Hans von Holst

Prognosis for mild traumatic brain injury: Results of the WHO collaborating centre task force on mild traumatic brain injury

We searched the literature on the epidemiology, diagnosis, prognosis, treatment and costs of mild traumatic brain injury. Of 428 studies related to prognosis after mild traumatic brain injury, 120 (28%) were accepted after critical review. These comprise our best-evidence synthesis on prognosis after mild traumatic brain injury. There was consistent and methodologically sound evidence that childrens prognosis after mild traumatic brain injury is good, with quick resolution of symptoms and little evidence of residual cognitive, behavioural or academic deficits. For adults, cognitive deficits and symptoms are common in the acute stage, and the majority of studies report recovery for most within 3-12 months. Where symptoms persist, compensation/litigation is a factor, but there is little consistent evidence for other predictors. The literature on this area is of varying quality and causal inferences are often mistakenly drawn from cross-sectional studies.

Incidence, risk factors and prevention of mild traumatic brain injury: Results of the WHO Collaborating Centre Task Force on Mild Traumatic Brain Injury

OBJECTIVE We undertook a best-evidence synthesis on the incidence, risk factors and prevention of mild traumatic brain injury. METHODS Medline, Cinahl, PsycINFO and Embase were searched for relevant articles. After screening 38,806 abstracts, we critically reviewed 169 studies on incidence, risk and prevention, and accepted 121 (72%). RESULTS The accepted articles show that 70-90% of all treated brain injuries are mild, and the incidence of hospital-treated patients with mild traumatic brain injury is about 100-300/100,000 population. However, much mild traumatic brain injury is not treated at hospitals, and the true population-based rate is probably above 600/100,000. Mild traumatic brain injury is more common in males and in teenagers and young adults. Falls and motor-vehicle collisions are common causes. CONCLUSION Strong evidence supports helmet use to prevent mild traumatic brain injury in motorcyclists and bicyclists. The mild traumatic brain injury literature is of varying quality, and the studies are very heterogeneous. Nevertheless, there is evidence that mild traumatic brain injury is an important public health problem, but we need more high-quality research into this area.

Diagnostic procedures in mild traumatic brain injury : results of the WHO Collaborating Centre Task Force on Mild Traumatic Brain Injury

We examined diagnostic procedures in mild traumatic brain injury by a systematic literature search. After screening 38,806 abstracts, we critically reviewed 228 diagnostic studies and accepted 73 (32%). The estimated prevalence of intracranial CT scan abnormalities is 5% in patients presenting to hospital with a Glasgow Coma Scale score of 15 and 30% or higher in patients presenting with a score of 13. About 1% of all treated patients with mild traumatic brain injury require neurosurgical intervention. There is strong evidence that clinical factors can predict computerized tomography scan abnormalities and the need for intervention in adults, but no such evidence for mild traumatic brain injury in children. We found evidence that skull fracture is a risk factor for intracranial lesions, but the diagnostic accuracy of radiologically diagnosed skull fracture as an indication of intracranial lesions is poor. There is only a little evidence for the diagnostic validity of cognitive testing and other diagnostic tools for mild traumatic brain injury.

Consequences of head size following trauma to the human head.

The objective of the present study was to evaluate whether variation of human head size results in different outcome regarding intracranial responses following a direct impact. Finite Element models representing different head sizes and with various element mesh densities were created. Frontal impacts towards padded surfaces as well as inertial loads were analyzed. The variation in intracranial stresses and intracranial pressures for different sizes of the geometry and for various element meshes were investigated. A significant correlation was found between experiment and simulation with regard to intracranial pressure characteristics. The maximal effective stresses in the brain increased more than a fourfold, from 3.6kPa for the smallest head size to 16.3kPa for the largest head size using the same acceleration impulse. When simulating a frontal impact towards a padding, the head injury criterion (HIC) value varies from the highest level of 2433 at a head mass of 2.34kg to the lowest level of 1376 at a head mass of 5.98kg, contradicting the increase in maximal intracranial stresses with head size. The conclusion is that the size dependence of the intracranial stresses associated with injury, is not predicted by the HIC. It is suggested that variations in head size should be considered when developing new head injury criteria.

Intracranial infusion of purified nerve growth factor to an Alzheimer patient : the first attempt of a possible future treatment strategy

We report on the clinical outcome of a first case of intracranial infusion of nerve growth factor (NGF) to an Alzheimer patient. The therapeutic attempt is based on animal research showing that NGF stimulates central cholinergic neurons of the type known to be lost during the development of Alzheimers disease (AD). Furthermore, our own previous clinical experience of infusing NGF to support the survival of intracranially transplanted adrenal chromaffin cells to Parkinsonian patients indicate this approach to be technically possible and safe and clinically of significant potential. Our first case was a 69-year-old woman, with symptoms of dementia since 8 years. Intraventricular infusion of 6.6 mg NGF over three months resulted in a marked transient increase in uptake and binding of [11C]nicotine in frontal and temporal cortex and a persistent increase in cortical blood flow as measured by PET as well as progressive decreases of slow wave EEG activity. After one month of NGF infusion, tests of verbal episodic memory were improved whereas other cognitive tests were not. No adverse effects of the NGF infusion were found. The results of this single case indicate that NGF may counteract cholinergic deficits in AD, and suggest that further clinical trials of NGF infusion in AD are warranted.

Non-surgical intervention and cost for mild traumatic brain injury: Results of the who collaborating centre task force on mild traumatic brain injury

We examined the evidence for non-surgical interventions and for economic costs for mild traumatic brain injury patients by a systematic search of the literature and a best-evidence synthesis. After screening 38,806 abstracts, we critically reviewed 45 articles on intervention and accepted 16 (36%). We reviewed 16 articles on economic costs and accepted 7 (44%). We found some evidence that early educational information can reduce long-term complaints and that this early intervention need not be intensive. Most cost studies were performed more than a decade ago. Indirect costs are probably higher than direct costs. Studies comparing costs for routine hospitalized observation vs the use of computerized tomography scan examination for selective hospital admission indicate that the latter policy reduces costs, but comparable clinical outcome of these policies has not been demonstrated. The sparse scientific literature in these areas reflects both conceptual confusion and limited knowledge of the natural history of mild traumatic brain injury.

MANDATE OF THE WHO COLLABORATING CENTRE TASK FORCE ON MILD TRAUMATIC BRAIN INJURY

In collaboration with outside experts, the WHO Collaborating Centre for Neurotrauma at the Karolinska Institute, Stockholm, Sweden, has assembled a task force to undertake a best-evidence synthesis of the literature on mild traumatic brain injury. The task force has addressed the epidemiology, diagnosis, prognosis, treatment and economic costs of mild traumatic brain injury in order to make recommendations to reduce the medical as well as the social consequences of mild traumatic brain injury.

Bifunctional Dendrimers: From Robust Synthesis and Accelerated One‐Pot Postfunctionalization Strategy to Potential Applications

A fourth wheel: Two sets of bifunctional AB(2)C dendrimers having internal acetylene/azides and external hydroxy groups were constructed utilizing benign synthetic protocols. An in situ postfunctionalization strategy was successfully carried out to illustrate the chemoselective nature of these dendrimers. The dendrimers were also transformed into dendritic nanoparticles or utilized as dendritic crosslinkers for the fabrication hydrogels.

Pet Study of Methionine Accumulation in Glioma and Normal Brain Tissue: Competition with Branched Chain Amino Acids

Five patients with glioma were examined with positron emission tomography using ([11C]methyl)-L-methionine. The study was repeated while the patient was being infused with branched chain amino acids (BCAA), 250 μmol/min. The accumulation rates of methionine in tumor tissue and in normal brain tissue were compared without and with the infusion of amino acids. Both tumor tissue and normal brain tissue showed a reduction in the methionine accumulation by 35% while the patient received the infusion. In one patient with a severe blood-tissue barrier disruption the tumor accumulation rate was unaffected. It is concluded that in gliomas without severe blood-tissue barrier disruption, the accumulation of methionine is governed by processes exhibiting similar properties regarding competition with BCAA as in normal brain tissue.

The epidemiology of head injuries in Sweden from 1987 to 2000

The purpose of the present study was to evaluate the variability in the annual head injury incidence rate in Sweden from 1987 to 2000. It was hypothesized that the annual incidence rate would decrease over time due to a variety of primary preventive strategies that have been introduced in Swedish society. We used the Hospital Discharge Register at the National Board for Health and Welfare and head injury codes 800-804, and 850-854 from ICD9 system and S2.0-S2.9, and S6.0-S6.9 codes from ICD-10 system. We evaluated the patterns of age, gender, external cause of injury (E-code), type of injury, length of hospital stay, and trends over time. Head injuries due to transportation collision were reduced over the 14-year period analysis. Falls persisted as the dominant cause of head injury. Overall, men had 2.1 times the incidence of head injury compared to women. There was a decline in younger ages experiencing a head injury over this interval, while the number of head injuries among elderly people increased over time. Concussion was about three times more frequent than fractures. Hematoma and diffuse or focal contusions had a much lower incidence rate than concussion. Concussions and fractures decreased over time. Diffuse or focal injuries showed a steady rate of occurrence over the study interval while hematoma increased. Although length of hospital stay varied widely from zero to more than 50 days, 73.6% of hospital days were confined to two days or less. The incidence rate is stable over this time frame. While head injuries attributable to transportation accidents decreased, falls made up an increasing proportion of head injuries. Since we observed an increase in head injuries among elderly, primary prevention strategies may need to be targeted at this age group, and at preventing falls.