PubMed Health⌕ Search

Biomedical subjects

H C Engell

Publications and source records attributed to H C Engell.

At least 91 records · Page 5Linked to original sources
PubMedDate not supplied

Regional cerebral blood flow in patients with transient ischemic attacks studied by Xenon-133 inhalation and emission tomography.

Cerebral blood flow CBF was studied in 14 patients with transient ischemic attacks TIA and arteriosclerotic neck vessel disease. CBF was measured by a rapidly rotating single photon emission computerized tomograph using Xenon-133 inhalation. This method yields images of 3 brain slices depicting CBF with a spatial resolution of 1.7 cm. Based primarily on the clinical evidence and on the angiographical findings embolism was considered the pathogenetic factor in 10 cases, whereas chronic hemodynamic insufficiency rendered symptomatic by postural factors probably accounted for the symptoms in 4 patients. Of the 14 patients, all studied days to weeks after the most recent TIA, four showed hypoperfused areas on the CBF-tomograms and with roughly the same location hypodense areas on CT-scanning, i.e. areas of complete infarction. However, an additional five patients showed reduction of CBF in areas with no abnormality on the CT-scan. The abnormal blood flow pattern was found to be unchanged after clinically successful reconstructive vascular surgery. This suggests the presence of irreversible ischemic tissue damage without gross emollition (incomplete infarction). It is concluded, that TIAs are often harmful events, as no less than 9 of the 14 patients studied had evidence of complete and/or incomplete infarction. Thorough examination and rational therapy should be instituted as soon as possible to prevent further ischemic lesions.

Adult↗
PubMedDate not supplied

Hemodynamic effect of carotid endarterectomy.

Cerebral blood flow was measured by the intravenous xenon-133 technique at rest and during cerebral vasodilation with acetazolamide in 32 patients before and after uncomplicated carotid endarterectomy. The results were compared with the internal carotid artery perfusion pressure measured during surgery. A significant improvement in side-to-side cerebral blood flow asymmetry occurred in 6 patients studied at baseline and in 11 patients during provoked cerebral vasodilation. These patients all belonged to a group of 14 patients who, in addition to a severe stenosis of the internal carotid artery, presented a reduction in cerebral perfusion pressure of at least 20%. No improvements occurred in 18 patients with no or only minor reduction in perfusion pressure, irrespective of the degree of stenosis. These findings indicate an improved perfusion reserve following carotid endarterectomy in most patients with marked reduction in perfusion pressure, whereas only some of these patients will experience an improvement in baseline cerebral blood flow.

Acetazolamide↗