Ischemic Stroke

An ischemic stroke occurs when a blockage, such as a blood clot, interrupts blood flow to the brain. Brain cells in that area will die within minutes if they don’t receive the oxygen and nutrients that blood carries. And death of brain cells can cause a loss of brain function.

Ischemic stroke accounts for almost 90 percent of all strokes. It’s usually caused by a narrowing of the arteries in the neck or head due to atherosclerosis, which occurs when plaque builds up inside the arteries.

The UT Southwestern Difference

UT Southwestern is the only Advanced Comprehensive Stroke Center in North Texas, as certified by The Joint Commission and the American Heart Association/American Stroke Association. Studies consistently show that patients treated at designated stroke centers have lower rates of mortality and morbidity – and better outcomes – than patients treated elsewhere.

When someone has stroke symptoms, it’s important to get to the nearest primary or comprehensive stroke center as soon as possible. A stroke is a medical emergency and we recommend calling 911 for emergency medical attention. If a stroke support facility or a primary stroke center is closer to you, however, EMS may need to take you to that hospital – versus our Advanced Comprehensive Stroke Center – to make sure you receive immediate medical attention and have your condition stabilized.

If you’re admitted to a stroke support or a primary stroke center and your stroke is complex, you may be transferred to a higher-level stroke center such as UT Southwestern once you’re stable. Your hospital can transfer you, or you and your family can request that you be taken to UT Southwestern.


If you arrive at UT Southwestern and have experienced or are experiencing a stroke, rapid diagnosis and evaluation are critical so you can receive appropriate medical attention right away. The first step in treating an ischemic stroke is to restore blood flow to the affected area of the brain as quickly as possible.

We use tissue plasminogen activator (tPA, also known as IV tPA) to dissolve the blood clot causing the stroke. However, tPA must be administered within 3–4.5 hours of the onset of stroke. It’s not a cure, but it can be very effective.

More recently, a highly effective new treatment called endovascular rescue therapy has proven to be the treatment of choice in certain patients who present with acute ischemic stroke. This includes patients with blockage of one of the larger blood vessels of the brain.

The treatment involves placement of a stent or very small catheter into the blocked artery to directly remove the clot. This procedure needs to be done within hours of the onset of the stroke but has a longer “time window” than IV tPA in many cases (6 to 8 hours depending on location versus 4.5).

UT Southwestern performed this type of intervention even before it was introduced as effective for the general population. It’s often done after IV tPA is given in patients who have their large cerebral vessels blocked by blood clots.

Since this type of therapy is only performed in patients who have a blockage in one of the large arteries in the brain, not all patients with ischemic stroke will benefit from it. Not all hospitals offer endovascular rescue therapy for complex strokes. UT Southwestern has it available 24 hours a day, with highly trained and experienced neurointerventional physicians ready to perform it.

Diagnosing Ischemic Strokes

We diagnose ischemic strokes by doing a physical exam, gathering medical history, and performing advanced imaging. We offer every option for diagnostic imaging, including:

  • Computed tomography (CT) scan, computed tomography angiography (CTA), and computed tomography perfusion (CTP)
  • Carotid ultrasonography
  • Transcranial Doppler ­– an advanced method of diagnosis of vessel blockage, spasm, and blood flow that’s not available everywhere
  • Magnetic resonance imaging (MRI) and magnetic resonance angiography (MRA), including specialized vessel wall imaging
  • Cerebral angiogram
  • Echocardiogram – transthoracic and transesophageal

Prevention and Diagnosis

Many ischemic strokes are preventable if you work with your doctor to manage key risk factors, including high blood pressure, smoking, atrial fibrillation, and physical inactivity. Our physicians are experts in helping to control these risk factors, often with medications that UT Southwestern researchers and clinicians helped discover and test.

Clinical Trials

Since we’re involved in many of the latest stroke clinical trials, our team has access to new therapies that can play an important role in the treatment, recovery, or prevention of future strokes.

Stroke Rehabilitation

What happens after a stroke depends on the magnitude of the stroke and its impact on your body, which can range from mild to severe. UT Southwestern offers a stroke rehabilitation unit dedicated to helping patients regain as much function as possible, as well as managing the permanent impact of a stroke.

Our therapists will assist patients who may have problems moving their arms or legs, problems speaking or understanding language (aphasia), difficulty swallowing (dysphagia), difficulty with walking/balance, and other effects of stroke.

Request an Appointment

If you or a loved one notices signs of a stroke, call 911 immediately and go to the nearest stroke center in an ambulance. These hospitals can administer tPA to break down the blood clot that’s causing the ischemic stroke. Once you’re stabilized, you may be transferred to a higher-level stroke center like UT Southwestern for further treatment, such as endovascular rescue therapy.

To schedule an appointment with an ischemic stroke specialist at UT Southwestern’s facilities in Dallas, or to learn more about our services, request an appointment or call 214-645-8300.