Considering the variability of the effects of microstimulation mentioned above, it becomes clear that surface DES during surgery evokes a complex summation effect in a large volume of brain tissue that is difficult to predict as it heavily depends on the morphology of the cortical area being stimulated. Determining the net effect of DES thus requires both local and distant neurophysiological measurements under conditions that are comparable to the conditions during neurosurgery in which DES is used. Perhaps surprisingly, such studies are very rare.
martedì 7 agosto 2012
CORSO ESTIVO DI BIOETICA 2012: NEUROBIOETICA (VI)
In conclusion, neurophysiological and optical imaging studies in humans that applied DES with parameters comparable to those used during neurosurgery have started to elucidate the complicated regional 'processes' surrounding the stimulation site. However, to evaluate whether both excitatory and inhibitory effects occur, it is essential to measure both pre- and postsynaptic sites (see above) in the stimulated area. The indirect measures of brain activity that are currently possible in humans limit the state of knowledge about the cortical changes induced by DES.