(Press-News.org) Charlottesville, VA (October 2, 2012). What does it mean to have a head concussion? Much has been written in recent years about the short- and long-term consequences of concussions sustained in sports, combat, and accidents. However, there appear to be no steadfast rules guiding the definition of concussion: the characteristics associated with this type of traumatic head injury have shifted over time and across medical disciplines. Within the context of a larger longitudinal investigation of the biomechanical factors in play that correlate with concussions in collegiate helmeted contact sports, researchers in New England and Virginia used data they obtained to investigate which signs, symptoms, and clinical histories were used by athletic trainers to define concussion in individual players. The investigators found that a heterogeneous collection of acute clinical characteristics currently exists for those events diagnosed as concussion in college athletes engaged in contact sports. A discussion of this "concussion spectrum" is given in "Spectrum of acute clinical characteristics of diagnosed concussions in college athletes wearing instrumented helmets. Clinical article," by Ann-Christine Duhaime, M.D., et al., published today online, ahead of print, in the Journal of Neurosurgery.
Together with her colleagues, Dr. Duhaime, Director of Pediatric Neurosurgery and of Neurotrauma and Intensive Care in the Neurosurgical Service of Massachusetts General Hospital, examined concussions diagnosed in athletes participating in helmeted contact sports (football and ice hockey) at three universities: Dartmouth, Brown, and Virginia Tech. Both male and female athletes participated in the study. The students' helmets were outfitted with Head Impact Telemetry (HIT) System™ technology to record and measure peak linear and angular acceleration of impacts. The helmets were worn during practice sessions and games throughout two to four seasons. The investigators did not attempt to influence how trainers and team medical personnel defined concussion operationally, but instead relied on the clinical characteristics deemed indicative of concussion by the universities' athletic departments.
More than 486,000 head impacts were recorded in 450 athletes, and concussion was diagnosed in 44 of these athletes (48 concussions) by team medical staff. Unlike concussions more often diagnosed in emergency departments, where a single, identified contact event leads to a loss of consciousness or other clear alteration in consciousness, most diagnoses in this sports setting were based on self-reports by athletes, and only a few were based on changes in athletes' clinical conditions that were observed by others. Thirty-one concussions could be directly associated with a specific impact, whereas a relationship with a specific impact could not be verified in the other cases of concussion. Only half of the athletes noted symptoms immediately after a contact event; in many athletes, the onset of symptoms was delayed. The most common reported symptoms were mental clouding, headache, and dizziness; only one case involved a loss of consciousness. The diagnosis of concussion by trainers often occurred in an even more delayed fashion: the diagnosis was made immediately after the event in 6 cases and at a later time in the other cases (median 17 hours postinjury).
In general, the mean peak linear and angular accelerations for specific impact events that could be directly linked to concussions tended be in the high percentiles for the sports examined; however, there was considerable variability in the ranges of these measurements (mean peak linear acceleration 86.1 ± 42.6 g [range 16.5.9 g], mean peak angular acceleration 3620 ± 2,166 rads/sec2 [range 183,589 rads/sec2]).
The variety of signs and symptoms, the imprecise timing of symptom appearance and relationship to a specific contact event, the lack of externally observed findings, and the broad ranges of the linear and angular accelerations of the impacts that coalesce in a diagnosis of concussion in college sports make it difficult to identify predictors of acute, intermediate, and long-term risks of adverse consequences resulting from sports-related head impacts. By describing the heterogeneity inherent in diagnoses of concussion as a "concussion spectrum," the authors point out the need for renewed efforts to determine which factors—clinical, mechanical, genetic, or others—influence outcomes in patients with single as well as repeated head impacts. The authors point out that while a clinical diagnosis is important to protect players from additional and potentially more serious consequences, it is also possible that athletes who do not receive the diagnosis of "concussion" may be at similar risk. Likewise, it is possible that some players who receive a diagnosis of concussion do not fall into a high-risk category for specific consequences. The authors note that there is still much to be learned, and that the terminology in use can sometimes oversimplify a more complex set of processes that still need to be teased apart. In their response to an accompanying editorial, they state, "By carefully characterizing exactly what we are talking about and by continued investigation, which will take more time ... , neurosurgeons and others will be best positioned to offer effective treatments and to advocate knowledgeably for appropriate injury-prevention strategies."
###
Duhaime A-C, Beckwith JG, Maerlender AC, McAllister TW, Crisco JJ, Duma SM, Brolinson PG, Rowson S, Flashman LA, Chu JJ, Greenwald RM: Spectrum of acute clinical characteristics of diagnosed concussions in college athletes wearing instrumented helmets. Clinical article. Journal of Neurosurgery, published online, ahead of print, October 2, 2012; DOI: 10.3171/2012.8.JNS112298.
Disclosure: Richard Greenwald, Jeffrey Chu, and Joseph Crisco have financial interests in the instruments (HIT System™, Sideline Response System™, Riddell, Inc.) used to collect the biomechanical data reported in this study. Jonathan Beckwith is an employee of Simbex, which manufactures the HIT System™. Research for this study is supported by the National Institute for Child Health and Human Development at the National Institutes of Health (Grant No. R01HD048638).
Two other research articles on sports-related brain injury are published online today in JNSPG journals:
Mattei TA, Bond BJ, Goulart CR, Sloffer CA, Morris MJ, Lin JJ: Performance analysis of the protective effects of bicycle helmets during impact and crush tests in pediatric skull models. Laboratory investigation. Journal of Neurosurgery: Pediatrics, published online, ahead of print, October 2, 2012; DOI: 10.3171/2012.8.PEDS12116.
Zuckerman SL, Solomon GS, Forbes JA, Haase RF, Sills AK, Lovell MR: Response to acute concussive injury in soccer players: is gender a modifying factor? Clinical article. Journal of Neurosurgery: Pediatrics, published online, ahead of print, October 2, 2012; DOI: 10.3171/2012.8.PEDS12139.
For additional information, please contact:
Ms. Gillian Shasby, Director of Publications–Operations
Journal of Neurosurgery Publishing Group
One Morton Drive, Suite 200
Charlottesville, VA 22903
Email: gshasby@thejns.org
Telephone 434-924-5555
Fax 434-924-5782
For 68 years, the Journal of Neurosurgery has been recognized by neurosurgeons and other medical specialists the world over for its authoritative, clinical articles, cutting-edge laboratory research papers, renowned case reports, expert technical notes, and more. Each article is rigorously peer reviewed. The Journal of Neurosurgery is published monthly by the JNS Publishing Group, the scholarly journal division of the American Association of Neurological Surgeons, an association dedicated to advancing the specialty of neurological surgery in order to promote the highest quality of patient care. The Journal of Neurosurgery appears in print and on the Internet.
Concussion spectrum in college athletes wearing helmets: 'Not so simple,' say researchers
2012-10-02
ELSE PRESS RELEASES FROM THIS DATE:
Children's bicycle helmets shown to be effective in impact and crush tests
2012-10-02
Charlottesville, VA (October 2, 2012). A favorite physical activity engaged in by Americans is bicycling, and children are perhaps its most ardent participants; it has been estimated that 70% of children ages 5 to 14 ride bicycles. Bicycling is not without its dangers, however, and one of the worst is the risk of head and brain injury during a crash. According to the US Centers for Disease Control, head injury is the most common cause of death and serious disability from bicycle crashes. The best protection offered to mitigate this injury is the bicycle helmet. However, ...
Does gender affect acute concussive injury in soccer players? 'No' according to this study
2012-10-02
Charlottesville, VA (October 2, 2012). Much has been printed suggesting gender-related differences in athletes' responses to sports-related concussion, including differences in concussion incidence, symptoms reported, and scores on neurocognitive tests before and after injury. Nevertheless, findings have not been unanimous, and no guidelines regarding gender-specific strategies for prevention or treatment of sports-related concussion have been developed. Researchers at Vanderbilt University, the University of Albany, and ImPACT Applications, Inc., set out to review symptoms ...
Study finds no gender-related difference in neurocognitive testing after sports-related concussions
2012-10-02
As female participation in sports grows rapidly, there is a popular notion that there are gender-related differences in athletes' responses to sports-related concussion, and prior research has supported these gender discrepancies.
However, a Vanderbilt University Medical Center study, conducted to review symptoms and neurocognitive findings in male and female high school soccer players, shows no gender-related differences.
"There has been good data that suggests girls score worse on neurocognitive testing following a sports-related concussion. Our hypothesis was that ...
'Superweeds' linked to rising herbicide use in GM crops
2012-10-02
PULLMAN, Wash. -- A study published this week by Washington State University research professor Charles Benbrook finds that the use of herbicides in the production of three genetically modified herbicide-tolerant crops -- cotton, soybeans and corn -- has actually increased. This counterintuitive finding is based on an exhaustive analysis of publicly available data from the U.S. Department of Agriculture's National Agriculture Statistics Service. Benbrook's analysis is the first peer-reviewed, published estimate of the impacts of genetically engineered (GE) herbicide-resistant ...
Work is more fun if the character fits the bill
2012-10-02
Character strengths can be defined as traits that are evaluated as morally positive, such as self-control, teamwork or kindness. Character strengths that are particularly distinctive for a person and which he or she likes to use frequently are referred to as signature strengths. Everybody typically has between three and seven of these signature strengths. For the first time, Claudia Harzer and Professor Willibald Ruch from the Section on Personality and Assessment at the University of Zurich now prove in two studies that a job is particularly cherished if it suits one's ...
Social scientists contribute to policy in central government
2012-10-02
According to latest research, social scientists with PhDs working in central government make valuable contributions to policy, and report that holding a PhD can enhance their credibility with senior officials. It also shows that they are more likely to have climbed the career ladder and progressed into leadership roles.
The Economic and Social Research Council (ESRC), which provides significant support for postgraduate training (PhD) and other schemes, commissioned the research. It was carried out over an eight-month period from October 2011 and was led by Mariell Juhlin, ...
Prehistoric builders reveal trade secrets
2012-10-02
A fossil which has lain in a museum drawer for over a century has been recognized by a University of Leicester geologist as a unique clue to the long-lost skills of some of the most sophisticated animal architects that have ever lived on this planet.
It has provided evidence that early organisms developed specialised roles and that these specialists displayed co-operation in order to construct their homes – much like today's builders employ a team of bricklayers, plasters and decorators.
The fossil is a graptolite, a planktonic colony from nearly half a billion years ...
Egyptian toe tests show they're likely to be the world's oldest prosthetics
2012-10-02
The results of scientific tests using replicas of two ancient Egyptian artificial toes, including one that was found on the foot of a mummy, suggest that they're likely to be the world's first prosthetic body parts.
The University of Manchester researcher Dr Jacky Finch wanted to find out if a three part wood and leather toe dating from between 950 to 710 BC found on a female mummy buried near Luxor in Egypt, and the Greville Chester artificial toe from before 600 BC and made of cartonnage (a sort of papier maché mixture made using linen, glue and plaster), could be ...
The water flow of the Amazon River in a natural climate archive
2012-10-02
Oxygen isotopes in tree rings are an excellent archive of precipitation dynamics in the tropical Amazon region. The precise determination of the ratios of stable oxygen isotopes (18O/16O) proves to be a new parameter for detecting the dynamics of the water cycle in tropical rain forest areas. It can therefore replace the classic climate observables such as tree ring width or wood density, which are unsuitable for high-quality reconstructions of climate conditions in tropical areas. These are the findings of a group of researchers from the GFZ German Research Centre for ...
The Journal of Evidence-Based Dental Practice focuses on periodontal and implant treatments
2012-10-02
St. Louis, MO, October 2, 2012 – What's the latest, research-supported best practice in periodontal care and implant dentistry? Dental specialists and generalists alike can read about it in the first of a new series from The Journal of Evidence-Based Dental Practice (JEBDP), the foremost publication of information about evidence-based dental practice, published by Elsevier.
The inaugural edition of the Annual Report on Periodontal and Implant Treatment is now available, containing concise, authoritative reviews based on the evidence about practice-critical topics. Mark ...