Objective:~The purpose of this study is to assess the effect of dexmedetomidine anesthesia on glymphatic flow in human subjects as visualized by diffusion tensor MRI.~Study Design:~This study will take place at the University of Pennsylvania. Investigators plan to enroll approximately 30 healthy volunteers to generate pilot data for a larger grant submission.~Characteristics of the Study Population:~Subjects will be healthy males or females aged 20 to 40 years of age who will be recruited to participate in an MRI scan designed to measure clinically established, safe imaging of diffusion tensor imaging and cerebral blood flow at baseline, during a continuous intravenous infusion of dexmedetomidine at doses designed to produce anesthesia-induced unconsciousness to simulate natural sleep, and again on return to wakefulness. They must be able to pass the standard MRI safety assessment (e.g., no metallic metal clips or implants or any other contraindications to undergoing an MRI).~Design:~Upon successful completion of screening questionnaire, urine drug, and urine pregnancy subjects will be scheduled for an MRI. On the day of the study subjects will receive an intravenous catheter (IV) for study drug and fluids. Set one of MRI scans will be done with no dexmedetomidine. Set two of scans will be done when subject is anesthetized with dexmedetomidine with the goal depth of sedation will be moderate sedation. Set three of scans will be done when dexmedetomidine is stopped and wakefulness is achieved.
This study is to assess the effect of dexmedetomidine anesthesia on glymphatic flow in 5 healthy human subjects as visualized by diffusion tensor MRI. The study is designed to measure clinically established, safe imaging of DTI and cerebral blood flow at baseline, during a continuous intravenous infusion of dexmedetomidine at doses designed to produce anesthesia-induced unconsciousness to simulate natural sleep, and again on return to wakefulness.