Autoradiographic measurement of regional brainstem blood flow. Findings after 2 hours of occlusion of the unilateral anterior inferior cerebellar artery and 30 minutes' occlusion of the unilateral vertebral artery.

Using [14C]iodoantipyrine, regional brainstem blood flow was measured in the rat 2 h after occlusion of the left anterior inferior cerebellar artery (AICA) and 30 min after occlusion of the left vertebral artery (VA). Two hours after occluding the left AICA, the mean +/- SEM value of blood flow in 6 animals in the right superior olive was 2.13 +/- 0.13 ml/g/min and in the left side, 1.13 +/- 0.11. Thirty minutes after occlusion of the left VA, there were no significant differences between the right and left sides. Blood flow changes were assessed in the hindbrain structures between the control group, 30 min after occlusion of the left VA and 2 h after occlusion of the left AICA. Changes observed in the blood flow in the hindbrain structures suggest that the extra volume of the blood flow might be concealed in the brainstem. However, whether the recovery of the blood flow rate indicates the recovery of the brainstem function remains unclear.