Neurological Outcome With Carotid Artery Stenting

Overview

The purpose of this study is to determine how well patients undergoing carotid artery angioplasty and/or stent-supported angioplasty for the treatment of carotid artery stenosis will perform on a battery of tests to assess brain function before and after the procedure. This study will serve as a pilot project: (a) to determine incidence of neurologic/neuropsychometric change in patients undergoing carotid artery angioplasty and/or stent-supported angioplasty, and (b) to ascertain the time it takes for these changes to resolve.

We hypothesize that the incidence of subtle neuropsychometric injury will be significantly greater than the incidence of stroke comparable to what we found in patients having carotid endarterectomy. Patients will be evaluated prospectively to determine the incidence of neurological morbidity based on both the neurologic/neuropsychometric examinations The results of this study will serve to (a) determine incidence of neurologic/neuropsychometric morbidity for patients undergoing carotid artery angioplasty and/or stenting at ColumbiaPresbyterian Medical Center, (b) ascertain the time course of these changes, (c) identify intraprocedural markers for these changes, and (d) design protocols to evaluate the efficacy of therapeutic interventions. Cerebral injury will be determined three ways. First, all patients will be evaluated using a battery of neuropsychometric tests before and after the procedure. Persons presenting to the hospital on the day of the procedure, referred to hereafter as "Same Day", will be evaluated on the day of the procedure, one day after and at the 1 month follow up. Preoperative neurological and neuropsychological evaluation will be performed. The neuropsychometric tests are designed to demonstrate general neuropsychological pathology. These tests can be divided into four types: (1) an evaluation of language, (2) an evaluation of speed of mental processing, (3) an evaluation of ability to learn using a list of words, and (4) an evaluation of visual perception requiring a patient to copy a complex figure. Before the battery is administered we will assess each patient's level of pain while sitting and standing using a 10 point Visual Analog Scale and then gauge their mood with a series called the Wong/Baker Faces Rating scale. We will also evaluate each patient's quality of life using two well-known examinations (Telephone Interview for Cognitive Status (TICS) and Centers for Disease Control and Prevention HealthRelated Quality-of-Life 14Item Measure (CDC HRQOL14)) and a series of questions investigating how well patients are able to perform activities of daily living (ADLs) and instrumental activities of daily living (IADLs). These tests will be given at two time points, once before the surgery and then one month after surgery. We will look for changes in quality of life that may correlate with neuropsychometric test performance. Serum levels of neuron specific enolase (NSE) and protein S100B, a neuronal enzyme and glial cell component respectively, markers of cell injury will demonstrate cerebral injury. Serum levels of TNFá (Tumor Necrosis Factor Alpha) and IL8 (Interleukin 8) will be used to evaluate the presence and degree of systemic inflammatory response. DNA genotyping will be performed either by isolating leukocytes from blood and/or by obtaining a buccal swab sample. Normally blood is sampled via the femoral arterial catheter for assessment of hematocrit, and blood gas analysis. Patients will undergo an intraprocedural transcranial Doppler ultrasonograph (TCD). TCD monitoring probes will be placed on the patient's head with a standard head frame after sedation, one probe on each side to measure the cerebral blood flow (CBF) velocity and determine the presence of emboli in the middle cerebral artery (MCA) on either side of the brain (Spencer Technologies, Seattle, WA). We hypothesize that there may be a relationship between emboli and subtle cognitive decline as ascertained by the battery of neuropsychometric exams. An electroencephalogram (EEG) will be applied to monitor for significant hemispheric cerebral ischemia which may occur when the balloon is inflated and occludes the artery. We routinely use EEG monitoring during carotid endarterectomy and its use exposes the patient to no risk.