Although DBS is an efficacious treatment for refractory ET and PD it is highly underulitized with some esitmates suggesting that only 10-15% of eligible patients undergo DBS. Patients often express their disliking to being awake (for clinical testing) during DBS. Therefore, DBS is now being performed under general anesthesia with magnetic resonance imaging (MRI) guidance (asleep DBS). Although transformative, this technique is not widely used due to the absence of clinical and physiological feedback during surgery. We are studying the brain network changes during asleep DBS to correlate those with long-term efficacy with a goal to develop an fMRI-based feedback for tremor surgery.