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PubMed1996

[Changes in the cerebral cortex in closed craniocerebral trauma of gunshot origin (experimental research)].

Cerebral cortex was studied morphologically in rabbits with concussion of brain induced by gunshot injury. The extent of severity was modelled by the bullet rate. No significant bleeding followed the injury allowing to observe the animals during the necessary terms (7-14 d.) Morphological study included light optical and electron microscopy. In neurons, glial cells and synapses a series of essential destructive changes in shown detectable predominantly on ultrastructural level that might be the base of psychoneurological complications of a distant period. Ballistic properties of a bullet were obviously fundamental to pathogenesis of brain concussion in these experiments as kinetic energy of the bullet was only sufficient for non significant damage of the skull soft tissue. But in contrast to the dull trauma, the blow was of a high speed and despite mild clinical characteristics caused essential diffuse structural disturbances in brain tissues.

Animals↗

PubMed1997

Serial sevens: not the most effective test of mental status in high school athletes.

OBJECTIVE: To evaluate the ability of uninjured high school athletes to pass three mental status tests that are commonly used on the sidelines for the evaluation of concussions: the serial sevens test, the serial threes test, and recitation of months of year in reverse order (MOYR). PARTICIPANTS: High school student athletes in grades 9, 10, 11, and 12 having sports preparticipation physical examinations. The initial study tested 522 consecutive athletes. The follow-up study tested 109 consecutive athletes. INTERVENTION: The athletes of the initial group were asked to perform a serial sevens test, followed by a serial threes test, and finally to recite the MOYR. The second group was asked to perform the same tests in a random order. MAIN OUTCOME MEASURES: Participants were given 1-min time limits for each test, with passing defined as either 7 consecutive correct iterations or 11 correct with one mistake. RESULTS: For the initial group, 51.3% successfully performed serial sevens, 78.7% successfully performed serial threes, and 89.5% successfully recited the MOYR. For the second group, 52.7% successfully performed serial sevens, 78.1% successfully performed serial threes, and 88.9% successfully recited the MOYR. The pass rates were significantly different for both groups. The pass rates were similar for both sexes, all grade levels, and all sports in both test groups. Participants, both overall and in all subgroups, failed serial sevens more often than serial threes and MOYR (p < 0.001 for the initial group; p < 0.0001 for the second group). They failed serial threes more often than MOYR (p < 0.001 for the initial group; p < 0.01 for the second group). CONCLUSIONS: The percentage of uninjured high school athletes successfully completing serial sevens is too low to make the test useful for evaluation of concussion; the test lacks specificity. The percentage of athletes passing the MOYR was greatest, perhaps making this a better sideline test than the traditional serial sevens test. However, testing needs to be done in injured athletes before clinical application can be recommended.

Adolescent↗

PubMedDate not supplied

[Subjective syndrome after head injury].

UNLABELLED: DEFINITION AND CLASSIFICATION PROBLEMS: Post-traumatic or post-commotion syndrome is one of the most controversial entities in studying consequences of craniocerebral trauma. Part of this problem arises from impossibility of adequate translation of the term brain concussion. Post-concussion syndrome is a broader concept than post-commotion and includes, if not a whole, than part of the post-contusion syndrome. There are also some other terms in the literature: post-traumatic syndrome, post head injury syndrome, post head injury syndrome or symptoms and the old term post-traumatic encephalopathy. Terminological imprecisions have not been solved yet, but the notion itself is determined by relative standard symptoms often associated with closed craniocerebral trauma, but without precise connection with the severity of the trauma. In the classification of mental disorders and behavior disorders, this syndrome is coded as FO7.2. ETIOLOGY: In regard to the etiology of this syndrome some authors speak in favor of psychogenic and some of organic etiology, while Levin considers symptoms of post-commotion syndrome to start as organic and persist as psychic. Wechsler classified subjective disorders after head injuries into 4 categories: simulation, traumatic hysteria, traumatic encephalopathy and traumatic neurosis. The author does not deal with the origin of symptoms, whereas the classification itself suggests priority of psychic to organic factors (11). Those who speak in favor of organic etiology, think that axon damage and neuron damage are organic substrate in mild brain injuries, while fibrous degenerations of the cerebral hemisphere and brain stem are the organic base in severe traumas. On the other hand, many scientists primarily point to psychic moments, especially to importance of aggravation and simulation as well as compensation or rental neurosis in persistent post-traumatic syndrome. Most scientists agree that personality characteristics influence the development of post-traumatic syndrome and can predispose aggravation and simulation, whereas these symptoms more often occur in neurotic persons. The latest investigations reveal that classification in regard to etiologic factors--organic and psychogenic--is an anachronism. Long and Novac state that 80% of persons with cerebral trauma spontaneously speak about symptoms of the post-traumatic syndrome, while by targeted evaluation the percentage rises to 90%, so that they think that universality of symptoms points to their common origin. CONCLUSION: If the post-traumatic syndrome is though of as a line with organic dementia at one end and traumatic neuroses at the other, then this syndrome can be placed at different positions. Some authors put it close to the neurotic syndrome or regard it to be the neurotic syndrome itself, while others, mostly due to homogenity of the clinical picture, believe that this syndrome has an organic cause.

Brain Concussion↗

PubMedDate not supplied

[Cranio-cerebral trauma and circadian rhythms of activity of several functions of the hypothalamo-hypophyseo-adrenal system in patients of different age groups].

The circadian rhythms of the androgenic and glucocorticoid activity of the adrenal cortex were examined in 7 patients with concussions of the brain, and in 22 -- with contusions. The excretion of 17-ketosteroids and of total 17-oxycorticosteroids was determined dynamically in separate 6-hour portions of the urine. In cases of brain concussions, both in the initial period of the trauma, and 10--12 days therafter, only a tendency towards increased excretion of corticosteroids during the night and decreased excretion in the morning hours was observed. In brain contusions the rhythm of andorgenic activity was altered. The most significant alterations caused by a severe trauma were observed in the rhythm of the glucocorticoid function of the adrenal cortex: its reduction in the morning hours, and increase during the night. Some 10--12 days after the brain contusions the rhythm of the hormonal activity remained altered, especially in young and middle-aged patients. These peculiarities of the rhythms should be taken into account when prescribing replacement corticosteroid therapy.

17-Hydroxycorticosteroids↗

PubMedDate not supplied

[The dynamics of aminotransferase activity in the blood plasma as a reflection of the characteristics of the pathological process in patients with craniocerebral trauma].

The activity of alanin-aminotransferase (ALT) and aspartate-aminotransferase (AST) was measured in blood plasma of 103 patients with brain trauma. Sex-related differences were found. One day after the trauma ALT and AST activity rose significantly both in men and women with brain concussion, in males with mild and moderate brain contusion. In severe brain contusion the enzymes activity did not change. Eight days after the trauma AST activity significantly lowered in patients with brain concussion. No changes in aminotransferases activity one day after severe brain contusion evidence for biochemical maladaptation.

Adult↗

PubMed2006

Acute hemispheric swelling associated with thin subdural hematomas: pathophysiology of repetitive head injury in sports.

INTRODUCTION: The most common head injury in sports is concussion, and repeated concussions occurring within a short period occasionally can be fatal. Acute subdural hematoma is the most common severe head injury and can be associated with severe neurologic disability and death in sports. We investigated severe brain damage resulting from repetitive head injury in sports, and evaluated the pathophysiology of sports-related repetitive injury. METHODS: We reviewed the literature containing detailed descriptions of repetitive severe sports-related head injury. In total, 18 cases were analyzed with regard to age, gender, type of sports, symptoms before second injury, and pathology of brain CT scans. RESULTS: The majority of cases involved young males aged 16 to 23 years old, who sustained a second head injury before symptoms from the first head injury had resolved. Ten of 15 cases did not suffer loss of consciousness at insult. Eight cases were confirmed on brain CT scans after the second injury, and all 8 cases revealed brain swelling associated with a thin subdural hematoma. CONCLUSIONS: Second impact syndrome is thought to occur because of loss of autoregulation of cerebral blood flow, leading to vascular engorgement, increased intracranial pressure, and eventual herniation. Our investigation suggests that the existence of subdural hematoma is a major cause of brain swelling following sports-related, repetitive head injury.

Adolescent↗

PubMed1987

Beneficial effects of the kappa opioid receptor agonist U-50488H in experimental acute brain and spinal cord injury.

The effects of the selective kappa opioid receptor agonist U-50488H (trans-3,4-dichloro-N-methyl-N[2-(pyrrolidinyl)-cyclohexyl]- benzeneacetamide) were examined in acute head and spinal injury models. First, in a blinded protocol, male CF-1 mice were treated intravenously with either saline or U-50488H (1, 3 or 10 mg/kg) within 3-5 min following a reproducible and quantifiable moderately severe (900 g/cm) concussive head injury. Using a grip test at 1 h postinjury to evaluate the neurological status of the injured mice, U-50488H produced a dose-related improvement in early recovery compared to the saline-treated mice. The effect was significant (P less than 0.05) after the 3 or 10 mg/kg i.v. doses. A similar concussive injury markedly reduced the % of cardiac output perfusing the forebrain (cerebral blood flow). U-50488H (10 and 20 mg/kg) partially reversed this effect to a significant degree 60 min after a 20 mg/kg dose. Secondly, the effects of U-50488H on the development of progressive post-traumatic spinal cord white matter ischemia after a 500 g/cm contusive injury were studied in pentobarbital-anesthetized cats. In 4 untreated cats, there was a progressive fall in spinal cord and blood flow (SCBF) from a 10-min postinjury level of 10.5 +/- 0.7 ml/100 g/min to 6.1 +/- 0.3 (P less than 0.03 by paired t at 4 h).(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dichloro-N-methyl-N-(2-(1-pyrrolidinyl)-cycloh↗

PubMed1989

Increased vulnerability of the mildly traumatized rat brain to cerebral ischemia: the use of controlled secondary ischemia as a research tool to identify common or different mechanisms contributing to mechanical and ischemic brain injury.

Fasted Wistar rats were subjected to either a mild mechanical injury, 6 min of transient forebrain ischemia, or a mild mechanical injury followed 1 h later by 6 min of forebrain ischemia. EEG and evoked potentials were assessed intermittently and morphological analyses were performed after 7 days postinjury survival. In all groups complete qualitative recovery of electrical activity and general behavior was observed with 7-day survival. However, rats subjected to combined concussion and ischemia displayed EEG spike activity and a delayed return of EEG and evoked potentials during acute recovery not evident in other groups. No overt neuronal cell loss was seen in trauma alone and was minimal or absent in ischemia alone. However, extensive bilateral CA1 and subicular pyramidal cell loss was found in the septal and mid-dorsal hippocampi in the combined trauma and ischemia group. In contrast, no overt axonal injury was found in any group. We conclude that even mild mechanical injury can potentiate selective ischemic hippocampal neuronal necrosis in the absence of overt axonal injury. This potentiation also occurs in conjunction with more generalized electrophysiological disturbances such as EEG evidence of postischemic neuronal hyperactivity suggesting that mild concussion may also decrease the threshold for post-ischemic neuronal excitation. These results suggest the potential of this model for examining common or different injury mechanisms in mechanical and ischemic brain injury.

Animals↗

PubMed1993

Cerebral activating properties of indeloxazine HCl and its optical isomers.

The cerebral activating actions of indeloxazine HCl and its optical isomers were evaluated in comparison with those of several selective monoamine uptake inhibitors. The effects of indeloxazine and its optical isomers on monoamine uptake were also determined. Indeloxazine was equipotent to the (-)-isomer in desynchronizing the spontaneous electroencephalogram (EEG) in both mature and aged rats and in accelerating recovery of consciousness induced by concussive head trauma in mice, whereas the (+)-isomer showed about 3 times less potent activity than indeloxazine and the (-)-isomer. The potency of indeloxazine and the (-)-isomer in inhibiting [14C]norepinephrine (14C-NE) uptake was approximately 25-30 times more potent than that of the (+)-isomer. Maprotiline and viloxazine, selective NE uptake inhibitors, also showed facilitatory actions in concussed mice. Selective 5-hydroxytryptamine (5-HT) uptake inhibitors such as citalopram, alaproclate, and zimeldine showed little effect. Indeloxazine, the (-)-, and the (+)-isomers facilitated passive avoidance learning behavior with a bell-shaped response curve in normal rats. The potency of the (+)-isomer in inhibiting [14C]5-HT uptake was equipotent to those of both indeloxazine and the (-)-isomer. While citalopram, alaproclate, and zimeldine also facilitated the acquisition of learning behavior, maprotiline and viloxazine, as well as the dopamine uptake inhibitor amantadine, showed little influence on the latency of step-through behavior. Amitriptyline, with anticholinergic activity, impaired learning behavior. Indeloxazine, its optical isomers, citalopram, alaproclate, and zimeldine also ameliorated cycloheximide-induced disturbance of learning behavior in mice, while maprotiline and viloxazine showed little effect.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1996

Vasomotor and permeability effects of bradykinin in the cerebral microcirculation.

All components of an intracerebral kallikrein-kinin system have been described. Thus, bradykinin (BK) acting from the parenchymal site as well as from the blood site may influence cerebral microcirculation. BK is a potent dilator of extra- and intraparenchymal cerebral arteries when acting from the perivascular site. The vasomotor effect of BK is mediated by B2 receptors which appear to be located at the abluminal membrane of the endothelial cell. The effect of BK is mediated by NO. prostanoids, free radicals, H2O2 or leukotrienes depending on the animal species and on the location of the artery. Selective opening of the blood-brain barrier for small tracers (Na(+)-fluorescein; MW, 376) has been found in cats during cortical superfusion or intraarterial application of BK. This leakage is mediated by B2 receptors located at the luminal and abluminal membrane of the endothelial cells. Formation of brain edema has been found after ventriculo-cisternal perfusion or interstitial infusion of BK. This can be explained by increase of vascular permeability and cerebral blood flow due to arterial dilation thus enhancing driving forces for the extravasation. An increase of the BK concentration in the interstitial space of the brain up to concentrations which induce extravasation, dilatation and oedema formation has been found under several pathological conditions. Thus, BK may be involved in oedema formation after cold lesion, concussive brain injury, traumatic spinal cord and ischemic brain injury. The mediator role of BK in brain edema is further supported by therapeutic results. Brain swelling due to cold lesion or ischemia could be diminished by treatment with kallikrein-inhibitors. Similarly, dilatation of cerebral arterioles after concussive brain injury was reduced by blockade of B2 receptors. Thus, all criteria favour BK as one mediator of vasogenic oedema.

Angiotensin-Converting Enzyme Inhibitors↗

PubMed2005

Verification of biomechanical methods employed in a comprehensive study of mild traumatic brain injury and the effectiveness of American football helmets.

Concussion, or mild traumatic brain injury, occurs in many activities, mostly as a result of the head being accelerated. A comprehensive study has been conducted to understand better the mechanics of the impacts associated with concussion in American football. This study involves a sequence of techniques to analyse and reconstruct many different head impact scenarios. It is important to understand the validity and accuracy of these techniques in order to be able to use the results of the study to improve helmets and helmet standards. Two major categories of potential errors have been investigated. The first category concerns error sources specific to the use of crash test dummy instrumentation (accelerometers) and associated data processing techniques. These are relied upon to establish both linear and angular head acceleration responses. The second category concerns the use of broadcast video data and crash test dummy head-neck-torso systems. These are used to replicate the complex head impact scenarios of whole body collisions that occur on the football field between two living human beings. All acceleration measurement and processing techniques were based on well-established practices and standards. These proved to be reliable and reproducible. Potential errors in the linear accelerations due to electrical or mechanical noise did not exceed 2% for the three different noise sources investigated. Potential errors in the angular accelerations due to noise could be as high as 6.7%, due to error accumulation of multiple linear acceleration measurements. The potential error in the relative impact velocity between colliding heads could be as high as 11%, and was found to be the largest error source in the sequence of techniques to reconstruct the game impacts. Full-scale experiments with complete crash test dummies in staged head impacts showed maximum errors of 17% for resultant linear accelerations and 25% for resultant angular accelerations.

Biomechanical Phenomena↗

PubMed2006

[Mild head trauma: complications and acousticovestibular sequelae].

Head injury with fracture of the petrous bone is frequent and directly related to the development of human activity. Head trauma is associated with nearly 75% of traffic accidents; 5% of them with petrous bone fracture. Based on a clinical case, the acute injuries and secondary acoustic or vestibular sequelae after low-energy cranio-cerebral trauma are discussed here. The subject was a victim of a low-energy head trauma with brief loss of consciousness and translabyrinthine fracture of the petrous bone. This fracture caused invalidating equilibrium disorders related to a perilymphatic fistula. These disorders persisted for 3.5 years and required several hospitalizations and three surgical procedures. The acoustic problems progressed towards cophosis and persistent and invalidating tintinus. We discuss the pathogenesis and treatment of these different sequelae of the middle ear as well as the external lesions. Among labyrinthine involvement, especially unilateral destruction, fistulization, concussion, and post concussion syndrome are especially descripted. Bony dislocations dominate middle ear sequelae. We also discuss the medicolegal problems associated with this type of pathology.

Adult↗

PubMed1980

CPK-MB isoenzyme determinations: diagnostic and prognostic value in evaluation of blunt chest trauma.

The incidence of myocardial contusion in patients with blunt chest trauma was examined. The criterion used for diagnosing contusion--actual cellular injury--was based on detection of the MB-isoenzyme of creatine phosphokinase, a sensitive and specific marker for cardiac cellular injury. Forty-nine patients with blunt chest trauma were evaluated using this diagnostic approach. Twenty-six demonstrated measurable serum levels of MB-CPK. Electrocardiographic (ECG) evaluation of this subgroup revealed that 85% exhibited anatomically localized ST-T wave abnormalities while 15% showed nonlocalized and nonspecific changes. Sixty-eight percent of those with localized abnormalities demonstrated ST segment changes depicting injury, most of which were localized to the anterior septal leads. The remaining 23 patients demonstrated non-detectable serum levels of MB-CPK and were classified as cardiac concussion on the basis of other clinical criteria. Twenty-six percent with concussion exhibited anatomically localized ECG changes. The remaining 74% had nonlocalized and nonspecific ECG changes.

Adolescent↗

PubMed1998

Epidemiology of athletic head injury.

Although more common in collision sports, head injuries (for this article confined to cerebral neurotrauma) may occur in virtually any form of athletics. A few such injuries result in death, especially the second-impact syndrome and subdural hematoma. The more minor cerebral injuries, mostly concussions, have wide-spread misunderstanding in definition and severity. These misunderstandings in the field have contributed to a paucity of reliable epidemiological information about its actual frequency. The concerns accompanying cerebral insult are discussed more than studied, but much can be gained in principle from the history of attention to concussions in football.

Athletic Injuries↗

PubMed1998

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.

Adolescent↗

PubMed1998

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.

Biomechanical Phenomena↗

PubMed1998

Comparison of injuries in elite senior and junior Australian football.

Three thousand and thirty one AFL and 1034 injuries in the VSFL U/18 competition were recorded by club doctors over the 1992, 1993 and 1994 seasons. Hamstring strains had the highest incidence (86.4 per 10,000 player hours) and prevalence (30.2 hours missed per 1000 hours) of any injury in the AFL, but were significantly less common in the U/18 competition. Other injuries which were common in both competitions were ankle sprains, thigh haematomas, concussion, groin strains and head lacerations. Injury prevalence was higher overall in the AFL, with lower limb muscle strains (hamstring, calf, quadriceps) being significantly more prevalent than in the U/18 competition. Injuries which were significantly more prevalent in the U/18 competition included stress fractures and concussion. Subsequent to this study, coaches and medical staff in the U/18 competition were made aware of the high risk of stress fractures in young footballers with heavy training loads. The AFL injury survey is ongoing and in the process of being computerised; risk factors for specific injuries with high rates are being studied further.

Adolescent↗

PubMed2004

Collision frequency in elite hockey on North American versus international size rinks.

OBJECTIVE: Body impact or collision is the risk factor underlying all sports-related concussions. This study sought to determine whether collision rates in elite hockey differ between games played on North American size rinks as compared to games played on larger international size ice surfaces. METHODS: Videotapes of games from the 2001 and 2002 National Hockey League Stanley Cup finals, World Junior championships and the 2002 Winter Olympics were analyzed, with all collisions counted and separated into various categories (player/player bodycheck, player/player into boards, player/boards, player/ice, head/stick, head/puck). Further subdivisions included collisions involving the head directly or indirectly. Twenty-two games were analyzed, 11 played on the small ice and 11 on the big ice. RESULTS: Significantly more collisions of all types (in all categories and subdivisions within categories) were found to occur on the smaller North American ice surface (P value differences from 0.01 to 0.00001). CONCLUSIONS: The results of this study showed significantly fewer collisions of all types in elite hockey games played on the international size ice surface. The comparison groups studied here did differ in some aspects other than ice size and so replication of the findings with even more closely matched groups will be needed before definitive conclusions can be drawn. However, if these findings are replicable, it would suggest that a change to uniform usage of the larger international rinks, with no rule changes or other alterations in the game, could provide direct primary prevention to reduce the number of collisions, and, by extension, concussions, that occur in the sport.

Athletic Injuries↗