This pilot study is designed to follow up on a previous, preliminary study and test the long-term safety and feasibility of the implantation of autologous peripheral nerve grafts into the substantia nigra, basal forebrain, putamen, and/or STN of participants with PD undergoing deep brain stimulation (DBS) surgery. Peripheral nerve tissue contains Schwann cells which produce growth factors that have been demonstrated to support the survival and function of neurons.

Participants will serve as their own donor for the tissue, which will be implanted at the time they undergo DBS surgery.

The primary objective of this pilot study is to demonstrate safety of the approach: introducing a minor modification of a standard, FDA approved neurosurgical procedure in use for over a decade to implant autologous peripheral nerve into the central nervous system. As such, the study is designed to pose minimal risk and minimal inconvenience to the subjects. Additionally, the test paradigm is performed strategically to not interfere with the surgery or delivery of the scheduled clinical DBS therapy. The scientific basis for this study is that the implanted peripheral nerve tissue is naturally well suited to provide multiple growth factors that have been shown experimentally to support the survival and function of dopaminergic neurons. Central to this proposal is the hypothesis that the implanted tissue will physiologically deliver growth factors to restore to normal function the afflicted neurons found in PD.

The first specific aim is to assess the feasibility and safety of the combined peripheral nerve graft/DBS surgical procedure. The second specific aim is to evaluate the long term clinical safety of the peripheral nerve implant.

This pilot study will provide safety data that can be used to generate a larger phase III clinical trial. If successful, it would herald the development of a new treatment for PD in which patients are able to provide their own tissue as a source of growth factors that could arrest or reverse the ongoing cellular loss that is responsible for their devastating dysfunction.

Inclusion Criteria:

• Undergoing DBS of the STN or GPi
• Between the ages of 40-75
• Able to give informed consent
• Show a positive response to Sinemet (carbidopa/levodopa)
• Be able to tolerate the surgical procedure

Exclusion Criteria:

• Any condition that would not make the subject a candidate for DBS of the STN or GPi
• Under the age of 40 or over the age of 75
• Unable to give informed consent
• Female who is pregnant, lactating, or of child-bearing potential unwilling to use an adequate birth control method during the period of the study