pupillometry in critical care","volume":"20","author":"Larson MD","year":"2016","unstructured":"Larson MD, Singh V: Portable infrared pupillometry in critical care. Crit Care 20:161, 201610.1186\/s13054-016-1349-727329287"},{"key":"b17","series-title":"Neuropsychol Rev","doi-asserted-by":"publisher","first-page":"115","DOI":"10.1023\/A:1009068804787","article-title":"Traumatic brain injury as a risk factor for Alzheimer\u2019s disease: a review","volume":"10","author":"Lye TC","year":"2000","unstructured":"Lye TC, Shores EA: Traumatic brain injury as a risk factor for Alzheimer\u2019s disease: a review. Neuropsychol Rev 10:115\u2013129, 20001093791910.1023\/A:1009068804787"},{"key":"b18","series-title":"Neurology","doi-asserted-by":"publisher","first-page":"623","DOI":"10.1212\/WNL.0000000000004214","article-title":"The spectrum of mild traumatic brain injury: a review","volume":"89","author":"Mayer AR","year":"2017","unstructured":"Mayer AR, Quinn DK, Master CL: The spectrum of mild traumatic brain injury: a review. Neurology 89:623\u2013632, 201710.1212\/WNL.000000000000421428701496"},{"key":"b19","series-title":"Clin J Sport Med","doi-asserted-by":"publisher","first-page":"13","DOI":"10.1097\/00042752-200401000-00003","article-title":"Unreported concussion in high school football players: implications for prevention","volume":"14","author":"McCrea M","year":"2004","unstructured":"McCrea M, Hammeke T, Olsen G, Leo P, Guskiewicz K: Unreported concussion in high school football players: implications for prevention. Clin J Sport Med 14:13\u201317, 20041471216110.1097\/00042752-200401000-00003"},{"key":"b20","series-title":"Br J Sports Med","doi-asserted-by":"publisher","first-page":"877","DOI":"10.1136\/bjsports-2016-097393","article-title":"What is the definition of sports-related concussion: a systematic review","volume":"51","author":"McCrory P","year":"2017","unstructured":"McCrory P, Feddermann-Demont N, Dvo\u0159\u00e1k J, Cassidy JD, McIntosh A, Vos PE, : What is the definition of sports-related concussion: a systematic review. Br J Sports Med 51:877\u2013887, 201710.1136\/bjsports-2016-09739329098981"},{"key":"b21","series-title":"Br J Sports Med","first-page":"838","article-title":"Consensus statement on concussion in sport\u2014the 5th International Conference on Concussion in Sport held in Berlin, October 2016","volume":"51","author":"McCrory P","year":"2017","unstructured":"McCrory P, Meeuwisse W, Dvo\u0159\u00e1k J, Aubry M, Bailes J, Broglio S, : Consensus statement on concussion in sport\u2014the 5th International Conference on Concussion in Sport held in Berlin, October 2016. Br J Sports Med 51:838\u2013847, 201728446457"},{"key":"b22","series-title":"Handb Clin Neurol","doi-asserted-by":"publisher","first-page":"245","DOI":"10.1016\/B978-0-444-63954-7.00024-0","article-title":"Subconcussive trauma","volume":"158","author":"Nauman EA","year":"2018","unstructured":"Nauman EA, Talavage TM: Subconcussive trauma. Handb Clin Neurol 158:245\u2013255, 201810.1016\/B978-0-444-63954-7.00024-030482352"},{"key":"b23","series-title":"Neurocrit Care","doi-asserted-by":"publisher","first-page":"251","DOI":"10.1007\/s12028-015-0182-1","article-title":"Interrater reliability of pupillary assessments","volume":"24","author":"Olson DM","year":"2016","unstructured":"Olson DM, Stutzman S, Saju C, Wilson M, Zhao W, Aiyagari V: Interrater reliability of pupillary assessments. Neurocrit Care 24:251\u2013257, 201610.1007\/s12028-015-0182-126381281"},{"key":"b24","series-title":"Handb Clin Neurol","doi-asserted-by":"publisher","first-page":"235","DOI":"10.1016\/B978-0-444-63954-7.00023-9","article-title":"Measuring head impacts: accelerometers and other sensors","volume":"158","author":"Rowson B","year":"2018","unstructured":"Rowson B, Tyson A, Rowson S, Duma S: Measuring head impacts: accelerometers and other sensors. Handb Clin Neurol 158:235\u2013243, 201810.1016\/B978-0-444-63954-7.00023-930482351"},{"key":"b25","series-title":"Concussion","first-page":"CNC3","article-title":"Sensitivity and specificity of an eye movement tracking-based biomarker for concussion","volume":"1","author":"Samadani U","year":"2015","unstructured":"Samadani U, Li M, Qian M, Laska E, Ritlop R, Kolecki R, : Sensitivity and specificity of an eye movement tracking-based biomarker for concussion. Concussion 1:CNC3, 201530202548"},{"key":"b26","series-title":"Nat Rev Neurol","doi-asserted-by":"publisher","first-page":"211","DOI":"10.1038\/nrneurol.2013.29","article-title":"Chronic neuropathologies of single and repetitive TBI: substrates of dementia?","volume":"9","author":"Smith DH","year":"2013","unstructured":"Smith DH, Johnson VE, Stewart W: Chronic neuropathologies of single and repetitive TBI: substrates of dementia? Nat Rev Neurol 9:211\u2013221, 20132345897310.1038\/nrneurol.2013.29"},{"key":"b27","series-title":"Nat Rev Neurol","doi-asserted-by":"publisher","first-page":"179","DOI":"10.1038\/s41582-018-0114-8","article-title":"Chronic traumatic encephalopathy\u2014confusion and controversies","volume":"15","author":"Smith DH","year":"2019","unstructured":"Smith DH, Johnson VE, Trojanowski JQ, Stewart W: Chronic traumatic encephalopathy\u2014confusion and controversies. Nat Rev Neurol 15:179\u2013183, 201910.1038\/s41582-018-0114-830664683"},{"issue":"4","key":"b28","series-title":"Neurosurg Focus","doi-asserted-by":"publisher","first-page":"E7","DOI":"10.3171\/2016.1.FOCUS15610","article-title":"Clinical evaluation of concussion: the evolving role of oculomotor assessments","volume":"40","author":"Sussman ES","year":"2016","unstructured":"Sussman ES, Ho AL, Pendharkar AV, Ghajar J: Clinical evaluation of concussion: the evolving role of oculomotor assessments. Neurosurg Focus 40(4):E7, 20162703292410.3171\/2016.1.FOCUS15610"},{"key":"b29","series-title":"J Athl Train","doi-asserted-by":"publisher","first-page":"1219","DOI":"10.4085\/1062-6050-51.1.06","article-title":"Early results of a helmetless-tackling intervention to decrease head impacts in football players","volume":"50","author":"Swartz EE","year":"2015","unstructured":"Swartz EE, Broglio SP, Cook SB, Cantu RC, Ferrara MS, Guskiewicz KM, : Early results of a helmetless-tackling intervention to decrease head impacts in football players. J Athl Train 50:1219\u20131222, 201510.4085\/1062-6050-51.1.0626651278"},{"key":"b30","series-title":"Brain Inj","doi-asserted-by":"publisher","first-page":"1420","DOI":"10.3109\/02699052.2015.1045029","article-title":"Pupillary responses to light in chronic non-blast-induced mTBI","volume":"29","author":"Thiagarajan P","year":"2015","unstructured":"Thiagarajan P, Ciuffreda KJ: Pupillary responses to light in chronic non-blast-induced mTBI. Brain Inj 29:1420\u20131425, 201510.3109\/02699052.2015.104502926182230"},{"key":"b31","series-title":"Nat Rev Neurol","doi-asserted-by":"publisher","first-page":"563","DOI":"10.1038\/nrneurol.2016.127","article-title":"Fluid biomarkers for mild traumatic brain injury and related conditions","volume":"12","author":"Zetterberg H","year":"2016","unstructured":"Zetterberg H, Blennow K: Fluid biomarkers for mild traumatic brain injury and related conditions. Nat Rev Neurol 12:563\u2013574, 201610.1038\/nrneurol.2016.12727632903"},{"key":"b32","series-title":"J Intern Med","doi-asserted-by":"publisher","first-page":"624","DOI":"10.1111\/joim.12863","article-title":"Head trauma in sports\u2014clinical characteristics, epidemiology and biomarkers","volume":"285","author":"Zetterberg H","year":"2019","unstructured":"Zetterberg H, Winblad B, Bernick C, Yaffe K, Majdan M, Johansson G, : Head trauma in sports\u2014clinical characteristics, epidemiology and biomarkers. J Intern Med 285:624\u2013634, 20193048140110.1111\/joim.12863"}],"container-title":["Journal of Neurosurgery"],"original-title":[],"link":[{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg\/133\/6\/article-p1886.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg\/133\/6\/article-p1886.xml","content-type":"text\/html","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/thejns.org\/downloadpdf\/journals\/j-neurosurg\/133\/6\/article-p1886.xml","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T00:51:49Z","timestamp":1792803109000},"score":1,"resource":{"primary":{"URL":"https:\/\/thejns.org\/view\/journals\/j-neurosurg\/133\/6\/article-p1886.xml"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,12]]},"references-count":32,"journal-issue":{"issue":"6"},"URL":"https:\/\/doi.org\/10.3171\/2019.7.jns191272","relation":{},"ISSN":["0022-3085","1933-0693"],"issn-type":[{"value":"0022-3085","type":"print"},{"value":"1933-0693","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,12]]}}}