Magnetic Resonance Imaging to Investigate Silent Strokes During Neck and Skull Angioplasty

Overview

This study will use magnetic resonance imaging (MRI) to determine if silent strokes occur during angioplasty of the blood vessels in the neck or skull. Neck and skull angioplasties are relatively new procedures whose possible complications are still under investigation. Patients 18 years of age or older who are admitted to Suburban Hospital in Bethesda, Maryland, for angioplasty of one or more of the blood vessels in the neck or skull may participate in this study. Participants must be able to undergo a brain MRI. Within 24 hours before their angioplasty, patients will provide a medical history and have a physical examination and brain MRI. The physical examination and MRI will be repeated within 24 hours after the angioplasty. MRI is a diagnostic test that uses a magnetic field and radio waves to show structural and chemical changes in tissues. This technique is more sensitive than X-rays in detecting some changes that occur in diseases of the brain. For the procedure, the patient lies on a table that slides into a metal cylinder (the scanner). The confined space may produce anxiety in some patients, and patients can talk to the technician at all times during the procedure. Earplugs are provided to muffle loud knocking and pulsing noises that occur while the scanner is taking pictures. During the study, the contrast material gadolinium may be injected into an arm vein. Gadolinium "brightens" the pictures, producing better images of brain blood flow. Patients will be contacted by telephone 30 days after the procedure to follow how they are doing and learn whether any complications resulted from the angioplasty.

Recently cervico-cranial angioplasty and stenting (CCAS) has been introduced as alternative treatment for occlusive disease of the extracranial and the intracranial vessels. Temporary or permanent clinically detectable neurological deficits occur in up to 13% of all patients undergoing CASS and are usually related to distal embolization or hemodynamic insufficiency. Silent cerebral micro-emboli are known to occur in patients undergoing carotid endarterectomy and angioplasty but are believed to be of little clinical significance. Distal embolization may be a technical concern when performing CCAS and could cause silent cerebral ischemia. High resolution diffusion-weighted MRI may detect silent hyperacute ischemic lesions in patients undergoing CCAS and examination by a stroke neurologist may detect clinical deficits otherwise unrecognized.