Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2012
Quantification of pulsatile cerebrospinal fluid flow within the prepontine cistern.
Phase-contrast MRI (PC-MRI) has previously been used for the quantification of CSF and blood flow throughout the body. We propose a new method of semi-automated segmentation for the prepontine cistern based on anatomical and pulsatility information. ⋯ Reliable quantification of volumetric CSF flow in complex cisternal spaces is possible using a methodology combining known anatomical features with the pulsatile nature of CSF flow.
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Acta Neurochir. Suppl. · Jan 2012
Association between ICP pulse waveform morphology and ICP B waves.
The study aimed to investigate changes in the shape of ICP pulses associated with different patterns of the ICP slow waves (0.5-2.0 cycles/min) during ICP overnight monitoring in hydrocephalus. Four patterns of ICP slow waves were characterized in 44 overnight ICP recordings (no waves - NW, slow symmetrical waves - SW, slow asymmetrical waves - AS, slow waves with plateau phase - PW). The morphological clustering and analysis of ICP pulse (MOCAIP) algorithm was utilized to calculate a set of metrics describing ICP pulse morphology based on the location of three sub-peaks in an ICP pulse: systolic peak (P(1)), tidal peak (P(2)) and dicrotic peak (P(3)). ⋯ Based on relative changes in variability of amplitudes of P(2) and P(3) we were able to distinguish between the combined groups NW + SW and AS + PW (p < 0.000001). The AS pattern can be differentiated from PW based on respective changes in the mean curvature of P(2) and P(3) (p < 0.000001); however, none of the MOCAIP feature separates between NW and SW. The investigation of ICP pulse morphology associated with different ICP B waves may provide additional information for analysing recordings of overnight ICP.
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Acta Neurochir. Suppl. · Jan 2012
Pressure reactivity index correlates with metabolic dysfunction in a porcine model of intracerebral hemorrhage.
We correlated oxygen, flow, and pressure indices of cerebrovascular reactivity (CR) with extracellular cerebral metabolite concentrations in a porcine model of intracerebral hemorrhage (ICH). ⋯ We found evidence for impaired CR in a porcine model of ICH. The findings suggest that, among other parameters of CR, positive PRx coefficients have the highest significance and could be associated with microdialysis alterations during hypoxic events.
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Acta Neurochir. Suppl. · Jan 2012
Influence of isoflurane on neuronal death and outcome in a rat model of traumatic brain injury.
In the developing brain agents clinically used for the purpose of analgosedation can cause severe neurodegeneration. In patients with TBI analgosedation is a first-line treatment for intracranial hypertension. At the same time, damaged neuronal networks undergo conformational changes and use developmental mechanisms to restore brain function. ⋯ Along with histological findings neurological outcome was worst as indicated by a higher score in the experimental group with deep sedation (mean ± SEM 4 h, 13.9 ± 0.6, n = 14 and 20 ± 0.7, n = 15; 48 h, 8.1 ± 0.6, n = 14 and 13.3 ± 0.6, n = 15). Although blood pressure was lower with deep sedation, no frank hypotension occurred. In our experiments deep sedation with high doses of isoflurane caused neurodegeneration and worse outcome compared with regular sedation.