The Effects of Dexmedetomidine and Propofol on Cerebral Blood Flow and Brain Oxygenation During Deep Brain Stimulation

The investigators will evaluate the effects of dexmedetomidine and propofol on cerebral blood flow and brain oxygenation during Deep Brain Stimulation (DBS) surgery. Specifically, the investigators will test the hypothesis that dexmedetomidine is non-inferior to propofol for cerebral blood flow as measured by transcranial Doppler and brain oxygenation as measured by near-infrared spectroscopy.

Inclusion Criteria:

• ASA I-III.
• Scheduled for DBS.

Exclusion Criteria:

• History of dystonia.
• Severe heart failure with ejection fraction less than 30%.
• History of obstructive sleep apnea.
• History of renal failure with creatinine level > 2 mg/dl.
• Allergies to α-2 agonists and propofol.
• Current use of α-2 agonist medications such as clonidine.