Recurrent cerebral ischemic attacks in patients with symptomatic atherosclerotic large-artery disease

To clarify the time and frequency of recurrent cerebral ischemic attacks in patients with symptomatic atherosclerotic large-artery disease, we analysed retrospectively 52 cases including 11 of M1 stenosis (>80%), 13 of M1 occlusion, 13 of ICA stenosis (>80%), and 14 of ICA occlusion. Recurrent ischemic attacks occurred 64 times in 26 cases (50.0%) out of the 52 cases during the followed-up period, and appeared most frequently between day 6 and day 10 from the first ischemic attack. The frequency of recurrent ischemic attacks between day 6 and day 10 was 0.0577 times per day per case, which was higher than that of 0.0013 times per day case after day 20. These reuslts suggest that the 20 days following the first ischemic attack represent a period characterized by an unstable stage of cerebral blood flow in acute cerebral ischemia, so that great care must be taken with such these patients during this period. A recurrent ischemic attack confined to after angiographic documentation of atherosclerotic large-artery disease occurred in 1 case (3.6%) out of 28 cases of M1 or ICA occlusion, which was a significantly low incidence compared to that in 24 cases of M1 or ICA stenosis where recurrent ischemic attacks occurred in 6 cases (25.0%) (X2-test, p