Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0917798 (cerebral ischemia)
 17,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifteen patients with symptoms of cerebral ischaemia and angiographically confirmed unilateral stenoses or occlusions of the extracranial internal carotid artery (ICA) and 20 controls were studied by a 2 MHz transcranial Doppler (TCD) at rest and after stimulation with 1 g acetazolamide i.v., a cerebral vasodilator. In addition, the patients underwent 99mTc-HM-PAO-Spect measurement of regional cerebral blood flow (rCBF) at rest and after stimulation with 1 g acetazolamide. In 10 patients with ICA stenoses greater than 80% or occlusions, time-mean velocity (Vmean) increase and pulsatility index (PI) decrease in the postobstructive middle cerebral artery (MCA) as well as the increase of the ipsilateral rCBF were reduced in comparison with the contralateral side. The remaining 5 patients showed a normal Vmean increase and PI decrease in TCD.
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PMID:Acetazolamide stimulation test in patients with unilateral internal carotid artery obstructions using transcranial Doppler and 99mTc-HM-PAO-Spect. 135 70

15 patients with suspected cerebral ischaemia were examined using 99mTc-HM-PAO-SPECT to assess cerebral blood flow. Results obtained from SPECT were correlated with CT and Doppler ultrasound findings. A 3D-display algorithm is proposed to enhance the lesion to non-lesion contrast compared to the standard 2D-image interpretation. In all cases contrast was superior on 3D-display to 2D-display (-0.38 versus -0.09). 3D-display of SPECT-data enhances lesion contrast due to postreconstructive data processing and may improve exact interpretation of cerebral blood flow studies.
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PMID:[Border-area cerebral ischemia--3D-SPECT for the imaging of the regional cerebral blood flow]. 155 Sep 16

Using single photon emission computed tomography (SPECT), cerebral blood flow was studied in eight patients with gradual deterioration in the level of consciousness after subarachnoid haemorrhage. Four had cerebral ischaemia and four had acute hydrocephalus. In patients with cerebral ischaemia, single photon emission computed tomography scanning showed multiple regions with decreased uptake of technetium-99M labelled d,l-hexamethyl-propylene amine oxime (99mTcHM-PAO) mainly in watershed areas. In patients with acute hydrocephalus, decreased uptake was seen mainly in the basal parts of the brain: around the third ventricle, around the temporal horns of the lateral ventricles, and in the basal part of the frontal lobe. After serial lumbar puncture, there was improvement of the uptake of 99mTc HM-PAO in these basal areas in three (convincingly in two and slightly in the other) of the four patients accompanied by clinical improvement in these three patients. These results suggest that patients with acute hydrocephalus and impaired consciousness after SAH, in contrast to patients with cerebral ischaemia, have decreased cerebral blood flow predominantly in the basal parts of the brain.
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PMID:Single photon emission computed tomography in patients with acute hydrocephalus or with cerebral ischaemia after subarachnoid haemorrhage. 188 May 9

Although the distribution of [99mTc]hexamethylpropyleneamine oxime (HM-PAO) in the brain is said to be in a flow-related manner without temporal change, we present cases with leakage of [99mTc]HM-PAO (filling out phenomenon) in the delayed image of brain single photon emission computed tomography (SPECT) and clarify its clinical significance. The filling out phenomenon was observed in seven out of 21 cases of cerebrovascular disease and four cases of arteriovenous malformation. The leakage of [99mTc]HM-PAO was also confirmed by visual and semiquantitative analysis. In the pharmacokinetics of [99mTc]HM-PAO in the blood, the percent dose of plasma fraction at 4 hr was reduced to 54% of activity at 30 min. The percent dose of brain blood could be predicted as 3.36%/1 at 30 min and 2.35%/1 at 4 hr after correction with the hematocrit of the brain. The filling out phenomenon of [99mTc]HM-PAO was attributed to a significant reduction of blood activity of [99mTc]HM-PAO in the plasma. Since the initial image might mask reduced rCBF with an increase of rCBV, the late image would have an advantage in accurately evaluating rCBF from the clearance of [99mTc] HM-PAO bound to the plasma. Therefore, the filling out phenomenon of [99mTc]HM-PAO in late images of brain SPECT could show the area of mild cerebral ischemia accompanying cerebral vascular reserve.
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PMID:Filling out phenomenon with technetium-99m HM-PAO brain SPECT at the site of mild cerebral ischemia. 278 83