Purpose of the Research
The purpose of this research is to determine if an MRI test of brain blood flow can determine which patients with a condition called vertebrobasilar disease (VBD) are at higher risk of stroke.
VBD is a blockage of the main blood vessels, called the vertebral and basilar artery, that supply blood to the back of the brain. This blockage can reduce the blood flow to the back of the brain and cause a risk of stroke or TIA (transient ischemic attack - similar to a stroke but with temporary symptoms lasting less than 24 hours).
Patients with VBD can have different degrees of blockage, which can affect the blood flow to the brain by variable amounts. The extent to which the blockage in the blood vessel reduces blood flow can be measured by a specialized picture of the brain using a MRI (magnetic resonance imaging) test. The research is being done to determine if there is a higher risk of repeated stroke in patients with VBD who have had a stroke or TIA, if they have lower blood flow on the MRI test.
For a patient to be eligible to participate in the study, they must be adults who have experienced a stroke or TIA from VBD. The degree of blockage of the vertebral or basilar artery must be severe, at least 50%. The exact degree of blockage is determined by a test called an angiogram, which provides a picture of the blood vessels; often this test is performed as part of the work-up in patients who have had a stroke or TIA. If not, the angiogram would be performed as part of the study to determine if the patient is eligible.
Patients who participate in the study will be followed over the course of one year and up to two years for any signs or symptoms of repeated stroke or TIA. Patients will undergo the standard treatments for VBD, such as aspirin, cholesterol lowering medication and blood pressure medication as prescribed by their physicians.
As part of the research study, a MRI test will be performed to examine the blood flow to the brain at the time of enrollment into the study, as well as 6 months, one year and up to two years later. These test results will be analyzed for the research purposes. Patients will return for follow-up visits every 6 months for up to two years for a medical checkup. They will also receive monthly phone calls to check on their status for 12 months.
Participation in the study is voluntary. A patient may choose not to participate or to withdraw consent at any time. There are no direct benefits for the patient in taking part in the study, but the information gained may benefit others in the future.