The Value of Regional Cerebral Blood Flow Measurements Compared to Angiography in the Assessment of Obstructive Neck Vessel Disease

Abstract

• In 50 patients with internal carotid artery occlusion and 40 patients with internal carotid artery stenosis hemispheric and regional cerebral blood flow (rCBF) was measured by the 1M Xenon clearance method. rCBF was evaluated according to the presence of ischemic or hyperemic foci and to the level of regional perfusion alteration. The degree of collateral circulation and diameter of stenosis were determined from the angiograms. The clinical symptoms were expressed in a score of motor deficiencies. In internal carotid artery occlusion no correlation of motor deficiency index with angiographically demonstrable collateral circulation was detectable, but there was good correlation with hemispheric CBF and an excellent correlation (P < 0.001) with the rCBF parameters. In internal carotid artery stenosis no correlation existed between motor deficiency and the degree of stenosis or hemispheric CBF, but good correlation was observed between motor deficiency and the rCBF parameters (P < 0.01).According to these findings, angiographical demonstration of collateral circulation and of stenosis does not provide as accurate information on impending or already developed tissue infarction as does rCBF measurement. Presence of hyperemic foci and lack of ischemic foci were related to lesser motor disturbances. Borderlines of 30 ml/100 gm per minute for threatening tissue ischemia and of 25 ml/100 gm per minute for present tissue ischemia are established. Some points favor the thromboembolic theory of infarction in internal carotid artery stenosis.

Flow and compartmental weight in relation to the cours of stroke.

“…The occurrence of hyperperfused patches as a sign of favorable prognosis was also indicated by a correlation analysis of flow data, neurological deficits and clinical course in patients with obstructive neck vessel disease. 18 Together with these reported results our data suggest that this type of hyperperfusion is an effective mechanism for improving perfusion in ischemic brain lesions.…”

Regional Cerebral Blood Flow in the Diagnosis of Vascular Headache

“…18 Short term variations in rCBF and inter-regional differences have been established for the method. 19,20 With intracarotid injection of 133 Xenon the gamma camera gives rCBF values comparable to the multiple probe system. 21 Serial intracarotid injections of 133 Xe and 99m Tc were made to measure rCBF and regional transit time, respectively.…”

History of the Letzte Wiese/Last Meadow Concept of Brain Ischemia

“…Therefore, regional flow measurements can detect these areas and assess the threat to develop damage. Regional CBF measurements with intracarotid injection of Xenon 133 were able to document the critical reduction in perfusion in the cortical watershed (CWS) areas in patients with obstructive neck vessel disease 34 ; they also indicated the potential of aggravation of the critical blood flow by intracerebral steal phenomenon induced by vasodilatation in unaffected arterioles with limited blood supply caused by arterial obstruction and the development of infarction in the further course. 35 Misery perfusion as characterized by the mismatch between critically reduced flow and sufficient oxygen supply (measured by the increase in oxygen extraction fraction) was observed in the parieto-occipital watershed area by positron emission tomography, and its reversal was documented after extra-intracranial arterial bypass surgery.…”