Deep Brain Stimulation (DBS) is an effective therapy for patients with medically refractory primary dystonia. However, DBS programming for dystonia is not standardized and multiple clinic visits are frequently required to adequately control symptoms. We aim to longitudinally record brain signals from patients using a novel neurostimulator that can record brain signals. We will correlate brain signals to clinical severity scores to identify pathological rhythms in the absence of DBS, and we will study the effects of DBS on these signals in order to guide clinical programming. We are going to recruit patients who receive the Medtronic Percept device, which allows for brain signal recordings (this feature is FDA approved). The investigators will be conducting an observational study using this device to collect data that the subjects receive as standard of care.

The development of newer technologies has allowed clinicians and researchers to better understand pathophysiological underpinnings of different disorders managed with neuromodulation. There is a paucity of information, however, on dystonia, likely due to its rarity of cases and variability in phenomenology to allow generalization of findings. Possible abnormal brain signals, such as high activity in theta band (defined as rhythms in the 4-12Hz range ), have been proposed by small case series. The development of newer technologies has allowed clinicians and researchers to better understand pathophysiological underpinnings of different disorders managed with neuromodulation. There is a paucity of information, however, on dystonia, likely due to its rarity of cases and variability in phenomenology to allow generalization of findings. Possible abnormal brain signals, such as high activity in theta band (defined as rhythms in the 4-12Hz range ), have been proposed by small case series

Inclusion Criteria:

• Patient gives an informed consent.
• Patient is over 18 years of age.
• Having a diagnosis of a primary dystonia confirmed by a trained movement disorders neurologist;
• Having failed or not tolerated conventional medical management, at the discretion of the neurologist managing the patient;

Exclusion Criteria:

• Having alternative diagnoses to a primary dystonic syndrome;
• Having comorbid neurodegenerative disorders that may affect mobility or cognition (e.g. comorbid Parkinson's disease);
• Having sequelae of prior brain insult (e.g. prior stroke or brain tumor);
• History of prior resectivebrain surgery (e.g. tumor resection);
• Not being a DBS candidate;
• Selection of alternative targets to conventional GPi;
• Receiving unilateral implants
• Having a higher surgical risk that precludes patient from having standard intraoperative mapping.

Patients with dystonia, who have been cleared for DBS surgery or receiving a battery change who will receive the Percept battery.