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PubMed2004

Rotational acceleration measurements--evaluating helmet protection.

PURPOSE: Current helmet testing standards do not address the rotational components of an impact to the head. We describe a new testing paradigm used to measure the rotational acceleration of a headform and a protective helmet following an impact to the head in the horizontal plane. This impact simulation allows for the testing of currently available head protection devices in conditions thought to be important for the generation of cerebral concussion. The degree to which a particular helmet dampens rotational acceleration, and thus protects against concussion, can be assessed. METHODS: Our testing device consists of a pneumatic piston that provides a measured impact to a standard headform. Four different helmets were tested using the described paradigm. RESULTS: Acceleration curves for each helmet and the corresponding headform are presented. CONCLUSIONS: Clear differences in rotational acceleration were demonstrated. Possible avenues of further investigation are discussed.

Acceleration↗
PubMed2001

Accumulation of the anandamide precursor and other N-acylethanolamine phospholipids in infant rat models of in vivo necrotic and apoptotic neuronal death.

It has been demonstrated that the endogenous cannabinoid receptor ligand, anandamide, and other N-acylethanolamines (NAEs), accumulate during neuronal injury in vitro, a process that may be linked to the neuroprotective effects of NAEs. The crucial step for generation of NAEs is the synthesis of the corresponding precursors, N-acylethanolamine phospholipids (NAPEs). However, it is unknown whether this key event for NAE formation is regulated differently in the context of insults causing necrotic or apoptotic neuronal death. To address this question, we monitored a range of cortical NAPE species in three infant rat models of in vivo neurodegeneration: (i) necrosis caused by intrastriatal injection of NMDA (25 nmol); (ii) apoptosis induced by systemic administration of the NMDA-receptor antagonist (+)MK-801 (3 x 0.5 mg/kg, i.p.); and (iii) apoptosis following focal necrosis triggered by concussive head trauma. A marked increase of all NAPE species was observed in both hemispheres 4 and 24 h after NMDA-induced injury, with a relatively larger increase in N-stearoyl-containing NAPE species. Thus, the percentage of the anandamide precursor fell from 1.1 to 0.5 mol %. In contrast, administration of (+)MK-801 did not alter cortical NAPE levels. Concussion head trauma resulted in a similar but less pronounced upregulation of NAPE levels at both 4 and 24 h as compared to NMDA injections. Increased levels of NAPE 24 h post-trauma possibly reflect that necrosis is still ongoing at this time point. Consequently, our data suggest that excitotoxic necrotic mechanisms of neurodegeneration, as opposed to apoptotic neurodegeneration, have a profound effect on in vivo NAE precursor homeostasis.

Animals↗
PubMed2001

Mandatory admission after isolated mild closed head injury in children: is it necessary?

BACKGROUND/PURPOSE: Children with closed head injuries diagnosed as concussion alone or concussion with brief loss of consciousness are admitted routinely for observation despite a normal central nervous system finding, negative computed tomography (CT) scan, and a Glasgow Coma Score (GCS) of 15. Recent studies have questioned the necessity of such an admission. The purpose of this study was to review a large pediatric database and study the length of stay as well as any required procedures or complications in these children. The hypothesis was that routine admission is unnecessary in this population. METHODS: The National Pediatric Trauma Registry-Phase II was reviewed for the period from October 1988 to January 1996. Entry criteria included age less than 18 and an isolated closed head injury after blunt trauma with an admission GCS of 15. Variables studied included age, gender, mechanism of injury, length of stay, procedures, and outcome. RESULTS: A total of 1,033 children met criteria for this study. The average age was 8.3 years. Males predominated at 61.9%. Falls, sports, and motor vehicle crashes were the most common mechanisms of injury. The average length of stay was 1.19 days, and 60 children were not admitted. A total of 583 children had no procedures performed, whereas 386 received a CT scan, and 148 had x-rays. None required neurosurgical intervention, and all were discharged alive. CONCLUSION: These findings indicate that routine admission may not be necessary for children with isolated mild closed head injuries with a negative CT scan and a normal neurologic finding and allows for a prospective randomized trial to confirm this.

Child↗
PubMed2000

Injury severity and neuropsychological and balance outcomes of four college athletes.

Recent evidence suggests significant short-term neurocognitive deficits following mild traumatic brain injury (MTBI) in sports. However, sequelae of mild head injuries is complicated by many factors including a history of multiple head injuries and injury severity. Few studies have considered the influence these variables may have on proper classification of a MTBI and their meaning for return-to-play guidelines. This study presents the short-term neuropsychological and balance outcomes of four college athletes who sustained mild head injuries of different severity (grade I, grade II, grade III and multiple head injured with a grade II based on American Academy of Neurology guidelines). The results demonstrated that self-report symptoms of concussion were slow to resolve in the grade III and multiple concussed individuals. For neuropsychological testing, Trails A & B, Symbol Digit Modalities Test and Digits Span Backwards were the most sensitive in identifying differences between the injuries. For balance assessments using the Neurocom Smart Balance System, the Sensory Organization Test and Reaction Time were also important variables in detecting differences among the various injuries. When these data are used together, it can assist physicians in determining safe return-to-play for athletes who sustain MTBI. There are contradindications in the numerous grading systems and return-to-play guidelines for MTBI. The results from this study provides new evidence which can be assimilated into a valid grading scale for MTBI sustained in sport.

Adult↗
PubMed2002

Electroencephalography in primary diagnosis of mild head trauma.

OBJECTIVE: the aim of this study was to compare the clinical examination and EEG examination regarding their relevance in diagnosing cerebral function changes in early head trauma. METHODS: ninety four male patients who suffered from mild head trauma (GCS 13-15) were assigned into two groups. The first group fulfilled at least one sign of cerebral concussion (amnesia, anisocoria, changes of vigilance or vegetative symptoms such as vomiting), the second group did not. EEG examination was performed in both groups. RESULTS: in the first group, more pathologic EEG records were found. These findings showed a statistical significance (p = 0.019). The concussion group showed more focal changes (p = 0.283) and specific changes (p = 0.317), but they were statistically not significant. CONCLUSION: EEG can be used for detecting pathologic unspecific alterations with a high accuracy, but is not useful in specifying the findings for an exact diagnosis.

Adolescent↗
PubMed1987

Eye injuries among children in Kuwait: pattern and outcome.

One hundred and ninety four children with ocular injuries were admitted to the Eye Department at Ibn Sina Hospital, Kuwait during a 1-year period (1983). They represented 8.7% of total admissions and 56% of all ocular injuries admitted in the same period. These figures are higher than any previously reported figures in comparable series. The risk of severe ocular injury to children was found to be 0.35% per 1000 per year. There were 47 (24%) perforating injuries and 111 (57%) concussion injuries. Catapulted missiles were the commonest cause of injury (26%). Early presentation to hospital accounted for a low rate of secondary infection. Visual outcome of 6/12 or better was achieved in 78.5% of concussion injuries and 27.3% of perforating injuries. Education in organized school programmes has been recommended to reduce the incidence of ocular injuries in children.

Adolescent↗
PubMed2001

Short-term sequelae of minor head injury (6 years experience of minor head injury clinic).

PURPOSE: It is known that post-concussive symptoms may persist after mild head injury. However, the majority of those patients are denied follow-up or support. A minor head injury clinic was thus established in North Staffordshire Hospital in 1993 to address these problems. METHODS: Patients 16-65 years old attending hospital with minor head injury were invited to attend the clinic two weeks after presentation. A specialized brain injury nurse and/or assistant clinical psychologist assessed them. Patients with persistent symptoms were invited to a second assessment four weeks later. RESULTS: One thousand two hundred and fifty-five patients were invited for first assessment, the most common cause of head injury was assault (454) followed by road traffic accident (334). Six hundred and sixteen patients did not attend the first assessment; most of non-attendees were those who had been assaulted (281). Six hundred and thirty-nine patients attended, (472) were male, their mean age was 33. Forty-three per cent of them had history of recent alcohol intake. One third had had a previous head injury. Although 391 attendees were in regular employment, 219 patients were unable to return to work 2 weeks after discharge (56%), and 49 people were still off sick 6 weeks after the injury. The most common complaints at both assessments were fatigue, headache, dizziness, irritability, sleep disturbances, poor concentration and poor memory in that order. CONCLUSION: This study shows a significant number of patients with minor head injury still complaining of post concussive symptoms, which may contribute to a delay in return to work. The high incidence of non-attendance among the assaulted victims may indicate that this group needs to be more effectively targeted. Further study to look at the longer-term consequences of minor head injury is required in view of these findings.

Adolescent↗
PubMedDate not supplied

Injuries to emergency medicine residents on EMS rotations.

OBJECTIVES: To study the incidence and nature of injuries sustained by emergency medicine (EM) residents during EMS rotations, and steps taken at EM residency programs to increase resident safety during field activities. METHODS: An eight-question survey form was mailed to all 114 U.S. EM residency directors, with a second mailing to nonresponders eight weeks after the initial mailing. RESULTS: A total of 105 surveys were returned (92%). Six surveys were from new programs whose residents have not yet rotated on EMS. These were excluded from further analysis, leaving 99 programs. Of these, 91 (92%) reported no injuries. One EM resident died in a helicopter crash in 1985. Seven other injury events were reported: 1) facial lacerations, rib fractures, and a shoulder injury in an ambulance accident; 2) an open finger fracture (crushed by a backboard); 3) contusions and a concussion when an ambulance was struck by a fire engine; 4) a groin pull sustained while entering a helicopter; 5) bilateral metatarsal fractures in a fall; 6) rib fractures, a pneumothorax, and a concussion in an ambulance accident; and 7) "minor injuries" sustained in a crash while responding to a scene in a program-owned response vehicle. Actions taken at residency programs to reduce the risk of injury include the use of ballistic vests (four programs), requiring helmets on flights (five programs), and changing flight experience from mandatory to optional (two programs). Ten programs (10%) reported using ground scene safety lectures, and nine programs (15% of those offering flights) reported various types of flight safety instruction. Sixty-nine programs (70%) reported no formal field safety training or other active steps to increase resident safety on EMS rotations. CONCLUSIONS: Injuries sustained by EM residents during EMS rotations are uncommon but nontrivial, with several serious injuries and one fatality reported. The majority of EM residency programs have no formal safety training programs for EMS rotations.

Accidents, Occupational↗
PubMed2004

Elevated serum S-100B protein as a predictor of failure to short-term return to work or activities after mild head injury.

Protein S-100B is an established serum marker of primary and secondary brain damage and stroke. A group of patients after mild head injury (MHI) develop post-concussion symptoms that interfere with the ability in the short-term to return to work or undertake certain activities. The aim of this study was to examine the correlation of serum S-100B with short-term outcome after MHI. We studied 100 subjects who were referred to the Emergency Department (ED) after a MHI. All subjects had a GCS of 15 either with or without loss of consciousness (LOC) and/or post-traumatic amnesia (PTA). Serum S-100B was collected within 3 h from the injury and a value of > or = 0.15 microg/L was considered as abnormal. Subjects with other injuries, including scalp or cervical spine, were excluded, as well as those with alcohol/narcotic drug consumption or history of serious physical/mental illness. An independent observer measured the return to work/activities within one week. Thirty-two (32%) subjects had elevated S-100B. The failure to return to work/activities was significantly correlated with elevated S-100B: subjects with increased S-100B had a failure rate of 37.5% versus 4.9% of those with normal values (p = 0.0001). In MHI, the elevated S-100B seemed to correlate with an unfavorable short-term outcome. This might be useful in (1) selecting patients who need closer observation, hospitalization, and further investigations (such as CT scan or MRI), and (2) the prognosis of genuine post-concussion symptoms, that interfere with return to work or activities, versus other causes such as premorbid personality, labyrinthine dysfunction, whiplash syndrome, postinjury stress, occupational injury, litigation, and malingering.

Activities of Daily Living↗
PubMed1994

Increased anticholinergic sensitivity following closed skull impact and controlled cortical impact traumatic brain injury in the rat.

Evidence suggests that prolonged memory deficits in several neurodegenerative diseases are attributable to deficits in central cholinergic neurotransmission. In traumatic brain injury (TBI), such cholinergic deficits also may contribute to prolonged memory disturbances. This study determined whether moderate magnitudes of TBI produced by controlled cortical impact and mild magnitudes of experimental TBI produced by a new closed head impact technique in rats would produce an enhanced vulnerability to the memory disruptive effects of scopolamine, a muscarinic cholinergic receptor antagonist. Water maze performance was used to determine changes in cholinergic hippocampal function following TBI. In the first experiment, rats received a moderate level of TBI by means of a controlled cortical impact. A Morris water maze task assessed spatial memory function on days 30-34 postinjury. During the 5 day assessment period, statistical analyses showed a group main effect for swim latency. Subsequent post hoc analyses indicated that injured rats had significantly longer latencies on days 30 and 31 (p < 0.05, injury vs sham controls). By days 32-35, injured rats showed no statistically significant deficits in spatial memory performance. On day 35, scopolamine (1 mg/kg, IP) was injected into injured rats and sham-injured rats 15 min prior to being retested in the maze. Results showed that although the scopolamine had no effects on the performance of the sham-injured rats, the same dose significantly (p < 0.05) increased the latency to find the hidden platform in the injured group. In the second experiment, rats received a mild concussive closed head impact. Water maze performance was assessed on days 8-12 postinjury. No significant water maze performance deficits were observed. On day 13, injured and uninjured rats were pharmacologically challenged with scopolamine (1 mg/kg) and retested. Similar to the first experiment, injured rats manifested a significantly greater (p < 0.05) sensitivity to scopolamine than sham controls. The results from both experiments suggest that concussive and more severe levels of TBI can produce an enhanced vulnerability to disruption of cholinergically mediated memory function, even when memory function appears normal in the absence of secondary challenges. These data demonstrate that covert deficits can persist after the recovery of normal function. These deficits may be attributable to a decrease in the ability of cholinergic neurons to function properly. These data also provide important insights into features of receptor-coupled disturbances that could contribute to the maintenance of enduring cognitive deficits following TBI.

Acetylcholine↗
PubMed2005

Mild traumatic brain injury induces persistent cognitive deficits and behavioral disturbances in mice.

Victims of mild traumatic brain injury (mTBI) do not show clear morphological brain defects, but frequently suffer from long-lasting cognitive deficits, emotional difficulties and behavioral disturbances. In the present study, we investigated the effects of experimental mTBI in mice on cognition, spatial and non-spatial tasks, and depressive-like behavior in mice. Experimental brain injury was induced using a concussive head trauma, which creates the TBI by a weight-drop device. Different groups of mice were tested at 7, 30, 60, and 90 days post-injury for cognitive function (the swim T-maze and the passive avoidance test) and for depression-like behavior (the forced swimming test). These tests have been used infrequently in the past in mTBI research. Significant differences were observed between the injured mice compared to the controls in both the swim T-maze (day 30: p < 0.001) and passive avoidance (day 30: p < 0.05) tests. In addition, a significant difference was detected in the forced swimming test between the injured mice and the controls (day 7: p < 0.05; day 90: p < 0.01), which showed a depressive- like state in the injured animals beginning 7 days post-injury. These results demonstrate that persistent deficits in these tests of cognitive learning abilities and emergence of depressive-like behavior in injured mice are similar to those reported in human post-concussion syndrome.

Animals↗
PubMed2005

Deformation of the human brain induced by mild acceleration.

Rapid deformation of brain matter caused by skull acceleration is most likely the cause of concussion, as well as more severe traumatic brain injury (TBI). The inability to measure deformation directly has led to disagreement and confusion about the biomechanics of concussion and TBI. In the present study, brain deformation in human volunteers was measured directly during mild, but rapid, deceleration of the head (20-30 m/sec2 peak, approximately 40 msec duration), using an imaging technique originally developed to measure cardiac deformation. Magnetic resonance image sequences with imposed "tag" lines were obtained at high frame rates by repeating the deceleration and acquiring a subset of image data each repetition. Displacements of points on tag lines were used to estimate the Lagrangian strain tensor field. Qualitative (visual) and quantitative (strain) results illustrate clearly the deformation of brain matter due to occipital deceleration. Strains of 0.02-0.05 were typical during these events (0.05 strain corresponds roughly to a 5% change in the dimension of a local tissue element). Notably, compression in frontal regions and stretching in posterior regions were observed. The motion of the brain appears constrained by structures at the frontal base of the skull; it must pull away from such constraints before it can compress against the occipital bone. This mechanism is consistent with observations of contrecoup injury in occipital impact.

Acceleration↗
PubMed2004

Six-month recovery from mild to moderate Traumatic Brain Injury: the role of APOE-epsilon4 allele.

The possession of at least one APOE-epsilon4 allele may be linked to poor outcome in patients with predominantly severe traumatic brain injury (TBI). In mild TBI, which accounts for approximately 85% of all cases, the role of the APOE-epsilon4 allele is less clear. Studies completed to date have relied on brief cognitive assessments or coarse measures of global functioning, thereby limiting their conclusions. Our study investigated the influence of the APOE-epsilon4 allele in a prospective sample of 90 adults with mild to moderate TBI in whom neuropsychiatric outcome 6 months after injury was assessed as follows: (i) a detailed neuropsychological battery; (ii) an index of emotional distress (General Health Questionnaire); (iii) a diagnosis of major depression (Structured Clinical Interview for DSM-IV); (iv) a measure of global functioning (Glasgow Outcome Scale); (v) an index of psychosocial outcome (Rivermead Head Injury Follow-up Questionnaire); and (vi) symptoms of persistent post-concussion disorder (Rivermead Post-Concussion Symptoms Questionnaire). No association was found between the presence of the APOE-epsilon4 allele and poor outcome across all measures. Given the homogeneous nature of our sample (mild to moderate injury severity), the uniform follow-up period (6 months) and the comprehensive markers of recovery used, our data suggest that the APOE-epsilon4 allele does not adversely impact outcome in this group of TBI patients.

Adult↗
PubMed1988

Head trauma and exposure to prolactin-elevating drugs as risk factors for male breast cancer.

On the basis of information obtained from a population-based cancer registry in Sweden, male patients with breast cancer (n = 95) were found to have experienced significantly more brain concussions and skull fractures than male patients with lung cancer (n = 383) or malignant lymphoma (n = 69). Other risk factors significantly associated with breast cancer among men were drug treatment associated with prolactin elevations, radiation treatment, family history of breast cancer among first-degree relatives, a history of gynecomastia, gonadal injury, and treatment for inguinal hernias. The results confirm some previously described risk factors for male breast cancer and suggest that events elevating plasma prolactin (e.g., drugs, brain concussions, and skull fractures) and events predisposing for inguinal hernias may be new risk factors for the disease. Using hospital charts is likely to underestimate exposure for different risk factors; therefore, the results need to be confirmed in studies that directly retrieve information. However, such studies are difficult or impossible to undertake in most countries because the disease is so rare.

Adult↗
PubMed1998

The Abbreviated Injury Scale: application to autopsy data.

Twenty autopsy reports, comprising 1 fall, 1 cutting, 1 burn, 1 drowning, 1 strangulation, 3 gunshot wound, and 13 traffic fatalities, were scored by the Abbreviated Injury Scale (AIS) and the Injury Severity Score (ISS). The codes were adequate for wounds of skin and long bones, and for most wounds of viscera. The autopsy descriptions were more detailed than the coding criteria for craniocerebral, cervicovertebral and muscular trauma, and less detailed for thoracoabdominal visceral, and long bone trauma. Lung contusions and rib fractures received scores that seemed unduly high, possibly reflecting the greater sensitivity of autopsy diagnosis over clinical diagnosis for these lesions. Complete hinge fractures of the skull base scored 4 (severe), which does not reflect the almost universally lethal nature of the accompanying cerebral concussion, which was itself not codeable. AIS scores were low and did not seem to reflect the lethal outcome when the lethal mechanism was purely physiologic and without a striking morphologic derangement, as in instances of cerebral or cardiac concussion, compression of the neck, occlusive airway hemorrhage, and visceral herniation into an adjacent body cavity. The scores were similarly low when therapy was delayed or adverse. Low AIS and ISS scores in a fatality from blunt or penetrating trauma may be useful retrospective clues to the presence of purely physiologic death mechanisms or therapeutic problems.

Abbreviated Injury Scale↗
PubMed1999

Crossbow suicide: mechanisms of injury and neuropathologic findings.

Crossbow injuries are rarely reported events in modern times. Two cases of death due to self-inflicted crossbow injuries to the head are reported in 2 men aged 18 and 27 years, respectively. Despite relatively low velocity and concussive force, the sharpness and propulsion force of crossbow bolts may be sufficient to enable penetration of the skull at short range. Due to the relatively low concussive force of the crossbow bolt, however, death may not be instantaneous but may occur from intraparenchymal cerebral damage sometime thereafter. Detailed neuropathologic evaluation of such cases may therefore demonstrate "red cell" hypoxic injury, as well as axonal injury, not limited to the region of the missile tract, but widely distributed, even to the point of extensive brain stem involvement. These changes may result from primary mechanical deformation at the time of injury, from secondary hypoxic damage, or from a combination of both factors. Immunohistochemical staining of brains for amyloid precursor protein to delineate more clearly the pattern of axonal damage may assist in determining the extent of injury in such cases.

Adolescent↗
PubMed1988

The epidemiology of mild, uncomplicated brain injury.

Mild brain injury accounts for a substantial proportion of all persons admitted to a hospital for brain trauma, yet the amount of information on the epidemiology of this problem is quite sparse. Data on mild brain injuries for San Diego County residents injured in 1981 were analyzed for incidence, external cause, prehospital factors, diagnoses, alcohol use, and in-hospital treatment costs. More than 80% of all San Diego County residents hospitalized for an acute brain injury had a mild uncomplicated brain injury: a rate of 130.8 per 100,000 per year. Three quarters of these had an ER Glasgow Coma Scale of 15. Rates are twice as high for males compared to females, with peak occurrence for males at ages 15-19 years. More than 40% of mild brain injuries are caused by motor-vehicle-related events. The most common diagnosis was concussion (80%) or other intracranial injury (14%). Median length of hospital stay was 2-3 days and depended on brain injury diagnosis or Glasgow Coma Scale. Although less than 30% of those aged 15 years and older were blood tested for alcohol, two thirds of those tested had a level of 100 mg% or higher. In-hospital treatment costs for concussion or other mild intracranial injury for San Diego County residents exceeded six million dollars in 1981.

Adolescent↗
PubMed1996

Head trauma: hearing loss and dizziness.

OBJECTIVE: Because the physicians who care for patients with head trauma may be family practitioners or internists, this article provides these physicians some knowledge of the causes and pathophysiology of such trauma with respect to neurologic sequelae to aid in their decisions to seek consultation with neurologists and otoneurologists in diagnosis and management. METHODS: This article reviews the literature concerning differential diagnosis, appropriate evaluation, and possible treatments of patients who exhibit hearing loss and dizziness after head trauma, whiplash injuries, or both. I also relate those findings to my extensive experience with such neurologic problems. FINDINGS: The findings are grouped according to injuries that cause dizziness, including trauma to the brain stem - eighth nerve complex, the semicircular canals (labyrinthine concussion), benign paroxysmal positional vertigo, Meniere's syndrome -- vestibular symptoms, perilymphatic fistula -- vestibular symptoms, and cervical vertigo; and those that cause hearing loss, including trauma to the brain, eighth nerve, middle ear, cochlear concussion, Meniere's syndrome, and perilymphatic fistula.

Craniocerebral Trauma↗