Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Concussion”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 289 records · Page 16Linked to original sources
PubMed2004

Statistical procedures for determining the extent of cognitive change following concussion.

Neuropsychological (NP) testing is now often used to help to determine if the cognitive function of a concussed athlete has declined. The NP test score after concussion is compared with the baseline test score. Many clinicians simply subtract one from the other and make a clinical decision about the significance or otherwise of the resulting "difference score". Such techniques are inadequate, as they fail to account for the many factors that may confound interpretation of serially acquired cognitive test scores. This is a review of a number of alternative approaches used in other areas of medicine for differentiating "true" changes from changes caused by these confounding factors. A case example is used to illustrate the effect that the statistical approach may have on clinical decision making.

Adult↗
PubMed1986

[Amnesia and responsibility following brain concussion. A study of 70 patients].

Hit- and run traffic accidents frequently occur because an intention to hide drunkenness. Later, the accused claims that he or she had amnesia due to concussion at the time of accident and what followed. In most cases, the question arises as to whether it is the truth or just a story to protect the defendant from punishment. To study this question, 70 patients (39 male, 31 female) were interrogated. They were asked about the duration of their amnesia and their ability to recall their own actions, or what they had been told. In 80% of the persons examined there was only a short period of amnesia (less than 30 min). Of 12 cases with a longer period of amnesia, 7 were also intoxicated from alcohol (one case had a concentration of 3.1%). In only one person suffering from concussion could it definitely be proved that the actions taking place long after the accident, were usually not comparable with evidence given in court.

Accidents, Traffic↗
PubMed1992

An immediate light microscopic response of neuronal somata, dendrites and axons to contusing concussive head injury in the rat.

Thirty-four rats were killed by transcardial perfusion fixation 1 min after a contusing concussive head injury, and 17 rats 1 day later. From the results obtained with a new silver method demonstrating traumatically damaged neuronal somata, dendrites and axons the following conclusions were drawn: (1) outside the contused territories all features of traumatically induced neuronal argyrophilia are similar to those found in non-contusing concussive head injury, as reported in an accompanying paper; (2) within contused territories the neuronal argyrophilia is abolished by some substance released either from damaged blood vessels or damage parenchymal cells, while the neuronal damage otherwise underlying the induction of argyrophilia is present; (3) different phenotypes of neurons are vulnerable to different values of the parameters of the intracranial pressure wave generated by the trauma; (4) some of the neurons may recover from the traumatically induced argyrophilic damage; (5) traumatically induced inundation of neurons with extracellular tracers, as reported by other authors, and somato-dendritic argyrophilia may be different manifestations of one and the same phenomenon; and (6) diffuse primary traumatic axonal injury in human neuropathology may be closely correlated to axonal argyrophilia.

Animals↗
PubMed1995

The Rivermead Post Concussion Symptoms Questionnaire: a measure of symptoms commonly experienced after head injury and its reliability.

After head injuries, particularly mild or moderate ones, a range of post-concussion symptoms (PCS) are often reported by patients. Such symptoms may significantly affect patients' psychosocial functioning. To date, no measure of the severity of PCS has been developed. This study presents the Rivermead Post Concussion Symptoms Questionnaire (RPQ) as such a measure, derived from published material, and investigates its reliability. The RPQ's reliability was investigated under two experimental conditions. Study 1 examined its test-retest reliability when used as a self-report questionnaire at 7-10 days after injury. Forty-one head-injured patients completed an RPQ at 7-10 days following their head injury and again approximately 24 h later. Study 2 examined the questionnaire's inter-rater reliability when used as a measure administered by two separate investigators. Forty-six head-injured patients had an RPQ administered by an investigator at 6 months after injury. A second investigator readministered the questionnaire approximately 7 days later. Spearman rank correlation coefficients were calculated for ratings on the total symptom scores, and for individual items. High reliability was found for the total PCS scores under both experimental conditions (Rs = + 0.91 in study 1 and Rs = + 0.87 in study 2). Good reliability was also found for individual PCS items generally, although with some variation between different symptoms. The results are discussed in relation to the major difficulties involved when looking for appropriate experimental criteria against which measures of PCS can be validated.

Adolescent↗
PubMed2004

Current concepts in concussion rehabilitation.

Active rehabilitation of sport injuries is a concept familiar to athletes and those caring for them. Rehabilitation goals aim to optimize recovery efficiency and diminish chances of repeat injury. Rehabilitation programs take many aspects of recovery and wellness into consideration including physical, social, and psychologic components. Ultimately, this is important in the recovery process after concussion. In this article we introduce the largely unexplored concept of multidimensional concussion rehabilitation and discuss physical, psychologic, social, and sport-specific issues. As well, we propose future directions in this field.

Athletic Injuries↗
PubMed1985

Depression of afferent-induced primary afferent depolarization at the lumbar spinal cord following concussive head injury.

Afferent-induced primary afferent depolarization (PAD) was depressed for 2-5 min following concussive head injury in the cat, as assessed by dorsal root potentials and augmentation of antidromic dorsal root potentials, both evoked by stimulation of adjacent dorsal roots. These changes in PAD were abolished by spinal cord transection but not affected by midpontine transection. Spontaneous dorsal root potentials, resting amplitudes of antidromic dorsal root potentials and reductions of antidromic dorsal root potentials following tetanic root stimulation were not substantially altered by injury. These findings suggest that concussive head injury depresses spinal interneuronal transmission by neurally mediated processes involving the bulbar brainstem.

Animals↗
PubMed1988

Effects of anticholinergic treatment on transient behavioral suppression and physiological responses following concussive brain injury to the rat.

Increasing doses (0.1, 1.0, 10.0 mg/kg) of scopolamine were systemically (i.p.) administered to rats subjected to moderate fluid percussion brain injury. Scopolamine treatment (1.0 mg/kg, i.p.) 15 min prior to trauma significantly reduced mortality and the duration of transient behavioral suppression assessed by a variety of measures. No differences were observed between saline- and scopolamine-treated animals in either the incidence or duration of transient apnea associated with injury. Preinjury treatment with methylscopolamine (1.04 mg/kg) or mecamylamine (1.0 mg/kg) had no effect on transient behavioral suppression. Except for increased heart rate, preinjury treatment with scopolamine (1.0 mg/kg) did not significantly alter systemic physiological responses to injury. Rats treated with scopolamine (1.0 mg/kg, i.p.) 30 s after injury tended to have shorter durations of reflex and response suppression. These experiments suggest that antimuscarinics can attenuate components of transient behavioral suppression associated with concussive brain injury. These findings are consistent with previous experimental and clinical observations and lend further support to the hypothesis that activation of a muscarinic system within the CNS mediates components of reversible traumatic unconsciousness following cerebral concussion.

Animals↗
PubMed1992

Changes in hippocampal monoamine concentration following halothane anesthesia and concussion.

The concentration of norepinephrine in the hippocampus of rats anesthetized with halothane (Wyeth-Ayerst, Philadelphia, Pa) is found to be markedly increased, presumably due to the stress of handling and administering the anesthetic. This increased norepinephrine concentration persists for about 50 minutes but is obliterated when the anesthetized rat is concussed. This 50-minute period corresponds to the time it takes for a rat (or human), comatose for 1-2 seconds following concussion, to regain normal memory. No changes in 3,4-dihydroxybenzene-acetic acid (DOPAC), 3-(3,4-dihydroxyphenyl) alanine (L-DOPA), and 3,4-dihydroxybenzylamine (DHBA) were noted. 5-Hydroxy indole acetic acid (HIAA) showed a depression at 5 minutes and again at 30 minutes, changes that were consistent but not considered statistically significant.

Anesthesia, Inhalation↗
PubMed1996

Evaluating cerebral concussion.

Years ago we developed a rat model that was consistently comatose for 1-2 seconds following 50 G acceleration of the head. Motor normalcy returned in about 10 seconds, and normal memory in an hour. There were immediate electroencephalogram and transmitter changes. All these returned to normal within an hour following 1 or 20 such concussions. We could find no light or electron microscopic changes. Halothane anesthesia precludes measurement of coma and introduces distortion of metabolite findings. To date our findings indicated concussion at this level is completely reversible.

Animals↗
PubMed2005

Impaired spatial learning in a novel rat model of mild cerebral concussion injury.

The aim of the present study was to develop a model of mild traumatic brain injury in the rat that mimics human concussive brain injury suitable to study pathophysiology and potential treatments. 34 male Wistar rats received a closed head trauma (TBI) and 30 animals served as controls (CON). Immediately following trauma, animals lost their muscle tone and righting reflex response, recovering from the latter within 11.4 +/- 8.2 min. Corneal reflex and whisker responses returned within 4.5 +/- 3.0 min and 6.1 +/- 2.9 min, respectively. The impact resulted in a short transient decrease of pO2 (P < 0.001), increase in mean arterial blood pressure (P = 0.026), and a reduction of heart rate (P < 0.01). Serial MRI did not show any abnormalities across the entire cerebrum on diffusion, T1, T2, and T2*-weighted images at all investigated time points. TBI animals needed significantly longer to locate the hidden platform in a Morris water maze and spent less time in the training quadrant than controls. TBI led to a significant neuronal loss in frontal cortex (P < 0.001), as well as hippocampal CA3 (P = 0.017) and CA1 (P = 0.002) at 9 days after the trauma; however, cytoskeletal architecture was preserved as indicated by normal betaAPP- and MAP-2 staining. We present a unique, noninvasive rat model of mild closed head trauma with characteristics of human concussion injury, including brief loss of consciousness, cognitive impairment, and minor brain injury.

Analysis of Variance↗
PubMed2002

Central nervous system trauma management of concussions in athletes.

The care of athletes with concussions is challenging because each patient has different symptoms. An athlete should never be returned to play until completely asymptomatic. Classification systems for concussions are not based on scientific evidence and represent some practitioners' best guess at what is safe for young athletes. Many experienced team physicians believe they can allow an athlete to play safely if there are no symptoms at rest and no symptoms with increasing intensity of exercise. Abbreviated neuropsychological testing and balance tests show promise for use in the field to increase the sensitivity of our neurological evaluation on injured athletes. Any neuropsychological or balance evaluation is more helpful if baseline data is collected on athletes before they are injured.

Adolescent↗
PubMed1977

Sequelae of concussion caused by minor head injuries.

Of 145 patients with concussion from minor head injuries admitted to the Royal Victoria Hospital, Belfast, over one year, 49.0 per cent had no symptoms, 38.9 per cent had between 1 and 6 symptoms, and 2.1 per cent had more than 6 symptoms about six weeks after the accident. There was significant correlation between a high symptom-rate at six weeks and positive neurological signs and symptoms at twenty-four hours. Post-concussion symptoms were more frequent in women, in those injured by falls, and in those who blamed their employers or large impersonal organisations for their accidents. The results suggest that both organic and neurotic factors are involved in the pathogenesis of symptoms at six weeks.

Accidents↗
PubMed2002

Information processing difficulty long after self-reported concussion.

Recovery of cognitive function after mild head injury (MHI) is thought to be relatively swift and complete. The present study replicates and extends previous work in which university students with self-reported concussion demonstrated reduced P300 amplitude on a set of easy and difficult attention tasks, in addition to performing more poorly than controls on demanding cognitive tasks many years after injury. In the present study, 13 students with self-reported concussion (MHI group: M time since injury = 8 years) and 10 controls were matched for age, sex, education, and a variety of cognitive, physical and emotional complaints. Controls outperformed the MHI group on the Digit Symbol substitution task and on a difficult dual task involving tone discrimination and visual working memory. Additionally, controls exhibited larger P300 amplitudes on both an easy and a difficult auditory discrimination task. A combination of electrophysiological, neuropsychological and self-report indices predicted group membership (MHI vs. control) with 88% accuracy. The present results, coupled with previous work, offer preliminary evidence that the combination of event-related potentials and demanding behavioral measures might reveal long-lasting, subtle cognitive problems associated with MHI. These findings may challenge existing notions of complete recovery after MHI.

Acoustic Stimulation↗
PubMed2003

Early predictors of post-concussion symptoms in patients with mild head injury.

A small proportion of patients with mild head injury (MHI) develop post-concussion symptoms (PCSs). We searched simple measures for the early detection of patients who are probable to develop PCSs. We recorded signs and symptoms, history of previous diseases, medications, and lifestyle factors and measured serum protein S-100B on admission in a series of 172 consecutive MHI patients admitted into the emergency room of a general hospital. A modified Rivermead Post-Concussion Symptoms Questionnaire was used to identify the patients with and without PCSs 1 month after the injury. We identified 37 patients with MHI who developed PCSs (22%). Odds ratios (OR) and 95% confidence intervals (CI) after adjustment for possible confounding variables were calculated by logistic regression. Independent early risk factors for PCSs in the MHI patients were skull fracture (OR 8.0, 95% CI 2.6-24.6), serum protein S-100B >/= 0.50 microg/l (OR 5.5, 95% CI 1.6-18.6), dizziness (OR 3.1, 95% CI 1.2-8.0), and headache (OR 2.6, 95% CI 1.0-6.5). Serum protein S-100B proved to be a specific, but not sensitive predictor of PCSs. The presence of skull fracture, elevated serum protein S-100B, dizziness, and headache may help the emergency room physician to identify patients at risk of PCSs and to refer them for further examination and follow-up.

Adolescent↗
PubMed2000

Concussion in sports and recreation.

More than 800 sports-related concussions occur in the United States each day, sometimes involving high-profile athletes whose injuries reach public awareness through sports broadcasts and news media. Although nonphysicians are often present and relied upon for the detection of concussion in the sports setting, the proper diagnosis and management of this neurological problem require a physician's thoughtful attention to the athlete's signs and symptoms. This article offers a diagnostic protocol and treatment recommendations as well as a useful grading scale and management strategy for return to competition.

Adult↗
PubMed2003

Interpreting change on ImPACT following sport concussion.

The purpose of this study was to examine the psychometric characteristics of Version 2.0 of ImPACT (Immediate Postconcussion Assessment and Cognitive Testing). The focus was on the stability of the test scores and the calculation of reliable change confidence intervals for the test-retest difference scores. A sample of 56 nonconcussed adolescents and young adults completed the test battery on two occasions. Test-retest coefficients, reliable change difference scores, and confidence intervals for measurement error are provided. These reliable change parameters were applied to a second sample of 41 concussed amateur athletes who were tested preseason and within 72 hr of injury. Applying these confidence intervals allows more precise determinations of deterioration, improvement, and recovery in the initial days following concussion.

Adolescent↗
PubMed1986

Task and driving performance of patients with a severe concussion of the brain.

Patients who had sustained a severe concussion of the brain more than 2 years earlier were tested in choice reaction time tasks in the laboratory in order to investigate their impaired reactive capacity. The focus of investigation was whether specific stages in the chain of the information process are affected by the injury. In addition, driving skills were measured in an instrumented car to determine if reaction time performance is predictive of car driving. In general, patients were much slower than control subjects, both in the reaction time and in the driving tasks. The results obtained in the reaction time tasks provide no conclusive evidence, however, that severe concussion of the brain affects particular stages in information processing. Reaction time tasks appear to have predictive value for the ability to drive a car.

Accidents, Traffic↗
PubMed2003

Are there sub-types of attentional deficits in patients with persisting post-concussive symptoms? A cluster analytical study.

AIM: The present study aimed to examine attentional deficits in patients with persisting post-concussive symptoms using a multi-componential framework of attention. DESIGN: A cross-sectional investigation using standardized tests and questionnaires of attention including 92 patients. METHOD: Participants were administered comprehensive measures of attention assessing sustained attention (Sustained Attention Response to Task, Backward Digit Span), selective attention (Stroop Word-Colour Test, Colour Trails Test), divided attention (Paced Auditory Serial Addition Test, Symbol Digit Modalities Test), and attentional control (Tower of Hanoi, Six Elements Test). Ecological tests of attention were used to validate the cluster solution. MAIN OUTCOME: Three clusters of patients with different combinations of attentional deficits were identified. They were 'mild sustained attentional deficits', 'selective and divided attentional deficits', and 'general attentional deficit'. A MANOVA indicated that these three clusters were statistically and clinically different from one another in terms of different attentional components proposed. CONCLUSION: This study provides preliminary evidence suggesting that sub-types of attentional impairments exit in patients with post-concussive symptoms.

Adult↗