Brain trauma exposure for American tackle football players 5 to 9 and 9 to 14 years of age.

American football helmets used by youth players are currently designed and tested to the same standards as professionals. The National Operating Committee on Standard and Safety requested research aiming at understanding the differences in brain trauma in youth American football for players aged five to nine and nine to fourteen years old to inform a youth specific American football standard. Video analysis and laboratory reconstructions of head impacts were undertaken to measure differences in head impact frequency, event types, and magnitudes of maximum principal strain (MPS) for the two age groups. Overall frequencies and frequencies for five categories of MPS representing different magnitudes of risk were tabulated. The MPS categories were very low (<0.08), low (0.08-0.169), medium (0.17-0.259), high (0.26-0.349) and very high (>0.35). Both cohorts experienced a majority of head impacts (>56%) at very low magnitude of MPS. Youth American football players aged 9-14 yrs. sustained a greater frequency of head impacts at MPS between 0.08 and 0.169 % associated with changes in brain structure and function. There were no differences in overall frequency, or in frequency of head impacts in other categories of MPS. The proportion of impacts considered injurious (MPS > 0.08) was greater in the 5-9 group (44%), than the 9-14 group (39%), and impacts above 0.35 % were only reported for the younger age group. The larger helmet-to-shoulder ratio in the younger age groups may have contributed to this finding suggesting that youth American football players under the age of nine would benefit from a child-specific football helmet.

Age of first exposure to American football and long-term neuropsychiatric and cognitive outcomes.

Previous research suggests that age of first exposure (AFE) to football before age 12 may have long-term clinical implications; however, this relationship has only been examined in small samples of former professional football players. We examined the association between AFE to football and behavior, mood and cognition in a large cohort of former amateur and professional football players. The sample included 214 former football players without other contact sport history. Participants completed the Brief Test of Adult Cognition by Telephone (BTACT), and self-reported measures of executive function and behavioral regulation (Behavior Rating Inventory of Executive Function-Adult Version Metacognition Index (MI), Behavioral Regulation Index (BRI)), depression (Center for Epidemiologic Studies Depression Scale (CES-D)) and apathy (Apathy Evaluation Scale (AES)). Outcomes were continuous and dichotomized as clinically impaired. AFE was dichotomized into <12 and ⩾12, and examined continuously. Multivariate mixed-effect regressions controlling for age, education and duration of play showed AFE to football before age 12 corresponded with >2 × increased odds for clinically impaired scores on all measures but BTACT: (odds ratio (OR), 95% confidence interval (CI): BRI, 2.16,1.19-3.91; MI, 2.10,1.17-3.76; CES-D, 3.08,1.65-5.76; AES, 2.39,1.32-4.32). Younger AFE predicted increased odds for clinical impairment on the AES (OR, 95% CI: 0.86, 0.76-0.97) and CES-D (OR, 95% CI: 0.85, 0.74-0.97). There was no interaction between AFE and highest level of play. Younger AFE to football, before age 12 in particular, was associated with increased odds for impairment in self-reported neuropsychiatric and executive function in 214 former American football players. Longitudinal studies will inform youth football policy and safety decisions.

Cerebral [18 F]T807/AV1451 retention pattern in clinically probable CTE resembles pathognomonic distribution of CTE tauopathy.

Chronic traumatic encephalopathy (CTE) is a neurodegenerative disorder most commonly associated with repetitive traumatic brain injury (TBI) and characterized by the presence of neurofibrillary tangles of tau protein, known as a tauopathy. Currently, the diagnosis of CTE can only be definitively established postmortem. However, a new positron emission tomography (PET) ligand, [18F]T807/AV1451, may provide the antemortem detection of tau aggregates, and thus various tauopathies, including CTE. Our goal was to examine [18F]T807/AV1451 retention in athletes with neuropsychiatric symptoms associated with a history of multiple concussions. Here we report a 39-year-old retired National Football League player who suffered 22 concussions and manifested progressive neuropsychiatric symptoms. Emotional lability and irritability were the chief complaints. Serial neuropsychological exams revealed a decline in executive functioning, processing speed and fine motor skills. Naming was below average but other cognitive functions were preserved. Structural analysis of longitudinally acquired magenetic resonance imaging scans revealed cortical thinning in the left frontal and lateral temporal areas, as well as volume loss in the basal ganglia. PET with [18F]florbetapir was negative for amyloidosis. The [18F]T807/AV1451 PET showed multifocal areas of retention at the cortical gray matter-white matter junction, a distribution considered pathognomonic for CTE. [18F]T807/AV1451 standard uptake value (SUV) analysis showed increased uptake (SUVr⩾1.1) in bilateral cingulate, occipital, and orbitofrontal cortices, and several temporal areas. Although definitive identification of the neuropathological underpinnings basis for [18F]T807/AV1451 retention requires postmortem correlation, our data suggest that [18F]T807/AV1451 tauopathy imaging may be a promising tool to detect and diagnose CTE-related tauopathy in living subjects.

Head injury in athletes.

HEAD INJURIES INCURRED during athletic endeavors have been recorded since games were first held. During the last century, our level of understanding of the types of cerebral insults, their causes, and their treatment has advanced significantly. Because of the extreme popularity of sports in the United States and worldwide, the implications of athletic head injury are enormous. This is especially true considering the current realization that mild traumatic brain injury (MTBI) or concussion represents a major health consideration with more long-ranging effects than previously thought. When considering athletic injuries, people who engage in organized sports, as well as the large number of people who engage in recreational activities, should be considered. There are 200 million international soccer players, a group increasingly recognized to be at risk for MTBI. The participation in contact sports of a large number of the population, especially youth, requires a careful and detailed analysis of injury trends and recommended treatment. There are numerous characteristics of this patient population that make management difficult, especially their implicit request to once again be subjected to potential MTBI by participating in contact sports. Recent research has better defined the epidemiological issues related to sports injuries involving the central nervous system and has also led to classification and management paradigms that help guide decisions regarding athletes' return to play. We currently have methods at our disposal that greatly assist us in managing this group of patients, including improved recognition of the clinical syndromes of MTBI, new testing such as neuropsychological assessment, radiographic evaluations, and a greater appreciation of the pathophysiology of concussive brain injury. The potential for long-term consequences of repetitive MTBI has been recognized, and we no longer consider the "dinged" states of athletic concussions to have the benign connotations they had in the past. We review the historical developments in the recognition and care of athletes with head injuries, the current theory of the pathophysiology and biomechanics of these insults, and the recommended management strategy, including return-to-play criteria.

Head and neck injuries in young athletes.

Careful study of the pathophysiology and epidemiology of sports-related spine injuries brings to light many common features. The incidence increases as the sport becomes increasingly violent and aggressive. Poor conditioning and lack of knowledge of the proper techniques of the sport put the athlete at significant risk for head and spine injury. Improper helmet fit and the use of the head as an offensive weapon also are common features of injury. Although recognition of these features has resulted in a dramatic reduction in catastrophic neurological injury, the athlete remains at risk for less severe head and spine injury, and concussion remains at epidemic proportions at high school, university, and professional levels. It is hoped that careful recognition of the signs of concussion and knowledge of return-to-play criteria will prevent catastrophic complications from minor head injuries, although the long-term effects of multiple concussions on cognition may be problematic.

Catastrophic football injuries: 1977-1998.

The primary purpose of this study was to investigate the occurrence of catastrophic football head and spine injuries, in an attempt to reduce their frequency. We analyzed epidemiological and medical data from 1977 through 1998. Catastrophic football injuries are defined as football injuries that result in death, brain or spinal cord injury, or cranial or spinal fracture. All studied cord injuries involved the cervical region. During the period covered by this study, 118 athletes died as a direct result of participation in the skills of football, 200 football players received a permanent cervical cord injury, and 66 sustained a permanent cerebral injury. Most cervical injuries occurred to defensive players during the act of tackling. The axial loading mechanism of spinal cord injury was identified in 27% of tackling injuries. To further reduce catastrophic injuries, players must stop tackling with the head down and using the head as a battering ram; instead, players should use the shoulder for blocking and tackling. Other recommendations for reducing catastrophic injuries are presented.

Cervical spine injuries in the athlete.

Special considerations must be brought into play when the physician is consulted about when to allow an athlete to return to play following injury. This is especially true for brain and spinal cord injury. Although it is generally best to be on the conservative side, being too reticent about allowing any athlete to return may be very detrimental to the athlete and/or the entire team. Therefore, it behooves the sports physician to be circumspect with regard to not only the type of injury the athlete has suffered but also the nature, duration, and the repetitive aspects of the trauma along with the inherent strengths of any player. This article will provide the sports physician with criteria for making sound decisions regarding return to competition after cervical spine injury and "functional" cervical spinal stenosis.

Fatalities and catastrophic injuries in high school and college sports, 1982-1997 lessons for improving safety.

The prohibition of 'spearing' in football and the rules regarding water depth and the racing dive in swimming are examples of how data on deaths and catastrophic injuries can be used to help promote the safety of young athletes. Other preventive measures supported by research include anchoring movable soccer goals to prevent tipping, improved training for high school wrestling coaches, increased awareness of pathogenic weight control in wrestling and gymnastics, rules against pushing or checking from behind in ice hockey, protective helmets for batting-practice pitchers in baseball, and barriers around the discus circle in track and field.

Second-impact syndrome.

Second impact syndrome (SIS) occurs when an athlete who has sustained an initial head injury, most often a concussion, sustains a second head injury before symptoms associated with the first have fully cleared. While most commonly reported in football, the SIS can occur during any sport that can produce head blows. Any athlete still complaining of post-concussion symptoms after a head injury must not be allowed to return to play.

Return to play guidelines after a head injury.

Presently there are no universally accepted definitions of the grades of concussion or criteria for when to allow the athlete to return to competition after a head injury. What is agreed upon is that in order to avoid cumulative brain damage and the second impact syndrome, no athlete still suffering post-concussion symptoms should return to competition. This article is meant to serve only as a guideline as the final decision in every instance is a clinical judgement.

The cervical spinal stenosis controversy.

Cervical spinal cord symptoms after a spine injury from contact sports require a more precise work up to detect cervical spinal stenosis than radiographic bone measurements alone can provide. Imaging technologies such as MRI, contrast-positive CT, and myelography more accurately identify true spinal stenosis and allow for safer return-to-play decisions.

Guidelines for return to contact or collision sport after a cervical spine injury.

Pro football is a violent, dangerous sport. To play it other than violently would be "imbecilic," according to the late Vince Lombardi. Many sports hold the potential for serious permanent spine and spinal cord injury. Fortunately, the incidence of catastrophic spine and spinal cord injuries has dramatically declined in the past 10 to 15 years. This decline is, in part, attributable to the development of sports-related spine injury registries, the education of the pathomechanics of these injuries, and the implementation of appropriate preventive measures. This article focuses on sports-related spinal cord and nerve injuries, ranging from the mild "stinger" syndrome to complete quadriplegia, with emphasis on recommendations for return to competition.

Stingers, transient quadriplegia, and cervical spinal stenosis: return to play criteria.

This article focuses on sports related spinal cord and nerve injuries, ranging from mild "stinger" syndrome to complete quadriplegia. Particular emphasis is placed on recommendations for return to competition after such injuries. Cervical spinal cord symptoms after a spine injury from contact sports require a more precise work up to detect cervical spinal stenosis than radiographic bone measurements alone can provide. Imaging technology such as MRI, contrast positive CT, and myelography more accurately identify true spinal stenosis and allow for safer return to play decisions.

Athletic head injuries.

Recent studies have shown a decrease in mortality from head and neck injuries, especially in American football. This has resulted from rule changes and their enforcement, equipment modification, improved coaching and training techniques, and educational programs for neck injuries. Morbidity data, however, are not as complete, particularly as they apply to concussion, the most frequent type of head injury in contact sports. Questions on this condition that still need to be answered before a sound medical disposition can be made are the possible cumulative damage from repeated concussions, and whether one concussion renders a player more susceptible to a second. Currently, decisions on when to allow a football player to return to a game or participate in future contests are arbitrary and based primarily on the experience of the team physician. Certainly, further studies are essential before these decisions can be based on sound scientific data. Thus, the pioneer work of Richard Schneider needs to be continued.

Head injuries in sport.

Injuries to the head and neck are the most frequent catastrophic sports injury, and head injuries are the most common direct athletic cause of death. Although direct compressive forces may injure the brain, neural tissue is particularly susceptible to injury from shearing stresses, which are most likely to occur when rotational forces are applied to the head. The most common athletic head injury is concussion, which may very widely in severity. Intracranial haemorrhage is the leading cause of head injury death in sports, making rapid initial assessment and appropriate follow up mandatory after a head injury. Diffuse cerebral swelling is another serious condition that may be found in the child or adolescent athlete, and the second impact syndrome is a major concern in adult athletes. Many head injuries in athletes are the result of improper playing techniques and can be reduced by teaching proper skills and enforcing safety promoting rules. Improved conditioning (particularly of the neck), protective headgear, and careful medical supervision of athletes will also minimise this type of injury.