Assessment of Cognitive Function in Patients Undergoing Carotid Artery Stent Placement

Inclusion Criteria: * 40-80 years of age * Right hand dominate * Asymptomatic:defined as: no symptoms of TIA/stroke in the previous 6 months * Baseline doppler study with a peak systolic velocity of 400cm/sec * Patient is deemed candidate for carotid artery stenting * TIMI flow of 1,2 or 3 * 80% or greater stenosis of distal common or internal carotid artery, as determined angiographically, as defined in ACAS * Subjects are able to give informed consent * Subjects are willing/able to complete follow-up visits Exclusion Criteria: * History of major stroke: within the past 6 months * History of Alzheimers disease or Dementia * Unable or willing to complete the baseline and 20 days neuro-cognitive testing planned major surgery within the next 2 months * Planned intervention opposite carotid artery within 2 months * Ineligibility for carotid stent procedure due to anatomy, thrombus, or inability to complete anti-platelet therapy * Any individual identified with cognitive impairment which would affect their performance during cognitive testing.