Clinical Electrophysiology of the Somatosensory Cortex: A Combined Study Using Electrocorticography, Scalp-EEG, and Magnetoencephalography

The clinical electrophysiology of the human somatosensory cortex was investigated with a combined approach using cortical stimulations and somatosensory evoked responses on electrocorticography, scalp-EEG, and magnetoencephalography, a new neurophysiological technique. The spatiotemporal structure of the evoked response was studied with novel biophysical modeling techniques which allowed identification of the three-dimensional intracerebral location, time activity, and interaction of the neuronal sources in human somatosensory cortex. Thus, new aspects on the functional anatomy of the human somatosensory cortex could be elicited. Furthermore, the somatotopy of the hand somatosensory cortex was investigated. Clinically, the results of comparison of the different techniques can improve the non-invasive localization criteria for primary motor and somatosensory cortex which is important in patients undergoing neurosurgical procedures adjacent to central fissure.