This dissertation aims to develop alternative technology that improves the current range of application of transcranial magnetic stimulation (TMS), on a scale that would permit defining specific non-invasive treatments for Parkinson’s disease and other neurological disorders. This is accomplished through three specific objectives. 1) The design of a neurostimulation system that increases the focality in TMS to regions of narrow target areas and variable depths in the brain cortex. 2) The assessment of the feasibility of novel high-frequency neuromodulation techniques that would allow increasing the focality in deeper areas beyond the cortical surface. 3) The development of a computational model of the motor pathway that allows studying the underlying mechanisms that originate PD symptoms, and the effects of TMS for the development of new treatments.
The results successfully demonstrated the feasibility of using the novel high-frequency neuromodulation technique as an effective manner to reduce the necessary current in TMS coils. This reduction, which reached an order of magnitude of 100 times compared to commercial TMS technology, made it possible to reduce the coil sizes, making them more focal to targets (in the order of a few millimeters square).
Finally, our innovative oscillatory model of the motor pathway allowed us to conclude that an internal regulatory mechanism that we believe neurons activate in advanced PD stages seems to be the pathological response of some neural subpopulations to dopamine depletion, trying to compensate for the downstream effects in the system. We also found that such a mechanism seems to the burstiness in PD
