..is that somehow when certain areas of SN neurons are "killed off", that they create "bottlenecks" in signal transmission along neural pathways. I'm thinking of why would a pallidotomy or a thalomotomy "work". Maybe these structures affect the neural transmissions that are part of a "circuit" that has a profound effect on desired messages for DA neurons to become processed, and their removal allows the messages to get through unimpeded. This could possibly be what's happening here. The DBS "rerouted" certain "channels" of neurite growth. or deactivated certain channels that were acting to dampen certain signals that control muscle movement, and when it shut off, the effects persisted. I would not expect this phenomenon to be a permanent effect because the systems are in constant change. We'll wait and see.