USE OF POSITRON EMISSION TOMOGRAPHY AND EVOKED-POTENTIALS IN THE DETECTION OF CORTICAL AFFERENTS FROM THE GASTROINTESTINAL-TRACT

Objective: Positron emission tomography permits precision identificati on of the cerebral regions involved in physiologic functions. As the c erebral localization for visceral sensation has not been identified, o ur aim was to examine the cerebral viscerotopic representation for rec tal sensation. Methods: Cerebral-evoked potentials were measured in fi ve healthy volunteers who underwent rectal balloon distension. Simulta neously, cerebral blood flow was measured using positron emission tomo graphy with (H2O)-H-15. Results: A cerebral-evoked potential occurred with rectal balloon distension. An increase in cerebral blood flow was noted in the pre- and postcentral gyrus and the thalamus. Conclusion: The techniques for measuring cerebral-evoked potentials and cortical blood flow are useful in the delineation of the cerebral regions subse rving visceral sensation.