Effect of Internal Jugular Vein Compression on Intracranial Hemorrhage in a Porcine Controlled Cortical Impact Model.

Internal jugular vein (IJV) compression has been shown to reduce axonal injury in pre-clinical traumatic brain injury (TBI) models and clinical concussion studies. However, this novel approach to prophylactically mitigating TBI through venous congestion raises concerns of increasing the propensity for hemorrhage and hemorrhagic propagation. This study aims to test the safety of IJV compression in a large animal controlled cortical impact (CCI) injury model and the resultant effects on hemorrhage. Twelve swine were randomized to placement of a bilateral IJV compression collar (CCI+collar) or control/no collar (CCI) prior to CCI injury. A histological grading of the extent of hemorrhage, both subarachnoid (SAH) and intraparenchymal (IPH), was conducted in a blinded manner by two neuropathologists. Other various measures of TBI histology were also analyzed including: ß-amyloid precursor protein (ß-APP) expression, presence of degenerating neurons, extent of cerebral edema, and inflammatory infiltrates. Euthanized 5 h after injury, the CCI+collar animals exhibited a significant reduction in total SAH (p = 0.024-0.026) and IPH scores (p = 0.03-0.05) compared with the CCI animals. There was no statistically significant difference in scoring for the other markers of TBI (ß-APP, neuronal degeneration, cerebral edema, or inflammatory infiltration). In conclusion, IJV compression was shown to reduce hemorrhage (SAH and IPH) in the porcine CCI model when applied prior to injury. These results suggest the role of IJV compression for mitigation of not only axonal, but also hemorrhagic injury following TBI.

Traumatic brain injury in older adults: characteristics, causes and consequences.

INTRODUCTION: Traumatic brain injury is of particular concern in the older population. We aimed to examine the trends in hospitalisations, causes and consequences of TBI in older adults in New South Wales, Australia. METHODS: TBI cases from 1 July 1998 to 30 June 2011 were identified from hospitalisation data for all public and private hospitals in NSW. Direct aged standardised admission rates were calculated. Negative binomial regression modelling was used to examine the statistical significance of changes in trend over time. RESULTS: There were 12,564 hospitalisations for TBI over the 13 year study period. Hospitalisation rates for TBI among the older population increased by 7.2% (95% CI 6.4-8.0, p<.0001) per year from 65.3/100,000 to 151.8/100,000. [corrected]. Males had a consistently higher hospitalisation rate. Just under one third of all hospitalisations were for adults aged 85 years and over. Traumatic subdural haemorrhage (42.9%), concussive injury (24.1%) and traumatic subarachnoid haemorrhage (12.7%) were the most common type of injury. Falls were the most common cause of TBI (82.9%). Rates of fall-related TBI increased by 8.4% (95% CI 7.5-9.3, p<.001) per year, whilst non-fall related head injury increased by 2.1% (95% CI 0.9-3.3, p<.0001) per year. The majority of falls were as a result of a fall on the same level and occurred at home. 13% of hospitalisations resulted in death, and the majority occurred in those who sustained a traumatic subdural haemorrhage. CONCLUSIONS: The rapid increase in hospitalised TBI is being predominantly driven by falls in the oldest old and the greatest increase predominantly in intracranial haemorrhages, highlighting the need for future research to quantify the risk versus benefit of anticoagulant therapies.

Correlates to traumatic brain injury in nonhuman primates.

BACKGROUND: Traumatic brain injury (TBI) is a major health problem, both in terms of the economic cost to society and the survivor's quality of life. The development of devices to protect against TBI requires criteria that relate observed injury to measurements of head kinematics. The objective of this study is to find the best statistical correlates to impact-induced TBI in nonhuman primates using a qualified, self-consistent set of historical kinematic and TBI data from impact tests on nonhuman primates. METHODS: A database was constructed and qualified from historical head impact tests on nonhuman primates. Multivariate logistic regression analysis with backwards stepwise elimination was performed. Variables considered are the peak rotational acceleration (Omegamax), the peak linear acceleration (Amax), and the number of impacts (N). RESULTS: Bivariate combinations of angular acceleration and the number of impacts are the best correlates to all modes of TBI considered, i.e., concussion, subarachnoid hemorrhage, brain contusion, and subdural hematoma. For a nonhuman primate with 100-g brain mass, the criteria that the probability of TBI is less than 10% by injury mode are:Concussion: OmegamaxN(0.84) < 70 krad/s/s SAH: OmegamaxN(0.70) < 160 krad/s/s Contusion: Omegamax N(0.35) < 160 krad/s/s SDH: Omegamax N(0.60) < 280 krad/s/s CONCLUSIONS: Based on this dataset, the best statistically based risk factor for all modes of TBI in nonhuman primates is the bivariate combination of rotational acceleration and number of impacts.