STROKE-ASSOCIATED PATHOLOGICAL SYMPATHETIC ACTIVATION RELATED TO SIZEOF INFARCTION AND EXTENT OF INSULAR DAMAGE

The relationship between size of brain infarction, extent of insular d amage, and stroke-associated pathological sympathetic activation was i nvestigated in 52 patients. Evaluation of plasma norepinephrine levels , frequency of cardiac arrhythmias and QT prolongation and analysis of circadian blood pressure patterns were used to determine the extent o f sympathetic activity. Whereas only a moderate correlation exists bet ween size in farction and norepinephrine levels (r = 0.69; p < 0.05), a highly significant relationship between percentage insular infarctio n and norepinephrine was found (r = 0.93; p < 0.001). Circadian blood pressure patterns were only moderately related to infarct size (p < 0. 05) but were correlated substantially with the extent of insular infar ction (p < 0.001). Patients with cardiac arrhythmias showed a signific antly larger averaged infarct size (p < 0.01) and a larger extent of i nsular damage (p < 0.01) than patients without arrhythmia. In contrast , QTc prolongation was only associated with a larger extent of insular infarction (p < 0.01), whereas averaged infarct size was not notably different. These findings suggest that analysis of insular infarction may be a useful parameter to appraise the extent of pathological sympa thetic activity following stroke.