Electrode in Brain Blood Vessel Shown to Stimulate Body Muscles

Stentrode device (Sarah Fisher, University of Melbourne)

3 Dec. 2018. Electrodes sent into a blood vessel in the brain with a catheter and stent are shown in tests with sheep to stimulate muscles in the animals’ faces and limbs. A team from the company Synchron Inc. in Palo Alto, California and University of Melbourne Medical School in Australia describe the device and test results in today’s issue of the journal Nature Biomedical Engineering (paid subscription required).

Researchers led by neuroscientist Thomas Oxley and biomedical engineer Nicholas Opie are seeking better methods for directly stimulating brain cells, which can help treat neurological disorders including Parkinson’s disease, depression, and epilepsy. To electrically stimulate brain cells today, however, usually means implanting electrodes into the skull, which requires sensitive surgery and can result in serious adverse effects, such as inflammation in the brain.

Oxley and Opie, directors of the Vascular Bionics Laboratory at University Melbourne and founders of Synchron Inc., are developing an alternative less-invasive method of delivering electronic stimulation. Their technology they call Stentrode inserts an electrode into the brain, but instead of drilling a hole in the skull, the electrode travels from a vein in the neck into a blood vessel in the brain, adjacent to the primary motor cortex that controls voluntary muscular movements in the body. The electrode is contained in a stent, a tiny wire basket that expands upon reaching the blood vessel, made of nitinol, a nickel-titanium alloy.

Signals from the electrodes are sent to areas of the motor cortex to stimulate specific muscles in the body. Those same signals are captured by a unit implanted in the chest, which relays the signals wirelessly to a nearby receiver. Synchron says it is developing software to help immobilized or disabled individuals operate assistive systems, such as robotic exoskeletons, with their thoughts and signals from the electrodes.

In a 2016 study published in the journal Nature Biotechnology and reported in Science & Enterprise, Oxley, Opie, and colleagues demonstrated that Stentrode devices, inserted in brains of sheep, operated successfully for 28 days, provided signals similar to those from surgically-implanted electrodes, and allowed the animals to move around freely.

In the new study, the Synchron-Melbourne team also inserted Stentrodes in brains of sheep. In this case, the researchers directed the electrodes to stimulate facial and limb muscles in the animals, by activating electrodes in different parts of the stent corresponding to those muscle-control regions in the brain. “By delivering current through these electrodes,” says Opie in a university statement, “we were able to stimulate different brain regions and observe different responses.”

The results show the appropriate sheep muscles responded on demand, similar to electrodes implanted surgically. The authors conclude that the findings show the safety and efficacy of Stentrode devices, and support advancing the technology into human clinical trials.

Synchron says the company is now preparing for those clinical trials. The following video tells more about the Stentrode.

More from Science & Enterprise:

• Nerve Stimulation Reduces Pain, Fatigue from Lupus
• NIH Supporting Electronic Neuro Drug Test Technology
• Brain-Controlled Home Rehab for Stroke in Development
• Electro-Pharmaceutical Device Tested to Heal Nerve Injuries
• Algorithms Advance Assistive Control for Spinal Cord Injury

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