Neurology Commons^™

Normobaric Hyperoxia Delays Perfusion/Diffusion Mismatch Evolution, Reduces Infarct Volume, And Differentially Affects Neuronal Cell Death Pathways After Suture Middle Cerebral Artery Occlusion In Rats, Nils Henninger, James Bouley, Julia Nelligan, Kenneth Sicard, Marc Fisher

Nils Henninger

Normobaric hyperoxia (NBO) has been shown to extend the reperfusion window after focal cerebral ischemia. Employing diffusion (DWI)- and perfusion (PWI)-weighted magnetic resonance imaging (MRI), the effect of NBO (100% started at 30 mins after middle cerebral artery occlusion (MCAO)) on the spatiotemporal evolution of ischemia during and after permanent (pMCAO) and transient suture middle cerebral artery occlusion (tMCAO) was investigated (experiment 3). In two additional experiments, time window (experiment 1) and cell death pathways (experiment 2) were investigated in the pMCAO model. In experiment 1, NBO treatment reduced infarct volume at 24 h after pMCAO by 10% when administered …

Comparison Of Ischemic Lesion Evolution In Embolic Versus Mechanical Middle Cerebral Artery Occlusion In Sprague Dawley Rats Using Diffusion And Perfusion Imaging, Nils Henninger, Kenneth Sicard, Karl Schmidt, Juergen Bardutzky, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: Differences among models in the temporal evolution of ischemia after middle cerebral artery occlusion (MCAO) in rats may considerably influence the results of experimental stroke research. Using diffusion and perfusion imaging, we compared the spatiotemporal evolution of ischemia in Sprague Dawley rats after permanent suture MCAO (sMCAO; n=8) and embolic MCAO (eMCAO; n=8).

METHODS: Serial measurements of quantitative cerebral blood flow (CBF) and the apparent diffusion coefficient (ADC) were performed up to 180 minutes after MCAO. ADC and CBF values within 5 different brain regions were analyzed. ADC and CBF lesion volumes were calculated by using previously …

Ischemic Lesion Volume Determination On Diffusion Weighted Images Vs. Apparent Diffusion Coefficient Maps, Bernt Bratane, Birgül Bastan, Marc Fisher, James Bouley, Nils Henninger

Nils Henninger

Though diffusion weighted imaging (DWI) is frequently used for identifying the ischemic lesion in focal cerebral ischemia, the understanding of spatiotemporal evolution patterns observed with different analysis methods remains imprecise. DWI and calculated apparent diffusion coefficient (ADC) maps were serially obtained in rat stroke models (MCAO): permanent, 90 min, and 180 min temporary MCAO. Lesion volumes were analyzed in a blinded and randomized manner by 2 investigators using (i) a previously validated ADC threshold, (ii) visual determination of hypointense regions on ADC maps, and (iii) visual determination of hyperintense regions on DWI. Lesion volumes were correlated with 24 hour 2,3,5-triphenyltetrazoliumchloride …

The Proteasome Inhibitor Velcade Reduces Infarction In Rat Models Of Focal Cerebral Ischemia, Nils Henninger, Kenneth Sicard, James Bouley, Marc Fisher, Nancy Stagliano

Nils Henninger

The potential neuroprotective effects of VELCADE were investigated in two different models of focal cerebral ischemia. For time-window assessment, male Wistar-Kyoto rats were treated with 0.2 mg/kg VELCADE at 1, 2, or 3 h after the induction of permanent middle cerebral artery occlusion (MCAO) using the suture occlusion method (experiment 1). To evaluate effects in a different model, male Sprague-Dawley rats received 0.2 mg/kg VELCADE after embolic MCAO (experiment 2). Infarct volume was calculated based on TTC-staining 24 h postischemia and whole blood proteasome activity was fluorometrically determined in both experiments at baseline, 1 and 24 h post-MCAO. In experiment …

Differences In Ischemic Lesion Evolution In Different Rat Strains Using Diffusion And Perfusion Imaging, Juergen Bardutzky, Qiang Shen, Nils Henninger, James Bouley, Timothy Duong, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: Interstrain differences in the temporal evolution of ischemia after middle cerebral artery occlusion (MCAO) in rats may considerably influence the results of experimental stroke research. We investigated, in 2 commonly used rat strains (Sprague-Dawley [SD] and Wistar-Kyoto [WK]), the spatiotemporal evolution of ischemia after permanent suture MCAO using diffusion and perfusion imaging.

METHODS: Serial measurements of quantitative cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) were performed up to 210 min after MCAO. Lesion volumes were calculated by using previously established viability thresholds and correlated with infarct volume defined by 2,3,5-triphenyltetrazolium chloride staining 24 hours after …

Stimulating Circle Of Willis Nerve Fibers Preserves The Diffusion-Perfusion Mismatch In Experimental Stroke, Nils Henninger, Marc Fisher

Nils Henninger

BACKGROUND AND PURPOSE: Stimulation of the nerves traversing the ethmoidal foramen (including postsynaptic, parasympathetic projections from the sphenopalatine ganglion [SPG], henceforth referred to as "SPG-stimulation") has been shown to elevate cerebral blood flow (CBF) and to be neuroprotective after permanent, middle cerebral artery occlusion (pMCAO). METHODS: Employing diffusion (DWI)- and perfusion (PWI) weighted MRI, the effect of SPG-stimulation (started at 60 minutes post-MCAO) on the spatiotemporal evolution of ischemia during and after pMCAO was investigated. In an additional experiment, regional CBF changes were investigated in the nonischemic brain. RESULTS: In the nonischemic brain, SPG stimulation significantly elevated CBF predominantly within …