1/46. 99mTc-bicisate and 99mTc-HMPAO SPECT imaging in early spontaneous reperfusion of cerebral embolism.Two patients with a cerebral embolism were evaluated by using both 99mTc-ethyl cysteinate dimer (ECD, or Bicisate) and 99mTc-hexamethylpropyleneamine oxime (HMPAO) single-photon emission computed tomography (SPECT). In one patient, 99mTc-ECD SPECT images revealed hypoactivity in a reflow hyperemic area where an infarct was seen later on CT scans. In another patient, a reperfused area showed hyperactivity on 99mTc-ECD SPECT without any abnormality on follow-up CT. 99mTc-ECD represents a potential agent with which to evaluate cerebral tissue viability in early reperfusion after ischemia.- - - - - - - - - - ranking = 1keywords = cerebral embolism, cerebral, embolism (Clic here for more details about this article) |
2/46. Permissible arterial occlusion time in aneurysm surgery: postoperative hyperperfusion caused by temporary clipping.The relationship between hyperperfusion and temporary clipping was evaluated to determine the safe limit for the duration of temporary clipping in aneurysm surgery. Twenty-one patients surgically treated for a ruptured aneurysm were examined using xenon-enhanced computed tomography on postoperative days 4 to 13. Eight of the 16 patients undergoing temporary clipping had focal hyperperfusion; whereas the five patients without temporary clipping had no hyperperfusion. Mean total temporary clipping time in patients with hyperperfusion was significantly longer than that in patients without (31.9 vs. 13.9 minutes, p = 0.0157) and mean maximum single temporary clipping time in patients with hyperperfusion was also significantly longer than in patients without (18.4 vs. 8.6 minutes, p = 0.0313). Moreover, cerebral infarction was related to hyperperfusion (p = 0.0027). These results support the hypothesis that temporary clipping during aneurysm surgery causes postoperative hyperperfusion and cerebral infarction. Temporary clipping may be harmful when performed for more than 20 minutes of total duration, since postoperative hyperperfusion was seen under this condition.- - - - - - - - - - ranking = 0.015236802684008keywords = cerebral (Clic here for more details about this article) |
3/46. brain infarcts due to scorpion stings in children: MRI.We report two children with severe neurological complications after having been stung by a scorpion. Clinical and MRI findings suggested brain infarcts. The lesions seen were in pons in one child and the right hemisphere in the other. The latter also showed possible hyperemia in the infarcted area. No vascular occlusions were observed and we therefore think the brain infarcts were a consequence of the scorpion sting. The cause of the infarct may be hypotension, shock or depressed left ventricular function, all of which are frequent in severe poisoning by scorpion sting.- - - - - - - - - - ranking = 0.00066454322921897keywords = brain (Clic here for more details about this article) |
4/46. A case of arrhythmia-induced transient cerebral hyperaemia.Transient cerebral hyperaemia following an arrhythmia has not been previously demonstrated in humans. We report the effects of head-up tilt on a 78-year-old man with neurocardiogenic syncope. During tilt, an asymptomatic arrhythmia caused arterial blood pressure and transcranial Doppler-recorded cerebral blood flow velocity to fall markedly. Upon spontaneous resumption of sinus rhythm, cerebral blood flow velocity increased to values greater than those prior to the arrhythmia. This occurred prior to a full recovery of arterial blood pressure, indicating spontaneous transisent hyperaemia. Pressure-flow velocity graphs support current methods of measuring critical closing pressure and demonstrate a rise in critical closing and a fall in resistance-area product after the arrhythmia.- - - - - - - - - - ranking = 0.05332880939403keywords = cerebral (Clic here for more details about this article) |
5/46. hyperemia of the intraperitoneal organs associated with scald burn.A 65-year-old man with a history of cerebral infarction sustained scald burns over 54% of the body surface. In spite of adequate fluid therapy, respiratory management with an artificial ventilator, and continuous hemodiafiltration, the patient died on day 5 post-admission. autopsy revealed necrotic change on the surface of the liver, and necrosis and perforation of the ileum. Histologic examination showed necrosis of the hepatocytes lining the surface and necrosis of the hepatocytes and congestion in the central area of the liver. We speculated that systemic responses to the extensive burn resulted in hyperemia of the intraperitoneal organs, thereby inducing acute liver failure and the subsequent development of multiple organ failure.- - - - - - - - - - ranking = 0.0076184013420042keywords = cerebral (Clic here for more details about this article) |
6/46. Occlusive hyperemia: a radiosurgical phenomenon?OBJECTIVE: Causes of neurological deficits after arteriovenous malformation (AVM) radiosurgery, including hemorrhage, radiation injury, and delayed cyst formation, are described. CONCEPT: Occlusive hyperemia has been described as a reason for neurological deterioration after AVM resection. thrombosis of draining veins or dural sinuses is thought to cause postoperative bleeding or neurological deficits secondary to venous hypertension. In a similar manner, local hemodynamic changes can occur in the brain adjacent to an AVM after radiosurgery if venous outflow is obstructed. Two patients are presented whose cases demonstrate this phenomenon. CONCLUSION: patients can experience clinical worsening after AVM radiosurgery from premature thrombosis of draining veins. Local hemodynamic changes could explain why imaging changes thought to be radiation related occur more frequently after radiosurgery of AVMs than of tumors.- - - - - - - - - - ranking = 0.0069756618786392keywords = thrombosis, brain (Clic here for more details about this article) |
7/46. Delayed, transient neurological deterioration after mild head injury--case report.A 16-year-old boy presented with delayed, transient neurological deterioration 18 days after mild head injury. Left hemiparesis and left homonymous hemianopsia appeared after right frontal contusional and mild subdural hematomas subsided. neuroimaging examinations including cerebral angiography, magnetic resonance imaging, and single photon emission computed tomography showed vasodilation and hyperemia in the right cerebral hemisphere. The present case is not typical of acute "juvenile head trauma syndrome," but may represent a possible pathophysiology of the delayed type of transient neurological deterioration after mild head injury.- - - - - - - - - - ranking = 0.015236802684008keywords = cerebral (Clic here for more details about this article) |
8/46. Hyperperfusion syndrome with hemorrhage after angioplasty for middle cerebral artery stenosis.Hyperperfusion syndrome is a well-documented complication of carotid endarterectomy, as well as internal carotid artery angioplasty and stent placement. We report a similar complication after distal intracranial (middle cerebral artery [MCA] M2 segment) angioplasty. To our knowledge, this is the first report of hyperperfusion syndrome after intracranial angioplasty of a distal MCA branch.- - - - - - - - - - ranking = 0.038092006710021keywords = cerebral (Clic here for more details about this article) |
9/46. Cerebral blood flow imaging in arteriovenous malformation complicated by normal perfusion pressure breakthrough.BACKGROUND: A patient with normal perfusion pressure breakthrough (NPPB) after surgical removal of an arteriovenous malformation (AVM) was evaluated using single photon emission computed tomography cerebral blood flow (CBF) imaging. CASE DESCRIPTION: A 48-year-old man suffered consciousness disturbance because of an intraventricular hemorrhage and underwent ventricular drainage. cerebral angiography showed a medium-sized AVM in the left parietal lobe. Three months after the ictus, a left parietal craniotomy was performed and total removal of the AVM was achieved. A brain region adjacent to the AVM with preoperative decreased vasoreactivity to acetazolamide showed marked hyperperfusion after AVM excision. hemorrhage subsequently occurred in this area. CONCLUSION: CBF mapping seems to offer a noninvasive method for the preoperative identification of AVM patients at risk for NPPB, and to allow for early postoperative diagnosis of NPPB.- - - - - - - - - - ranking = 0.0079506729566137keywords = cerebral, brain (Clic here for more details about this article) |
10/46. Very early and standard Tc-99m ethyl cysteinate dimer SPECT imaging in a patient with reperfusion hyperemia after acute cerebral embolism.It has been reported that Tc-99m ethyl cysteinate dimer (ECD) SPECT imaging may not show reperfusion hyperemia in patients with subacute stroke. The authors describe a patient with embolic middle cerebral artery occlusion who was examined using xenon-133 and dynamic and standard Tc-99m ECD SPECT immediately after early recanalization. Standard Tc-99m ECD SPECT images revealed hypoactivity in the ipsilateral middle cerebral artery territory. In contrast, the dynamic Tc-99m ECD SPECT images from the first scan (very early images acquired 36 seconds after injection) showed hyperactivity in the same region and provided imaging contrast comparable to what would be obtained with xenon-133 tomography. Hemorrhagic transformation later developed in this region. These results indicate that images from very early dynamic Tc-99m ECD SPECT of areas with irreversible changes produced by acute stroke can reveal reflow hyperemia that standard Tc-99m ECD SPECT images fail to show.- - - - - - - - - - ranking = 0.80914208161041keywords = cerebral embolism, cerebral, embolism (Clic here for more details about this article) |
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