Carotid revascularization can significantly reduce the risk of stroke in patients with severe carotid stenosis; however, it has been associated with cognitive decline in 25% of the older adults who undergo the procedure. Characterizing risk factors for cognitive decline following carotid interventions and individualizing treatment strategy based on those risks can minimize procedure-associated cognitive dysfunction. Neuroimaging techniques that characterize white matter integrity and regional hypoperfusion have the potential to provide sensitive brain structure indicators that may be associated with memory decline following revascularization procedures. In this protocol, we hope to determine how cerebral blood flow and baseline white matter abnormality in the vulnerable region modify the frequency and cognitive effect of microembolization following carotid revascularization procedures.

Inclusion Criteria:

• Patient is male or female >40 yrs of age.
• Patient has occlusive extracranial carotid stenosis (≥70%)
• Patient is scheduled to undergo a carotid revascularization procedure
• Patient agrees to voluntarily participate in the study and signs an informed consent.
• Patient agrees to be available for follow-up and is able to participate in all study testing procedures.
• Patient has sufficient visual and auditory acuity for cognitive testing.

Exclusion Criteria:

• Patient is unable to safely and comfortably undergo MR imaging procedures (e.g., claustrophobia, implanted medical devices that are MRI incompatible such as pacemaker, defibrillator, neural stimulator etc)
• Patient has an untreated or unsuccessfully controlled psychiatric disease (schizophrenia, bipolar disorder).
• Patient has prominent suicidal or homicidal ideation.
• Patient has acute illness or unstable chronic illness (e.g. uncontrolled hypertension, hepatic encephalopathy, portal hypertension, ascites, and esophageal varices, pancreatitis).
• Patient with a history of neurological (e.g., multiple sclerosis, seizure disorder, Parkinson's disease) or systemic illness affecting central nervous system function.
• Patient has prior closed head injury with ≥24 hours of amnesia.

Patients undergoing carotid intervention