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

PERCUTANEOUS COMPRESSION OF the trigeminal ganglion, which is currentl y being used for the control of trigeminal neuralgia, induces marked i ntraoperative 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 res ponse and the cardiac rhythm changes induced by percutaneous compressi on of the trigeminal ganglion in 42 consecutive, unselected patients u ndergoing operations for essential trigeminal neuralgia under three di fferent regimens of anesthesia. The first 22 patients (Group 1) underw ent operations under brief general anesthesia without endotracheal int ubation. The following 10 patients (Group 2) had general anesthesia wi th intubation and mechanical ventilation and received larger doses of hypnotic and analgesic agents. Finally, 10 more patients (Group 3), wh o also had general anesthesia with intubation, underwent local anesthe tic blockade of Meckel's cave (injection of 1 ml of 1% lidocaine) befo re ganglion compression. Foramen ovale puncture elicited bradycardia i n the majority of the patients of Groups 2 and 3, but only four patien ts (18%) of Group 1 showed bradycardia. Ganglion compression caused ma rked 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 c ompression, did not develop tachycardia or extrasystoles. Foramen oval e puncture elicited marked elevations of the systemic blood pressure i n all patients. Ganglion compression further increased blood pressure, except in patients of Group 3, who had local anesthetic blockade of M eckel'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 (preoperat ive) levels within few minutes of the end of the stimulus. According t o our findings, the sympathoadrenal response induced by the therapeuti c compression of the trigeminal ganglion is not modified by the depth of general anesthesia. By contrast, the injection of lidocaine into Me ckel's cave before ganglion compression seems to be an effective metho d for preventing the development of systemic arterial hypertension and tachycardia.