[Changes in regional and local brain circulation in patients with subarachnoid hemorrhage due to ruptured aneurysm].

It is well known that cerebral blood flow (CBF) is altered corresponding to the severity of the subarachnoid hemorrhage (SAH) in different extents. The extent of CBF reduction and its regional accentuation is regarded as a pathophysiological correlation of clinical conditions. Therefore, we agree that CBF of patients in grade IV+V (Hunt and Hess) are clearly lower than in grade I+II. There are quite different results in grade III. Disturbance of consciousness and/or neurological deficits, as described in the definition of grade III, can be a consequence of different kinds of CBF changes. 45 Xe-CT studies were performed on 19 patients (mean age 44 +/- 14 years) after SAH. 8 patients were of grade I+II, 7 of grade III, and 4 patients of grade IV+V. The studies were performed preoperatively, at a time of clinical change, and before discharge. The evaluation of flow-maps was done by measuring 15 regions per hemisphere. Mean CBF data were evaluated in each area. To show the CBF differences between both hemispheres within each group of patients, a difference index (%) was calculated. The results demonstrated a mean CBF reduction in nearly all regions from grade I+II to grade III up to grade IV+V. The mean CBF reduction between grade I+II and grade III was 10% for gray and 20% for white matter (p < 0.05). On the other hand the difference index of gray matter in grade III with 17% is significantly higher than in grade I+II. For the white matter there was no significant side difference. Our findings demonstrate a visually evaluable pattern of CBF corresponding to grade I+II, grade III, and grade I+V. Intention of this study was to show a correlation between clinical conditions of patients after SAH and the CBF changes by the use of Xe-CT method.