New noninvasive device promises early stroke risk detection

A team of researchers from the Keck School of Medicine of USC and California Institute of Technology (Caltech) have developed a potential new way to measure a person's stroke risk that is cost-effective and noninvasive, akin to a cardiac stress test. If validated through further tests, the device could transform stroke care, making early detection of increased risk a standard part of medical exams around the world.

Strokes are the leading cause of neurological disability. Close to 90% of them are caused by the reduction or blockage of blood flow to a part of the brain, leading to the death of brain cells. Currently, there is no widely accessible way to screen patients for physical signs that a stroke is likely to occur. Health care providers rely largely on indirect markers of stroke risk, such as details about a patient's lifestyle and family history.

In a proof-of-concept study of the new device, funded in part by the National Institutes of Health, the researchers recruited 50 participants to complete a breath-holding "stress test" for the brain while wearing the device. The team found that the SCOS device could differentiate people with high stroke risk from those with low risk based on changes in blood flow and volume during the stress test. The results were just published in the journal Biomedical Optics Express.

More research is needed to refine the test's parameters and to confirm its utility in a larger population, but it holds the potential to revolutionize stroke care, Liu said. The device could help providers assess the risks and benefits of various medical treatments, such as whether to prescribe blood thinners, depending on a person's individual stroke risk. It might ultimately provide more reliable data than existing questionnaires, and it is affordable and portable enough that it could quickly become widespread.

"This is so simple that you can imagine it being included in your annual physical, along with measuring your weight and blood pressure," Liu said.

A stress test for the brain

Liu and his team used the SCOS device to collect images from the brains of participants at rest, then again during a neurological "stress test," where participants held their breath for as long as they could tolerate. Breath-holding temporarily puts the brain under stress in order to reveal its vulnerabilities, similar to the way running on a treadmill taxes the heart during a cardiac stress test.

Compared to participants in the low-risk group, those in the high-risk group showed significant differences in blood flow and volume during the stress test, indicating steeper increases in blood pressure. Those findings suggest that the new approach has utility for assessing stroke risk.

Refining the tool

The SCOS device could provide a much easier way to assess a patient's stroke risk than currently available methods. Today, health care providers use expensive tests, such as magnetic resonance imaging (MRI) or computed tomography (CT), to view the brain's blood vessels. But the new technology is simple, affordable and portable enough to be scaled across primary care offices, emergency departments and community clinics, as well as to less developed countries.

Next, the research team will work to refine the technology and prepare it for clinical use. They will conduct a clinical trial among a larger group of patients, tracking progress over two or more years to examine how changes in stress test scores relate to real-world health outcomes.

About this research

This work was supported by the National Institutes of Health [5R21EY033086-02] and the USC Neurorestoration Center.

Source:

Keck School of Medicine of USC

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