Diagnosing Stroke: The Key Factors Doctors Must Know Before Treatment

“As a stroke neurologist, I think of myself as a detective.”

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If you think you’re having symptoms of a stroke, getting to the emergency room promptly is critical. Don’t “wait and see” if it’s a false alarm, and don’t take an aspirin at home. Call an ambulance and get professional care ASAP.

Once you’re in professional care, doctors will evaluate your symptoms and medical history to see if you’re actually having a stroke, and what kind of stroke you’re having, before moving forward with treatment.

What Doctors Look for When Diagnosing Stroke

Doctors look at three key factors before beginning treatment for stroke, according to Carolyn Brockington, MD, neurologist at Mount Sinai Hospital:

  • Patient history, such as high blood pressure or atrial fibrillation

  • A physical examination, including blood tests

  • Imaging of the brain with CT or MRI scans

Imaging of the brain can show if and where a stroke has occurred, as well as help doctors see which type of stroke may have occurred. “You have two main categories: a bleeding stroke, which is called hemorrhagic,” says Dr. Brockington, “versus an ischemic stroke, which means reduction in blood flow.” (Learn more about the two types of stroke here.)

How Calling 911 Can Speed Up Stroke Diagnosis

One of the major benefits of calling an ambulance when you are having a stroke is that it can shorten the amount of time before your diagnosis—so you can begin potentially life-saving treatment sooner.

“When EMS is bringing in a stroke patient, many times they pre-notify the emergency room,” says Dr. Brockington.

By calling ahead to alert the hospital of an incoming stroke patient, the hospital can call a “stroke code,” bringing together the team of stroke responders in the hospital. By the time you arrive at the ER, a crew of doctors and nurses may be ready to respond.

“We rapidly look at the patient but then take them right away to have imagining,” says Dr. Brockington. “We’re trying to shorten the time period … to begin treatment.” Here are more reasons to call 911 if you’re having a stroke.

Other Tests that Impact Stroke Treatment

Even once doctors are confident you are having a stroke, they must consider important factors before beginning treatment. The goal is to detect or rule out underlying conditions that may cause a misdiagnosis, complications, efficacy of treatment, or other risks.

Blood tests can check that glucose levels are within a safe range. Low blood sugar (hypoglycemia) can produce similar symptoms as a stroke, according to the National Heart, Lung, and Blood Institute. On the other hand, high blood sugar at the time of stroke may make tPA (the most effective treatment for ischemic stroke) less effective or even dangerous.

“We also have to do an EKG because we know the brain and the heart are obviously connected,” says Dr. Brockington. “Sometimes if people are having a stroke, they might also have some heart problems.” People with heart disease, angina, or a history of heart attack have double the risk of having a stroke, according to the American Stroke Association.

Since certain conditions, surgeries, and medications can impact the risk of stroke, learning your personal medical history is important to your doctor’s evaluation.

Learning your possible health conditions and current medications helps doctors decide if you can be given blood thinners, a common treatment for ischemic strokes to restore blood flow to the brain.

Better Late Than Never: Seeing a Doctor After Stroke

The most effective treatment for stroke is only useful within three to four hours after the onset of stroke symptoms. However, if those hours have passed, you should still visit the hospital immediately.

“When someone has a stroke, the first 24 hours is the greatest risk of having another stroke,” says Dr. Brockington. “Whatever caused the stroke can happen again.” Doctors can figure out what caused the stroke and possibly prevent another from occuring.

For more information, here are ways a stroke affects the brain, and check out how doctors use the acronym F-A-S-T for quick stroke recognition and treatment.