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PubMed1977

Concussion.

We have observed the effects of concussion on nonanesthetized rats and humans. We believe the phenomenon in both to be identical. There are four obvious stages to concussion and the recovery therefrom: fourth stage--visceral (respiratory) and somatic immobility; third stage--return of irregular visceral (respiratory) mobility with continuing somatic immobility; second stage--normal visceral mobility with impaired somatic mobility; and first stage--normal somatic mobility with impaired performance. Zero stage is complete normality. Our method of testing detects no lingering or permanent change after a single concussion. This proves only that we must continue with open minds on the question, "Does concussion always leave permanent brain damage?"

Animals↗
PubMed1989

Clinical presentation of spinal cord concussion.

Spinal cord concussion is a transient disturbance of spinal cord function, with or without vertebral damage and no demonstrable pathologic changes, that results from a rapid change in velocity following trauma, and resolves within 48 hours. In a retrospective review of patients with spinal injury referred to a tertiary care center, spinal cord concussion was observed in 3.7% of patients. Thirteen cases are presented. A variety of clinical presentations may occur, all of which can be explained on the basis of the magnitude or direction of acceleration of the spinal cord. The cervical cord is most commonly affected, but concussion can occur at any level of the spinal cord. Spinal cord concussion is often associated with pre-existing vertebral abnormalities that result in narrowing of the spinal canal or areas of hypermobility.

Adult↗
PubMedDate not supplied

Concussion: comparison of humans and rats.

Concussion is the most primitive and probably the most simple central nervous system response to an outside agent. Although millions of neurons undergo a very rapid reversal with loss and restoration of function, many physicians argue that every knockout blow leaves some residual damage, i.e., some or all of these neurons stop short of recovery. Clinical experience shows a wide discrepancy in the appearance or persistence of certain signs and symptoms after all types of head injury, but particularly after concussing blows, when third party or grievance cases are involved. Using slow motion filmstrips of boxing ring knockouts, we established a grading system for concussion and duplicated these grades in nonanesthetized rats. When we compared the performance, learning, and memory of concussed rats with their preconcussion performance and with the performance of nonconcussed controls, we were unable to find any differences.

Animals↗
PubMed1983

Concussion incidences and severity in secondary school varsity football players.

The head coaches and players of 103 secondary school football teams in Minnesota were asked to respond to mail questionnaires. Information about injury incidence and concomitant health care provision was elicited. Responses from 3,063 players (81 per cent) yielded a total injury rate of 78 injuries/100 players; 19/100 players reported a concussion experience characterized by loss of consciousness and/or loss of awareness. Of the players who experienced a loss of consciousness, 69 per cent were returned to play the same day. Persistent concussion symptoms were reported as long as six to nine months following the end of the season; six cases involved permanent disabilities. Continued use of illegal techniques of butt-blocking and face-tackling by as many as 40 per cent of the players was associated with apparent increased risks of concussions and concussion symptoms. Players with a prior history of loss of consciousness had a risk of loss of consciousness four times that of the player without a prior history.

Athletic Injuries↗
PubMedDate not supplied

[Concussive convulsions in the differential diagnosis of post-traumatic epilepsy].

INTRODUCTION: Concussive convulsions are motor manifestations in acute head injury. This clinical phenomenon should be distinguished from epileptic seizures. We present two young men with motor and convulsive manifestations in acute head injury. Patient 1. A 18-year old basketball player fell on the parquet during a game. Initially he was struck on the right shoulder which caused brief and vigorous twitch of the head towards the ground and additional temporal impact. At the moment of impact he lost consciousness and developed tonic leg and arm posturing with both clenched fists. His legs were extended during next 20 seconds. Thereafter he was still and his loss of consciousness lasted 3 minutes. Patient 2. A 26-year old man fell on the wooden ground from a 4 m high ferry. He got head impact and lost consciousness. In a few seconds he had tonic/clonic convulsions for the next 10-15 seconds. Ten minutes later he awaked. Results of subsequent neurological examination, electroencephalography and cerebral magnetic resonance imaging studies were normal in both patients. They returned to their occupations after four weeks without problems for a further one year. CONCLUSION: Described motor manifestations present concussive convulsions. These clinical features are due to transient functional decerebration and corticomedullary dissociation during cerebral concussion. Concussive convulsions are a non-epileptic phenomenon, they are not associated with structural brain injury and have good prognosis. Antiepileptic treatment is not indicated.

Adolescent↗
PubMed2003

Evidence for the Factorial and Construct Validity of a Self-Report Concussion Symptoms Scale.

OBJECTIVE: To evaluate the factorial and construct validity of the Head Injury Scale (HIS) among a sample of male and female collegiate athletes. DESIGN AND SETTING: Using a cross-sectional design, we established the factorial validity of the HIS scale with confirmatory factor analysis and the construct validity of the HIS with Pearson product moment correlation analyses. Using an experimental design, we compared scores on the HIS between concussed and nonconcussed groups with a 2 (groups) x 5 (time) mixed-model analysis of variance. SUBJECTS: Participants (N = 279) in the cross-sectional analyses were predominately male (n = 223) collegiate athletes with a mean age of 19.49 +/- 1.63 years. Participants (N = 33) in the experimental analyses were concussed (n = 17) and nonconcussed control (n = 16) collegiate athletes with a mean age of 19.76 +/- 1.49 years. MEASUREMENTS: All participants completed baseline measures for the 16-item HIS, neuropsychological testing battery, and posturography. Concussed individuals and paired controls were evaluated on days 1, 2, 3, and 10 postinjury on the same testing battery. RESULTS: Confirmatory factor analysis indicated that a theoretically derived, 3-factor model provided a good but not excellent fit to the 16-item HIS. Hence, the 16-item HIS was modified on the basis of substantive arguments about item-content validity. The subsequent analysis indicated that the 3-factor model provided an excellent fit to the modified 9-item HIS. The 3 factors were best described by a single second-order factor: concussion symptoms. Scores from the 16-item HIS and 9-item HIS were strongly correlated, but there were few significant correlations between HIS scores and scores from the neuropsychological and balance measures. A significant group-by-day interaction was noted on both the 9-item HIS and 16-item HIS, with significant differences seen between groups on days 1 and 2 postconcussion. CONCLUSIONS: We provide evidence for the factorial and construct validity of the HIS among collegiate athletes. This scale might aid in return-to-play decisions by physicians and athletic trainers.

Journal Article↗
PubMed1994

Analysis of cerebral concussion frequency with the most commonly used models of football helmets.

Data on helmet models used and occurrence of cerebral concussions over five seasons were collected from a representative sample of college football teams including a total of 8,312 player-seasons and 618,596 athlete-exposures to the possibility of being injured in a game or practice. Results showed that players with a history of concussion any time during the previous 5 years were six times as likely to suffer a new concussion as those with no previous history. In light of previous studies showing cognitive deficits for up to 30 days following even minor head injuries, and the growing awareness of "second impact" fatalities, these data support a need for reconsideration of the common practice of immediate return to play following non-loss-of-consciousness head injuries. Results on concussion frequency in ten models of football helmets indicated a significantly lower than expected frequency in the Riddell M155 and a significantly higher frequency in the Bike Air Power. All other models performed within expectations. This study demonstrates the need for monitoring on-the-field performance of football helmets through continuing epidemiological studies to supplement laboratory test data, which cannot duplicate all the factors involved in actual helmet performance.

Journal Article↗
PubMed1998

Acute subdural hematoma after a reported mild concussion: a case report.

OBJECTIVE: This case details the possible relationship between a reported mild concussion and an acute subdural hematoma in a football athlete. Concussion grading scales and return-to-play guidelines are also discussed. BACKGROUND: An otherwise healthy athlete suffered a re- ported mild concussion, and continued symptoms led to the diagnosis of postconcussion syndrome. The patient returned to football 25 days after the injury and sustained a second head injury 10 days later. He became unconscious and presented with decerebrate posturing, a fixed and dilated left pupil, shallow breathing, right-sided paralysis, and bilateral Babinski signs. DIFFERENTIAL DIAGNOSIS: Possible pathologies included subdural hematoma, epidural hematoma, cerebrovascular accident, cerebral edema, and intracerebral hemorrhage. TREATMENT: Computerized tomography indicated fluid overlying the left hemisphere and temporal fossa. Two burr holes released acute and clotted subdural blood. After 19 days, the patient was discharged without neurologic deficit. UNIQUENESS: Traditionally, acute subdural hematomas are thought to result from single traumatic incidents. However, individuals may be more susceptible to such pathology after recent head trauma. CONCLUSIONS: Recent mild head injury may increase the risk for catastrophic pathology. This case emphasizes the importance of using concussion grading scales and adhering to return-to-play guidelines, as well as the use of additional diagnostic techniques after mild head Injury.

Journal Article↗
PubMed1979

The morphopathologic substrates of concussion?

Neuronal inundation with i.v. infused horseradish peroxidase was studied following concussive brain injury by means of both light and electron microscopy. In animals sustaining mechanical brain injury of insufficient intensity as to elicit either microscopic intraparenchymal hemorrhage or other neuropathological change, yet of sufficient intensity as to provoke a physiological concussive response, vascular peroxidase exudation concomitant with neuronal peroxidase inundation occurred throughout the raphe and reticular core. Initially such inundated neurons were totally flooded with the tracer and as such appeared reminiscent of cells visualized in Golgi preparations. However, over the course of a 24-h period these peroxidae flooded neurons apparently organized the peroxidase into vesicles and vacuoles which assumed a perinuclear position from where the peroxidase ultimately reached both the nucleus and nucleolus. It was remarkable that these events occurred without any evidence of subcellular alteration. We interpret such initial inundation with this protein tracer, its ultimate reorganization, and its nuclear and nucleolar uptake as being consistent with some form of subtle and transient neuronal perturbation. We speculate that as such this neuronal perturbation may constitute a morphological correlate of the concussive episode.

Animals↗
PubMed1979

Experimental cerebral concussion. A histochemical study.

The activity of mitochondrial enzymes (succinic dehydrogenase and cytochrome oxidase) and enzymes associated with blood-brain barrier function (butyrylcholinesterase and alkaline phosphatase) in the CNS of rats was studied from 5 minutes to 62 hours after cerebral concussion. There was a transient increase in succinic dehydrogenase activity during the first hour after concussion in the neurons of the structures close to the impact. The alkaline phosphatase activity, strongly positive in the walls of normal blood vessels, decreased within five minutes after concussion; it virtually disappeared in 15 minutes but returned to normal level after 62 hours. These findings are in good correlation with previous electron microscopic observations. Their significance is discussed.

Alkaline Phosphatase↗
PubMed1999

Concussion in sport: diagnosis, management, return to competition.

Concussions can occur in any sports activity. Although no standards for grading and managing concussions exist, many sets of guidelines have been proposed. Therefore, physicians should be familiar with at least one set to assist in diagnosing and managing concussions.

Athletic Injuries↗
PubMed2006

The Rivermead Post Concussion Symptoms Questionnaire: a confirmatory factor analysis.

OBJECTIVE: To investigate the factor structure of the Rivermead Post Concussion Symptoms Questionnaire (RPQ) among individuals seen as part of routine follow-up following traumatic brain injury. METHODS: RPQ data from 168 participants was examined (mean age 35.2, SD 14.3; 89% with post traumatic amnesia duration<24 hours) six months after admission to an Accident & Emergency Department following TBI. Structural equation modelling was carried out to evaluate proposed models of the underlying structure of post-concussion symptoms (PCS). RESULTS: The results support the existence of separate cognitive, emotional and somatic factors, although there was a high degree of covariation between the three factors. A two-factor model that collapsed the emotional and somatic factors together showed a similar goodness-of-fit to the data, whilst a one-factor model proved a poor fit. CONCLUSION: The results support the notion of post-concussion symptoms as a collection of associated but at least partially separable cognitive, emotional and somatic symptoms, although questions persist regarding symptom specificity. The use of the RPQ is discussed, and classification bands for use in clinical practice are suggested.

Adolescent↗
PubMed1982

Concussion in rats causes an immediate change in occupancy but not affinity of hypothalamic cholinergic receptors.

Experimental concussion in rats is associated with subsequent enhanced binding in vitro of certain ligands to hypothalamic tissue but not to other brain regions. Scatchard analysis shows that the number of specific binding sites for [3H]quinuclidinylbenzilate increases within 3 s after concussion with no significant change in binding affinity. The apparent increase in receptors is likely the result of a deficit in binding of endogenous ligand. We propose that concussion produces a pressure wave that deforms cholinergic and possibly other receptors selectively in the hypothalamus, resulting in a transient deficit in transmitter binding and interruption of neuronal circuits concerned with the state of consciousness.

Animals↗
PubMed1988

The effect of concussive head injury on central cholinergic neurons.

This study examined the effect of fluid percussion head injury on the activity of cholinergic neurons in specific brain areas of the rat 12 min, 4 h and 24 h following injury. Acetylcholine (ACh) turnover, used as an index of cholinergic neuronal activity, was determined using a gas chromatographic-mass spectrometric technique. The most striking changes in cholinergic activity were observed in the dorsal pontine tegmentum, where concussive head injury produced an increase in ACh turnover 12 min and 4 h following injury. This area has been previously associated with behavioral changes observed following concussive injury. ACh turnover in the thalamus, a region to which pontine cholinergic neurons project, also tended to increase 4 h following injury. On the other hand, ACh turnover tended to decrease in the amygdala 4 h following injury. Although there were no significant changes in hippocampal ACh content or turnover following injury. ACh content did tend to increase in that brain region 12 min following injury. There were no significant effects of injury on cholinergic neurons in the cingulate/frontal cortex. These changes in cholinergic neuronal activity may contribute to the neurological deficits following concussive injury. In particular, activation of cholinergic neurons in the pontine region may contribute to components of behavioral suppression associated with reversible traumatic unconsciousness. More generalized changes in cholinergic function may lead to the production of more chronic deficits.

Acetylcholine↗
PubMed1985

A simple device for experimentally concussing the rat.

A device is described for eliciting acceleration concussion in the awake rat. Animals, which were manually restrained, were struck on the occipital crest by a rubber knob attached to the striker wire of a spring-loaded rat trap. This method produced concussion with survival in over 50% of animals tested. The remainder were either simply stunned or else died shortly after the blow to the head. The device is compared with a number of alternate techniques designed to concuss the rat.

Animals↗
PubMed1992

Concussion is completely reversible; an hypothesis.

It is hypothesized that there is an entity properly called 'concussion', a transient loss of neuronal function without permanent neuronal damage, as defined years ago by Derek-Denny Brown. This implies that multiple concussions leave no deficit. n +1 times zero is still zero. Arguments are presented indicating that there is a margin of safety between the acceleration inducing 1-10 s loss of function (concussion) and that inducing permanent damage (contusions, lacerations).

Boxing↗
PubMed2006

The validity of post-concussion syndrome in children: a controlled historical cohort study.

The aim of this controlled historical cohort study was to assess the validity of post-concussion syndrome in children. We identified 301 children aged 4-15 years who had sustained an isolated brain concussion, and another group of 301 children who sustained any other mild body injury excluding the head. Parents from both groups filled in standardized questionnaires containing questions about the health condition of the children: headache, neck pain, dizziness, malaise, fatigability, exercise or noise intolerance, irritability, weepiness, sadness, anxiety, nocturnal enuresis, tics, sleep disorders, memory or learning difficulties, hyperactivity, seizures, attention disorder, buzzing in the ears, subjective parental concerns about the child's health condition, and parental concerns about their child having a brain disorder. The severity of the complaints was rated on the Visual Analogue Scale. After the final exclusion, 102 pairs strictly matched by sex, age, and the date of trauma were analyzed. The differences of parental complaints about the health condition of their children between case and control groups were statistically insignificant for all symptoms, except parental concerns about their child having brain damage which were significantly higher in the case group. The likelihood of parental concerns about the possibility of their child having brain damage was 2.7 times higher in the case group. Headache, learning difficulties, and sleep disorders were significant variables predicting the concerns. These results question the validity of the post-concussion syndrome in children.

Adolescent↗
PubMed1997

Brain concussion produces transient hypokalemia in children.

Hyperglycemia and hypokalemia caused by catecholamine discharge have been reported to occur in patients after severe head trauma. The aim of this prospective study was to evaluate whether a similar neuroendocrine and metabolic response is found in children after minor head trauma such as brain concussion (Glasgow Coma Scale (GCS) > or = 13). One hundred fifty patients aged 2 to 14 years (average, 6 years) were divided into three groups (n = 50 in each group). Group 1 included patients admitted to the emergency department for brain concussion (Glasgow Coma Scale (GCS) > or = 13); group 2 included patients admitted for fractures of long bones without head injury; and group 3 were control patients electively admitted for hernia repair. All patients had complete physical and neurological examinations. Complete blood count and blood chemistry were obtained on admission. All blood tests were repeated at 6, 12, and 24 hours in patients belonging to group 1. An electrocardiogram was obtained in selected patients and catecholamine levels were measured in some patients. Statistical analysis was performed using analysis of variance (ANOVA). Serum potassium and sodium levels in patients with brain concussion (group 1) were 3.6 +/- 0.6 and 136 +/- 3 mEq/L, respectively and were significantly lower (P < 0.01) than those in patients belonging to group 2, 4 +/- 0.4 and 138 +/- 3, respectively, and the controls (group 3), 4.2 +/- 0.5 and 140 +/- 2, respectively. Serum glucose level was 124 +/- 34 and 118 +/- 32 mg% in groups 1 and 2 and was significantly higher than that of the controls (group 3), 90 +/- 23 mg%. There was no correlation between serum electrolytes and GCS. No electrocardiogram changes or elevation of serum catecholamines were found. Hypokalemia resolved spontaneously within 24 hours. All patients recovered without neurological sequalae. Transient hypokalemia frequently occurs in children even with minor head trauma. This hypokalemia resolves spontaneously, without treatment and within 24 hours.

Adolescent↗