Search results for "intracranial pressure"
showing 10 items of 82 documents
Instrument transfer as knowledge transfer in neurophysiology: François Magendie's (1783-1855) early attempts to measure cerebrospinal fluid pressure.
2007
Francois Magendie's (1783-1855) experimental model for measuring blood pressure in animals, which he developed in 1838, had a major impact on French physiology in the nineteenth century, especially upon Etienne-Jules Marey (1830-1904) in Paris. In due course it was also adopted by other European investigators, such as the Leipzig physiologist Carl Ludwig (1816-1895), and by clinicians who developed it into a major measuring tool. Historians of science, however, have paid hardly any attention to Magendie's further laboratory investigations conducted with the assistance of Jean-Louis Marie Poiseuille's (1799-1869) sphygmometre (blood pressure meter). After having used the apparatus to conduct…
Cerebral blood flow and cerebral death
1969
At present the diagnosis of cerebral death is based on the absence of manifestations of cerebral function (deep coma, wide pupils, absence of reflexes and spontaneous respiration, isoelectric EEG, etc.) during a variable period of time. However, the absence of vital signs of an organ, even for prolonged periods, is no proof of its death. The death of an organ can only be considered as proved by the demonstration that this organ has remained completely deprived of its blood flow during a period of time that surpasses its ability to survive circulatory arrest. In the case of the brain, the permanent absence of clearance of a radioactive tracer deposed within the brain is considered to demonst…
Tumors of the central nervous system in children and adolescents.
2011
Multimodal treatment approaches for children with tumors of the central nervous system (CNS) have markedly contributed to improved survival. Before 1970, the survival rate among children with medulloblastoma, the most common malignant CNS tumor in children, was about 20%. At present, in contrast, cure can be achieved in more than 75% of children with a favorable constellation of risk factors. In this review article for clinicians, we give an overview of the current understanding of the pathology, presenting manifestations, early diagnosis, and treatment of CNS tumors in children and adolescents.We report the research findings of the German Treatment Network "HIT" and selectively review the …
Ketamine in acute phase of severe traumatic brain injury “an old drug for new uses?”
2021
AbstractMaintaining an adequate level of sedation and analgesia plays a key role in the management of traumatic brain injury (TBI). To date, it is unclear which drug or combination of drugs is most effective in achieving these goals. Ketamine is an agent with attractive pharmacological and pharmacokinetics characteristics. Current evidence shows that ketamine does not increase and may instead decrease intracranial pressure, and its safety profile makes it a reliable tool in the prehospital environment. In this point of view, we discuss different aspects of the use of ketamine in the acute phase of TBI, with its potential benefits and pitfalls.
The consequences of regulation of desat1 expression for pheromone emission and detection in Drosophila melanogaster.
2010
AbstractSensory communication depends on the precise matching between the emission and the perception of sex- and species-specific signals; understanding both the coevolutionary process and the genes involved in both production and detection is a major challenge. desat1 determines both aspects of communication—a mutation in desat1 simultaneously alters both sex pheromone emission and perception in Drosophila melanogaster flies. We investigated whether the alteration of pheromonal perception is a consequence of the altered production of pheromones or if the two phenotypes are independently controlled by the same locus. Using several genetic tools, we were able to separately manipulate the tw…
Intracranial Pressure and Mass Displacements of the Intracranial Contents
1976
The brain is completely surrounded by the bony skull and its closely adherent, tough, dural inner lining. This converts the enclosed space into a watertight chamber with the exception of the small, basally situated foramen magnum. In adults, these factors combine to prevent the skull from expanding. Consequently, the intracranial volume cannot fluctuate. In addition, the intracranial contents — blood, brain, and spinal fluid — are essentially noncompressible.
The Influence of Systemic Hypertension on Intracranial Pressure and Edema Formation in Experimental Intracerebral Hemorrhage
1986
Systemic hypertension is not only the most frequent cause of intracerebral hemorrhage but also the most important complication of this disease. In our clinical investigation of 117 cases almost 70% of the patients suffered from systemic hypertension. Despite advances in diagnosis (Schiirmann, Dei Anang, 1980) mortality of hypertensive patients was 48%. Normotensive hemorrhages showed a better prognosis: only 31% of the patients died and 33% (17% in hypertensive patients) obtained good neurological recovery (Wallenfang et al., 1985).
Prevention and treatment of intracranial hypertension
2007
Intracranial pressure (ICP) is the pressure exerted by cranial contents on the dural envelope. It comprises the partial pressures of brain, blood and cerebrospinal fluid (CSF). Normal intracranial pressure is somewhere below 10 mmHg; it may increase as a result of traumatic brain injury, stroke, neoplasm, Reye's syndrome, hepatic coma, or other pathologies. When ICP increases above 20 mmHg it may damage neurons and jeopardize cerebral perfusion. If such a condition persists, treatment is indicated. Control of ICP requires measurement, which can only be performed invasively. Standard techniques include direct ventricular manometry or measurement in the parenchyma with electronic or fiberopti…
Transcranial Doppler and Cortical Microcirculation at Increased Intracranial Pressure and during the Cushing Response
1995
The effect of increased intracranial pressure on the flow velocity of the basilar artery was measured with transcranial ultrasonic Doppler in New Zealand White rabbits under alpha-chloralose anesthesia and artificial respiration. Laser Doppler flowmetry served to study changes of the cortical microcirculation. The results confirm a high inverse correlation of the diastolic flow velocity, the pulsatility index, and the resistance index with the cerebral perfusion pressure (CPP). During acute intracranial hypertension, however, these parameters do not show a good correlation with the local cortical blood flow. The absence of a correlation was evident over a wide CPP range down to values of 35…
Occurrence of Spontaneous Cortical Spreading Depression Is Increased by Blood Constituents and Impairs Neurological Recovery after Subdural Hematoma …
2019
Acute subdural hemorrhage (ASDH) is common and associated with severe morbidity and mortality. To date, the role of spontaneous cortical spreading depression (sCSD) in exaggerating secondary injury after ASDH, is poorly understood. The present study contains two experimental groups: First, we investigated and characterized the occurrence of sCSD after subdural blood infusion (300 μL) via tissue impedance (IMP) measurement in a rat model. Second, we compared the occurrence and influence of sCSD on lesion growth and neurological deficit in the presence and absence of whole blood constituents. In the first experimental group, three IMP traits could be distinguished after ASDH: no sCSD, recurre…