Mechanisms of deep brain stimulation.

The mechanism of action of high frequency deep brain stimulation is still unknown. However, in all circumstances and in all target nuclei so far stimulated, the effects mimic those of lesions previously made during thalamotomies, pallidotomies or even subthalamotomies, suggesting an inhibition of at least the neuronal network containing the target, if not of the target itself. On the contrary, fiber bundles are consistently activated at low or high frequencies.