Neuroscientists prove ultrasound can be tweaked to stimulate different sensations
2012 12 06
A century after the world’s first ultrasonic detection device – invented in response to the sinking of the Titanic – Virginia Tech Carilion Research Institute scientists have provided the first neurophysiological evidence for something that researchers have long suspected: ultrasound applied to the periphery, such as the fingertips, can stimulate different sensory pathways leading to the brain.
And that’s just the tip of the iceberg. The discovery carries implications for diagnosing and treating neuropathy, which affects millions of people around the world.
"Ideally, neurologists should be able to tailor treatments to the specific sensations their patients are feeling," said William "Jamie" Tyler, an assistant professor at the Virginia Tech Carilion Research Institute, who led the study published this week in PLOS ONE. "Unfortunately, even with today’s technologies, it’s difficult to stimulate certain types of sensations without evoking others. Pulsed ultrasound allows us to selectively activate functional subsets of nerve fibers so we can study what happens when you stimulate, for example, only the peripheral fibers and central nervous system pathways that convey the sensation of fast, sharp pain or only those that convey the sensation of slow, dull, throbbing pain."
An estimated 20 million people in the United States alone suffer from neuropathy, a collection of nervous system disorders that may cause pain, numbness, and sensations of burning, itching, and tingling. One of the most common causes of neuropathy is Type 2 diabetes. Autoimmune disorders, such as lupus and Guillain-Barré syndrome; traumatic nerve injury; genetic abnormalities; movement disorders; and infectious diseases such as HIV/AIDS, Lyme disease, and leprosy can also trigger neuropathy.
"Neuropathy involves both motor nerves that control how muscles move and sensory nerves that receive sensations such as heat, pain, and touch," Tyler said. "So clinicians may use, for example, small resonator devices to vibrate the skin or lasers to heat the surface of the skin. But we wanted to develop a method that could activate superficial and deep mechanical receptors, thermal receptors, and even combinations of both. So we used pulsed ultrasound."
In the 1970s, a group of Soviet scientists made observations that ultrasound could stimulate distinct neural pathways, but their evidence was only anecdotal, with subjects merely describing sensations of heat, pain, or vibration. In the current study, the researchers used functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to provide physiological proof of those early observations.
Study participants rested their index fingers on ultrasound transducers while having their brain activity monitored with fMRI and EEG. The scientists found that they could stimulate specific somatosensory pathways just by tweaking the ultrasound waveforms.
Tyler believes the finding has important implications for pain diagnosis.
"Current methods of diagnosing and characterizing pain can sometimes seem archaic," Tyler said. "To measure pain through mechanical stimulation, for example, physicians might touch the skin with nylon monofilaments known as von Frey hairs, or they’ll stroke the skin with a paintbrush. For thermal sensory testing, patients may even plunge their hands into ice water until the pain becomes too great. We’re hoping to provide physicians with more precise diagnostic tools."
Better diagnostics will lead to better therapeutics, said neuroscientist Michael Friedlander, executive director of the Virginia Tech Carilion Research Institute.
"By combining pulsed ultrasound with the technologies to record brain activity, Jamie Tyler and his colleagues are taking this to a whole new level of diagnostics," Friedlander said. "And the diagnostics will ultimately drive the therapeutics. This research is a great example of how new technologies can be adapted for real-world, patient-centered diagnoses and treatments."
Tyler noted the discovery could lead to other applications.
"Ultrasound transducers could be fashioned into flexible, flat insoles to provide sensory stimulation to people who have lost sensation in their feet, including the elderly, who are at such risk of falling," he said. "Surgical instruments could provide tactile feedback to surgeons in training. And I can imagine countless applications for consumer electronics. Users already rely on two-way somatosensory communication with their devices, and peripheral stimulation using ultrasound could add new dimensionalities to this communication."
Researchers will now investigage which ultrasound parameters stimulate which types of nerve fibers or receptors. Tyler also hopes to study people with Type 2 diabetes who have not yet developed neuropathy, with the ultimate goal of providing clues to treating or even preventing the pain associated with the condition.
This research may get a boost from a discovery that surprised Tyler during the PLOS ONE study.
"One thing we didn’t expect is that some brain scans showed activation of pain pathways, yet the volunteers reported feeling no discomfort," Tyler said. "That’s an intriguing finding. Though we don’t yet know its full implications, being able to activate classic pain pathways without inducing perceptual pain can help us understand how the brain processes pain."
Article from: sciencecodex.com
Tune into Red Ice Radio:
Richard Alan Miller - Hour 1 - The Non-Local Mind in Holographic Reality
Carol de la Herran - Hour 1 - Robert Monroe & Altered States of Consciousness
Nick Begich - Hour 1 - Controlling the Human Mind
David Icke - Limitations of Belief & Awakening
Seth Farber & Paul Levy - Hour 1 - The Spiritual Gift of Madness
Susan Joy Rennison - A New Cosmic Age, Space Weather & Cosmic Radiation
"Network Your Senses" Siggraph2009
New optical probe senses neural activity
Neural stem cells successfully implanted into the brains of four boys
Compassion Meditation May Boost Neural Basis of Empathy
Placebo Effect’s Neural Activity Photographed for First Time
Blue Brain Project accurately predicts connections between neurons
Neuroscientists successfully control the dreams of rats. Could humans be next?
How mapping neurons could reveal how experiences affect mental wiring
Neuroscience could mean soldiers controlling weapons with minds
Synesthesia - Wikipedia
Synesthesia May Explain Healers Claims of Seeing People’s ’Aura’
Synchromusicology, Chromotherapy, Synesthesia, and the Aural Current of Electric Audiomancy (Video)
Neuroscientists produce a guide for using ultrasound to treat brain disorders in clinical emergencies
Latest News from our Front Page
DARPA’s mirror-killing membrane could change astronomy, allow total global surveillance
2013 12 06
When it launches in 2018, the James Webb Space Telescope will let us see deeper into the universe than ever before. Its enormous eye is centered around 18 octagonal mirrors which assemble to form the largest telescope mirror ever built, but someday even the James Webb Telescope (formerly the Next-Gen Space Telescope) will outlive its usefulness — and then what ...
The Nightwatchman: Crime-predicting robot aims to patrol our streets and schools
2013 12 06
Get Ready. They’ll be watching.
These new robots that are an unnerving mix between Star Wars’ R2-D2 and Doctor Who’s Daleks, are being touted as the new way to "monitor, map, and secure" the humans around them.
The robots are purported to replace security guards and watchmen, in a bid to reduce labor costs and streamline surveillance.
A company in California ...
Microsoft’s Smart Bra Will Monitor Mood & Reduce Overeating
2013 12 06
Microsoft is designing a “smart bra” that will monitor women’s health by tracking their heart rate, her emotional state, whether or not she is over-eating and more.
Sensors in the bra detect when the wearer is bored, stressed or discouraged and send a warning signal to the woman’s smartphone that she should caution from making bad food choices.
In a paper entitled, ...
“Saint” Mandela? Not So Fast!
2013 12 06
President Barack Obama has compared him to George Washington. MSNBC’s Chris Matthews heralded him as “perhaps the world’s greatest hero.”
The Las Vegas Guardian Express dispensed with the “perhaps,” declaring in headline: “Nelson Mandela World’s Greatest Hero.”
Others have christened him “the greatest man of the 20th century.” Many revere him as “the savior” of South Africa. School children worldwide read books, ...
The Legacy of Nelson Mandela: A Dissenting Opinion
2013 12 06
Nelson Mandela, rights activist, political icon and former president of South Africa, dies age 95
There is no doubt that Nelson Mandela suffered for his cause of an end to bloody apartheid, racial segregation and government oppression in South Africa:
[Mandela was a] South African anti-apartheid revolutionary as well as a politician and philanthropist who served as President of South Africa ...
|More News » |