May is designated as Stroke Awareness Month. I would like to take this opportunity to paint a very simplistic and personal picture of where we have progressed as a stroke community and where we have faltered. It is in many aspects an exercise in self-awareness as an ex-stroke doc.
Most dramatically, the treatment of acute stroke patients has been revolutionized. As a representative of the American Academy of Neurology to a newly formed Brain Attack group in the late 1980s, the focus was on the rapid evaluation of persons with different types of bleeding in the brain (e.g., subarachnoid and other intracranial hemorrhages). My career pivoted toward reperfusion therapy (treatments that restore blood flow to the brain) in persons with large vessel blockage after the successful treatment of a patient with an almost certainly fatal basilar occlusion (blocked artery in the back of the brain) by intra-arterial instillation of urokinase through a catheter to help dissolve blood clots. Opening cerebral arteries clogged by a clot was difficult then, but the emergency opening of a large brain blood vessel is now commonplace thanks to the explosion in intra-arterial devices like catheters. The advent of effective intravenous (IV) and intra-arterial treatments for acute ischemic stroke completely changed acute stroke care in the US. It is comforting to reflect that the lack of enthusiasm in caring for persons with massive ischemic stroke deficits has been replaced by a “time is brain” urgency that mirrors the care of a person with a heart attack. The benefits in terms of preventing terrible injury have been so exciting to see and so appreciated by those affected and their families. However, access to time-dependent reperfusion remains a major problem in our country. It is so unfair that a person is left with the inability to live the life they wished for because of lack of widespread knowledge of the signs of stroke or access to necessary emergency medical care. The reasons for poor access to acute IV and intra-arterial stroke therapies are varied but in a large part it is fixable with greater awareness of the signs of stroke and dedicated efforts and system resources. Access to timely reperfusion would be greatly enhanced by intravenous thrombolytics (or clot-busting drugs) that are more effective in opening large brain arteries.
A period of great excitement in the 1990s was followed by severe disappointment after failed neuroprotective trials in the early 2000s. Our science has not yet led to treatments that slow down the progression of ischemic brain damage prior to reperfusion therapy enabling greater benefit from the opening of the culprit blood vessel. The National Institute of Neurological Disorders and Stroke (NINDS) efforts to rigorously identify such agents in the preclinical SPAN network and to test them in the context of large vessel reperfusion are attempts to bridge this translational divide. Additionally, advances have been frustratingly slow in improving the treatment of persons with acute hemorrhagic stroke; including preventing vasospasm (the sudden contraction of blood vessel walls after subarachnoid hemorrhage (bleeding that occurs in the area between the brain and the tissues covering it) and reducing brain injury after intracerebral hemorrhage. So even with the many exciting advances in stroke care overall, I can only give the translation of NINDS’s research to improve acute stroke care a B.
The greatest public health impact in the stroke field has been prevention. Stroke risk has dropped by over 60% since the 1970s, saving many lives. The number of persons who have been spared is staggeringly impressive. But very worrisome is the recent 7.8% worsening in the stroke rates in the past decade, thought to be related to increasing obesity in the US. Almost certainly the steady drop in stroke risk over decades was due to the reduction of vascular risk factors, especially hypertension (high blood pressure). Every appropriately powered trial has shown that a reduction in blood pressure is associated with decreased stroke incidence. The SPRINT-MIND trial demonstrated that aggressive blood pressure lowering in older adults with vascular risk factors also decreased the onset of the combined outcome of cognitive impairment/dementia. What could be better than a proven means to prevent stroke, heart attack, death, and cognitive impairment/dementia? So why are so many with high blood pressure not on treatment? Why are 47% of people with high blood pressure not controlled on their medications? Why is the stroke prevalence more than twice as high in Mississippi than Montana? Here we have failed as people committed to health. And there are no viable excuses for the disparate, tragic outcomes. These data cry out for national programs to encourage people to check their blood pressure and push their caregivers for help until it is under control. I can’t help but ascribe to the admonition of my mentor, Dr. C. Miller Fisher, who preached that every stroke is a failure of the medical care system. So even with the dramatic drop in stroke risk since the 1970’s, I can only give stroke prevention a B+.
Advances in acute stroke care and stroke prevention, though not complete, shine in comparison to the lack of advances in improving recovery after stroke. Next to prevention, this is where a major public health impact could be made if we identify a means to help the brain rewire and return function to the 750,000 people in the U.S. per year who do suffer a stroke. The rule is that the brain has considerable recovery potential. In fact some evidence points to a 70% rule of improvement in persons after strokes that don’t involve damage to the deep compact pathways. The neuroscience of plasticity is robust yet hasn’t been explored or matured to the point that it offers treatment possibilities to patients. I am hopeful that the technologies coming from the NIH BRAIN Initiative might enable scientists to track how the brain rewires its circuits after stroke and how this process might be enhanced. Our stroke recovery score is a C- at best. As my college German professor scolded me once: “You got a C-, but you could just have easily failed.”
NINDS is committed to fund the research that is necessary to achieve an A+ in all these broad areas of cerebrovascular disease that cause immense suffering, death, and disability. The future of stroke research is so much more promising now. We have new technologies to explore cerebrovascular biology and the mechanisms that underlie its disorders. The advances in stroke care have increased the clinical workforce in stroke, and the role of cerebrovascular disease in driving age-related decreases in cognition and dementia have brought new approaches, resources, and a cohort of new scientists to the problem. As a research community NINDS funded investigators together with persons affected by stroke can approach cerebrovascular disorders with greater focus that is born of lessons learned. And importantly we must aggressively petition for campaigns that can turn what we know about what works to prevent stroke to work for everyone.
Selected references:
1) Inequities in access and delivery of acute stroke care. A Brain Attack Coalition Symposium report.(pdf, 755 KB) October 2022.
2) CDC Stroke Facts October 2024.
3) Prevalence of Stroke — Behavioral Risk Factor Surveillance System, United States, CDC Mobidity and Mortality Weekly 2011–2022 | MMWR
4) Effect of Intensive vs Standard Blood Pressure Control on Probable Dementia: A Randomized Clinical Trial - PubMed, 2019.