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PubMed2002

The clinical management of sports concussion.

Concussion is among the hottest topics in sports medicine today. It is a highly individualized injury which oftentimes has a subtle presentation that is easily misdiagnosed, and therefore mishandled. When to return a concussed athlete to participation is a highly controversial topic that, to this point, has been primarily based on any one of 17 sets of guidelines. Neuropsychologic and cognitive testing has introduced a quantitative and sensitive measure that allows the clinician to verify an athlete's return to normal functioning levels. It is based on the firm belief that every concussion is a unique event, and must be handled as such. The realization that there is no one formula that can handle an injury this complex and multifaceted is perhaps the greatest breakthrough in mild traumatic brain injury research in the past decade.

Athletic Injuries↗
PubMed1996

[Montirelin hydrate (NS-3), a TRH analog, improved the disturbance of consciousness caused by head concussion and pentobarbital in mice].

Effects of a novel TRH analog, montirelin hydrate (NS-3), on the coma caused by head concussion and narcosis induced by pentobarbital were compared with those of TRH in mice. Head concussion caused a behavioral comatose state with loss of the righting reflex and spontaneous motor activity. NS-3 shortened the latent periods to the recovery of the righting reflex (0.03-0.1 mg/kg, i.v.) and spontaneous motor activity (0.1 mg/kg, i.v.) following the head concussion. In the case of TRH, higher doses were needed to induce such effects. NS-3 (0.1-0.3 mg/kg, i.v.) reversed the pentobarbital-induced narcosis in a dose-dependent manner. A similar effect was elicited by 30- to 100-fold higher doses of TRH than NS-3. The analeptic effect of NS-3 in the pentobarbital-narcotized mice was antagonized by SCH23390, a dopamine D1 antagonist or by the combined treatment with prazosin and scopolamine, while neither prazosin nor scopolamine alone antagonized the analeptic effect of NS-3. Taken together with the finding that NS-3 did not bind to dopamine, adrenaline or muscarine receptors, it is suggested that NS-3 may restore the disturbance of consciousness by activating the brain dopamine, noradrenaline and acetylcholine neurons without stimulating these receptors directly.

Anesthesia↗
PubMed2004

"Heads up": concussions in high school sports.

In the United States, sports-related head injuries occur frequently. The Centers for Disease Control estimates more than 300,000 sports-related concussions occur each year in the United States. There are a number of myths and misunderstandings among health care professionals regarding concussions. In this article, we clarify some reasons for these misunderstandings and provide some of the possible causes for the increased susceptibility of the adolescent athlete, along with evidence-based assessment tools for assisting physicians in making return-to-play decisions. Finally, suggestions for a concussion safety program in the high school setting are also provided.

Adolescent↗
PubMed2005

Posttraumatic migraine characteristics in athletes following sports-related concussion.

OBJECT: The object of this study was to compare symptom status and neurocognitive functioning in athletes with no headache (non-HA group), athletes complaining of headache (HA group), and athletes with characteristics of posttraumatic migraine (PTM group). METHODS: Neurocognitive tests were undertaken by 261 high-school and collegiate athletes with a mean age of 16.36 +/- 2.6 years. Athletes were separated into three groups: the PTM group (74 athletes with a mean age of 16.39 +/- 3.06 years), the HA group (124 athletes with a mean age of 16.44 +/- 2.51 years), and the non-HA group (63 patients with a mean age of 16.14 +/- 2.18 years). Neurocognitive summary scores (outcome measures) for verbal and visual memory, visual motor speed, reaction time, and total symptom scores were collected using ImPACT, a computer software program designed to assess sports-related concussion. Significant differences existed among the three groups for all outcome measures. The PTM group demonstrated significantly greater neurocognitive deficits when compared with the HA and non-HA groups. The PTM group also exhibited the greatest amount of departure from baseline scores. CONCLUSIONS: The differences among these groups can be used as a basis to argue that PTM characteristics triggered by sports-related concussion are related to increased neurocognitive dysfunction following mild traumatic brain injury. Thus, athletes suffering a concussion accompanied by PTM should be examined in a setting that includes symptom status and neurocognitive testing to address their recovery more fully. Given the increased impairments observed in the PTM group, in this population clinicians should exercise increased caution in decisions about treatment and when the athlete should be allowed to return to play.

Adolescent↗
PubMed1999

Repeated measures of cognitive processing efficiency in adolescent athletes: implications for monitoring recovery from concussion.

OBJECTIVE: The objective of this study was to determine whether an adolescent athlete, in the absence of concussion, would be expected to show an improvement in cognitive function during the course of a high school football season. BACKGROUND: At least 60,000 American high school football players suffer cerebral concussion every year, and symptoms may persist for 4 or more years in as many as 24%. METHOD: 34 members of a cohort of healthy athletes, aged 13-18, were administered a computerized neuropsychologic test battery from the Automated Neuropsychological Assessment Metrics (ANAM) before and after the 1997 high school football season, with a mean interval of 16.1 (range 12.3-20.4) weeks between tests. Preseason and postseason scores on eight tests were compared, with significance determined by paired t-test. For those tests in which an improvement was noted, one-way analysis of variance and Wilcoxon tests were used with both preseason and postseason data to determine if there was a measurable difference in cognitive processing efficiency between older and younger subjects. RESULTS: Improvements in processing efficiency (p < 0.001) were noted on tests designed to measure visual scanning and sustained attention (CDS), immediate recall (CDI), and short-term memory (CDD). Older subjects generally performed better on each of these tests, though the difference was significant in only one case (postseason CDI, 17-18 year olds vs. 13-14 year olds, Wilcoxon, p = 0.043). CONCLUSIONS: Our findings suggest that ANAM is sensitive to differences and improvements in cognitive function during a 4 month interval in adolescence. They also suggest that using "return to baseline" cognitive function as the criterion for evidence of recovery from concussion may be insufficient, especially when the baseline measurement was obtained 4 or more months prior to the date of "full recovery."

Adolescent↗
PubMed1999

[Headache as the consequence of brain concussion and contusion in closed head injuries in children].

The most frequent type of head injury in children is closed head trauma with brain concussion or contusion, and headache is the dominant complaint of early and late postinjury period. Because of scant number of studies on the problem of occurrence, characteristics and persistence of posttraumatic headache this study was undertaken in a group of 100 children (29 girls and 71 boys), aged 3-14 years old, 90 after brain concussion and 10 after contusion. Children with a history of injuries, central nervous system infections, with headaches before injury and chronic diseases were excluded. In 9 cases linear skull fracture was present after injury. The material was examined within one week after trauma, and then after 3, 6, and 12 months. After 3 months EEG was performed and repeated after 6 and 12 months in children with persistent headache or those without headache but with abnormal EEG results in the first examination. According to the additional diagnostic examinations, I excluded other causes of headache, besides head injury. In my observation 83% of children had headache after brain concussion and contusion. The majority--56%--had acute posttraumatic headache, but 27% of children complained of chronic headache, mainly tension type headache. Only 3% had migraine. In 21% of all group of 100 children, I noticed the headache persisting during the whole year of my observation. The important risk factor for the occurrence of posttraumatic headache were the age of child at the moment injury and the period of unconsciousness. The electroencephalographic recording still remains the important additional examination of posttraumatic consequences.

Acute Disease↗
PubMed1992

[Brain concussion in patients with chronic vascular, gastrointestinal and pulmonary diseases].

Examined were 317 patients with brain concussion ranging in age from 16 to 75 years. Of them in 133 (41.91%), chronic diseases (I-II degree chronic insufficiency of cerebral circulation, arterial hypertension, chronic cholecystitis, gastric and duodenal ulcer disease, chronic bronchitis, bronchial asthma) were revealed. Peculiarities of the course of brain concussion in these patients are noted. The author stresses that it is necessary to take into account chronic diseases when observing and treating the sufferers with brain concussion.

Adolescent↗
PubMed2005

[Headache occurrence and assessment of regional blood flow after brain concussion in children].

BACKGROUND AND PURPOSE: Headaches which can last for many months and even years belong to the most frequent consequences of closed head injuries in children. The method which makes it possible to demonstrate the presence and extent of the nervous tissue damage caused by trauma is the regional cerebral blood flow (rCBF) evaluation with single photon emission computerized tomography (SPECT). In the present study the regional cerebral blood flow (rCBF) was assessed 10-15 days after trauma, 3 months and one year in cases of brain concussion. We tried to establish whether there was a correlation between changes in rCBF and the occurrence of posttraumatic headache. MATERIAL AND METHODS: SPECT was applied in 32 children, aged 6-16, 10-15 days, and then 3 and 12 months after brain concussion. In all children no changes were found in CT and MRI examinations. RESULTS: In the studied group in the early period after trauma, blood flow impairment was found in 21 children, mostly in frontal areas. One year after trauma the rCBF improved in 11 children, in 10 cases the pattern was normal. In a group of 4 children with headache one year after brain concussion, three of them still presented the impairment of blood flow. CONCLUSIONS: SPECT shows a great sensitivity and usefulness in the assessment of consequences of head trauma and it can explain some posttraumatic complaints in children.

Adolescent↗
PubMed2006

An analysis of referees and referrals to a specialist concussion clinic in New Zealand.

AIM: This study reviews the characteristics of referrals to a specialist concussion clinic (Burwood Hospital Concussion Clinic, Christchurch, New Zealand) in its first two years of operation. METHOD: Information regarding referral source, demographic and clinical features, time since mild traumatic brain injury (MTBI), assessment and treatment provided, service follow-up, and outcome at discharge were collected from a file search of all referrals received in the two years ending in October 2004. RESULTS: Cases reflected the clinical and demographic diversity expected of those incurring an MTBI. Age and referral source were associated with failing to keep initial appointments. Assessments typically resulted in ongoing treatment from the service, although many were 'one-off' assessments. One-in-five cases resulted in ongoing treatment for more than 7 months. Gender, cause of MTBI, and time delay between injury and assessment were significantly associated with receiving long-term follow-up. Most cases had a good clinical outcome at discharge. CONCLUSIONS: While the Concussion Clinic services the intended clinical population, referrals for assault-related MTBIs were greater than expected, and men may be under-referred. The disproportional number of non-attending patients referred from Christchurch Hospital Emergency Department along with the unanticipated proportion of cases receiving long-term follow-up, suggest a need for review of the referral response systems and the scope of service provision.

Accidental Falls↗
PubMed1985

Effects of bencyclane on concussion following head injury in mice.

Bencyclane showed a dose-dependent anti-concussive effect with a duration of at least 60 minutes in an experimental model of concussion induced by head injury. This long-lasting effect cannot be explained only by the changes in the serum level of the agent or the increase in brain circulation due to its vasodilative action, both of which are of much shorter durations. Our findings suggest that bencyclane causes alterations in brain metabolism, which is partly responsible for reduction in the duration of the experimental concussion.

Animals↗
PubMedDate not supplied

EEG and brainstem abnormalities after cerebral concussion. Short term observations.

Four hundred patients (221 young, 179 adults) with a cerebral concussion (317 minor, 83 mild) were examined within 48 hours after blunt head injury. In mild concussions there is a threefold homogeneous increase in the different EEG and BEP abnormalities compared to minor concussions. In the younger group EEG abnormalities are far more frequent than BEP abnormalities. An early EEG and/or BEP could be more useful than an EEG and/or BEP in the reconvalescent phase. Follow-up studies will have to prove their value in determining the risk of later posttraumatic epilepsy.

Adolescent↗
PubMed1995

Management of concussion in collision sports. Guidelines for the sidelines.

During high-risk sports events, it is important for team physicians to be alert to the possibility of concussion in athletes who may not realize they have been injured or may want to conceal their injury. If concussion is suspected and the player is conscious, history taking should include inquiries about loss of consciousness, loss of memory of events before and after the impact, headache, visual abnormalities, motor and sensory changes, and back, neck, and extremity pain. In an unconscious player, the airway, breathing, circulation, and cervical spine should be checked. The cervical spine must be stabilized before the player is moved if injury to it is suspected. Athletes with such an injury and those who have lost consciousness require hospital evaluation. If there is no cervical spine injury, a complete neurologic evaluation should be carried out on the sidelines and the player checked for signs of skull fracture. The Colorado Medical Society guidelines for grading concussions and deciding when athletes may return to competition are an excellent aid to clinical judgment.

Athletic Injuries↗
PubMed1992

Light microscopic response of neuronal somata, dendrites and axons to post-mortem concussive head injury.

Forty anesthetized rats were cooled below 3 degrees C by 30-min transcardial perfusion of chilled physiological saline before a concussive head injury. The animals were then perfusion-fixed with a buffered formaldehyde-glutaraldehyde solution. Another forty rats were fixed by 30-min transcardial perfusion of the same fixative before a similar concussive head injury. In brain sections of both groups of animals a new silver method stained, in a Golgi-like fashion, a number of neurons and long axonal segments scattered among unstained ones. The similarity between these findings and those obtained following in vivo concussive head injuries described in accompanying papers suggests that the formation of traumatically induced argyrophilic neuronal damage is independent of metabolic processes, i.e., it may be a primary morphopathological process.

Animals↗
PubMed1991

Diffuse prolonged depression of cerebral oxidative metabolism following concussive brain injury in the rat: a cytochrome oxidase histochemistry study.

Utilizing a lateral fluid percussion injury as a model of cerebral concussion, rats were studied histochemically measuring the degree of cytochrome oxidase activity present within different structures at different times following injury. After concussion, the cerebral cortex ipsilateral to the site of injury exhibited a diffuse decrease in its level of chromotome oxidase (CO) activity beginning at as soon as one day and lasting for up to 10 days after the insult. The ipsilateral dorsal hippocampus also exhibited an injury-induced decrease in CO activity, however, it was not as severe as in the cortex. These results indicate that oxidative metabolism is depressed primarily within the cerebral cortex and hippocampus for several days following a cerebral concussion. We propose that this period of metabolic depression may delineate a period of time during which the injured brain is unable to function normally and thus would be vulnerable to a second insult.

Animals↗
PubMed1994

alpha-Phenyl-tert-butyl-nitrone inhibits free radical release in brain concussion.

Traumatic brain injury (TBI) is one of the important causes of mortality and morbidity. The pathogenesis of the underlying brain dysfunction is poorly understood. Recent data have suggested that oxygen free radicals play a key role in the primary and secondary processes of acute TBI. We report direct electron spin resonance (ESR) evidence of hydroxyl (.OH) radical generation in closed-head injury of rats. Moderate brain concussion was produced by controlled and reproducible mechanical, fixed, closed-head injury. A cortical cup was placed over one cerebral hemisphere within 20 min of the concussion, perfused with artificial cerebrospinal fluid (aCSF) containing the spin trap agent pyridyl-N-oxide-tert-butyl nitrone (POBN, 100 mM), and superfusate samples collected at 10 min intervals for a duration up to 130 min post brain trauma. In addition, POBN was administered systemically (50 mg/kg body wt.) 10 min pretrauma and 20 min posttrauma to improve our ability to detect free radicals. ESR analysis of the superfusate samples revealed six line spectra (alpha N = 15.4 G and alpha beta H = 2.5 G) characteristic of POBN-OH radical adducts, the intensity of which peaked 40 min posttrauma. The signal was undetectable after 120 min. Administration of alpha-phenyl-tert-butyl-nitrone (PBN), a spin adduct forming agent systemically (100 mg/kg body wt. IP 10 min prior to concussion) alone or along with topical PBN (100 mM PBN in aCSF), significantly (p < 0.001) attenuated the ESR signal, suggesting its possible role in the treatment of TBI.

Animals↗
PubMed1996

The reliability of electric pulp test after concussion injury.

Traumatic injuries to teeth present a difficult diagnostic problem with respect to determining the vitality of the affected teeth. Conventionally, a latency period of 4 to 6 weeks is proposed as the amount of time required for the return of a positive electric pulp test (EPT) response; however, this has been based on empirical data. The purpose of this study was to 1) determine a time frame during which a return of a reliable response to EPT may be measured, and 2) correlate this time frame with pulpal vascular changes that occur after traumatic injuries. Four canines from each of nine ferrets were used for this experiment (18 traumatized and 18 control teeth). A reproducible concussion injury was devised by releasing a known weight at a constant height above the facial surface of the experimental teeth. The EPT response was confirmed by the use of an EMG muscle recorder. Animals were killed at 24, 48 and 72 h and 6, 12 and 28 days after the injury and the teeth analyzed histologically. The histological sections showed an absence of inflammatory cells in both groups; however, according to the NIH image system, an increase in the number of vessels was detected in the experimental group when compared to the controls. In a majority of the cases, a positive response to the EPT returned within 12 days post concussion injury and as early as 10 days. In addition, a significant vascular change was accompanied with the loss of the EPT response. This study provided a reliable method by which concussion injuries may be studied using an animal model.

Analysis of Variance↗
PubMed1981

Inhibition by free radical scavengers and by cyclooxygenase inhibitors of pial arteriolar abnormalities from concussive brain injury in cats.

We studied the role of prostaglandins and free radicals in the induction of the functional and morphological pial arteriolar abnormalities produced by concussive brain injury. Anesthetized cats equipped with a cranial window for the observation of the pial microcirculation were subjected to concussive brain injury using a fluid-percussion device following administration of cyclooxygenase inhibitors (indomethacin or AHR-5850) or the vehicle for the solution of these agents (NaCl or Na2CO3 solution). Pial arterioles from vehicle-treated animals displayed sustained dilation, reduced responsiveness to the vasoconstrictor effect of arterial hypocapnia, and a high density of endothelial lesions. Animals pretreated with cyclooxygenase inhibitors showed less pronounced vasodilation, normal responsiveness to hypocapnia, and a significantly reduced number of lesions. The vasodilation and reduced responsiveness to the vasoconstrictor effects of hypocapnia after brain injury also were inhibited by topical application of free radical scavengers (nitroblue tetrazolium, superoxide dismutase, or mannitol). The vessels from cats pretreated with free radical scavengers also had a lower density of endothelial lesions than controls. The results support the view that the immediate cause of cerebral arteriolar damage in concussive brain injury is the generation of free oxygen radicals associated with increased prostaglandin synthesis.

Animals↗
PubMed2001

Principles of Liability for Athletic Trainers: Managing Sport-Related Concussion.

OBJECTIVE: To provide an overview of the general legal principles of negligence for sports medicine professionals and apply these principles to situations involving athletes with head injury. DATA SOURCES: Case law dating back to 1976 and recent studies of sport-related concussion. SUMMARY: One of the most difficult problems facing athletic trainers and team physicians is the recognition and treatment of sport-related concussion. Providing medical clearance for sports participation and treatment of athletic injuries involves legal as well as medical issues. The threat of lawsuits exists for the sports medicine professional, whether the athlete is allowed to play or not. In general, established medical malpractice principles govern claims by athletes for injury or death caused by improper treatment by health care providers. The elements of negligence are examined, as well as the primary defenses an athletic trainer would use in court and risk management techniques to avoid litigation. CONCLUSIONS/RECOMMENDATIONS: Athletic trainers may protect themselves from liability by including standardized cognitive or postural stability testing in preparticipation examinations, using objective tests rather than subjective judgement to evaluate athletes who have sport-related concussion, working closely with physicians, and keeping excellent records.

Journal Article↗