Comparison of regional cerebral blood flow in TIA patients with and without occlusion or stenosis of major vessels.

The purpose of this study is to compare the background regional cerebral blood flow (rCBF) in TIA patients with and without angiographically demonstrable lesions. 147 TIA patients with severe stenosis or occlusion of major vessels supplying the brain (A group) were compared with a similar group without any arterial lesion demonstrable by angiography (B group). Their rCBFs were measured by the intravenous Xe133 technique. The average of mean rCBF (MrCBF) in (A) group (119 cases) with a mean age of 59.9 yrs was 50.1 +/- 12.3 ml/100g/m and the average of MrCBF in (B) group (31 cases) with a mean age of 59.3 years was 47.6 +/- 11.8 ml/100g/m. In spite of no angiographic lesion in (B) group, the MrCBF was lower in value than that in (A) group. The average of hemispheric rCBF (HrCBF) was approximately the same bilaterally in a control group (55.4 ml/100g/m), and even in (B) group there was no significant difference between the symptomatic side and the non-symptomatic side. In (A) group, HrCBF on the symptomatic side (48.1 ml/100g/m) was significantly lower on the average than that on the opposite side (51.5 ml/100g/m). Comparing probe by probe in TIA patients, the average rCBF of the symptomatic site was 44.1 +/- 11.9 ml/100g/m and that of the symmetrically opposite site was 47.6 +/- 13.0 ml/100g/m in (A) group. In (B) group, the average rCBF of the symptomatic site was 46.2 +/- 10.8 ml/100g/m, and 47.7 +/- 10.8 ml/100g/m for the non-symptomatic site. These values in both group (A) and (B), have a significant difference between symptomatic probes and non-symptomatic probes (p less than 8.0 X 10(-7) and p less than 6.5 X 10(-3)).