Stroke; a journal of cerebral circulation
-
Comparative Study Clinical Trial
Parametric perfusion imaging with contrast-enhanced ultrasound in acute ischemic stroke.
Color-coded perfusion maps can be calculated from ultrasound harmonic gray-scale imaging data after ultrasound contrast agent bolus injection to analyze brain tissue perfusion. First reports indicate that this method can display cerebral perfusion deficits in acute ischemic stroke. We performed a prospective patient study to evaluate this approach. ⋯ With PHI, it is possible to display cerebral perfusion deficits in acute ischemic stroke. PHI yields additional information on the perfusion state of the human brain compared with extracranial and transcranial color-coded duplex sonography.
-
Subarachnoid hemorrhage (SAH) frequently results in myocardial necrosis with release of cardiac enzymes. Historically, this necrosis has been attributed to coronary artery disease, coronary vasospasm, or oxygen supply-demand mismatch. Experimental evidence, however, indicates that excessive release of norepinephrine from the myocardial sympathetic nerves is the most likely cause. We hypothesized that myocardial necrosis after SAH is a neurally mediated process that is dependent on the severity of neurological injury. ⋯ The degree of neurological injury as measured by the Hunt-Hess grade is a strong, independent predictor of myocardial necrosis after SAH. This finding supports the hypothesis that cardiac injury after SAH is a neurally mediated process.
-
Comparative Study
Magnetic resonance imaging improves detection of intracerebral hemorrhage over computed tomography after intra-arterial thrombolysis.
Unenhanced CT is routinely performed after intra-arterial (IA) thrombolysis. The presence of residual contrast causing staining of injured brain may mimic intracerebral hemorrhage (ICH). We evaluated MRI with diffusion-weighted imaging (DWI) and susceptibility-weighted imaging (SWI) for detection of ICH after IA thrombolysis, specifically in equivocal areas of hyperdensity seen on postprocedure CT, to help guide the decision to use anticoagulation or antiplatelet therapy after the IA thrombolysis. ⋯ MRI is an effective means to detect the presence of blood within an equivocal region on post-IA thrombolysis CT. This may influence the decision to use anticoagulation or antiplatelet therapy.
-
Recently, we focused on the cerebrovascular protective effects of moderate hypothermia after traumatic brain injury, noting that the efficacy of posttraumatic hypothermia is related to the rate of posthypothermic rewarming. In the current communication, we revisit the use of hypothermia with varying degrees of rewarming to ascertain whether, in the normal cerebral vasculature, varying rates of rewarming can differentially affect cerebrovascular responsiveness. ⋯ Posthypothermic rapid rewarming caused cerebral vascular abnormalities, including a diminished response to acetylcholine, hypercapnia, pinacidil, and SNP. Our data with acetylcholine and SNP suggest that rapid rewarming most likely causes abnormality at both the vascular smooth muscle and endothelial levels.
-
Multicenter Study Comparative Study Clinical Trial
Stroke magnetic resonance imaging is accurate in hyperacute intracerebral hemorrhage: a multicenter study on the validity of stroke imaging.
Although modern multisequence stroke MRI protocols are an emerging imaging routine for the diagnostic assessment of acute ischemic stroke, their sensitivity for intracerebral hemorrhage (ICH), the most important differential diagnosis, is still a matter of debate. We hypothesized that stroke MRI is accurate in the detection of ICH. To evaluate our hypotheses, we conducted a prospective multicenter trial. ⋯ Hyperacute ICH causes a characteristic imaging pattern on stroke MRI and is detectable with excellent accuracy. Even raters with limited film-reading experience reached good accuracy. Stroke MRI alone can rule out ICH and demonstrate the underlying pathology in hyperacute stroke.