At-home taVNS for Neurorehabilitation in Parkinson's Disease

The goal of this clinical trial is to learn if taVNS works to treat symptoms of Parkinson's Disease in adults. It will also learn about the feasibility and preliminary efficacy of taVNS administered at home by the participant. The main questions it aims to answer are: 1. Is at-home taVNS feasible and effective for treating symptoms of Parkinson's Disease? How often are participants completing the stimulation protocol? What are the side effects of stimulation experienced by participants? How do participants rate the experience of taVNS sessions at home? How do participants' scores on assessments and questionnaires change with taVNS treatments? 2. How does taVNS impact connections between neural networks in the brain of patients with Parkinson's Disease at rest? Participants will: * Have a baseline MRI scan to take images of their brain. * Complete a series of assessments and questionnaires to evaluate their Parkinson's Disease motor symptoms, cognitive and neuropsychiatric symptoms, and other non-motor symptoms. * Have an initial taVNS session where their threshold to perceive the stimulation will be measured. This value will be used to stimulate each participant at a specific dose relative to their individual perception of stimulation. * Be trained on how to use the taVNS device and system and have one 1-hour taVNS session where their vitals will be monitored. * Self-administer 1-hour daily taVNS sessions for 8 weeks at-home, complete tolerability questionnaires, and weekly remote check-ins with study staff. * After 4-weeks of at-home taVNS, participants will come in-person to repeat the questionnaires and assessments from the first visit. * Following the 8 weeks of taVNS sessions, participants will repeat the MRI scan, assessments and questionnaires from visit 1. * Participants will complete questionnaires remotely 1 month following their last taVNS sessions.

Inclusion Criteria: * Issues with walking, balance, and gait as determined by a movement disorders neurologist (a score of equal to or greater than 1 on MDS-UPDRS items 2.12 (walking and balance), and 3.10 (gait)) * Diagnosis of idiopathic Parkinson's Disease based on UK Brain Bank diagnostic criteria * Hoehn and Yahr Stage 2-4 as determined by a movement disorders neurologist * Stable on dopaminergic medications over the past 30 days prior to enrollment in the study Exclusion Criteria: * A history of taVNS in the last 6 months * A history of brain surgery, traumatic brain injury or stroke * Diagnosis of a nervous system disorder besides PD, alcohol or substance use disorder, or unstable cardiovascular conditions * History of myocardial infarction or arrhythmia, bradycardia * A history of other significant gait impairment unrelated to PD (e.g. orthopedic deformities) * Inability to complete gait/ motor assessments (without assistance or assistance devices) * Ear trauma, facial pain, anatomical abnormalities or other barriers preventing earpiece fit * Failure to meet all criteria on a standardized MRI/taVNS safety screening: This includes, but is not limited to, the presence of claustrophobia, implanted electronic devices that are not 3T MRI compatible (e.g., pacemakers), metallic objects or fragments (e.g., bullets), and non-removable hair clips or piercings. * Individuals with a diagnosis of cognitive impairment (MoCA \< 24) that would make them unable to understand and follow study instructions or to consent for themselves. * Pregnancy * Visual hallucinations or other psychotic symptoms, other than mild visual hallucinations secondary to PD medications, not requiring treatment, or well controlled on stable doses of quetiapine or pimavenserin. * Individuals with a history of seizure(s) * Inability to perform at-home taVNS procedures safely and properly (either alone or with the aid of a caregiver) * Uncorrected visual or hearing impairments that would impact performance on cognitive tests or ability to follow study procedures * Use of B-Blockers, dopamine blocking agent (other than quetiapine or pimavenserin in stable doses), antiarrhythmic medication, acetylcholine esterase inhibitor (study doctor will consider if on stable doses), midodrine, fludrocortisone, droxidopa, or anticholinergic drugs