Featured Research

from universities, journals, and other organizations

Electrical brain disturbances linked to worse outcomes following neurotrauma

Date:
May 19, 2011
Source:
University of Cincinnati Academic Health Center
Summary:
Electrical disturbances that spread through an injured brain like tsunamis have a direct link to poor recovery and can last far longer than previously realized, researchers have found.

Electrical disturbances that spread through an injured brain like tsunamis have a direct link to poor recovery and can last far longer than previously realized, researchers at the University of Cincinnati Neuroscience Institute (UCNI) have found.

Related Articles


The disturbances, known as cortical spreading depolarizations, are short-circuits (electrical failures) that occur in a localized, or specific, area of injury and result in dampened brain waves. Because of their localization, the depolarizations are invisible in routine electroencephalography (EEG) exams. But they represent an extreme change in voltage -- up to 10 times greater than any brain pattern that is normally present.

"Over the last several years we've learned how to measure and record spreading depolarization in the human brain, and we have known that these depolarizations occur in many patients who have suffered neurotrauma," says Jed Hartings, PhD, research assistant professor in UC's department of neurosurgery and director of clinical monitoring for the Mayfield Clinic. "But we didn't know what they meant or whether they were relevant. For the first time we now know that they relate to worse outcomes for patients who have suffered trauma to the brain."

That finding, Hartings adds, could eventually lead to new therapies. "If we can find a way to stabilize the brain's electrical activity and block spreading depolarizations, perhaps we can improve patients' outcomes."

An Advance Access, online version of the research, published April 7 by the neurology journal Brain appears online in its complete, paginated form May 19.

The observational, multi-site study of 53 patients represents the initial phase of a four-year, $1.96 million grant awarded by the Department of Defense (DOD). The topic of spreading depolarizations is of keen interest to the U.S. military because head injuries have emerged as the signature wounds of the wars in Iraq and Afghanistan.

Of the study's 53 participants, 10 had experienced the most severe form of depolarizations. All died or had severe disabilities six months after their injury.

"Spreading depolarizations, which occur in up to 60 percent of patients who have experienced serious neurotrauma, are electrical failures of the brain's local networks," explains Hartings, the study's principal investigator. "When these networks fail, brain waves can no longer be generated, and they become dampened, or depressed, in amplitude."

Hartings likens each brain cell, or neuron, to a battery. When spreading depolarization occurs, the cell discharges its electricity completely. "The neuron, once alive with electrical activity, stops working and has to be resuscitated with glucose and oxygen," Hartings says. "You could also liken it to a battery in your car. If it drains, then the car doesn't work."

Because networks of the brain's cortex are connected in a continuum, a depolarization triggered by an injury will spread across the cortex like a tsunami on the ocean. The wave of short-circuiting cells travels almost imperceptibly, at a speed of 1 to 5 millimeters per minute.

Previous studies had suggested that depolarizations would last no longer than two or three minutes. But Hartings and his team have shown that, after trauma, they can be very long-lasting.

"We found that 25 percent of the cortical spreading depolarizations lasted longer than three minutes, with durations that ranged up to 16 minutes," Hartings says. "These are the types of depolarizations that are typically observed with a developing brain infarction, or stroke. It was a surprise to see them in trauma."

To measure depolarizations, researchers placed a linear strip of electrodes on the surface of the brain, near the injured area, during neurosurgery at UC Health University Hospital. Only patients who required neurosurgery to treat their injuries were enrolled in the study. The electrode strip records computerized brainwaves similar to those of an EEG. But whereas EEG electrodes are placed on the scalp, spreading depolarization electrodes must be placed inside the skull, on the surface of the brain. The electrodes are removed three to seven days after implantation, without additional surgery.

New technology enabled the researchers not only to determine whether or not spreading depolarizations were occurring, but also -- for the first time -- to measure their duration. "A new signal-processing technique that we developed allowed us to measure exactly how long the cerebral cortex remains short-circuited, or depolarized," Hartings says. "This measurement -- called the direct-current shift duration -- is a direct index of how harmful the depolarization is, and of the brain's degree of injury."

The signal-processing technique is a computer program that Hartings and his colleagues published in 2009 in the Journal of Neurophysiology.


Story Source:

The above story is based on materials provided by University of Cincinnati Academic Health Center. Note: Materials may be edited for content and length.


Journal Reference:

  1. J. A. Hartings, T. Watanabe, M. R. Bullock, D. O. Okonkwo, M. Fabricius, J. Woitzik, J. P. Dreier, A. Puccio, L. A. Shutter, C. Pahl, A. J. Strong. Spreading depolarizations have prolonged direct current shifts and are associated with poor outcome in brain trauma. Brain, 2011; DOI: 10.1093/brain/awr048

Cite This Page:

University of Cincinnati Academic Health Center. "Electrical brain disturbances linked to worse outcomes following neurotrauma." ScienceDaily. ScienceDaily, 19 May 2011. <www.sciencedaily.com/releases/2011/05/110519135114.htm>.
University of Cincinnati Academic Health Center. (2011, May 19). Electrical brain disturbances linked to worse outcomes following neurotrauma. ScienceDaily. Retrieved October 25, 2014 from www.sciencedaily.com/releases/2011/05/110519135114.htm
University of Cincinnati Academic Health Center. "Electrical brain disturbances linked to worse outcomes following neurotrauma." ScienceDaily. www.sciencedaily.com/releases/2011/05/110519135114.htm (accessed October 25, 2014).

Share This



More Mind & Brain News

Saturday, October 25, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Academic Scandal Shocks UNC

Academic Scandal Shocks UNC

AP (Oct. 23, 2014) A scandal involving bogus classes and inflated grades at the University of North Carolina was bigger than previously reported, a new investigation found. (Oct. 23) Video provided by AP
Powered by NewsLook.com
Working Mother Getaway: Beaches Turks & Caicos

Working Mother Getaway: Beaches Turks & Caicos

Working Mother (Oct. 22, 2014) Feast your eyes on this gorgeous family-friendly resort. Video provided by Working Mother
Powered by NewsLook.com
What Your Favorite Color Says About You

What Your Favorite Color Says About You

Buzz60 (Oct. 22, 2014) We all have one color we love to wear, and believe it or not, your color preference may reveal some of your character traits. In celebration of National Color Day, Krystin Goodwin (@kyrstingoodwin) highlights what your favorite colors may say about you. Video provided by Buzz60
Powered by NewsLook.com
First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

First-Of-Its-Kind Treatment Gives Man Ability To Walk Again

Newsy (Oct. 21, 2014) A medical team has for the first time given a man the ability to walk again after transplanting cells from his brain onto his severed spinal cord. 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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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