When a stroke happens, seconds count. As soon as blood flow to the brain is disrupted, neurons that control motion, function and thinking start to die. “You want to figure out exactly what is going on so you can do treatment as quickly as possible,” says Gordon Sze, MD, professor of radiology and biomedical imaging and chief of Yale Medicine’s Neuroradiology section.
Thanks to Yale Medicine, people in or near Connecticut have a strong chance of avoiding serious long-term damage after a stroke. Physicians from Yale Medicine and the Stroke Center at Yale New Haven Hospital offer acute stroke care, including state-of-the-art intra-arterial clot removal. They also provide remote “telestroke” neurologic evaluations of patients at many nearby hospitals.
What is a stroke?
The word “stroke” refers to a sudden neurological defect. For example: One minute, you can move your arm and talk. The next minute, you cannot.
Sometimes a doctor can determine that you are having a stroke just by hearing about your symptoms and examining you. Other times, it is not so obvious.
“We all know the classic symptoms, but there are many cases where it’s not totally clear exactly what’s going on,” Dr. Sze says. Weakness or numbness in a hand or arm could be the result of a stroke, he says, or it could be caused by multiple sclerosis or a pinched nerve in the neck.
“In those cases, imaging can be very helpful,” he says.
Tests such as a computerized tomography (CT) scan or magnetic resonance imaging (MRI) can reveal, or rule out, a stroke. They can show the exact location and extent of the problem, including the brain tissue at risk if the blockage cannot be opened. They can also indicate when it happened.
“Not all strokes are the same. Some are silent,” says Dr. Sze. “We can look at a stroke, and we can tell you with some degree of accuracy, using either CT or MRI, when it happened.”
Types of stroke
Strokes may be either hemorrhagic or ischemic. A hemorrhagic stroke occurs when an artery in the brain tears and leaks blood into surrounding tissue. Some cases may be treated medically, with open surgery, or by using a catheter to insert coils or other devices that block the bleeding vessel.
An ischemic stroke occurs when a blood clot plugs up an artery carrying blood to part of the brain. About 80 percent of strokes are ischemic.
To learn more about stroke care at Yale Medicine, click here.
An innovative intervention
Twenty-five years ago a person who suffered an acute ischemic stroke had few treatment options.
A major breakthrough came with tissue plasminogen activator (tPA), a clot-busting drug administered through a vein that relieves blockages in the brain. In 1996, tPA was approved by the U.S. Food and Drug Administration (FDA) for treatment of ischemic stroke.
But tPA must be administered no more than four and a half hours after the onset of symptoms, and it does not always work. As medical technology has advanced, doctors have learned new and more effective ways to thwart ischemic strokes.
At major stroke centers, including Yale Medicine’s, “we can do interventional procedures where you can actually put a catheter up into somebody’s brain and take the clot out,” says Dr. Sze.
To accomplish this, the interventional radiologists at Yale Medicine use stent retrievers, suction catheters or a combination of the two.
A stent retriever resembles a tiny, tubular window screen. It is inserted through a catheter in the femoral artery in the groin, with a tether wire remaining outside the body for the physician to manipulate. The physician advances the stent up through the aorta and into the blockage, using X-ray pictures for guidance. The body’s heat causes the stent to relax into the clot, and the doctor carefully pulls it out, often opening the blood vessel very quickly.
The suction approach involves advancing the catheter through the femoral artery up to the clot. The physician then turns on a suction machine positioned outside the body to try to pull the clot into the catheter.
Awake but comfortable
During these procedures, patients are kept awake but comfortable with anesthesia while the interventional radiologists do their work. That way, doctors can get a quick answer about whether the procedure has worked, such as when a patient who was not able to move his or her arm regains that function.
When everything goes smoothly, clot removal can take less than an hour, but the team will try for as long as it takes, especially if the consequences of the blockage are dire, as with clots in the basilar artery in the back of the head. Patients with a major vessel blockage do better if the clot is removed, compared to receiving only an intravenous (I.V.) clot-busting drug.
The interventional radiologists perform their lifesaving work in several interventional suites, which are akin to operating rooms, at Yale New Haven Hospital. They are assisted by a team that includes an anesthesiologist, a technologist, a nurse and a stroke attending physician. This critical care team keeps the patient’s blood pressure stable and searches for the source of the clot, which could be anything from a blood disorder to heart disease to cancer.
Although Yale Medicine’s stroke center is based at Yale New Haven Hospital, Yale Medicine’s experts reach patients across Connecticut and parts of New England with the “telestroke” service.
Participating hospitals use a video feed to allow Yale Medicine physicians to assess patients in real time—performing neurological tests while also considering lab and imaging results—and getting people the treatment they need.
At most health care centers, patients get a CT scan right away if stroke is suspected. “The CT determines what’s going on to some degree,” Dr. Sze says. “But MRI is the most sensitive way to show stroke. There’s a technique that indicates whether a stroke has occurred in a very short time, whereas on CT it might take hours to see something.”
At Yale Medicine, an emergency MRI can be done within an hour, “which is very fast, because the MRI itself is quite a big procedure and you have to make sure it will be safe for a particular patient,” Dr. Sze says.
Once they have performed evaluations of patients, the Yale Medicine physicians will suggest a treatment approach, which may involve administration of tPA or other interventions. Some procedures can be performed up to eight hours after the onset of the symptoms, but often they happen long before that. Yale Medicine teams can mobilize rapidly after they diagnose a stroke to guarantee the best possible outcomes.