Discrepancies between CT and EEG findings after acute cerebrovascular disease

Combined EEG and brain CT examinations were performed in 33 patients during the 1st and 2nd week after stroke. CT was abnormal in 17 patients (51%) and EEG was abnormal in 24 patients (72%). In 17 patients CT and EEG showed conflicting results; in 5 patients with normal EEG findings CT was pathological, and 12 patients had normal CT but pathological EEG findings. In this latter group, there were 5 particularly interesting cases with normal CT and a prominent unilateral EEG abnormality. Recently patients with this combination of findings have been described where further investigations disclosed internal carotid occlusion, which could be treated surgically. It is suggested that EEG should be more extensively used when CT findings are negative after stroke, and if a major unilateral EEG abnormality is encountered in such cases, further investigations with angiography should be considered in order to exclude surgically treatable internal carotid occlusion.