Illustration of a person holding their head in their hand with the brain highlighted in red and showing signs of ischemic stroke
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Research led by the University of California, Los Angeles, suggests electrical brain stimulation could help treat patients with acute ischemic stroke.

The study, published in JAMA Network Open, showed that high-definition cathodal transcranial direct current stimulation (HD C-tDCS) has the potential to help treat this kind of stroke and also to help rescue at-risk brain tissue in these individuals.

Every year, almost 800,000 people in the U.S. have a stroke and, of these, 87% are ischemic in nature, where blood flow to part of the brain is blocked by a clot. There is a drug that can dissolve clots and surgical intervention can allow clot removal, but most ischemic stroke patients are not eligible for these two interventions.

“In animal models of acute cerebral ischemia, C-tDCS salvages ischemic tissue at risk of infarction, both through direct neuroprotection by inhibiting peri-infarct excitotoxic effects, inflammatory and apoptotic pathways, and through collateral perfusion enhancement by inducing vasodilation,” write the authors.

“C-tDCS is a regionally directed therapy that instantly reaches maximum local concentration. In addition, via high-definition electrode montages, electrical field shape and coverage location can be tailored to the ischemic tissue at risk of infarction.”

This pilot study, led by Mersedeh Bahr-Hosseini, an Assistant Clinical Professor based at UCLA Comprehensive Stroke Center, recruited 10 patients with acute ischemic stroke who were not eligible for other treatments to test the non-invasive electrical stimulation as a therapy.

The trial was randomized, with control patients receiving a sham treatment. Overall, three patients were recruited to the control group and seven to the treatment group within 24 hours from stroke onset, with most receiving treatment in less than 15 minutes.

“This treatment was aimed at being as targeted and as individualized as possible, only to the area of the brain that has low blood flow or is suffering from stroke,” said Bahr-Hosseini, in a press statement. “With this high-definition form of C-tDCS, we were able to refine this electrical field to focus it just on this area.”

The treatment was well tolerated by the patients. The region of the brain with reduced blood flow was reduced by 46–100% in the treatment group and increased by 112-412% in the control group. Change in blood volume in the brain shortly after treatment was 40–110% in patients receiving HD C-tDCS versus—7–10% in control patients.

Overall, between 29 and 81% of penumbral tissue around the clot was preserved using the HD C-tDCS therapy versus 0% in controls.

Notably, those receiving 2 milliamps (n=4) compared to 1 milliamp (n=3) had a better response to the treatment, suggesting the higher dose would achieve more benefit.

A much larger multi-site study with Johns Hopkins, Duke University, and the University of Pennsylvania is now being planned to test the technology further.

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