Measuring Blunt Force Head Impacts in Athletes

INTRODUCTION

Although concussion continues to be a major source of acute and chronic injuries, concussion injury mechanisms and risk functions are ill-defined. This lack of definition has hindered efforts to develop standardized concussion monitoring, safety testing, and protective countermeasures. To overcome this knowledge gap, we have developed, tested, and deployed a head impact monitoring mouthguard (IMM) system.

MATERIALS AND METHODS

The IMM system was first calibrated in 731 laboratory tests. Versus reference, Laboratory IMM data fit a linear model, with results close to the ideal linear model of form y = x + 0, R2 = 1. Next, during on-field play involving n = 54 amateur American athletes in football and boxing, there were tens of thousands of events collected by the IMM. A total of 890 true-positive head impacts were confirmed using a combination of signal processing and National Institute of Neurological Disorders and Stroke/National Institutes of Health Common Data Elements methods.

RESULTS

The median and 99th percentile of peak scalar linear acceleration and peak angular acceleration were 20 and 50 g and 1,700 and 4,600 rad/s2, respectively. No athletes were diagnosed with concussion.

CONCLUSIONS

While these data are useful for preliminary human tolerance limits, a larger population must be used to quantify real-world dose response as a function of impact magnitude, direction, location, and accumulation. This work is ongoing.

[Walcher's hat brim line rule--a literature review]

The first description in the forensic medical literature of a demarcation line for the localization of head injuries resulting from falling to the ground appears in Kratter (1919). Regarding a similar line, Walcher (1931) later introduced the relation to the hat brim (Hutkrempe), which gave the rule its name: the hat brim line rule (Hutkrempenregel). Thenceforth it was supposed to be called Kratter's and Walcher's hat brim line rule (Kratter-Walcher'sche Hutkrempenregel). Over the following decades, not only its content but also the area of application and the definition of the hat brim line rule were repeatedly, and in part significantly, altered. This could be one of the reasons for the confusing diversity of academic opinions about the rule's applicability. Generally, the hat brim line rule should be retained in its original sense: Fall-related injuries do not lie above the hat brim line if the fall occurred from a standing position to the ground, without intermediary blows to the head. If applied in this way, the rule can be a helpful point of orientation for experts. The demarcation line in the original anatomical definition according to Kratter (1919) should also be used henceforth: the line which connects "the frontal eminence, the parietal eminence and the tip of the occipital plate" and lies "somewhat.above the usual saw-line of the calvarium". This line corresponds roughly to the hat brim line as it is understood by hat makers. The hat brim line rule should not be applied with regard to small children, as they show a different falling behaviour due to their disproportionately large and heavy heads. The rule is also in no way applicable to the assessment of injuries from blows, falls from a height (including from stairs) or traffic accidents. There is an urgent need for research as to the applicability of the hat brim line rule in relation to falling backwards, particularly in cases of high alcohol consumption.

[About the Geserick sign--a literature study]

Fractures of the medial and basal orbital wall as well as the petrous part of the temporal bone were described first in 1980 by a Berlin-based study group led by Geserick as new cranium findings resulting from a contrecoup mechanism. Experimental and comparative examinations revealed that indirect fractures of the orbital walls are caused by a coup action of the eyeballs, whereas the mechanogenesis of the petrous bone fractures continues to be unclear. The frequently combined occurrence with the orbital sign nonetheless permits an allocation to the contrecoup mechanism. Both signs are important criteria for forensic and clinical assessment of craniocerebral injuries.

Low-level laser therapy for closed-head traumatic brain injury in mice: effect of different wavelengths

BACKGROUND AND OBJECTIVES

Traumatic brain injury (TBI) affects millions worldwide and is without effective treatment. One area that is attracting growing interest is the use of transcranial low-level laser therapy (LLLT) to treat TBI. The fact that near-infrared light can penetrate into the brain would allow non-invasive treatment to be carried out with a low likelihood of treatment-related adverse events. LLLT may treat TBI by increasing respiration in the mitochondria, causing activation of transcription factors, reducing inflammatory mediators and oxidative stress, and inhibiting apoptosis.

STUDY DESIGN/MATERIALS AND METHODS

We tested LLLT in a mouse model of closed-head TBI produced by a controlled weight drop onto the skull. Mice received a single treatment with continuous-wave 665, 730, 810, or 980 nm lasers (36 J/cm(2) delivered at 150 mW/cm(2)) 4-hour post-TBI and were followed up by neurological performance testing for 4 weeks.

RESULTS

Mice with moderate-to-severe TBI treated with 665 and 810 nm laser (but not with 730 or 980 nm) had a significant improvement in Neurological Severity Score that increased over the course of the follow-up compared to sham-treated controls. Morphometry of brain sections showed a reduction in small deficits in 665 and 810 nm laser treated mouse brains at 28 days.

CONCLUSIONS

The effectiveness of 810 nm agrees with previous publications, and together with the effectiveness of 660 nm and non-effectiveness of 730 and 980 nm can be explained by the absorption spectrum of cytochrome oxidase, the candidate mitochondrial chromophore in transcranial LLLT.

Evidence-based community consultation for traumatic brain injury

OBJECTIVES

The objective was to determine if geospatial techniques can be used to inform targeted community consultation (CC) and public disclosure (PD) for a clinical trial requiring emergency exception from informed consent (EFIC).

METHODS

Data from January 2007 to December 2009 were extracted from a Level I trauma center's trauma database using the National Trauma Registry of the American College of Surgeon (NTRACS). Injury details, demographics, geographic codes, and clinical data necessary to match core elements of the clinical trial inclusion criteria (Glasgow Coma Scale [GCS] 3-12 and blunt head injury) were collected on all patients. Patients' home zip codes were geocoded to compare with population density and clustering analysis.

RESULTS

Over a 2-year period, 179 patients presented with moderate to severe traumatic brain injury (TBI). Mapping the rate and frequency of TBI patients presenting to the trauma center delineated at-risk populations for moderate to severe head injury. Four zip codes had higher incidences of TBI than the rest, with one zip code having a very high rate of 80 per 100,000 population.

CONCLUSIONS

Geospatial techniques and hospital data records can be used to characterize potential subjects and delineate a high-risk population to inform directed CC and public disclosure strategies.

Reality and risk of contact-type head injuries related to bicycle-mounted child seats

OBJECTIVE

The authors have treated numerous children who have been injured by falling from bicycle-mounted child seats. Despite the greatly increased use of such seats, the understanding of their risk and the importance of helmet use remains alarmingly poor. The objective of this study was to confirm the risk of bicycle-mounted child seats and to evaluate the efficacy of helmets, seat belts, and back seat height in terms of preventing or mitigating contact-type head impacts that occur in falls from bicycle-mounted child seats.

MATERIALS AND METHODS

Biometrical dummy tests were performed to examine contact-type head injuries in falls from stationary bicycles. A bicycle with an anthropometric test dummy placed in a bicycle-mounted child seat was tipped over. Each test was repeated three times and three-dimensional acceleration was measured using accelerometer. Head Injury Criteria (HIC) were calculated and the respective influences of a helmet, a seat belt, and increased height of the back of the seat on such impacts were evaluated.

RESULTS

Only helmets unequivocally lowered maximal acceleration and/or HIC values with statistical significance. The seat belt lowered HIC values as long as it was used with the high-back seat. Only when the dummy wore a helmet sitting in a high-back seat did the HIC show less than the threshold of 570 for three-year-old children. The HIC showed the lowest score of 161.5 when the dummy wore both a helmet and a seat belt sitting in a high-back seat.

CONCLUSIONS

Riders in bicycle-mounted child seats definitely have higher risks of contact-type head injuries. In transporting a child on a bicycle-mounted child seat, parents must use both a child-bicycle helmet and a high-back child seat at least; a seat belt is highly recommended as long as it is used with the other safety devices.

IMPACT ON INDUSTRY

The bicycle-mounted child seat should have a high enough back and an appropriate seat belt to protect the head of the child from a contact-type injury.

[Analysis on clinical classification and injury certification in 30 cases of acute closed head trauma]

OBJECTIVE

In order to improve accuracy of forensic expert conclusion and provide scientific and reasonable accordance for revising identifying criteria for the injury degree, correlation between clinical classification and injury certification of acute closed head trauma were explored.

METHODS

A total of 30 cases about acute closed head trauma were selected. Comparison and analysis were made about their differences and the correlation between the clinical classification and the injury degree certification.

RESULTS

Mild craniocerebral injury is equal to mild or moderate injury, moderate craniocerebral injury is equivalent to mild or severe injury, severe craniocerebral injury is mostly equivalent to severe injury.

CONCLUSION

There are some correlation between the clinical classification and the injury certification in acute closed head trauma. It is necessary to refer to the criteria of clinical classification when revising identifying criteria for the injury degree so as to enhance scientific rigor and rationality.

Shaken baby syndrome: a common variant of non-accidental head injury in infants

BACKGROUND

Recent cases of child abuse reported in the media have underlined the importance of unambiguous diagnosis and appropriate action. Failure to recognize abuse may have severe consequences. Abuse of infants often leaves few external signs of injury and therefore merits special diligence, especially in the case of non-accidental head injury, which has high morbidity and mortality.

METHODS

Selective literature review including an overview over national and international recommendations.

RESULTS

Shaken baby syndrome is a common manifestation of non-accidental head injury in infancy. In Germany, there are an estimated 100 to 200 cases annually. The characteristic findings are diffuse encephalopathy and subdural and retinal hemorrhage in the absence of an adequate explanation. The mortality can be as high as 30%, and up to 70% of survivors suffer long-term impairment. Assessment of suspected child abuse requires meticulous documentation in order to preserve evidence as well as radiological, ophthalmological, laboratory, and forensic investigations.

CONCLUSIONS

The correct diagnosis of shaken baby syndrome requires understanding of the underlying pathophysiology. Assessment of suspected child abuse necessitates painstaking clinical examination with careful documentation of the findings. A multidisciplinary approach is indicated. Continuation, expansion, and evaluation of existing preventive measures in Germany is required.

Guardian availability in children evaluated in the emergency department for blunt head trauma

BACKGROUND

Enrolling children in research studies in the emergency department (ED) is typically dependent on the presence of a guardian to provide written informed consent.

OBJECTIVES

The objectives were to determine the rate of guardian availability during the initial ED evaluation of children with nontrivial blunt head trauma, to identify the reasons why a guardian is unavailable, and to compare clinical factors in patients with and without a guardian present during initial ED evaluation.

METHODS

This was a prospective study of children (<18 years of age) presenting to a single Level 1 trauma center after nontrivial blunt head trauma over a 10-month period. Physicians documented patient history and physical examination findings onto a structured data form after initial evaluation. The data form contained data points regarding the presence or absence of the patient's guardian during the initial ED evaluation. For those children for whom the guardian was not available during the initial ED evaluation, the physicians completing the data forms documented the reasons for the absence.

RESULTS

The authors enrolled 602 patients, of whom 271 (45%, 95% confidence interval [CI] = 41% to 49%) did not have a guardian available during the initial ED evaluation. In these 271 patients, 261 had reasons documented for lack of guardian availability, 43 of whom had multiple reasons. The most common of these was that the guardian did not ride in the ambulance (51%). Those patients without a guardian available were more likely to be older (mean age, 11.4 years vs. 7.6 years; p < 0.001), be victims of a motor vehicle collision (MVC; 130/268 [49%] vs. 35/328 [11%]; p < 0.001), have a Glasgow Coma Scale (GCS) score <14 (21/269 [7.8%] vs. 11/331 [3.3%]; p = 0.02), and undergo cranial computed tomography (CT) scanning (224/271 [83%] vs. 213/331 [64%]; p < 0.001). Multivariate analysis identified similar independent risk factors for lack of guardian presence.

CONCLUSIONS

Nearly one-half of children with nontrivial blunt head trauma evaluated in the ED may not have a guardian available during their initial ED evaluation. Patients whose guardians are not available at the time of initial ED evaluation are older and have more severe mechanisms of injury and more serious head trauma. ED research studies of pediatric trauma patients that require written informed consent from a guardian at the time of initial ED evaluation and treatment may have difficulty enrolling targeted sample size numbers and will likely be limited by enrollment bias.

Diffusion Tensor MR Imaging in Pediatric Head Trauma

PURPOSE

We propose to investigate the fractional anisotropy (FA) values in pediatric patients with closed head trauma and correlate them with the initial Glasgow Coma Scale (GCS).

MATERIALS AND METHODS

A retrospective evaluation of 24 pediatric patients (15 men, 9 women; mean age, 13 years; range, 2-18 years) who underwent both unenhanced head computed tomography and cerebral magnetic resonance imaging (MRI), including the tensor diffusion sequence, within 30 days of the incident. Twenty-two atraumatic control patients (9 men, 13 women; mean age, 9 years; range, 4-17 years) were randomly selected from the records of the radiology department within the same period. Fractional anisotropy measurements were taken from each of 6 major white matter volumes. Data extracted from the record of each subject included GCS, initial head computed tomographic results, and length of hospital stay. Kruskal-Wallis and t tests were used for statistical evaluation.

RESULTS

The mean acute score on the GCS was 9.7 +/- 5. Mean duration of hospitalization days was 8.7 +/- 10. Statistically significant differences in mean FA values between trauma and control subjects were noted in corpus callosum. Trauma patients with positive findings on MRI and with GCS less than 10 also had lower FA values than patients with GCS greater than 10 and patients who had normal MRI findings. There was a negative correlation between time to discharge and FA values.

CONCLUSIONS

In pediatric head trauma, MRI diffusion FA measurements can show abnormalities despite normal-appearing brain MRI findings. Larger investigations are required to verify the stability of correlations.

Validation of a Relative Head Injury Severity Scale for Pediatric Trauma

BACKGROUND

Brain injury is the most important independent predictor of mortality and morbidity in pediatric trauma. The Glasgow Coma Score (GCS) is the commonly used clinical instrument to assess brain injury. However, the GCS or one of its components is often not applicable in children under a certain age or cannot be computed reliably because of the patient's condition or the circumstances surrounding resuscitation efforts. This limits its usefulness in statistical models of trauma outcomes, which rely on complete data collection and entry into trauma registries. This study provides evidence validating use of a relative head injury severity scale (RHISS) derived from available International Classification of Diseases, 9th Revision (ICD-9) diagnosis codes to stratify degree of head injury.

METHODS

The patient population was derived from the National Pediatric Trauma Registry (NPTR;1994-2001). Survival Risk Ratios (SRRs) were computed for each head injury ICD-9 code. ICD-9 diagnosis codes related to head injury were then assigned to a RHISS category based on duration of loss of consciousness, location of skull fracture, or both: 0 = none; 1 = mild; 2 = moderate, or 3 = severe head injury. Analysis of variance compared mean SRRs across RHISS categories. Each patient was then assigned to a RHISS category based on their single worst ICD-9 head injury code. Logistic regression analysis was used to predict mortality based on New Injury Severity Score (NISS), whether the patient had been intubated, RHISS, and the Abbreviated Injury Score (AIS) for head and neck injuries.

RESULTS

GCS score was missing for 96% of nonsurvivors in the NPTR. Mean SRRs differed significantly (p < 0.001) among ICD-9 codes assigned to each RHISS category, as follows (Mean +/- SD): RHISS (0) = 0.93 +/- 0.16; RHISS (1) = 0.89 +/- 0.22; RHISS (2) = 0.85 +/- 0.26; RHISS (3) = 0.55 +/- 0.35. Logistic regression identified RHISS as an independent significant predictor (p < 0.01) of mortality.

CONCLUSION

RHISS is a valid index of degree of head injury in the pediatric trauma population. Unlike GCS, RHISS is more likely to be available in trauma registries, and can be computed from administrative data. RHISS provides a feasible and valid method for quantifying the degree of brain injury in statistical models of pediatric trauma outcome.

Posttraumatic balance disorders

Head trauma is being more frequently recognized as a causative agent in balance disorders. Most of the published literature examining traumatic brain injury (TBI) after head trauma has focused on short-term prognostic indicators and neurocognitive disorders. Few data are available to guide those individuals who see patients with balance disorders secondary to TBI. Our group has previously examined balance disorders after mild head trauma. In this study, we study all classes of head trauma. We provide a classification system that is useful in the diagnosis and management of balance disorders after head trauma and we examine treatment outcomes. As dizziness is one of the most common outcomes of TBI, it is essential that those who study and treat dizziness be familiar with this subject.

Thalamic nuclei after human blunt head injury

Paraffin-embedded blocks from the thalamus of 9 control patients, 9 moderately disabled, 12 severely disabled, and 10 vegetative head-injured patients assessed using the Glasgow Outcome Scale and identified from the Department of Neuropathology archive. Neurons, astrocytes, macrophages, and activated microglia were differentiated by Luxol fast blue/cresyl violet, GFAP, CD68, and CR3/43 staining and stereological techniques used to estimate cell number in a 28-microm-thick coronal section. Counts were made in subnuclei of the mediodorsal, lateral posterior, and ventral posterior nuclei, the intralaminar nuclei, and the related internal lamina. Neuronal loss occurred from mediodorsal parvocellularis, rostral center medial, central lateral and paracentral nuclei in moderately disabled patients; and from mediodorsal magnocellularis, caudal center medial, rhomboid, and parafascicular nuclei in severely disabled patients; and all of the above and the centre median nucleus in vegetative patients. Neuronal loss occurred primarily from cognitive and executive function nuclei, a lesser loss from somatosensory nuclei and the least loss from limbic motor nuclei. There was an increase in the number of reactive astrocytes, activated microglia, and macrophages with increasing severity of injury. The study provides novel quantitative evidence for differential neuronal loss, with survival after human head injury, from thalamic nuclei associated with different aspects of cortical activation.

Do trauma patients with a Glasgow Coma Scale score of 3 and bilateral fixed and dilated pupils have any chance of survival?

BACKGROUND

Low Glasgow Coma Scale score (GCS) and pupillary status predict poor outcomes in head injury (HI) patients. We compared the mortality of GCS 3 patients having bilateral fixed and dilated pupils (BFDP) with GCS 3 patients having reactive pupils (RP). We then determined if trauma system or patient factors were responsible for the difference in mortality.

METHODS

We reviewed all adult, blunt HI patients with GCS=3, admitted to our institution from January 1, 2001 to December 31, 2003. Demographics, injury data, prehospital times, procedures, and outcomes were recorded.

RESULTS

During this period, 245 patients were admitted with GCS of 3, and met inclusion criteria. In all, 173 patients were analyzed, after excluding 23 patients who were dead-on-arrival, and 45 others, who were intoxicated with alcohol, or received paralytic agents in the trauma room. All BFDP patients died, whereas 42.0% of reactive pupil (RP) patients died (p < 0.0001). With regards to patient factors, BFDP patients were more likely to be unstable, have extra-axial bleeding, and evidence of midline shift and/or herniation. Trauma system factors, however, may also have had an impact on outcome. Despite having more extra-axial bleeding, BFDP patients were less likely to have a neurosurgical operation than RP patients.

CONCLUSION

Patients with GCS of 3 and BFDP have a dismal prognosis. These patients have suffered devastating brain injuries and tend to be hemodynamically unstable. Clinicians, however, are less likely to aggressively treat BFDP patients than RP patients. Further prospective studies are required to determine which patients with GCS of 3 and BFDP are likely to benefit from aggressive treatment.

Predictors of intracranial injuries in children after blunt head trauma

This study was conducted to determine if clinical features can predict the risk of intracranial injury (ICI) in pediatric closed head trauma. We enrolled 3,806 children under 16 years consecutively referred for acute closed head trauma to the paediatric emergency room of five Italian children's hospitals. Relevant outcomes were death and diagnosis of ICI. Clinical symptoms and signs were evaluated as possible outcome predictors. Children were also classified into five groups according to their clinical presentation. The association of ICI with signs and symptoms and the appropriateness of the five-group classification in predicting the likelihood of ICI were evaluated by logistic regression analyses. ICI was diagnosed in 22 children; 2 of them died. The risk of fatal and nonfatal ICI was 0.5 and 5.2 per 1,000 children with closed head trauma respectively. Significant associations were found between ICI and loss of consciousness, prolonged headache, persistent drowsiness, abnormal mental status, focal neurological signs, signs of skull fracture in non-frontal areas and signs of basal skull fracture. The five-group classification of children allowed an excellent prediction in terms of likelihood of ICI (ROC area 0.972).

CONCLUSIONS

Selection of children with closed head trauma based on different combinations of signs and symptoms allows for early identification of subjects at different risk for ICI. In patients with minor head injuries, the absence of loss of consciousness, drowsiness, amnesia, prolonged headache, clinical evidence of basal or non-frontal skull fracture identified 100% of children without lesions. Validation of our results with a larger sample of patients with ICI would be highly desirable.

CT prediction of contusion evolution after closed head injury: the role of pericontusional edema

BACKGROUND

Cerebral contusions have a 51% incidence of evolution in the first hours after injury. Evolution is associated with clinical deterioration and is the reason for ICP monitoring or surgical intervention. We sought to define CT features that predict cerebral contusion evolution.

METHODS

Patients treated for cerebral contusion who had 2 CT scans within 24 hours after injury were evaluated (n = 21). CT scans were analyzed for area of contusion, hemorrhagic components, and edema. Increase (%) in contusion size was recorded. Contusion evolution was defined as > 5% size increase. Ratios of hemorrhagic components to surrounding edema were calculated.

RESULTS

Ten patients (47.6%) showed contusion evolution and 11 (52.4%) did not. Age, sex ratio, or injury severity between the 2 groups did not differ. Eight of 10 patients with evolving contusions had minimal or no perilesional edema on first CT; only 2 of 11 nonevolution patients had perilesional edema (p < 0.005). Mean ratio of area of surrounding edema to area of hemorrhagic products on first CT was 0.770 in evolution group versus 2.22 in non-evolution group (p = 0.055).

CONCLUSIONS

A higher proportion of patients without contusion evolution had perilesional edema present on first CT scan. The absence of pericontusional edema on early CT may be a useful marker to predict contusion evolution.

Force and acceleration corridors from lateral head impact

This study was conducted to provide force and acceleration corridors at different velocities describing the dynamic biomechanics of the lateral region of the human head. Temporo-parietal impact tests were conducted using specimens from ten unembalmed post-mortem human subjects. The specimens were isolated at the occipital condyle level, and pre-test x-ray and computed tomography images were obtained. They were prepared with multiple triaxial accelerometers and subjected to increasing velocities (up to 7.7 m/s) using free-fall techniques by impacting onto a force plate from which forces were recorded. A 40-durometer padding (50-mm thickness) material covering the force plate served as the impacting boundary condition. Computed tomography images obtained following the final impact test were used to identify pathology. Four specimens sustained skull fractures. Peak force, displacement, acceleration, energy, and head injury criterion variables were used to describe the dynamic biomechanics. Force and acceleration responses obtained from this experimental study along with other data will be of value in validating finite element models. The study underscored the need to enhance the sample size to derive probability-based human tolerance to side impacts.

Classification and Regression Tree for Prediction of Outcome after Severe Head Injury Using Simple Clinical and Laboratory Variables

Many previous studies have constructed several predictive models for outcome after severe head injury, but these have often used expensive, time consuming, or highly specialized measurements. The goal of this study was to develop a simple, easy to use a model involving only variables that are rapidly and easily achievable in daily routine practice. To this end, a classification and regression tree (CART) technique was employed in the analysis of data from 345 patients with isolated severe brain injury who were admitted to Asclepeion General Hospital of Athens from January, 1993, to December, 2000. A total of 16 prognostic indicators were examined to predict neurological outcome at 6 months after head injury. Our results indicated that Glasgow Coma Scale was the best predictor of outcome. With regard to the other data, not only the most widely examined variables such as age, pupillary reactivity, or computed tomographic findings proved again to be strong predictors, but less commonly applied parameters, indirectly associated with brain damage, such as hyperglycemia and leukocytosis, were found to correlate significantly with prognosis too. The overall cross-validated predictive accuracy of CART model for these data was 86.84%, with a cross-validated relative error of 0.308. All variables included in this tree have been shown previously to be related to outcome. Methodologically, however, CART is quite different from the more commonly used statistical methods, with the primary benefit of illustrating the important prognostic variables as related to outcome. This technique may prove useful in developing new therapeutic strategies and approaches for patients with severe brain injury.

Does an isolated history of loss of consciousness or amnesia predict brain injuries in children after blunt head trauma?

BACKGROUND

A history of loss of consciousness (LOC) is frequently used as an indication for cranial computed tomography (CT) in the emergency department (ED) evaluation of children with blunt head trauma.

OBJECTIVE

We sought to determine whether an isolated LOC and/or amnesia is predictive of traumatic brain injury (TBI) in children with blunt head trauma.

METHODS

We prospectively enrolled children <18 years old presenting to a level I trauma center ED between July 1998 and September 2001 with blunt head trauma. We evaluated the association of LOC and/or amnesia with 1) TBI identified on CT and 2) TBI requiring acute intervention. We defined the latter by a neurosurgical procedure, antiepileptic medication for >1 week, persistent neurologic deficits, or hospitalization for > or =2 nights. We then investigated the association of LOC and/or amnesia with TBI in those patients without other symptoms or signs of TBI ("isolated" LOC and/or amnesia).

RESULTS

Of eligible children, 2043 (77%) were enrolled, 1271 (62%) of whom underwent CT; 1159 (91%) of these 1271 had their LOC and/or amnesia status known. A total of 801 (39%) of the 2043 enrolled children had a documented history of LOC and/or amnesia. Of the 745 with documented LOC and/or amnesia who underwent CT, 70 (9.4%; 95% confidence interval [CI]: 7.4%, 11.7%) had TBI identified on CT versus 11 of 414 (2.7%; 95% CI: 1.3%, 4.7%) without LOC and/or amnesia (difference: 6.7%; 95% CI: 4.1%, 9.3%). Of the 801 children known to have had LOC and/or amnesia (regardless of whether they underwent CT), 77 (9.6%; 95% CI: 7.7%, 11.9%) had TBI requiring acute intervention versus 11 of 1115 (1%; 95% CI: 0.5%, 1.8%) of those without LOC and/or amnesia (difference: 8.6%; 95% CI: 6.5%, 10.7%). For those with an isolated LOC and/or amnesia without other signs or symptoms of TBI, however, 0 of 142 (95% CI: 0%, 2.1%) had TBI identified on CT, and 0 of 164 (95% CI: 0%,1.8%) had TBI requiring acute intervention.

CONCLUSIONS

Isolated LOC and/or amnesia, defined by the absence of other clinical findings suggestive of TBI, are not predictive of either TBI on CT or TBI requiring acute intervention. Elimination of an isolated LOC and/or amnesia as an indication for CT may decrease unnecessary CT use in those patients without an appreciable risk of TBI.

Working memory after mild, moderate, or severe childhood closed head injury

Children with closed head injury (CHI) perform poorly on complex tasks requiring working memory (WM). It is unclear to what extent WM itself is compromised, and whether WM varies with factors related to the CHI, such as injury severity, age at injury, and time since injury. We studied verbal WM in 126 school-age children with CHI, divided into mild, moderate, and severe injury severity groups. WM distributions were significantly skewed toward lower scores in the moderate and severe groups, although the distribution in the mild group was normal. Age at injury and time since injury predicted WM components only for the moderate group. Survivors of moderate or severe childhood CHI have persisting WM deficits limiting the computational workspace required for many cognitive tasks.

Identifikation von Hochrisikopatienten nach leichtem Sch�del-Hirn-Trauma

The indication for an initial cranial computed tomography (CCT) in minor head trauma (MHT) patients remains the subject of discussion. The aim of this study was to investigate whether a newly developed, rapid test system (ELECSYS S100, Roche Diagnostics) might allow a diagnostically valid, reproducible measurement of S 100 in MHT patients. Blood samples were drawn from 75 MHT patients, a CCT scan was performed, and those with a post-traumatic intracranial lesion counted as CCT+. Results were compared to a healthy control group (n=17). Of the 75 patients included in the study, 14 were stratified as CCT+. The systemic concentration of S 100 in these CCT+ patients was significantly increased (0.31 microg/l) compared to the healthy control group (0.04 microg/l) as well as to the CCT-negative patients (0.08 microg/l). The ELECSYS S100 system allows a rapid, valid, and reproducible assessment of S 100B in patient serum and this concentration is significantly elevated in patients suffering from intracranial lesions as shown by initial CCT scan. Hence, this study is the basis for a multicenter trial currently underway to confirm the results of our pilot study.

Changes in Working Memory After Traumatic Brain Injury in Children

The impact of traumatic brain injury (TBI) on working memory (WM) was studied in 144 children (79 with mild, 23 with moderate, and 42 with severe injuries) who underwent magnetic resonance imaging (MRI) at 3 months and were tested at baseline and at 3, 6, 12, and 24 months postinjury. An n-back WM task for letter identity was administered with memory load ranging from 1- to 3-back and a 0-back condition. A TBI Severity x Quadratic Tune interaction showed that net percentage correct (correct detections of targets minus false alarms) was significantly lower in severe than in mild TBI groups. The Left Frontal Lesions x Age interaction approached significance. Mechanisms mediating late decline in WM and the effects of left frontal lesions are discussed.

Objective indications for early tracheostomy after blunt head trauma

BACKGROUND

Early tracheostomy has been shown to be beneficial after trauma; however, there are few objective data to identify early in the recovery period which patients will ultimately require tracheostomy after blunt head trauma.

METHODS

The charts of all patients admitted to the surgical intensive care unit intubated at a level 1 urban trauma center, over a 5-year period with a primary admission diagnosis of blunt head trauma were retrospectively reviewed.

RESULTS

Sixty-four patients met inclusion and exclusion criteria and were divided into two groups: those extubated and those that required tracheostomy. By day 3 the Glasgow Coma Scores for the two groups were significantly different and on day 4 the Simplified Acute Physiology (SAPS) Scores were significantly different.

CONCLUSIONS

Calculating objective scores such as GCS and SAPS can aid in identifying those patients who will ultimately require a tracheostomy for prolonged airway protection after blunt head trauma with high positive predictive value.

Social deprivation and adult head injury: a national study

OBJECTIVES

To establish the association between measures of social deprivation, mechanisms of injury, patterns of care, and outcome following closed head injury.

METHODS

All Scottish adult A&E attendees with closed head injury (AIS Head > or =3) between July 1996 and December 2000 were studied.

RESULTS

Trauma was more common in individuals from more deprived areas. Within the trauma population head injury was relatively more common in patients from deprived areas; these individuals were more likely to sustain an isolated head injury as a result of an assault. Admission GCS was higher and normal physiology (as assessed by the RTS) was more common in individuals from more deprived areas. Recorded co-morbidity was similar between the two groups with the exception of a history of alcohol or substance abuse which was more common among patients from more deprived areas. Similar proportions of patients from more deprived and less deprived areas were transferred to the Regional Neurosurgical Centre. For patients who were transferred directly from A&E, time to neurosurgical theatre was similar for both groups. Length of hospital and ITU stay was less in patients from more deprived areas. After adjusting for known predictors of outcome using logistic regression analysis, there was no significant difference in mortality between patients from more deprived and less deprived areas.

CONCLUSIONS

Residing in a more deprived area is not associated with increased mortality from head injury among adults in Scotland. It is associated with different patterns of injury and a different process of care following presentation to hospital.

Short-term and long-term outcome of athletic closed head injuries

The continued development of the sport environment as a laboratory for clinical investigation of mild head injury has greatly advanced the use of neuropsychological assessment in evaluating brain-injured athletes, and tracking their symptoms and recovery in an objective manner. The use of neurocognitive baseline measures has become critical in determining whether a brain-injured athlete has recovered function sufficiently to return to play. The rapid growth of computerized and web-based neurocognitive assessment measures provides an efficient, valid technology to put such testing within the reach of most institutions and organizations that field sport teams. Moreover, the knowledge of the recovery curve following mild head injury in the sport environment can be generalized to the management of MTBI in general clinical environments where baseline measures are unlikely. What we know today is that sideline assessments of severity are not predictive of which athletes will show the most typical 5- to 10-day recovery period and which will report persistent PCS complaints and exhibit impaired neurocognitive performance for an extended time. The research on mechanisms of brain injury in MTBI suggests that unpredictable, diffuse white-matter damage may control much of the variability in functional impairments and recovery duration.

Necessity of hospital admission for pediatric minor head injury

The objective of this study was to evaluate the need for mandatory hospital admission of all pediatric patients with minor head injury (MHI) and negative computed tomographic (CT) scans for head injury. The study was a retrospective chart review of all patients admitted to a pediatric trauma service over a period of 4 years. MHI was defined as blunt head trauma with a Glasgow Coma Scale (GCS) score of 15 and a nonfocal neurological examination. Only patients < or = 13 years of age and with a negative head CT scan were included, and during hospitalization all patients were observed for delayed complications. A total of 197 patients met the inclusion criteria. The patients' mean age was 7.1 years, with a range of 2 months to 13 years. The most common mechanisms of injury were being struck by a motor vehicle while walking (82 patients), and falling (75 patients). No complications were observed, and although persistent symptoms occurred in 5 patients, they did not delay discharge. We conclude that pediatric patients with MHI and negative CT scans of the head do not require routine admission for observation for delayed complications.

Serum S100B concentrations are increased after closed head injury in children: a preliminary study

Traumatic brain injury (TBI) is a leading cause of death and disability in children. The current gold standards for diagnosis of TBI after closed head injury (CHI) have limitations, particularly in cases of inflicted injury. S100B is a protein that is specific to astrocytes. Serum S100B concentrations are increased in adults after CHI; there are no studies of serum S100B after CHI in children. The goal of this study was to measure the serum concentrations of S100B in children inflicted and noninflicted mild, moderate, and severe CHI. CHI severity was defined by initial Glasgow Coma Scale score. Forty-five children aged 0-13 years with mild (n = 27), moderate (n = 6), and severe (n = 12) CHI were enrolled prospectively. Blood was obtained as soon as possible after injury (range: 0.5-15.25 h) and every 12 h for up to 5 days when vascular access was available. Single control samples were obtained from 16 children aged 0-11 years with isolated long-bone fractures. Twenty-two patients (49%), including both patients with inflicted CHI, had an abnormal initial serum S100B concentration where an abnormal concentration was defined as greater than mean control concentration plus two standard deviations. S100B was detectable more than 12 h after injury only in patients with severe CHI. We conclude that serum S100B is increased in almost half of children after mild, moderate, and severe inflicted and noninflicted CHI. The increase is transient, lasting less than 12 h after injury, except in children with severe injury. Future research will focus on the possibility of using serum S100B as a screening test for inflicted CHI.

[Forensic medical evaluation of head injuries inflicted by blows with blunt objects]

A statistical evaluation of injuries of head tissues inflicted by blows with human body parts and with blunt hard objects of communal use was carried out. Characteristic morphometrical and topographical features of injuries and factors essential for their severity are defined.

Evaluation of the traumatic coma data bank computed tomography classification for severe head injury

This study determines the interrater and intrarater reliability of the Traumatic Coma Data Bank (TCDB) computed tomography (CT) scan classification for severe head injury. This classification grades the severity of the injury as follows: I = normal, II = diffuse injury, III = diffuse injury with swelling, IV = diffuse injury with shift, V = mass lesion surgically evacuated, or VI = mass lesion not operated. Patients with severe closed head injury were included. Outcome was assessed using the Glasgow Outcome Score (GOS) at 3 and 6 months. Four observers, two of them classifying the scans twice, independently evaluated CT scans. Of the initial CT scans of 63 patients (36 males, 27 females; age, 34+/-24 years), 6.3% were class I, 26.9% class II, 28.6% class III, 6.3% class IV, 22.2% were class V, and 9.6% class VI. The overall interrater and intrarater reliability was 0.80 and 0.85, respectively. Separate analyses resulted in higher inter- and intrarater reliabilities for the mass lesion categories (V and VI), 0.94 and 0.91, respectively, than the diffuse categories (I-IV) 0.71 and 0.67. Merging category III with IV, and V with VI resulted in inter- and intrarater reliabilities of 0.93 and 0.78, respectively. Glasgow outcome scores after 6 months were as follows: 19 dead (30%), one vegetative (2%), five severely disabled (8%), 17 moderately disabled (27%), and 21 good recovery (33%). Association measures (Sommers' D) between CT and GOS scores were statistically significant for all observers. This study shows a high intra- and interobserver agreement in the assessment of CT scan abnormalities and confirms the predictive power on outcome when the TCDB classification is used.

Diagnostic confusion in mild traumatic brain injury (MTBI). Lessons from clinical practice and EFNS--inquiry. European Federation of Neurological Societies

A 1997 inquiry of 130 neurosurgeons throughout Germany, dealing with diagnosis and therapy of patients with mild traumatic brain injury showed a mainly inhomogeneous picture. The European Federation of Neurological Societies inquiry form 'Management of Patients with Mild Head Injury' was sent on behalf of the German Society of Neurological Surgeons to every leading neurosurgeon in Germany, of whom only 74 (57%) answered. The diagnosis 'mild brain injury' is used by 63%, 'commotio cerebri' by 49%, and 'brain concussion' by 4% of the institutions. GCS is used for classification by 60%, PTA 48%, retrograde amnesia by 50%, and LOC by 63% of institutions. Guidelines are used in 78%. Diagnostic x-ray of the skull is used in 77%, cervical spine in 62%, CT in 66%, MRT in 7%; and routine EEG in 35%. Fourteen per cent of the patients are not admitted; home observation is used in 45% of institutions, full bedrest in 19%, working pause in 48%, pain medication in 27%, control in 51%. Seperate guidelines for children in 54% of those departments.

A review of outcome after moderate and severe closed head injury with an introduction to life care planning

Forensic consultation regarding moderate and severe closed head injury (CHI) generally focuses on determination of severity of residual deficits and the implications of these deficits for future health care needs, personal independence, and employment. This information can be used to develop a life care plan that describes the patient's needs for continued medical care, rehabilitation, and daily assistance or supervision and estimates the long-term costs for these services. This article provides brief reviews of CHI classification, epidemiology, residual deficits, expected outcomes, and factors predictive of outcome. An introduction to the process of developing a life care plan is presented.

Sports-specific concerns in the young athlete: football

There are over 1.5 million males playing American football at all levels in the United States. American football is the most common participant sport among high-school-aged males. Owing to its high rate of injury per exposure hour, American football injuries are commonly treated in the emergency department during the autumn sports season. This article will review the history, epidemiology, and specific injury patterns seen in American football, with a focus on head and shoulder injuries.

Attentional skills following traumatic brain injury in childhood: a componential analysis

Recent research has documented residual deficits in attention following traumatic brain injury in childhood. The present study aimed to investigate whether such deficits are global, or affect specific components of attention differentially. Four attentional domains were examined using a newly developed test of attention, the Test of Everyday Attention for Children: sustained attention, focussed attention, divided attention, and response inhibition. Eighteen children with a history of traumatic brain injury, aged between 8 and 14 years, and 18 non-injured matched controls participated in the study. Results indicated that attentional skills may be differentially impaired after TBI, with children who have sustained moderate-to-severe TBI exhibiting significant deficits for sustained and divided attention, and response inhibition, but relatively intact focussed attention.

Alternative approaches to the assessment of mild head injury in athletes

OBJECTIVES

Athletic trainers and team physicians are often faced with decisions concerning the severity and timing of an athletes return to play following mild head injury (MHI). These decisions can be the most difficult ones facing clinicians because of the limited amount of quantitative information indicating injury severity. Several authors have published guidelines for return to play following MHI, however these guidelines are based on limited scientific data. The purpose of this paper was to examine the effects of MHI on two objective measures, postural stability and cognitive function, to determine their usefulness in MHI assessment. The data gathered from these two measures has the potential to establish recovery curves based on objective data.

METHODS

Eleven Division I collegiate athletes who sustained a MHI and eleven matched control subjects were assessed for postural stability and cognitive function at four intervals following injury. Postural stability was assessed using the Sensory Organization Test on the NeuroCom Smart Balance Master. Cognitive functioning was measured through the use of four neuropsychological tests: Stroop Test, Trail Making Test, Digits Span and Hopkins Verbal Learning Test. Separate mixed model repeated measures ANOVAs were calculated for the composite score and three ratio (vestibular, visual and somato-sensory) scores from the Sensory Organization Test and the scores from the neuropsychological test to reveal significant differences between groups and across days postinjury.

RESULTS

A significant group by day interaction for overall postural stability (composite score) revealed that MHI athletes displayed increased postural instability for the first few days following MHI (p < .05). Analysis of the ratio scores revealed a significant interaction for the visual ratio. No significant group differences were revealed for any of the neuropsychological tests (p > .05), however significant day differences were revealed (p < .05).

CONCLUSIONS

The results from this study indicate that athletes demonstrate decreased stability until 3 days postinjury. It appears this deficit is related to a sensory interaction problem, whereby the injured athlete fails to use their visual system effectively. These findings suggest that measures of postural stability may provide clinicians with a useful clinical tool for determining when an athlete may safely return to competition, although these findings need to be confirmed in larger groups of athletes.

[Blank fright guns as assault weapons. Forensic medicine and legal aspects]

Frequently blank guns are used at perpetrations as instruments for blows, mainly at robberies. These weapons are constructed in a compact, relatively heavy manner and possess angular bounds. First of all the head is the aim for such attacks. Blows with blank guns against the head are classified as potential dangerous to life. The cause of death is mainly due to bleeding, direct trauma of the brain, and air embolism. The typical resulting trauma as well as the criminal classification of perpetrations with blank guns used as instruments for blows are discussed.

Magnetic resonance imaging in relation to functional outcome of pediatric closed head injury: a test of the Ommaya-Gennarelli model

OBJECTIVE

To characterize late neuropathological findings of pediatric closed head injury (CHI), to assess depth of brain lesion in relation to acute severity, and to assess long-term outcome to test the Ommaya-Gennarelli model.

METHODS

Magnetic resonance imaging (MRI) at least 3 months postinjury in a prospective sample (n 5 169) and at least 3 years after CHI in a retrospective sample (n 5 82) was studied. Lesion volume was measured by planimetry. Acute CHI severity was measured by the Glasgow Coma Scale. Patients were classified according to the depth of the deepest parenchymal lesion into no lesion, subcortical, and deep central gray/brain stem groups. The outcomes were assessed by the Glasgow Outcome Scale and the Vineland Adaptive Behavior Scale, which were performed at the time of the MRI in the retrospective sample and up to 3 years postinjury in the prospective sample.

RESULTS

Focal brain lesions were present in 55.4% of the total sample. Depth of brain lesion was directly related to severity of acute impairment of consciousness and inversely related to outcome, as measured by both the Glasgow Outcome Scale and the Vineland Adaptive Behavior Scale. A rostrocaudal gradient of hemispheric lesion frequency was observed, whereas the posterior lesions of the corpus callosum were particularly common. Total lesion volume could not explain the depth of lesion effect.

CONCLUSION

Our findings extend support for the Ommaya-Gennarelli model to pediatric CHI, indicating that depth of brain lesion is related to functional outcome. The relative frequency of focal brain lesions revealed by late MRI is higher than that of previous findings using acute computed tomography. Future investigations could explore whether depth of lesion observed using late MRI is sensitive to neuroprotective interventions.

Long-term follow up of children with head injuries-classified as "good recovery" using the Glasgow Outcome Scale: neurological, neuropsychological and magnetic resonance imaging results

The primary issues addressed in this study were: (1) determination of the significance of the classification "good outcome" utilizing the Glasgow Outcome Scale (GOS) in children at least 1 year after brain injury; (2) detection of residual lesions of brain parenchyma in these children upon follow up MRI scans; and (3) detection of relationships between neuropsychological test performance and MRI results. Selection criteria included children 6-15 years of age at the time of testing who received an initial CT scan at the time of their head injury and who had been injured at least 12 months prior to the follow up test. Only children who did not demonstrate neurological disability at the time of follow up examination were selected. The children showed a status of "good outcome" as defined by the GOS. Neurological examination, neuropsychological tests and an MRI were done. The test results of 59 patients were compared to those of a matched control group. Children, after receiving head injuries, showed significantly poorer results with respect to cognitive, motor and fine motor skills. Of all MRI-scans 66% revealed pathological findings. Cortical lesions were detected on MRI in 14% of cases; subcortical injuries were detected in 12% and, deep white matter lesions in 31%. Furthermore, corpus callosum damage was observed in 26% of cases. Pathological MRI findings were also observed in children with mild head injuries. All of the children with normal MRI findings showed abilities comparable to those of children in the control group. Patients with cortical lesions exhibited only motor deficits, whereas motor and cognitive deficits were seen in patients with deep white matter lesions. Children with multiple lesions demonstrated test results in all variables 1 to 2 standard deviations below those of the control group.

CONCLUSION

Children suffering a brain injury who 1 year later are classified within the "good outcome" group according to the Glasgow Outcome Scale often have significant morphological and functional brain deficits.

Guidelines for treatment of head injury in adults. Opinions of a group of neurosurgeons

There are a number of parallel activities world wide to devise guidelines for the treatment of head injuries. A Group of neurosurgeons from various European countries worked on guidelines during three informal meetings, which may serve as a base for discussion of national or local protocols. Three levels of certainty were distinguished: Measures that must be taken which such a high degree of certainty, that they have not seriously been challenged-principles. Measures, that should be taken, as there is reasonable evidence in the literature about its efficacy-recommendations and measures that may be taken, but proof of its efficacy is lacking-optional measures. Protocols based on these guidelines are felt to help young neurosurgeons in training, define neurosurgical needs for other specialities and enhance the general efficacy of care for the head injured patient including multiple injuries.

Mild head injury: differences in prognosis among patients with a Glasgow Coma Scale score of 13 to 15 and analysis of factors associated with abnormal CT findings

We performed a retrospective study of 2484 consecutive patients with mild head injury (Glasgow Coma Scale score 13-15) who were seen during a period of 18 months. Of these, 2351 (94.6%) patients scored 15 points, 88 (3.5%) scored 14 points and 45 (1.3%) 13 points. A multivariate analysis showed that advanced age, a lower GCS (13-14) and the presence of skull fracture, and focal signs, significantly increased the incidence of abnormal computed tomography (CT) findings. By contrast, the gender, the mechanism of injury, the occurrence of initial loss of consciousness, posttraumatic amnesia and coagulation disorders did not significantly increase the incidence of abnormal CT findings. Patients with 13-14 GCS had a significantly higher incidence of initial loss of consciousness, of skull fracture, abnormal CT findings, need for hospital admission, delayed neurological deterioration and need for operation than patients with a GCS of 15. Thus, we suggest separating patients with a GCS of 13-14 into a different category and recommend performing CT in all those not improving within 4-6 h of injury. Such a policy makes skull radiography unnecessary in this subgroup. By contrast, skull radiographs may be useful for the triage of patients with a GCS of 15 that represent most of the mild head injury cases; radiographs should be obtained in patients presenting with initial loss of consciousness or posttraumatic amnesia (27.9% of the total cases) as these two findings were associated with a significantly higher incidence of fracture. Patients without these two findings (72.1% of the cases) showed a very low incidence of skull fracture (0.9% in this study) and may be discharged home with a warning sheet.

An integrated approach to team assessment in head injury

The development of multidisciplinary teams for the assessment and treatment of traumatic brain injury has not seen a parallel development in methods of coordinating and collating the information gathered by different professions. The team at the Head Injury Rehabilitation Centre (HIRC), Sheffield uses a process of assessment that encourages the coordination of such information, particularly across the areas that do not fall neatly into the remit of specific disciplines. The framework of the assessment is presented, together with discussion of methods of gathering information and of sharing that information. The advantages of this approach are discussed in terms of benefits for the client, for the professionals involved in the assessment and for other services that might be involved with the client.

Minor head injury: attempts at clarifying the confusion

Traumatic brain injury (TBI) refers to a broad range of neurological, cognitive and emotional factors that result from the application of a mechanical force to the head. Mechanical force can be applied on a continuum from none to very severe, and the extent of brain injury is related to the severity of this force. A review of the literature reveals that, while considerable research has been done on minor head injury, there remain several major sources of confusion. First, one of the most noticeable problems relates to the fact that the mild head injury has lower limits which are vaguely defined. This leads to individuals being categorized as having sustained a mild TBI despite minimal or no neurological damage being present. A second source of confusion in the literature is related to the failure to differentiate between cognitive consequences of TBI and post-concussion symptoms (PCS). Since PCS can occur in the absence of head injury, and are often present beyond the period of cognitive recovery from mild TBI, the two clearly result from different factors. Researchers have often failed to separate these two factors when studying recovery of function, and this has led to varying findings on outcome. Finally, many pre-injury factors (age, education, emotional adjustment) and post-injury factors (pain, family support, stress) interact with cognitive functioning and significantly affect recovery from TBI. These problems are reviewed and discussed.

Head injuries in lateral impact collisions

Individual non-minor injuries (Abbreviated Injury Scale (AIS) > or = 2) to the head that occurred to belted and unbelted drivers and front seat passengers on the stuck side of impacted vehicles were examined. Injury type, injury combination, collision severity in relation to type of injury as well as contact sources were assessed. Forty-eight percent of injuries were moderate in severity (AIS 2). The most common type of injury was the diffuse brain injury, typically marked by a short period of unconsciousness, which occurred in collisions of lower severity than focal brain and skull fracture injuries. One-hundred and five out of 216 (48.6%) of contact sources for all injury types originated from outside the vehicle and such exterior sources were more likely to result in high severity injuries. Thirty percent of injuries resulted from head contacts with other vehicles. The most frequent vehicle interior contact source was the side window glass. Diffuse injuries tended to occur independently of other injury types and were more likely to originate from an interior rather than exterior contact. Preventative measures for head injury reduction in lateral collisions are discussed. Overall, the data show that proposed and present European and U.S. lateral impact test methods do not address many head injury problems such as those included in this study.

Classification of brain compartments and head injury lesions by neural networks applied to MRI

An automatic, neural network-based approach was applied to segment normal brain compartments and lesions on MR images. Two supervised networks, backpropagation (BPN) and counterpropagation, and two unsupervised networks, Kohonen learning vector quantizer and analog adaptive resonance theory, were trained on registered T2-weighted and proton density images. The classes of interest were background, gray matter, white matter, cerebrospinal fluid, macrocystic encephalomalacia, gliosis, and "unknown." A comprehensive feature vector was chosen to discriminate these classes. The BPN combined with feature conditioning, multiple discriminant analysis followed by Hotelling transform, produced the most accurate and consistent classification results. Classification of normal brain compartments were generally in agreement with expert interpretation of the images. Macrocystic encephalomalacia and gliosis were recognized and, except around the periphery, classified in agreement with the clinician's report used to train the neural network.

The Head Injury Severity Scale (HISS): a practical classification of closed-head injury

The authors introduce a two-dimensional scale for rating closed-head injury, the Head Injury Severity Scale (HISS). This system is based on a five-interval severity classification (minimal through critical), determined primarily by the initial post-resuscitation Glasgow Coma Scale score. The second dimension is predicated on the presence or absence of complications, appropriate for each severity interval. The outcomes of almost 25,000 patients with head injury encountered at our institution over a 7-year period were evaluated. We discovered that adding a complication dimension to each severity category resulted in significant outcome differences and effectively divided patients into groups with very different risks, prognosis and treatment requirements. The HISS is proposed as a framework on which further research can be done to guide care to predict outcome and to perform audits on head-injured patients.

Classification of the spectrum of mild traumatic brain injury

Mild traumatic brain injury (TBI) is a very common injury, resulting in immediate and possible long-term symptoms. The accurate and consistent definition of mild TBI is important in the initial and rehabilitation management of the injury, and in research concerning mild TBI. A definition of mild TBI has been developed by the Head Injury Interdisciplinary Special Interest Group of the American Congress of Rehabilitation Medicine. Within the spectrum of injury severity in mild TBI there are several classification systems, primarily used in management of acute mild TBI, that breakdown mild TBI into grades of injury severity. These are based upon the presence or absence of mental status changes, amnesia, loss of consciousness, anatomical lesion or neurological deficit.

MMPI and MMPI-2 profile and code type congruence in a brain-injured sample

Examined the comparability of the Minnesota Multiphasic Personality Inventory (MMPI) and Minnesota Multiphasic Personality Inventory-2 (MMPI-2) in a sample of brain-injured patients. There were 53 patients (36 males, 17 females; M age = 27.25, SD = 11.45), the majority of whom had suffered a closed-head injury. The MMPI-2 and MMPI items were administered in the context of an extensive neuropsychological examination. Results revealed a lack of congruence between the MMPI and MMPI-2 when the entire profile was compared using profile analysis. Analyses of code types found congruence to be high for single point elevations but modest for 2-point code types. The degree of congruence appears related to the nature of analysis, and for clinical purposes, code-type interpretation may be most relevant. These results provide some support for the congruence of the MMPI and MMPI-2 for brain-injured patients, but particular caution should be exercised in the interpretation of 2-point code types.

Subpopulations in closed-head injury: preliminary results

The classification systems currently utilized to categorize closed-head injury (CHI) patients are all based on severity levels. However, these scales are unable to account for the wide variability among CHI patients. Another way to classify these patients is to use the clinical picture independent of the overall severity level. That approach is used with aphasic patients but not with the CHI population. These preliminary data indicate that there are distinct subgroups in the CHI population. These subgroups can be identified by their overall pattern of performance on a battery of tests covering language, memory, visuospatial, cognitive and discourse skills. The characteristics of the tentative subgroups are described, but a more extensive study is needed to confirm the robustness of this classification.