Asleep Versus Awake Deep Brain Stimulation Surgery

All patients will undergo DBS surgery using regular surgical techniques. In this surgery a
halo is attached to the skull. A CT scan is obtained. MRI - based targeting is conducted to
identify to target location to implant the electrode deep in the brain. The patients have a
burr hole placed just behind their hair line in the frontal lobe. Then a guide tube is
inserted in the brain. Neurophysiological Comment [CL1]: The investigators have a number of
lay members on our board. Please review and revise the application to describe the study in
lay language as applicable. ersion 11-13 4 identification and confirmation of the target is
conducted with multiple techniques including microelectrode recording to listen to single
neurons in the brain, and macrostimulation to test clinical effect. The electrode is
implanted and its clinical effect is tested. The halo is removed and the patient is taken to
the recovery room. Patients will be randomized to undergo the surgery awake or asleep. Our
current standard surgical technique is awake with intravenous anesthesia used briefly during
drilling of a burr hole in the skull.

But in selected cases patients have remained sedated throughout the entire surgery. Patients
in the asleep group will have intravenous anesthesia maintained throughout the entire case.

Standard intraoperative neurophysiological and imaging techniques will be used. In awake
patients these techniques are used to identify and confirm that the DBS electrode is
implanted in accurate position. These techniques include microelectrode recording where
individual neurons are monitored as the electrode is inserted through the brain tissue.
Early research reports suggest that sedation may affect the neuronal activity. But our
preliminary data indicates that is still reliable under intravenous anesthesia.
Macrostimulation using the implanted DBS electrode can suppress tremor, stiffness, and
slowness of Parkinson's disease, and assists in confirmation of electrode position. It also
causes side effects including tingling, and facial contractions. These methods will also be
studied in the asleep patients. The O-arm is an intraoperative CT scanner that visualizes
the DBS electrode. O-arm images will be obtained in the standard fashion in both groups. The
accuracy of intraoperative imaging will be compared to standard postoperative MRI. The
clinical outcome from these two techniques will be compared. The clinical outcome will be
measured with standard Parkinson's disease research tools including video taped and
independently rated motor exam, as well as the Unified Parkinson's Disease Rating Scale
(UPDRS). Gait analysis will be collected using the APDM system. These will be tested before
and at 3 months after surgery by the neurologist.

Inclusion Criteria:

- All patients will have moderate to advanced Parkinson's disease.

- Patients must be medically safe for asleep or awake surgery.

- Ability to speak English well.

Exclusion Criteria:

- Parkinson's patients with concurrent dementia as measured by neurocognitive testing,
or with significant strokes identified on MRI will be excluded. Other similar
diseases will be excluded from the study such as Essential Tremor, and Parkinson's
plus disorders.

- Patients that are obese or that have severe potential airway issues.