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].

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.

scholarly journals Mismatch between Tissue Partial Oxygen Pressure and Near-Infrared Spectroscopy Neuromonitoring of Tissue Respiration in Acute Brain Trauma: The Rationale for Implementing a Multimodal Monitoring Strategy

2021 ◽  
Vol 22 (3) ◽  
pp. 1122
Author(s):  
Mario Forcione ◽  
Mario Ganau ◽  
Lara Prisco ◽  
Antonio Maria Chiarelli ◽  
Andrea Bellelli ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Near Infrared Spectroscopy ◽  
Oxygen Pressure ◽  
Near Infrared ◽  
Optical Signal ◽  
Brain Trauma ◽  
Partial Oxygen Pressure ◽  
Tissue Respiration ◽  
The Brain ◽  
Partial Oxygen

The brain tissue partial oxygen pressure (PbtO2) and near-infrared spectroscopy (NIRS) neuromonitoring are frequently compared in the management of acute moderate and severe traumatic brain injury patients; however, the relationship between their respective output parameters flows from the complex pathogenesis of tissue respiration after brain trauma. NIRS neuromonitoring overcomes certain limitations related to the heterogeneity of the pathology across the brain that cannot be adequately addressed by local-sample invasive neuromonitoring (e.g., PbtO2 neuromonitoring, microdialysis), and it allows clinicians to assess parameters that cannot otherwise be scanned. The anatomical co-registration of an NIRS signal with axial imaging (e.g., computerized tomography scan) enhances the optical signal, which can be changed by the anatomy of the lesions and the significance of the radiological assessment. These arguments led us to conclude that rather than aiming to substitute PbtO2 with tissue saturation, multiple types of NIRS should be included via multimodal systemic- and neuro-monitoring, whose values then are incorporated into biosignatures linked to patient status and prognosis. Discussion on the abnormalities in tissue respiration due to brain trauma and how they affect the PbtO2 and NIRS neuromonitoring is given.

Attenuation of Haemodynamic Response to Placement of Mayfield Skull Pin Head Holder - Comparison of Dexmedetomidine Versus Propofol Infusion - A Randomized Interventional Trial Done in a Tertiary Centre in Central Kerala

2021 ◽  
Vol 8 (29) ◽  
pp. 2639-2643
Author(s):  
Sruthy Unni ◽  
Ranju Sebastian ◽  
Elizabeth Joseph ◽  
Remani Kelan Kamalakshi ◽  
Jamsheena Muthira Parambath
Keyword(s):  
Blood Pressure ◽  
Nervous System ◽  
Stress Response ◽  
Intracranial Pressure ◽  
Cerebral Perfusion ◽  
Perfusion Pressure ◽  
Neurosurgical Procedures ◽  
Sympathetic Nervous ◽  
The Brain ◽  
Group 1

BACKGROUND Anaesthesia for neurosurgery requires special considerations. The brain is enclosed in a rigid cranium, so the rise in intracranial pressure (ICP) which impairs cerebral perfusion pressure (CPP), results in irrepairable damage to various vital areas in the brain. Stable head position is required in long neurosurgical procedures. This is obtained with the use of clamps which fix the head rigidly. This is done usually under general anaesthesia because it produces intense painful stimuli leading to stimulation of sympathetic nervous system which in turn causes release of vasoconstrictive agents. This can impair perfusion in all organ systems. The increase in blood pressure due to sympathetic nervous system causes increase in blood flow. This causes increases in intracranial pressure which result in reduction in cerebral perfusion pressure once the auto regulatory limits are exceeded. We compared the effects of dexmedetomidine 1 µgm/kg and propofol 100 µgm/kg given as infusion over a period of 10 minutes before the induction of anaesthesia and continued till 5 minutes after pinning to attenuate the stress response while cranial pinning. In this study, we wanted to compare the effects of dexmedetomidine and propofol as infusion to attenuate the stress response while cranial pinning in patients undergoing neurosurgical procedures. METHODS This is a randomized interventional trial. Patients were divided into 2 groups of 20 each. Group 1 receiving dexmedetomidine and group 2 receiving propofol, both drugs given as infusion. Haemodynamic variables were monitored before and after cranial pinning. Data was analysed using IBM statistical package for social sciences (SPSS) statistics. The parameters recorded were analysed with the help of a statistician. RESULTS The two groups were comparable in demographic data. Incidence of tachycardia between group 1 and 2 showed that tachycardia to pinning was better controlled with propofol than dexmedetomidine (P < 0.05) which is statistically significant. There is no statistically significant difference in blood pressure values between group 1 and 2 after pinning. CONCLUSIONS From our study, we came to a conclusion that propofol was superior to dexmedetomidine in attenuating the heart rate response to cranial pinning. The effect of propofol and dexmedetomidine was comparable in attenuating the blood pressure response to cranial pinning. KEYWORDS Cranial Pinning, Dexmedetomidine, Propofol

scholarly journals SURVIVAL OF POLIOMYELITIC VIRUS IN THE BRAIN OF THE RABBIT

1918 ◽  
Vol 27 (3) ◽  
pp. 443-447 ◽  
Author(s):  
Harold L. Amoss
Keyword(s):  
Intracranial Pressure ◽  
Pressure Effects ◽  
Rabbit Brain ◽  
High Dilution ◽  
Increased Intracranial Pressure ◽  
Intracerebral Inoculation ◽  
Pathological Lesions ◽  
Active Virus ◽  
The Brain

Suspensions of the central nervous tissues of monkeys, containing the active filterable virus of poliomyelitis, may be injected into the brain of rabbits without setting up symptoms, provided the volume of injection does not cause dangerous increased intracranial pressure. Aside from the pressure effects which develop quickly, no other symptoms or pathological lesions are produced by the suspensions. The active virus of poliomyelitis survives in the brain of rabbits for 4 days, as determined by tests in the monkey, into which the excised site of injection in the rabbit brain is reinoculated. It cannot be detected by this test after the expiration of 7 days. The virus of poliomyelitis is unadapted to the rabbit, and neither induces lesions nor survives long in the central nervous organs of that animal. In this respect it differs from certain streptococci cultivated from poliomyelitic tissues. A monkey immunized to streptococcus cultivated from human poliomyelitic nervous tissues yielded a serum which agglutinated the streptococcus in high dilution, but was without neutralizing action on the filtered virus; and the streptococcus-immune monkey was not protected against the effects of an intracerebral inoculation of the filtered virus. The experiments recorded provide additional reasons for concluding that the streptococcus cultivated from cases of poliomyelitis differs essentially from the filterable virus and is not the microbic cause of epidemic poliomyelitis.

Intracranial Pressure Measurement

2011 ◽  
pp. 191-197
Author(s):  
Jessie Welbourne ◽  
Basil Matta
Keyword(s):  
Intracranial Pressure ◽  
Pressure Measurement
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