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Impact energy attenuation performance of football headgear.

OBJECTIVES: Commercially available football head protectors were tested to determine their impact energy attenuation performance and ability to reduce the likelihood of concussion. METHODS: Prospective study using standardised impact test methods with both rigid (magnesium) and Hybrid III headforms. RESULTS: Eight commercially available head protectors from six manufacturers were tested. The magnitude of the headform accelerations increased as the drop height was increased, ranging from a minimum of 64 g from a height of 0.2 m to a maximum of 1,132 g from a height of 0.6 m. The head injury criterion and maximum headform acceleration values followed a similar trend. A steep increase was noted in the magnitude of maximum headform acceleration and head injury criterion when the drop height was increased from 0.4 to 0.5 m. This indicates that the foam material was completely compressed at an impact energy above about 20 J and therefore offers little protection against impacts of greater severity. Repeated tests using a drop height of 0.3 m showed that some helmets exhibit a "memory" effect, whereby impact performance is reduced by up to 50% with repeated impacts. CONCLUSIONS: Laboratory tests indicate that current commercially available football headgear performance will not reduce the likelihood of concussion. The absence of internationally recognised standards for soft headgear designed to ameliorate concussion is a major deficiency in sports injury prevention.

Craniocerebral Trauma↗

A comparison of facial protection and the incidence of head, neck, and facial injuries in Junior A hockey players. A function of individual playing time.

A cohort of 282 elite amateur ice hockey players were analyzed to 1) record the number, type, location, and severity of head, neck, and facial injuries sustained during games; 2) examine the relationship between injuries and the type of facial protection (none, partial, or full) according to individual playing time; and 3) determine whether full or partial facial protection is associated with an increased incidence of concussions, eye injuries, and neck injuries. Fifty-two injuries (158.9 per 1000 player-game hours) occurred in players wearing no facial protection, 45 (73.5 per 1000 player-game hours) in players wearing partial facial protection (half shield), and 16 (23.2 per 1000 player-game hours) in players wearing full facial protection (full cage or shield). Players wearing no protection were injured at a rate more than twice that of players wearing partial protection and almost seven times higher than those wearing full protection. Concussions occurred in four players wearing no protection, five players wearing partial protection, and two players wearing full protection; these differences were not significant. The risk of eye injury was 4.7 times greater for players wearing no protection compared with those wearing partial protection. No eye or neck injuries occurred in players wearing full protection. This study demonstrates that both full and partial facial protection significantly reduce injuries to the eye and face without increasing neck injuries and concussions.

Athletic Injuries↗

Common injuries in horseback riding. A review.

The most common location of horse-related injuries is the upper extremity (24% to 61%) with injuries to the lower extremity second in frequency (36% to 40%). The head and face sustain 20% of horse-related injuries. The most common type of injury is a soft tissue injury (92% to 1%), followed by a fracture (57% to 3%). Concussion is the third most common type of injury (63% to 2%). The most frequent cause of hospitalisation is concussion (38% to 4%) with fracture second. The most common injury which leaves residual impairment is injury to the central nervous system. The age at which most injury occurred is less than 21 years. In the latest NEISS report (1987-1988), injuries have decreased in the younger riders, but have increased in the older riders (above 24 years). More women are injured than men, but over the age of 44 years more men are injured than women, with the difference more marked in the 1987-1988 NEISS report. Previous horse-related injuries are reported frequently (37% to 25%). In mortality studies from Australia and the United States, head injuries caused the majority of deaths (78% and 60%), followed by chest injuries (9%). In the Australian study each sex had 50% of the deaths. In the United States, 60% were male, 40% female. Above the age of 24 years male deaths increasingly predominate, being 15 male deaths to 1 female above the age of 64. Concussion is divided into 3 divisions of severity which require different medical evaluation and treatment: mild in which rider is stunned or disoriented for a brief period; moderate in which there is loss of consciousness for less than 5 minutes; and severe in which there is a loss of consciousness for more than 5 minutes. Investigative need is cited in the areas of previous horse-related injury, lessons, experience vs knowledge, epilepsy, drowning, gender, deaths, safety helmets, stirrups, and body protectors. No horse is a safe horse; some are safer than others but the horse is a potentially lethal animal. Prevention of accidents and injuries is dependent upon using knowledge previously obtained from studying horse activities. Much more information is available than in the past through the medical studies that have been done and the recommendations made by these investigators. The medical community has a responsibility to educate the horse riding public and to participate in investigations requested by the horse organizations.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

Late outcome of mild head injury: results from a controlled postal survey.

There is insufficient information about the long-term sequelae of mild head injury (postconcussional symptoms, PCS). Therefore, a questionnaire-based investigation was carried out in patients 1-5 years after mild head injury (MHI) and in non-concussed subjects in order to study the nature of long-term complaints after MHI. A three-factor model of residual subjective and psychological complaints that contained a dysthymic factor, a vegetative/bodily complaints factor, and a cognitive performance factor were identified in the patient population. Three rating scales were constructed from the relevant items or factors, and were used to compare the MHI patients with non-concussed controls. It was found that the profile of distresses and discomforts mentioned by a population of MHI patients 1-5 years after the trauma was similar to that of a non-concussed control population. These symptoms were indistinguishable from those encountered in ordinary everyday life. These symptoms were significantly more severe in the MHI patients. Stepwise regression analysis in the patient population indicated that a number of parameters were statistically of predictive importance: comorbidity, sex, and neurological complication at the time of the trauma. The results support the hypothesis that MHI may not ever be completely reversible.

Adult↗

Axonal degeneration induced by experimental noninvasive minor head injury.

Minor head injury or concussion was produced in experimental animals by an acceleration-deceleration non-impact injury. The animals sustained a brief loss of consciousness and no sequelae were observed. The brains were examined at 7 days by means of the Nauta and Fink-Heimer techniques. Degenerating axons were noted in the inferior colliculus, pons, and dorsolateral medulla. Degeneration was not seen in the subcortical white matter, thus suggesting a primary brain-stem locus for concussion. These findings also suggest that, in some instances, minor head injury or concussion can be associated with organic damage to the central nervous system.

Animals↗

Pain, cognition and traumatic brain injury.

There has been considerable controversy concerning the problem of the persisting post-concussive syndrome and whether cognitive or other sequelae might be attributed to the effects of brain injury or other causes. Headache is the predominant problem in virtually all surveys of the post-concussive syndrome. It is suggested that pain and related problems may account for most of the difficulties in those presenting with the persisting post-concussive syndrome or other cases in which mild to moderate brain injury is suspected. A survey of the literature concerning the relationship of pain, cognition and traumatic brain injury indicates that cognitive difficulties are common in acute or chronic pain, with or without any indication of brain injury. However, numerous methodological problems are apparent and there is clearly need for further study. Consideration is given both to psychosocial and neurobiological effects underlying any such relationships.

Journal Article↗

Classification of Sport-Related Head Trauma: A Spectrum of Mild to Severe Injury.

OBJECTIVE: To identify the types of injuries the human brain incurs as a result of traumatic forces applied to the cranium. In athletic events and endeavors, the full spectrum of intracranial hemorrhages in various compartments, raised intracranial pressure, and diffuse nonhemorrhagic damage may be seen. In this review, we describe these serious injuries and the more common mild traumatic brain injury in their clinical presentations and relate concussion classification to the overall picture of traumatic brain injury. METHODS: Our cumulative experience with athletic injuries, both at the catastrophic and mild traumatic brain injury levels, has led us to a management paradigm that serves to guide us in the classification and treatment of these athletes. DISCUSSION: The occurrence of intracranial injuries in sports has now been well documented. Intracranial hematomas (epidural, subdural, and parenchymal) and cerebral contusions can result from head injury. Many patients sustain a diffuse brain injury, resulting in elevated intracranial pressures, without a blood clot or mass lesion. The classification of concussion and the use of concussion guidelines are not uniform. However, the major emphases are agreed upon: the close and careful scrutiny of the athlete, an expeditious but reliable neurologic examination, and proper on-field management. Return-to-play decisions are based on many factors that affect normal functioning, both on and off the playing field. CONCLUSIONS: Sufficient knowledge now exists to allow us to carefully evaluate the injured athlete, to place him or her in the management scheme to minimize the potential for permanent cerebral dysfunction, and to know when the athlete can safely return to contact sport participation.

Journal Article↗

Heading in Soccer: Integral Skill or Grounds for Cognitive Dysfunction?

OBJECTIVE: To critically review the literature concerning the effect of purposeful heading of a soccer ball and head injuries on reported cognitive dysfunction in soccer players. DATA SOURCES: We searched MEDLINE (1965-2001) and SPORTDiscus (1975-2001) for refereed articles in English combining key words for soccer (eg, soccer, football, association football ) with key words for head injuries (eg, concussion, head injury). In addition, literature on cognition and head injuries was obtained. We reviewed reference lists of current literature for pertinent citations that might not have been found in the search procedures. DATA SYNTHESIS: The fact that soccer players (and other athletes) have selected cognitive deficits is not questioned, and the popular press is quick to publicize results of questionable validity. The reasons for such deficits are many. Much of the early data implied that heading was the culprit; however, subsequent research has suggested that other interpretations and factors may be potential explanations for these deficits. The current focus is on concussions, a known factor in cognitive dysfunction and a common head injury in soccer. CONCLUSIONS/RECOMMENDATIONS: It is difficult to blame purposeful heading for the reported cognitive deficits when actual heading exposure and details of the nature of head-ball impact are unknown. Concussions are a common head injury in soccer (mostly from head-head or head-ground impact) and a factor in cognitive deficits and are probably the mechanism of the reported dysfunction.

Journal Article↗

Performance on the Balance Error Scoring System Decreases After Fatigue.

OBJECTIVE: To determine the immediate effects of a whole-body fatigue protocol on performance of the Balance Error Scoring System (BESS), a postural-stability test commonly used as part of a concussion-assessment battery. DESIGN AND SETTING: Subjects were assigned to a fatigue or control group and were assessed before and immediately after a 20-minute fatigue protocol or rest period. SUBJECTS: Fourteen fatigue subjects and 13 control subjects participated in this study. All subjects were male and free of vestibular disorders, and none had suffered a mild head injury or lower extremity injury in the preceding 6 months, as described through self-report. MEASUREMENTS: We measured performance on the BESS for 9 stance-surface conditions and summed each condition to obtain a total score. Using the Borg scale, we also measured ratings of perceived exertion before, during, and after the fatigue protocol or rest period. RESULTS: We found a significant increase in total errors from pretest to posttest in the fatigue group (14.36 +/- 4.73 versus 16.93 +/- 4.32), a significant decrease in errors in the control group (13.32 +/- 3.77 versus 11.08 +/- 3.88), and a significant difference between groups on the posttest. The rating of perceived exertion scores were significantly different between the fatigue and control groups at the middle (13.29 +/- 1.59 versus 6.23 +/- 0.83) and end (15.86 +/- 2.38 versus 6.15 +/- 0.55) of the fatigue or rest period. CONCLUSIONS: The BESS error scores increased immediately after the fatigue protocol, demonstrating that balance ability diminished. Clinicians who use the BESS as part of their sideline assessment for concussion should not administer the test immediately after a concussion due to the effects of fatigue.

Journal Article↗

[Autoantibodies to glutamate receptors in children with chronic posttraumatic headache].

Autoantibodies (aAB) to AMPA (Glu R1 subunit) and NMDA (NR 2A subunit) glutamate receptors were studied in blood serum of 60 children, aged 7-16 years, with chronic posttraumatic headache after mild skull injury. All the children were divided into 2 groups: group 1 included 48 children with concussion of the brain, group 2--12 children with brain contusion. Group 1 was divided into 2 subgroups: subgroup 1a comprised 34 children with single concussion and subgroup 1b--14 children with repeated concussion. The aAB level was determined 6 months and 1 year after skull injury. The aAB concentration was expressed in percents to the control level being considered significant if the increase was higher than 120%. The increased NMDA aAB level was observed during the first year after skull injury. In the la subgroup, the NR2 aAB level in blood serum was 145 +/- 12,6%, in the 1b one--108 +/- 12,4%, in group 2--165 +/- 34%. The content of aAB to AMPA receptors was elevated only in children of lb subgroup and group 2 (150 +/- 16,8% and 167 +/- 31,3%, respectively). The EEG examination of this group revealed the nonspecific paroxysmal discharges in 18% of cases and epileptiform activity in 6% of children. The results obtained suggest that children with posttraumatic headache have elevated levels of aAB to glutamate receptors, hyperstimulation of which reflects hypoxic processes in the brain, and are in need of metabolic therapy.

Adolescent↗

Football helmets and neurotrauma--an epidemiological overview of three seasons.

During the 1975, 1976, and 1977 football seasons, the National Athletic Injury/Illness Reporting System (NAIRS) obtained records of the nature and severity of injuries and illnesses experienced by an annual average of 5361 high school and college athletes. Associated circumstances, including type and brand of helmets being worn by the injured and non-injured, also were obtained. From these data, and against specified epidemiologic criteria for significance, the possibility that particular helmets were associated unduly with cerebral and spinal neurotrauma was examined. The results revealed that (1) one permanent severe neurological injury (cervical spinal cord) was experienced, the mechanism of which was unrelated to helmet design; (2) cerebral concussions were infrequent (one significant concussion per 10,000 athlete exposures) and of a consistent rate from year to year; and (3) no particular helmet was associated with a disproportionate number of concussions or cervical spine fractures within those experienced. Continuing surveillance with multivariate analysis of possible causal relationships among all factors associated with these injuries is in progress.

Athletic Injuries↗

Pathomorphological observations of gunshot wounds.

Soft tissue wounds of hind limbs were engendered in 64 dogs by shooting rifle bullets of 5.56 and 7.62 mm calibres at a range of twenty meters with impact velocities ranging from 516.7 m/s to 959.7 m/s. Gross and microscopical examinations of these wounds were then made. The main results were as follows: 1. At conventional velocity, the injuries caused by 5.56 mm bullets were much more severe than those caused by 7.62 mm bullets. The reason for this is that the former has greater velocity and liability to tumbling, breaking or deformation in tissues. 2. The gunshot wound track presented itself in three parts: a primary wound track, a contusion zone and a concussion zone. The mean maximum diameter of primary wound track was 1.16 to 3.34 cm and the thickness of contusion zone was about 0.5 cm. Sometimes there was no definite demarcation between the contusion zone and the concussion zone found by conventional histological examination. The thickness of the contusion zone measured grossly was usually greater than that measured microscopically. 3. Perfusion of arteries of the injured legs with Chinese ink proved to be a useful method for determining the demarcation between the contusion zone and the concussion zone. 4. Pathological changes in the three zones were described in detail and the mechanism of wounding was discussed.

Animals↗

[Several pathophysiologic grounds for radical removal of contusion foci from the cerebral hemispheres].

Local circulation and PO2 of the cerebral tissue were studied in 26 patients during the acute period of a severe craniocerebral trauma. It was demonstrated that pronounced changes in the microcirculation developed in the area of the concussion focus in the cerebral hemispheres. Three zones of disorders in the local circulation were distinguished, and it was shown that in case of an unremoved concussion focus the extending of its necrosis zone took place. The most effective surgical management of patients with severe craniocerebral traumas attended by concussion foci is its radical removal.

Acute Disease↗

Neurologic aspects of boxing.

The assessment and prevention of potentially adverse neurologic consequences of boxing requires two important considerations. Acute neurologic injuries should be distinguished from chronic brain injuries and the level of competitive boxing (ie, amateur vs professional) must also be taken into account. Acute neurologic injuries such as concussion, post-concussion syndrome, intracranial hemorrhage, and brain contusion are more readily identified than chronic neurologic injuries because of their immediate devastation of the nervous system. In contrast, chronic neurologic injuries differ in their pathophysiologic mechanisms that are exemplified by an insidious onset and progression after the cessation of boxing. Accordingly, the chronic traumatic encephalopathy of boxing poses the most serious neurologic threat of boxing. Amateur boxing differs from professional boxing in the duration of fights, rules and regulatory policies, medical evaluation, and protective devices. These factors could produce a differential effect on the risk of injury to the brain. The prevention of neurologic injuries in boxing requires the integration of proper neurologic evaluation by qualified ring-side physicians, the design and utilization of effective protective devices, and the establishment of national regulatory agencies.

Athletic Injuries↗

Hearing loss after head injury.

This work reports on the hearing loss of 395 patients who were hospitalized after brain concussion. The percentage of hearing loss and vestibular disturbances appearing after fracture of the temporal bone is higher than in cases with skull fractures without fracture of the temporal bone or with brain concussion alone. Conductive deafness caused by head injury usually disappears in two months time. If conductive deafness remains, the suspicion of dislocation of the ossicular bones arises and such patients must undergo an operation. As the cases where sensorineural deafness disappeared within six months after head injury were rare, final evaluation of the hearing loss can be made one year after the head injury. In the majority of cases, vestibular disturbances and positional nystagmus disappear within six months after the head injury.

Adolescent↗

Diffuse axonal injury and traumatic coma in the primate.

Traumatic coma was produced in 45 monkeys by accelerating the head without impact in one of three directions. The duration of coma, degree of neurological impairment, and amount of diffuse axonal injury (DAI) in the brain were directly related to the amount of coronal head motion used. Coma of less than 15 minutes (concussion) occurred in 11 of 13 animals subjected to sagittal head motion, in 2 of 6 animals with oblique head motion, and in 2 of 26 animals with full lateral head motion. All 15 concussioned animals had good recovery, and none had DAI. Conversely, coma lasting more than 6 hours occurred in one of the sagittal or oblique injury groups but was present in 20 of the laterally injured animals, all of which were severely disabled afterward. All laterally injured animals had a degree of DAI similar to that found in severe human head injury. Coma lasting 16 minutes to 6 hours occurred in 2 of 13 of the sagittal group, 4 of 6 in the oblique group, and 4 of 26 in the lateral group, these animals had less neurological disability and less DAI than when coma lasted longer than 6 hours. These experimental findings duplicate the spectrum of traumatic coma seen in human beings and include axonal damage identical to that seen in sever head injury in humans. Since the amount of DAI was directly proportional to the severity of injury (duration of coma and quality of outcome), we conclude that axonal damage produced by coronal head acceleration is a major cause of prolonged traumatic coma and its sequelae.

Acceleration↗

Blunt basal head trauma: aspects of unconsciousness.

Two cases of street violence directed to the skull base level and transverse to the cervical axis are described. No skeletal damage. The violence resulted in the so-called "traumatic subarachnoid haemorrhage", an often used, unspecified forensic "diagnosis"; it was here revealed to be due to rupture of the wall of the posterior inferior cerebellar artery (p.i.c.a). However, this was only one of the possible explanations for the acute symptoms of unconsciousness (concussion) and almost immediate death. The careful examination of these two cases and of a series of control cases revealed that at the trauma, stress and strain may have occurred to arterial branches serving as feeding perforant vessels to the medulla oblongata; in these cases they were coursing directly from the p.i.c.a. region.--The type of direct impact has often been regarded as mild! However, its location suboccipitally as in these cases can become dangerous. The resulting direct or indirect deficit of brain stem functions are discussed in these cases as well as "concussion-related symptoms" resulting after other types of head and neck injury.

Adult↗

Sports related mild traumatic brain injury in adolescents.

While head injuries are not common in youth sports, they may have catastrophic results. Concussion is also referred to as mild traumatic brain injury (MTBI). Although the occurrence of head injuries has been studied more extensively in American football, the findings have wider application for any MTBI. Recently, more attention has been directed at other sports in which both boys and girls participate. The diagnosis of MTBI is based on subjective findings and subtle changes in mental status. Other cerebral injuries requiring emergent or urgent neurosurgical attention should be ruled out. Objective tests such as CT scans and Magnetic Resonance Imaging (MRI) are usually without significant findings in MTBI. Neuropsychological testing may demonstrate areas of deficiencies, however, results may be difficult to interpret because of confounding factors. Complications following MTBI have been known to occur. The most catastrophic of these is second impact syndrome. There are a variety of guidelines for return to play following a concussion, which have been designed in an effort to avoid problems such as second impact syndrome. These guidelines are based more on clinical experience than on scientific evidence. Education, good training and coaching techniques, improved equipment, and rule changes and enforcement, can all help in curbing the sports related head injuries in adolescents.

Adolescent↗