EXTENT OF AUTONOMIC ACTIVATION FOLLOWING CEREBRAL-ISCHEMIA IS DIFFERENT IN HYPERTENSIVE AND NORMOTENSIVE HUMANS

Objective: To evaluate whether the extent of autonomic activation foll owing brain infarction differs between hypertensive and normotensive h umans, and to investigate the role of the insular cortex for this symp athetic activation. Design: Prospective, hospital-based study. Setting : Department of Neurology of a university medical center. Subjects: Fo rty-two patients with essential hypertension and 45 patients who were normotensive. Main Outcome Measures: Extent of autonomic activation fo llowing stroke as indicated by circadian blood pressure patterns, seru m norepinephrine levels, and cardiovascular variables. Results: Normot ensive patients with insular infarction showed a significantly reduced circadian blood pressure variation and a higher frequency of nocturna l blood pressure increase compared with patients suffering from essent ial hypertension and insular stroke. These findings were also associat ed with higher serum norepinephrine concentrations and more frequent e lectrocardiographic abnormalities. No significant changes in these var iables were seen between normotensive and hypertensive patients withou t insular involvement. Conclusions: Our findings suggest a difference in cortical control of autonomic function between hypertensive and nor motensive patients after stroke and point to a possible role of the in sular cortex in the pathogenesis of essential hypertension.