Diagnosis

A diagnostic work-up for stroke includes physical and neurological examinations, patient’s medical history, blood tests (to measure blood glucose levels, blood coagulation time, cardiac enzymes, and other factors), and imaging tests. Many of the same procedures are used to diagnose a stroke and to evaluate the risk of future major stroke in patients who have had a transient ischemic attack (TIA).

For patients who have suffered a major stroke, the first step is to determine as quickly as possible whether the stroke is ischemic (caused by blood clot blockage) or hemorrhagic (caused by bleeding). Clot-busting drug therapies can be life-saving for ischemic stroke patients, but they are most effective only in the first 3 - 4 hours. However, if the stroke is caused by a hemorrhage, thrombolytic drugs cause will likely increase the bleeding and can be lethal.

Imaging Tests Used for Stroke and Risk Factors for Stroke

Carotid Ultrasound. Carotid ultrasound procedures such as carotid duplex are valuable tools for measuring the width of the artery and how the blood flows through it. Carotid ultrasound can help determine the severity of plaque build-up and narrowing and blocking of the carotid arteries (carotid stenosis).

Computed Tomography and Magnetic Resonance Imaging. Imaging tests can help distinguish between ischemic and hemorrhagic strokes. Computed tomography (CT) and magnetic resonance imaging (MRI) scans can help show signs of bleeding and can also help indicate whether a stroke is relatively new or recent.

MRIs are better than CT scans at differentiating between a hemorrhagic stroke and an ischemic stroke during the first few hours after symptoms begin. MRIs are also the preferred imaging technique for evaluating patients with probable TIA. However, an MRI can take longer to perform than a CT and is sometimes not as widely available. For these reasons, a CT scan may be used instead of MRI.

Cerebral Angiography. Cerebral angiography is an invasive procedure that may be used for patients with TIAs who need surgery. It can also detect aneurysms and monitor thrombolytic therapy. It requires the insertion of a catheter into the groin, which is then threaded up through the arteries to the base of the carotid artery. At this point a dye is injected, and x-rays, CTs, or MRI scans determine the location and extent of the narrowing, or stenosis, of the artery.

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Review Date: 05/06/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)