Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism
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J. Cereb. Blood Flow Metab. · Nov 2015
Observational StudyNoninvasive cerebral oximetry during endovascular therapy for acute ischemic stroke: an observational study.
Implementing endovascular stroke care often impedes neurologic assessment in patients who need sedation or general anesthesia. Cerebral near-infrared spectroscopy (NIRS) may help physicians monitor cerebral tissue viability, but data in hyperacute stroke patients receiving endovascular treatment are sparse. In this observational study, the NIRS index regional oxygen saturation (rSO2) was measured noninvasively before, during, and after endovascular therapy via bilateral forehead NIRS optodes. ⋯ After the intervention, higher rSO2 variability predicted poor outcome (modified Rankin scale > 3, P=0.032). Our findings suggest that bi-channel rSO2-NIRS has potential for guiding neuroanesthesia and predicting outcome. To better monitor local revascularization, an improved stroke-specific set-up in future studies is necessary.
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J. Cereb. Blood Flow Metab. · Nov 2015
Selective neuronal vulnerability of human hippocampal CA1 neurons: lesion evolution, temporal course, and pattern of hippocampal damage in diffusion-weighted MR imaging.
The CA1 (cornu ammonis) region of hippocampus is selectively vulnerable to a variety of metabolic and cytotoxic insults, which is mirrored in a delayed neuronal death of CA1 neurons. The basis and mechanisms of this regional susceptibility of CA1 neurons are poorly understood, and the correlates in human diseases affecting the hippocampus are not clear. Adopting a translational approach, the lesion evolution, temporal course, pattern of diffusion changes, and damage in hippocampal CA1 in acute neurologic disorders were studied using high-resolution magnetic resonance imaging. ⋯ Hypoxic-ischemic insults led to a significant lower ADC suggesting that the ischemic insult results in a stronger impairment of cellular metabolism. The evolution of diffusion changes show that CA1 diffusion lesions mirror the delayed time course of the pathophysiologic cascade typically observed in animal models. Studying the imaging correlates of hippocampal damage in humans provides valuable insight into the pathophysiology and neurobiology of the hippocampus.
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J. Cereb. Blood Flow Metab. · Nov 2015
The effects of perturbed cerebral blood flow and cerebrovascular reactivity on structural MRI and behavioral readouts in mild traumatic brain injury.
This study investigated the effects of perturbed cerebral blood flow (CBF) and cerebrovascular reactivity (CR) on relaxation time constant (T2), apparent diffusion coefficient (ADC), fractional anisotropy (FA), and behavioral scores at 1 and 3 hours, 2, 7, and 14 days after traumatic brain injury (TBI) in rats. Open-skull TBI was induced over the left primary forelimb somatosensory cortex (N=8 and 3 sham). We found the abnormal areas of CBF and CR on days 0 and 2 were larger than those of the T2, ADC, and FA abnormalities. ⋯ T2, ADC, and FA abnormalities in the impact core were detected on day 0, peaked on day 2, and pseudonormalized by day 14. Lesion volumes peaked on day 2 and were temporally correlated with forelimb asymmetry and foot-fault scores. This study quantified the effects of perturbed CBF and CR on structural magnetic resonance imaging and behavioral readouts.