The maintained vasodilatation1produced by sympathectomy in the treatment of certain types of peripheral vascular diseases has stimulated us to investigate surgical procedures on the sympathetic and central nervous systems with the hope that severe forms of hypertension of young people might be controlled. REASONS FOR TRYING SURGICAL MEASURES In 1923 Brüning2suggested sympathectomy for the possible control of hypertension. In the treatment of vasospastic lesions of arteries of the extremities, by sympathetic ganglionectomy and trunk resection, we have observed that the blood flow has been increased as measured in degrees of increased elimination of heat. The measurement of retinal arteries and veins by an ophthalmoscopic micrometer before and after cervicothoracic ganglionectomy shows that the caliber of these vessels has been increased by the sympathectomy3from a third to a half the preoperative size. Therefore we dared to postulate that it might be possible to interrupt sufficient