Cerebral blood flow measurement as an indicator of the haemodynamic severity of carotid artery disease in man

Summary The non-invasive xenon-l33 inhalation technique was used to measure regional cerebral blood flow in 61 patients with cerebrovascular disease in whom. carotid angiography had been performed before carotid endarterectomy or extracranial/intracranial arterial bypass were considered. Hemispheric cere­ bral blood flow (CBF) was significantly lower in patients with an ipsilateral internal carotid artery occlusion than in those with a patent vessel. CBF . values were also influenced by disease of the contra- . lateral carotid artery. The cerebrovascular response to hypercapnia was a more sensitive index of carotid disease; a significant reduction in CO2 responsiveness was found both with occlusion and stenosis ofthe ipsilateral internal carotid artery. These data suggest that CBF measurements may be clinically useful in selecting patients for angiography and surgery. S Air MedJ 1984; &5: 429-431. A patient who suffers a transient ischaemic anack (TIA), reversible ischaemic neurological deficit (RIND) or a minor completed stroke· is at risk of developing a major cerebral infarct. l More recently it has been shown that certain subgroups of patients with these symptoms are at greater risk than others. Patients with TIAs and carotid occlusion have the highest risk of stroke whereas those with TIAs and normal carotid vessels have a lower risk. 2 Funhermore, among patients with carotid stenosis, those in whom the stenosis is haemodynamically significant carry a higher risk of subsequent stroke. 3