Lemborexant on Perioperative Sleep Quality in Patients With Parkinson's Disease Undergoing Deep Brain Stimulation

This study tests whether lemborexant, an approved sleep medicine, can improve sleep and recovery in people with Parkinson\'s disease undergoing deep brain stimulation (DBS) surgery. Sleep problems are common around surgery and may worsen pain and slow recovery. Participants will be randomly assigned to take lemborexant or a placebo the night before surgery. Researchers will compare anesthesia use, wake-up time, sleep quality (objective and subjective), pain, recovery, and blood markers. The study will show whether lemborexant is safe and helpful for this group.