Effects of Head Orientation on the Intracranial Pressure of Rats Exposed to Shock Waves

2012 ◽  
Author(s):  
Alessandra Dal Cengio Leonardi ◽  
Nickolas Keane ◽  
Cynthia Bir ◽  
Pamela VandeVord
Keyword(s):  
Shock Wave ◽  
Intracranial Pressure ◽  
Experimental Studies ◽  
Head Orientation ◽  
Blast Exposure ◽  
Plate Elements ◽  
Biomechanical Response ◽  
Response Modes ◽  
The Individual ◽  
The Brain

With the increasing number of military personnel returning from conflicts with neurological manifestations of traumatic brain injury (TBI), there has been a great focus on the effects resulting from blast exposure (Okie 2005; Hicks et al. 2010). Recently, experimental studies have been reported which investigated the biomechanical response of the rat head exposed to a shock wave. The results indicated that the imparted shock wave may induce multiple response modes of the skull, including global flexure, which may have a significant contribution to the mechanism of injury (Bolander et al. 2011; Dal Cengio Leonardi et al. 2011). However, the question of whether head orientation could play a role in the level of energy imparted on the brain is still of concern. This study quantitatively measured the effect of head orientation on intracranial pressure (ICP) of rats exposed to a shock wave. Furthermore, the study examined how skull maturity affects ICP response at various orientations. It was hypothesized firstly that skull flexural modes dominate the ICP response, hence varying head orientation would be expected to alter this imparted stress waveform. The head orientation affects not only the shape and size of the “presented area” exposed to the incident wave, but the degree and nature of the response of the individual skull plate elements due to the variance of skull physiology. As such, this has a significant influence on the stress that the shock wave imparts on the brain due to changes in skull dynamics.

Evaluation of Intracranial Pressure Response in Rats Exposed to Complex Shock Waves

2012 ◽  
Author(s):  
Alessandra Dal Cengio Leonardi ◽  
Nickolas Keane ◽  
Cynthia Bir ◽  
Pamela VandeVord
Keyword(s):  
Intracranial Pressure ◽  
Shock Waves ◽  
Blast Wave ◽  
Preliminary Investigation ◽  
Free Field ◽  
Three Dimensional ◽  
Head Orientation ◽  
Reflected Shock ◽  
Complex Wave ◽  
The Individual

Studies on blast neurotrauma have focused on investigating the effects of exposure to free-field blast representing the simplest form of blast threat scenario without considering any reflecting surfaces. However, in reality personnel are often located within enclosures or nearby reflecting walls causing a complex blast environment, that is, involving shock reflections and/or compound waves from different directions. In fact, when a blast wave interacts with nearby structures, reflected shock waves are generated and complex three-dimensional shock waves are formed. Complex shock wave overpressure-time traces are significantly different from free-field profiles because reflections can cause super-positioning of shock waves resulting in increased pressure magnitudes and multiple pressure peaks. Very importantly, the shocks arrive from different directions which would invoke a different biomechanical response than a one-dimensional exposure. It has been reported that in complex wave environments, the extent of the injuries becomes a function of the location related to the surrounding structures rather than a function of the distance from the center of the explosion, as it is for free-field conditions (Yelverton et al. 1993; Mayorga 1997; Stuhmiller 1997). Furthermore, the resulting injuries when the individual is in confined spaces are noted to be more severe (Yelverton et al. 1993; Leibovici et al. 1996). The purpose of this study was to design a complex wave testing system and perform a preliminary investigation of the intracranial pressure (ICP) response of rats exposed to a complex blast wave environment. Furthermore, we explored the effects of head orientation in the same environment.

Head orientation affects the intracranial pressure response resulting from shock wave loading in the rat

2012 ◽  
Vol 45 (15) ◽  
pp. 2595-2602 ◽  
Author(s):  
Alessandra Dal Cengio Leonardi ◽  
Nickolas J. Keane ◽  
Cynthia A. Bir ◽  
Anne G. Ryan ◽  
Liaosa Xu ◽  
...  
Keyword(s):  
Shock Wave ◽  
Intracranial Pressure ◽  
Pressure Response ◽  
Head Orientation ◽  
Shock Wave Loading ◽  
Wave Loading

Intracranial Pressure Measurement Within the Rat Skull is Sensitive to Shock Wave Intensity and Weight of the Specimen

2011 ◽  
Author(s):  
Richard Bolander ◽  
Cynthia Bir ◽  
Pamela VandeVord
Keyword(s):  
Shock Wave ◽  
Intracranial Pressure ◽  
Pressure Measurement ◽  
Wave Exposure ◽  
Brain Trauma ◽  
Wave Intensity ◽  
Associated Injuries ◽  
Pressure Pulses ◽  
The Brain

Blast associated injuries have been quantified into different classes based on the type of trauma that they create [1]. Of these types of trauma, the neuropathology invoked by shock wave exposure is the most ambiguous [1]. The properties associated with shock wave exposure have lead to multiple hypothesized mechanisms for brain trauma including: acceleration-based damage, a thoracic squeeze resulting in pressure pulses to the brain, or transference of energy from the shock wave into the brain via the skull [2, 3].

scholarly journals Untangling the Effect of Head Acceleration on Brain Responses to Blast Waves

2015 ◽  
Vol 137 (12) ◽  
Author(s):  
Haojie Mao ◽  
Ginu Unnikrishnan ◽  
Vineet Rakesh ◽  
Jaques Reifman
Keyword(s):  
Quantitative Description ◽  
Blast Waves ◽  
Head Model ◽  
Maximum Pressure ◽  
Head Acceleration ◽  
Brain Responses ◽  
Biomechanical Response ◽  
The Individual ◽  
The Brain ◽  
Brain Pressure

Multiple injury-causing mechanisms, such as wave propagation, skull flexure, cavitation, and head acceleration, have been proposed to explain blast-induced traumatic brain injury (bTBI). An accurate, quantitative description of the individual contribution of each of these mechanisms may be necessary to develop preventive strategies against bTBI. However, to date, despite numerous experimental and computational studies of bTBI, this question remains elusive. In this study, using a two-dimensional (2D) rat head model, we quantified the contribution of head acceleration to the biomechanical response of brain tissues when exposed to blast waves in a shock tube. We compared brain pressure at the coup, middle, and contre-coup regions between a 2D rat head model capable of simulating all mechanisms (i.e., the all-effects model) and an acceleration-only model. From our simulations, we determined that head acceleration contributed 36–45% of the maximum brain pressure at the coup region, had a negligible effect on the pressure at the middle region, and was responsible for the low pressure at the contre-coup region. Our findings also demonstrate that the current practice of measuring rat brain pressures close to the center of the brain would record only two-thirds of the maximum pressure observed at the coup region. Therefore, to accurately capture the effects of acceleration in experiments, we recommend placing a pressure sensor near the coup region, especially when investigating the acceleration mechanism using different experimental setups.

Fit Vs Faint: Assessing Work Causation in “Idiopathic Fall” Cases

2014 ◽  
Vol 19 (5) ◽  
pp. 3-12
Author(s):  
Lorne Direnfeld ◽  
David B. Torrey ◽  
Jim Black ◽  
LuAnn Haley ◽  
Christopher R. Brigham
Keyword(s):  
Blood Flow ◽  
Electrical Activity ◽  
Loss Of Consciousness ◽  
Brain Electrical Activity ◽  
Medical Terminology ◽  
Scientific Analysis ◽  
Medical Causation ◽  
The Individual ◽  
The Brain ◽  
Current Science

Abstract When an individual falls due to a nonwork-related episode of dizziness, hits their head and sustains injury, do workers’ compensation laws consider such injuries to be compensable? Bearing in mind that each state makes its own laws, the answer depends on what caused the loss of consciousness, and the second asks specifically what happened in the fall that caused the injury? The first question speaks to medical causation, which applies scientific analysis to determine the cause of the problem. The second question addresses legal causation: Under what factual circumstances are injuries of this type potentially covered under the law? Much nuance attends this analysis. The authors discuss idiopathic falls, which in this context means “unique to the individual” as opposed to “of unknown cause,” which is the familiar medical terminology. The article presents three detailed case studies that describe falls that had their genesis in episodes of loss of consciousness, followed by analyses by lawyer or judge authors who address the issue of compensability, including three scenarios from Arizona, California, and Pennsylvania. A medical (scientific) analysis must be thorough and must determine the facts regarding the fall and what occurred: Was the fall due to a fit (eg, a seizure with loss of consciousness attributable to anormal brain electrical activity) or a faint (eg, loss of consciousness attributable to a decrease in blood flow to the brain? The evaluator should be able to fully explain the basis for the conclusions, including references to current science.

Individual Uniqueness in the Neonatal Functional Connectome

2021 ◽  
Author(s):  
Qiushi Wang ◽  
Yuehua Xu ◽  
Tengda Zhao ◽  
Zhilei Xu ◽  
Yong He ◽  
...  
Keyword(s):  
Individual Differences ◽  
Individual Identification ◽  
Imaging Data ◽  
Functional Connectome ◽  
Middle Range ◽  
Human Connectome Project ◽  
The Individual ◽  
And Behavior ◽  
Identification Analysis ◽  
The Brain

Abstract The functional connectome is highly distinctive in adults and adolescents, underlying individual differences in cognition and behavior. However, it remains unknown whether the individual uniqueness of the functional connectome is present in neonates, who are far from mature. Here, we utilized the multiband resting-state functional magnetic resonance imaging data of 40 healthy neonates from the Developing Human Connectome Project and a split-half analysis approach to characterize the uniqueness of the functional connectome in the neonatal brain. Through functional connectome-based individual identification analysis, we found that all the neonates were correctly identified, with the most discriminative regions predominantly confined to the higher-order cortices (e.g., prefrontal and parietal regions). The connectivities with the highest contributions to individual uniqueness were primarily located between different functional systems, and the short- (0–30 mm) and middle-range (30–60 mm) connectivities were more distinctive than the long-range (>60 mm) connectivities. Interestingly, we found that functional data with a scanning length longer than 3.5 min were able to capture the individual uniqueness in the functional connectome. Our results highlight that individual uniqueness is present in the functional connectome of neonates and provide insights into the brain mechanisms underlying individual differences in cognition and behavior later in life.

Medicinal correction of cerebrovascular reactivity — a necessary component of the treatment of cerebral blood circulation disorders

1999 ◽  
Vol 80 (2) ◽  
pp. 94-96
Author(s):  
V. I. Danilov
Keyword(s):  
Blood Circulation ◽  
Organic Phosphorus ◽  
Experimental Studies ◽  
Cerebrovascular Reactivity ◽  
Cerebral Vessels ◽  
Regulatory Mechanisms ◽  
Phosphorus Compounds ◽  
Low Toxic ◽  
The Brain ◽  
Cerebral Blood Circulation

The results of experimental studies made it possible to draw a conclusion on the reality of cerebral vessels reactivity recovery using drugs with primary neurometabolic activity, in particular, dimephosphone, sermion and pyracetam. The advantages of low-toxic nonauticholinesterasic organic phosphorus compounds among the correctors of regulatory mechanisms of circular provision of the brain are shown.

Coaching skills for recovery a decade of providing coaching skills for recovery training at a healthcare NHS foundation trust

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Helen Kathryn Cyrus
Keyword(s):  
Work Practice ◽  
Clinical Approach ◽  
Personal Recovery ◽  
Content Type ◽  
Coaching Skills ◽  
The Difference ◽  
To Come ◽  
The Individual ◽  
The Impact ◽  
The Brain

Purpose Overview of coaching for recovery. The paper aims to show an overview of work that was carried out over 11 years with groups of mental health and physical staff. As the facilitator who had run this course for the duration in Nottingham, this was an excellent opportunity to be at the forefront of a brand new project. Design/methodology/approach The introduction of the skills are taught over two consecutive days followed by a further day a month later. The idea of coaching is to be enabled to find the answers in themselves by the use of powerful questions and using the technique of the grow model, combined with practice enables the brain to come up with its own answers. Using rapport and enabling effective communication to deliver the outcome. Findings Evidence from staff/clients and the purpose of the paper shows that when you step back it allows the individual patients/staff to allow the brain to process to create to come up with their solutions, which then helps them to buy into the process and creates ownership. Research limitations/implications The evidence suggests that the approach that was there prior to the course was very much a clinical approach to working with clients and treating the person, administering medication and not focussing on the inner person or personal recovery. The staff review has shown that in the clinical context change is happening from the inside out. Practical implications “Helps change culture”; “change of work practice”; “it changed staff focus – not so prescriptive”; “powerful questions let clients come to their own conclusions”; “coaching gives the ability to find half full. Helps to offer reassurance and to find one spark of hope”. Social implications This has shown that the approach is now person-centred/holistic. This has been the “difference that has made the difference”. When this paper looks at the issues from a different angle in this case a coaching approach, applying technique, knowledge and powerful questions the results have changed. The same clients, same staff and same problems but with the use of a different approach, there is the evidence of a different outcome, which speaks for itself. The coaching method is more facilitative, therefore it illicit’s a different response, and therefore, result. Originality/value The results/evidence starts with the individual attending and their commitment to the process over the two-day course. Then going away for the four weeks/six for managers and a commitment again to practice. Returning to share the impact if any with the group. This, in turn, helps to inspire and gain motivation from the feedback to go back to work invigorated to keep going.

Febrile Convulsions, by J. Gordon Millichap, M.D., M.R.C.P. New York: The Macmillan Company, 1968, 239 pp., $7.95

PEDIATRICS ◽  
1968 ◽  
Vol 42 (2) ◽  
pp. 381-382
Author(s):  
Randolph K. Byers
Keyword(s):  
New York ◽  
Relevant Literature ◽  
Febrile Seizures ◽  
Cerebral Injury ◽  
Extensive Review ◽  
Cerebral Disease ◽  
Febrile Convulsions ◽  
The Individual ◽  
The Brain ◽  
Made In

This rather modest-looking monograph deals not only with the large experiences of the author in relation to febrile seizures, but also presents an extensive review of the modern relevant literature (266 references in the bibliography). The most useful point made in the book, it seems to me, is that febrile convulsions are just that: i.e., convulsions coinciding with fever, the result of illness not directly involving the brain or its meninges. Such a seizure may be an isolated occurrence in the life of the individual, or it may recur a few times with fever; it may be the first sign of idiopathic chronic epilepsy, or it may be evidence of more or less apparent cerebral injury of a static sort; or, it may be the presenting symptom heralding progressive cerebral disease.

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