A New Device for Monitoring Stroke Patients Before a Recurrence

About one-third of those who have a stroke suffer a second in the hospital, and before now there wasn't a good way to monitor brain health.

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Researchers at the Mayo Clinic in Florida have shown that cerebral optically-based near infrared spectroscopic oximetry applied to patients who have suffered a stroke can help monitor regional cerebral perfusion in real time, and thus "may serve as a useful, noninvasive, bedside intensive care unit monitoring tool to assess brain oxygenation in a direct manner." The study was using the device called Fore-Sight from Casmed of Branford, Connecticut, that measures blood oxygen, similar to a finger clip pulse oximeter. The Mayo study results in post-stroke patients have been published in Journal of Neurosurgery this month.

Regional cerebral blood flow monitoring devices such as Fore-Sight are already in wide use in cardiac surgery, where they are applied to prevent brain ischemia in patients undergoing major surgeries on bypass (such as valve replacements, aortic arch surgeries, etc.).

In the Fore-Sight device, the sensors stick on like adhesive bandages above each of the patient's eyebrows. The technique, known as near-infrared spectroscopy (NIRS), emits near-infrared light that penetrates the scalp and underlying brain tissue. The Mayo Clinic team set up a study to compare measurements from NIRS with CT perfusion scanning in eight stroke patients.

More from William Freeman, neuro-critical care specialist and associate professor at the Mayo Clinic, who was the senior investigator in this project:

About one-third of stroke patients in the hospital suffer another stroke, and we have few options for constantly monitoring patients for such recurrences. This was a small pilot study initiated at  the Mayo Clinic's campus in Florida, but we plan to study this device more extensively and hope that this bedside tool offers significant benefit to patients by helping physicians detect strokes earlier and manage recovery better.

Currently, at most hospitals nurses monitor patients for new strokes and, if one is suspected, patients must be moved to a hospital's radiology unit for a test known as a CT perfusion scan, which is the standard way to measure blood flow and oxygenation.

Although the results show that both tests offer statistically similar results, NIRS has a more limited field for measuring blood oxygen and flow. According to the researchers, this suggests that perhaps not all patients would benefit from this kind of monitoring.


This post also appears on medGadget, an Atlantic partner site.