Featured Research

from universities, journals, and other organizations

Brain Implants May Help Stroke Patients Overcome Partial Paralysis

Date:
November 13, 2008
Source:
Washington University in St. Louis
Summary:
Scientists have shown for the first time that neuroprosthetic brain implants may be able to help stroke patients with partial paralysis.

Scientists have shown for the first time that neuroprosthetic brain implants may be able to help stroke patients with partial paralysis.

Researchers found that implants known as brain-computer interfaces (BCI) may be able to detect activity on one side of the brain that is linked to hand and arm movements on the same side of the body. They hope to use these signals to guide motorized assistance mechanisms that restore mobility in partially paralyzed limbs.

Partial paralysis on one side of the body results from stroke damage to the opposite side of the brain. This fits with the conventional model of how the brain controls movement, which says signals in one half of the brain control the opposite half of the body. That model led scientists to assume that stroke damage would make it impossible for BCIs to pick up any useful movement control signals from the brain and restore function in the body's paralyzed half.

"In recent years, though, we've come to realize that there's actually some ipsilateral, or same-sided control signals involved in movement," says senior author Eric C. Leuthardt, M.D., assistant professor of neurological surgery, of neurobiology and of biomedical engineering at Washington University School of Medicine in St. Louis and a physician at Barnes-Jewish Hospital. "Now we've shown these signals can be detected and are separable from signals that control the opposite side of the body, which means we may be able to use a BCI to restore function."

BCIs bridge gaps from brain damage and other injuries by using implanted electrodes to link the brain to a computer. The implant relays brain signals to the computer, which interprets those signals to control prosthetic devices or other means of interacting with the environment. In an earlier demonstration of the technology's potential, the same team of scientists showed in 2005 that a patient with a BCI could use the implant to control a video game.

BCIs formerly consisted of small electrodes implanted inside brain tissue to record from individual brain cells. Leuthardt and his colleagues have been developing a different approach known as electrocorticography (ECoG), which uses a plastic sheet filled with electrodes. The sheet rests on the surface of the brain, recording from many neurons at once.

"The old approach was good for acquiring significant signal control, but it suffered from the problem of scar encapsulation," Leuthardt explains. "When the electrodes are in the brain for 3-6 months, scars will form around them that prohibit them from recording brain signals."

Scar tissue does not form around the ECoG grid because it is implanted on the surface of the brain.

Leuthardt's team has shown that the ECoG approach can reveal useful insights into what a patient wants to do by analyzing signals from groups of neurons, rather than single neurons. Examples include a desire to move a hand or to speak.

For the new study, researchers worked with six epilepsy patients. To identify brain areas where seizures originated for possible surgical removal, physicians had temporarily implanted grids of electrodes on the surfaces of patients' brains. This allowed the researchers to ask the patients to perform tasks with their hands and check if the electrode grids could pick up ipsilateral brain signals during the tasks.

"We were able to identify distinct anatomic locations in the brain where these ipsilateral hand control signals occur and to show that they typically are found in the lower-frequency regions of the spectrum of brain activity detected by the BCI," says Leuthardt. "Three of our patients could use these signals or opposite-sided hand control signals to move a computer cursor on a screen."

Although the ECoG implants are currently left in place only temporarily, researchers hope to one day implant them for long-term usage.

Funding from the James S. McDonnell Foundation provided support for this research.


Story Source:

The above story is based on materials provided by Washington University in St. Louis. Note: Materials may be edited for content and length.


Journal Reference:

  1. Wisneski KJ, Anderson N, Schalk G, Smyth M, Moran D, Leuthardt EC. The unique cortical physiology associated with ipsilateral hand movements and neuroprosthetic implications. Stroke, Oct. 16, 2008

Cite This Page:

Washington University in St. Louis. "Brain Implants May Help Stroke Patients Overcome Partial Paralysis." ScienceDaily. ScienceDaily, 13 November 2008. <www.sciencedaily.com/releases/2008/11/081112093350.htm>.
Washington University in St. Louis. (2008, November 13). Brain Implants May Help Stroke Patients Overcome Partial Paralysis. ScienceDaily. Retrieved August 27, 2014 from www.sciencedaily.com/releases/2008/11/081112093350.htm
Washington University in St. Louis. "Brain Implants May Help Stroke Patients Overcome Partial Paralysis." ScienceDaily. www.sciencedaily.com/releases/2008/11/081112093350.htm (accessed August 27, 2014).

Share This




More Mind & Brain News

Wednesday, August 27, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Have You Ever Been 'Sleep Drunk?' 1 in 7 Has

Newsy (Aug. 26, 2014) A study published in the journal "Neurology" interviewed more than 19,000 people and found 15 percent suffer from being "sleep drunk." Video provided by Newsy
Powered by NewsLook.com
Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Does Medical Marijuana Reduce Painkiller Overdose Deaths?

Newsy (Aug. 26, 2014) A new study found fewer deaths from prescription drug overdoses in states that have legalized medical marijuana. But experts disagree on the results. Video provided by Newsy
Powered by NewsLook.com
Heart Group: E-Cigarettes May Help Smokers Quit

Heart Group: E-Cigarettes May Help Smokers Quit

AP (Aug. 25, 2014) The American Heart Association's first policy statement on electronic cigarettes backs them as a last resort to help smokers quit and calls for more regulation to keep them away from youth. (Aug. 25) Video provided by AP
Powered by NewsLook.com
Doctors Push For Later Start Times As School Year Kicks Off

Doctors Push For Later Start Times As School Year Kicks Off

Newsy (Aug. 25, 2014) The American Academy of Pediatrics is the latest group pushing for middle schools and high schools to start later, for the sake of their kids. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

    Technology News



    Save/Print:
    Share:

    Free Subscriptions


    Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

    Get Social & Mobile


    Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

    Have Feedback?


    Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
    Mobile: iPhone Android Web
    Follow: Facebook Twitter Google+
    Subscribe: RSS Feeds Email Newsletters
    Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins