Diagnosing Stroke

The Ronald O. Perelman Center for Emergency Services and Emergency Department at NYU Langone Hospital—Brooklyn are the first line of care at NYU Langone for people with a suspected stroke. A stroke is a medical emergency, so it’s important to know the symptoms and warning signs.

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Time is of the essence for getting effective treatment. If you think you or a family member are having or have had a stroke, call 911 or go to the nearest emergency room immediately.

Stroke Symptoms and Warning Signs

Common stroke symptoms include the following:

  • numbness, tingling, or weakness of the face, arms, or legs—especially on one side of the body
  • confusion or trouble communicating
  • trouble seeing in one or both eyes
  • trouble walking, dizziness, or a loss of balance or coordination
  • severe headache with no known cause

Symptoms vary depending on the location of the stroke, but they are typically sudden. The acronym FAST—which stands for face, arms, speech, and time—is a quick way to remember the warning signs of a stroke:

  • Face: Ask the person to smile. Does one side of the face droop?
  • Arms: Ask the person to raise both arms. Does one arm drift downward?
  • Speech: Ask the person to repeat a simple phrase. Is the speech slurred or strange?
  • Time: If you observe any of these signs, call 911 immediately.

If a person is having a stroke, every minute counts. The longer it goes untreated, the greater the potential for brain damage and the less the likelihood of recovery.

Diagnostic Tests

NYU Langone’s emergency care team quickly evaluates a person’s symptoms and determines the type of stroke he or she is having. Next, our experts perform a physical exam, in which they check for mental alertness, coordination, and balance. They also look for the hallmark signs of stroke: sudden numbness or weakness in the face, arms, and legs; confusion; and trouble speaking and seeing clearly.

The doctor also asks you or a family member about your risk factors for stroke, such as high blood pressure, smoking, heart disease, or a family history of stroke. To rule out other possible causes of your symptoms, such as a brain tumor or a drug reaction, a doctor may order one or more tests.

Cerebral Angiography

Cerebral angiography is a sophisticated imaging test that uses contrast dye and X-rays to highlight the carotid and vertebral arteries, the vessels that carry blood from the heart to the brain. The doctor inserts a small tube called a catheter into an artery, usually in the groin area. The catheter is then threaded into one of these important arteries.

The doctor then injects the contrast agent into the artery. The dye moves through the artery and makes it visible on an X-ray. Angiography can help a doctor identify an aneurysm, a weak area in a blood vessel that may rupture, or a vascular malformation. Both of these problems may result in a hemorrhagic stroke.

The test may also reveal areas of narrowing or a blockage in a blood vessel.

CT Scan

A CT scan uses X-rays and a computer to create three-dimensional, cross-sectional images of the body. Doctors may order a CT scan to determine if you have any brain abnormalities that might cause stroke-like symptoms. They can also check for blood vessel blockages.

CT Angiography

To assess the head and neck arteries, a doctor may order a CT angiography. This test uses an X-ray machine to identify blockages, aneurysms, and vascular malformations in the blood vessels—usually the arteries.

MRI Scan

A doctor may order an MRI scan—which uses a magnetic field and radio waves to create computerized, two- or three-dimensional images—to view the structure of the brain. He or she looks for any abnormalities that may be causing stroke-like symptoms.


An echocardiogram can help a doctor pinpoint a heart abnormality that could lead to a stroke. This ultrasound test uses sound waves to create a live image of the heart. It reveals the size, shape, and structure of the heart and can help doctors determine if the organ is working properly.


An electrocardiogram, or EKG, is a tool used to record electrical activity in the heart. Heart rhythm abnormalities can lead to a stroke, so this is an important tool.

Hospital Admittance

After the initial evaluation or treatment, people who are having a stroke are transferred to our intensive care unit, stroke unit, or a neurology unit at NYU Langone.

While hospitalized, people are evaluated by several members of our interdisciplinary team, including neurologists, nurses, physical therapists, occupational therapists, speech and language therapists, and social workers.