Neuroscientists produce guide for ultrasound use to treat brain disorders in clinical emergencies

September 8, 2011 in Medical research

The discovery that low-intensity, pulsed ultrasound can be used to noninvasively stimulate intact brain circuits holds promise for engineering rapid-response medical devices. The team that made that discovery, led by William "Jamie" Tyler, an assistant professor with the Virginia Tech Carilion Research Institute, has now produced an in-depth article detailing this approach, which may one day lead to first-line therapies in combating life-threatening epileptic seizures.

Status epilepticus is a condition in which the brain is in a state of persistent seizure and which, if not halted, can lead to Sudden Unexplained Death in Epilepsy (SUDEP). But, as the recent article by Tyler and colleagues shows, ultrasonic neuromodulation does not necessarily need to be focused to attenuate , meaning that it can be quickly applied in neurocritical care situations.

"Imagine a device like an automatic external defibrillator except for the brain," said first author Yusuf Tufail, who is now a postdoctoral associate at the Salk Institute for Biological Sciences.

Published in the September issue of Nature Protocols, the article, "Ultrasonic Neuromodulation by Brain Stimulation with Transcranial Ultrasound," provides a guide for the further development and of ultrasonic neuromodulation. The authors — Yusuf Tufail, Anna Yoshihiro, and Monica M. Li of Arizona State University's School of Life Sciences; Sandipan Pati of Barrow Neurological Institute at St. Joseph's Hospital and Medical Center in Phoenix, Ariz.; and corresponding author Tyler — also published their earlier research into the feasibility of this approach in Neuron in 2010.

Ultrasound is an acoustic wave occurring at frequencies exceeding the range of human hearing. Uses range from food processing to communication and include medical imaging. Tyler and his research group have spent several years developing noninvasive methods for brain stimulation employing low-intensity, low-frequency (LILFU) ultrasound. "Much of our time had been spent on understanding the biological effects of LILFU on intact and how to control neural activity using LILFU," Tyler said.

The team has observed that the mechanical bioeffects of ultrasound are indeed capable of stimulating neuronal activity, meaning that ultrasound could join other therapies for neurological disorders — namely, implanted electrodes, such as those used in deep-brain stimulation, and external magnetic stimulators used for transcranial magnetic stimulation to treat disorders such as Parkinson's disease, major depression, and dystonia. The major advantage of using ultrasound for brain stimulation is that it can confer spatial resolution at millimeter precision while being focused through the skull to deep-brain regions without the need for invasive brain surgery, Tyler said.

"We have also shown that ultrasound can be used to stimulate synaptic transmission between groups of neurons within the brain in a manner similar to conventional implanted stimulating electrodes without generating significant heating of the brain tissue," said Tyler.

"Further studies are required to fully elucidate the many potential mechanisms underlying the ability of ultrasound to stimulate neuronal activity in the intact brain," the article states. However, while using ultrasound for brain stimulation represents a powerful new tool for clinical neuroscience, there are potential concerns, since high-intensity ultrasound is also capable of destroying biological tissues, the researchers write.

The article reports that ultrasound has been used for many hours across many weeks, "stimulating cellular circuits in the living brain without producing damage in mice as assessed with cellular, histological, ultrastructural, and behavioral methods." The researchers added a note of caution: "Additional investigations across animal species and dosage levels are required, however, before the safety can be fully ascertained."

Moving this technology forward will require scientists, engineers, and physicians spanning many disciplines. The impetus for the Nature Protocols article is to disseminate basic methods for conducting ultrasonic neuromodulation. "There is a major need for increased open communication among engineers designing ultrasound-based medical devices, neuroscientists studying the core biological effects of ultrasound, and clinicians implementing ultrasound for therapeutic interventions," said Tyler.

The Nature Protocols article poses specific questions needing to be addressed, such as how ultrasound affects neurons on a molecular and cellular level, how to correct for impedance mismatches between skin and skull interfaces, and the need for characterizing safety across different exposure times, applications, and disease states.

The research reported in the article provides the provocative demonstration that ultrasonic neuromodulation is capable of attenuating seizure activity during pharmacologically induced status epilepticus in rodents. "While other research groups have reported that focused ultrasound can modulate seizure activity in the , the approaches used in those earlier studies require timely preparations and the implementation of MRI to focus the ultrasound in an approach known as magnetic resonance-guided focused ," said Tyler. "Our findings show that clinicians may not need to take such complicated, costly, and time-consuming approaches to treating patients in critical situations."

More information: http://www.nature. … 011.371.html

Provided by Virginia Tech search and more info website

5 /5 (2 votes)  

Rank 5 /5 (2 votes)
Relevant PhysicsForums posts
  • Potential Breakthrough in Seizure Control
    created4 hours ago
  • Popping/Cracked sternum.
    created9 hours ago
  • Which Mental Illness Encompasses This Problem?
    created9 hours ago
  • A question about drug tolerance
    createdMay 23, 2012
  • Poor nutrition leading to overeating?
    createdMay 23, 2012
  • Math and dyslexia?
    createdMay 21, 2012
  • More from Physics Forums - Medical Sciences

More news stories

Implantable pain disk may help those with cancer

An estimated 3.5 million cancer patients around the globe are in severe pain from their disease, but many get no relief.

Medical research created 21 hours ago | popularity not rated yet | comments 0 | with audio podcast

Energy levels link sleep control mechanisms

Sleep, or lack of it, can determine level of cognitive performance which is linked with accidents as well as increased risk of serious health problems. Links between cell energy levels, gene transcription ...

Medical research created 23 hours ago | popularity not rated yet | comments 0

Researchers identify key brain cell in antidepressant action

(Medical Xpress) -- Antidepressant medications such as Prozac have helped improve mood and lessen anxiety in millions of people with major depression. But scientists know surprisingly little about how these drugs work.

Medical research created 23 hours ago | popularity 4.5 / 5 (2) | comments 0 | with audio podcast

Rockefeller scientists pioneer new method to determine mechanisms of drug action

(Medical Xpress) -- Knowing that a drug works is great. Knowing how it works is a luxury. And until now, determining a drug’s mechanism of action has been a tedious and difficult process for scientists.

Medical research created May 25, 2012 | popularity not rated yet | comments 0 | with audio podcast

Like curry? New biological role identified for compound used in ancient medicine

Scientists have just identified a new reason why some curry dishes, made with spices humans have used for thousands of years, might be good for you.

Medical research created May 25, 2012 | popularity 4.4 / 5 (10) | comments 2 | with audio podcast


Travel to high altitudes tied to Crohn's, colitis flare-ups

(HealthDay) -- People with inflammatory bowel disease, which includes Crohn's disease and colitis, may be at increased risk for flare-ups when they fly or travel to high altitudes for skiing or mountain climbing, ...

Of mice and mental models: Neuroscientific implications of risk-optimized behavior in the mouse

(Medical Xpress) -- Regardless of an organism’s biological complexity, every encephalized animal continuously makes under-informed behavioral choices that can have serious consequences. Despite its ubiquity, ...

Cancer may require simpler genetic mutations than previously thought

Chromosomal deletions in DNA often involve just one of two gene copies inherited from either parent. But scientists haven't known how a deletion in one gene from one parent, called a "hemizygous" deletion, can contribute ...

Inherited DNA change explains overactive leukemia gene

A small inherited change in DNA is largely responsible for overactivating a gene linked to poor treatment response in people with acute leukemia.

Tongue analysis software uses ancient Chinese medicine to warn of disease

For 5,000 years, the Chinese have used a system of medicine based on the flow and balance of positive and negative energies in the body. In this system, the appearance of the tongue is one of the measures used to classify ...

Skp2 activates cancer-promoting, glucose-processing Akt

HER2 and its epidermal growth factor receptor cousins mobilize a specialized protein to activate a major player in cancer development and sugar metabolism, scientists report in the May 25 issue of Cell.