Cardiovascular effects of human insular cortex stimulation
Oppenheimer SM, Gelb A, Girvin JP, and Hachinski VC (1992) Cardiovascular effects of human insular cortex stimulation. Neurology 42:9 1727–32.
Abstract: Recent investigations indicate a site of cardiac representation within the left insular cortex of the rat. Moreover, the results of lesion studies suggest left-sided insular dominance for sympathetic cardiovascular effects. It is unclear whether similar representation exists within the human insular cortex. Five epileptic patients underwent intraoperative insular stimulation prior to temporal lobectomy for seizure control. On stimulation of the left insular cortex, bradycardia and depressor responses were more frequently produced than tachycardia and pressor effects (p less than 0.005). The converse applied for the right insular cortex. We believe this to be the first demonstration of cardiovascular changes elicitable during insular stimulation in humans, and of lateralization of such responses for a cortical site. In humans, unlike the rat, there appears to be right-sided dominance for sympathetic effects. These findings may be of relevance in predicting the autonomic effects of stroke in humans and in the explanation of sudden unexpected epileptic death.
- In 5 patients undergoing temporal lobectomy for seizure control the insular cortex of was stimulated. Stimulation of the left insula was more likely to cause drops in heart rate and blood pressure than increases. Stimulation of the right insular cortex was more likely to cause increases in HR and BP than drops. This seems consistent with the findings of Zamrini et al., 1990 that inactivation of the left hemisphere (during sodium amobarbitol 'Wada' test) resulted in increases in heart rate, whereas inactivation of the right side led to decreases in heart rate.