CHANGES IN SYSTEMIC BLOOD-PRESSURE AND CARDIAC-RHYTHM INDUCED BY THERAPEUTIC COMPRESSION OF THE TRIGEMINAL GANGLION

PERCUTANEOUS COMPRESSION OF the trigeminal ganglion, which is currently being used for the control of trigeminal neuralgia, induces marked intraoperative elevations of the systemic blood pressure and heart rate changes, which may increase the risk of cardiovascular complications, We have analyzed the characteristics of the arterial hypertensive response and the cardiac rhythm changes induced by percutaneous compression of the trigeminal ganglion in 42 consecutive, unselected patients undergoing operations for essential trigeminal neuralgia under three different regimens of anesthesia. The first 22 patients (Group 1) underwent operations under brief general anesthesia without endotracheal intubation. The following 10 patients (Group 2) had general anesthesia with intubation and mechanical ventilation and received larger doses of hypnotic and analgesic agents. Finally, 10 more patients (Group 3), who also had general anesthesia with intubation, underwent local anesthetic blockade of Meckel's cave (injection of 1 ml of 1% lidocaine) before ganglion compression. Foramen ovale puncture elicited bradycardia in the majority of the patients of Groups 2 and 3, but only four patients (18%) of Group 1 showed bradycardia. Ganglion compression caused marked tachycardia in all patients of Groups 1 and 2; about one-third of the patients also had extrasystoles. By contrast, patients of Group 3, who had local anesthetic blockade of Meckel's cave before ganglion compression, did not develop tachycardia or extrasystoles. Foramen ovale puncture elicited marked elevations of the systemic blood pressure in all patients. Ganglion compression further increased blood pressure, except in patients of Group 3, who had local anesthetic blockade of Meckel's cave. Blood pressure increases elicited by both foramen ovale puncture and ganglion compression coincided with marked elevations of serum adrenaline and noradrenaline, which returned to basal (preoperative) levels within few minutes of the end of the stimulus. According to our findings, the sympathoadrenal response induced by the therapeutic compression of the trigeminal ganglion is not modified by the depth of general anesthesia. By contrast, the injection of lidocaine into Meckel's cave before ganglion compression seems to be an effective method for preventing the development of systemic arterial hypertension and tachycardia.