Not that long ago, physicians had little idea what caused the "brain attack," let alone how to treat it effectively.
But stoke survival rates have improved considerably because of stroke research that has led to new approaches to diagnosis and treatment. Now we know that about 80 percent of strokes are ischemic, caused by a blood clot that stops the flow of blood to the brain. The other 20 percent are hemorrhagic, in which a burst blood vessel cuts off the blood supply. We also know that as many as 80 percent of strokes can be prevented with lifestyle changes and by treating risk factors such as high cholesterol.
Let's take a look at key developments in stroke research that have brought us to where we stand with advanced stroke treatment today.
Researchers identified major risk factors for stroke, such as smoking and high blood pressure. This gave physicians and people at risk of stroke hope for preventing strokes with medical intervention and lifestyle changes.
The next advances focused on early diagnosis of stroke, differentiation between ischemic and hemorrhagic stroke, and increased understanding and assessment of brain function. Diagnostic technology, such as computed tomography (CT) and positron emission tomography (PET) scans, helped increase researchers' understanding of brain function and led to diagnostic procedures that helped differentiate between the two types of stroke. Researchers also showed that aspirin can help prevent and treat blood clots that can lead to ischemic stroke.
The age of modern stroke treatment dawned in 1996 with the introduction of tPA, or tissue plasminogen activator, says Lucian Maidan, MD, Regional Medical Director of Stroke and Vascular Services at the Dignity Health Neurological Institute and neuroendovascular surgeon at Mercy Medical Group, a service of Dignity Health Medical Foundation. Administered intravenously within 4.5 hours of the onset of a stroke, this medication can dissolve blood clots and allow blood to flow to the brain again.
Every minute counts in the administration of this treatment because an estimated 1.9 million brain cells die every minute until the blood supply is reestablished. This fact has led to the saying "time is brain."
With the new lifesaving treatment tPA available, it became critical to get the word out to physicians and the public about the signs of stroke and the importance of early intervention. Many hospitals and health systems developed stroke centers and centers of excellence to increase availability of the latest in stroke treatment. In 2004, the Joint Commission—the nonprofit that accredits U.S. health care organizations—introduced the Primary Stroke Center certification for hospitals qualified to evaluate stroke patients, administer tPA, and provide intensive care and customized rehabilitation services.
The development of tPA changed the stroke treatment landscape, but access to expert stroke care can be uneven in some parts of the country. In 2008, Dignity Health introduced its telemedicine service, which links smaller hospitals with experienced specialists in other parts of California or the country via high-quality videoconferencing. Dignity Health continues to offer this lifesaving telestroke service.
In 2012, the Joint Commission introduced the Comprehensive Stroke Center certification to identify high volume stroke centers that offer the most advanced care for their patients. These highly specialized centers, such as the Mercy San Juan Medical Center, offer 24/7 neurointerventional coverage, neurointensive care, the most advanced imaging capabilities, and participate in research studies. In this decade, new devices were developed to carefully remove large blood clots from the intracranial vessels. Additionally, the FDA approved the first stent retriever devices, giving new hope to people dealing with stroke. And in 2018, the treatment window for patients with large vessel occlusions was extended in certain cases up to 24 hours from the onset of the symptoms.
Thanks to advances in research, the number of stroke cases continues to decline while stroke survival improves. The pace of discovery has quickened in recent years, leading to more effective treatment that helps ensure happy endings for more and more stroke stories.