THE SENSATION OF ANGINA CAN BE EVOKED BY STIMULATION OF THE HUMAN THALAMUS

We have performed single-neuron recording and microstimulation in the region of the thalamic principal sensory nucleus (ventrocaudal nucleus , Vc) prior to implantation of a deep brain-stimulating electrode in a patient with pain secondary to arachnoiditis and with a past history of unstable angina. Cells located in the 16 mm lateral plane had cutan eous receptive fields on the chest wall. At and posterior to the locat ion of these cells stimulation coincided precisely with the sensation of angina (stimulation-associated angina). The description of stimulat ion-associated angina was measured using a questionnaire and was ident ical to the patient's usual angina except that it began and terminated suddenly. Stimulation-associated angina was coincident with a tinglin g sensation in the leg. Clinical, hemodynamic, electrophysiologic and biochemical measures of cardiac function showed no evidence of myocard ial strain or injury related to stimulation-associated angina. Since c ells in the region of the principle sensory nucleus of thalamus respon d to cardiac injury in animals, the present results suggest that this region mediates the sensation of angina.