Neurotransmitter Measurements Using (WINCS) During Deep Brain Stimulation Neurosurgery

In this study, we will monitor extracellular neurotransmitter levels using a probe that is
able to perform realtime electrochemical detection during DBS neurosurgery. The overall
question this study is designed to answer is: Are there neurotransmitters released during
deep brain stimulation? We propose to enroll 45 patients (15 patients each at the three
targets for DBS) with Essential Tremor, Parkinson's Disease, and Dystonia who are undergoing
DBS neurosurgery. This will be an acute study. Patients with medically identifiable symptoms
of the above diseases who have been approved by Mayo DBS committee for implantation of DBS
will be selected for this study. These patients will then be consented preoperatively to
undergo extracellular electrophysiology which is typical in these cases to determine the
target site for implantation of the DBS electrodes. Following this electrophysiologic
procedure, the patient will have electrochemical electrode implanted to (1) determine
whether there is adenosine release at the site of stimulation during VIM thalamic DBS, (2)
determine whether there is dopamine and adenosine release within the caudate nucleus or
putamen during subthalamic nucleus DBS, and (3) determine whether there is dopamine and
adenosine release at the site of stimulation during Globus Pallidus DBS.

Inclusion Criteria:

- adult Patients with medically intractable Essential Tremor, Parkinson's Disease, and
Dystonia who have been approved for DBS surgery by the interdisciplinary Mayo DBS
committee.

Exclusion Criteria:

- pregnant patients,

- prisoners,

- children (age less than 18), and

- any patients identified as unsuitable for these protocol by the Mayo DBS committee.