Some basic features of the pathological and normal motor system studied by chronic deep electrodes

Our stereotactic experiences in agreement with the literature showed, that different target points could influence the same motor disturbance. To choose the best target point or target point combinations we generally implant the electrodes into VL, Vim, CM, P, dentate nucleus and motor cortex. To ensure the correct sequence of therapeutic lesions we developed an investigation system, taking into consideration the resting and the working state of the motor system. We elicited events centrally (stimulation of the different target points) and peripherally (reflexes) and recorded the evoked potentials at the non-stimulated sites along with the motor and motor modulation effects in the appropriate muscles. The elicited events depend on the site of stimulation and registration and on the state of muscle activity. The centrally and peripherally elicited events influence each other. With our technique the elicited events and their functional dependency is most explicit within the motor system. The results help to explain some basic motor functions and help to answer some of our therapeutic questions.