 The primary aim of this protocol is to investigate a possible new, neuroprotective treatment to prevent cognitive deficits that occur after carotid endarterectomy. We will investigate whether a widely used antibiotic agent - minocycline - that has shown neuroprotective effects in animal models of neurological diseases - can reduce the cognitive deficits associated with the surgical procedure of carotid endarterectomy CEA. Because these cognitive deficits are believed to be a result of small strokes due to emboli andor hypoperfusion, this study will provide preliminary data on the use of this drug as a neuroprotective agent in stroke - a leading cause of disability. 