Tag: ultrasound

‘Sweet Spot’ for Focused Ultrasound Provides Relief from Essential Tremor

A surgical lesion site is highlighted in orange following MR-guided focused ultrasound treatment. Structural brain connections associated with optimal tremor response or side effects, as identified in the present study, are depicted in various colors. The background features an ultra-high resolution MRI image acquired at Massachusetts General Hospital. Image courtesy of Andreas Horn, Mass General Brigham.

Essential tremor, a common neurological movement disorder, causes uncontrollable shaking, most often in the hands, but it can also occur in the arms, legs, head, voice, or torso. Essential tremor impacts an estimated 1% of the worldwide population and around 5% of people over 60.

Investigators from Mass General Brigham identified a specific subregion of the brain’s thalamus that, when included during magnetic resonance-guided focused ultrasound (MRgFUS) treatment, can result in optimal and significant tremor improvements while reducing side effects. Their results are published in Science Advances.

“This one-time, noninvasive treatment can have immediate, long-lasting and lifechanging effects for patients and was pioneered here at Brigham and Women’s Hospital 30 years ago,” said co-senior author G. Rees Cosgrove, MD, FRCSC, director of functional neurosurgery at Brigham and Women’s Hospital. “The results of this study will help make the procedure even more safe and effective than it already is and will help other centres around the world improve their outcomes.”

MRgFUS treatment of essential tremor creates a small, permanent lesion in a specific nucleus in the thalamus that is thought to be part of the brain circuit mediating the disorder and disrupts the tremor-causing activity. The research team analysed data from 351 thalamotomy patients that were treated across three international hospitals, the largest cohort assessed to date, to identify the optimal location for this procedure and better understand its impacts on clinical improvements and side effects.

The study identified a set of optimal sites and brain connections to target, as well as locations and connections to avoid that lead to side effects. The team then tested whether this ‘sweet spot’ could be used as a model to predict the outcomes in a cohort of patients treated with the same procedure at another centre, which proved true. The more the ‘sweet spot’ was lesioned, the better the outcome was in all patients’ one-year, post-procedure comparison data. According to the researchers, when thalamotomy patients have good tremor control at one year, it is typically sustained over multiple years.

“Seeing how this procedure can make such a huge impact on patients’ lives is what motivated me to pursue this research,” said lead author Melissa Chua, MD, a senior resident in the Brigham’s Department of Neurosurgery. “It is very exciting to have such robust validation and to be moving toward this treatment becoming even more precise and personalized in the future.”

Next, the team plans to further analyse patient data for a more detailed picture of the evolution of this technology and how patient outcomes have improved, to fully understand the parameters that go into achieving long-term tremor control and minimise side effects.

“It is incredible when you can provide a patient with relief from these tremors,” Cosgrove said. “It is like a gift when patients who have not been able to sing, speak in public, write, or even drink from a cup for years can once again do so – we see it in case after case.”

Source: Mass General Brigham

Preventing Unnecessary Pancreatic Cancer Surgery

Pancreatic cancer. Credit: Scientific Animations CC BY-SA 4.0

Pancreatic cysts are fluid-filled sacs that can form in the pancreas. Some remain benign, while others have the potential to develop into pancreatic cancer. A recent study, which followed 257 patients in Japan for an average of five years, showed that the presence or absence of invasive nodules in pancreatic cysts is key to assessing whether these cysts are benign or cancerous.

The findings, published in the journal Annals of Surgery, may help patients diagnosed with a high risk of pancreatic cancer to avoid unnecessary surgery.

Pancreatic cancer is one of the most life-threatening and rapidly growing cancers. Pancreatic cysts, known as pancreatic intraductal papillary mucinous neoplasms (IPMNs), are gaining attention as one of the precursors of the cancer that can be identified by radiological imaging. In this context, patients diagnosed with pancreatic cysts are referred for further evaluation, and if they meet the criteria for being at particularly high risk of developing cancer, called high-risk stigmata, they are often recommended for surgery.

However, it was not clear whether all patients who met the criteria would need to undergo surgery. “In fact, among patients who underwent surgery, there were a number of cases where pathological examination results showed that their IPMNs were still benign and had not progressed to cancer,” explained Ryohei Kumano from Nagoya University, the first author of the study. “Pancreatic surgery is a significant burden for patients, so we wanted to find a more accurate way to diagnose whether their IPMNs are benign or cancerous in order to avoid unnecessary surgery.”

A research group consisting of Professor Hiroki Kawashima and Dr Kumano from Nagoya University Graduate School of Medicine, Professor Eizaburo Ohno from Fujita Health University, and their colleagues focused on the presence or absence of invasive nodules in 257 IPMN patients with high-risk stigmata. The researchers evaluated the prognosis of the patients with and without these nodules.

Invasive nodules, solid growths within cysts that have begun to invade surrounding tissues, are difficult to detect with a conventional method that uses a CAT scan. Therefore, the researchers instead used contrast-enhanced endoscopic ultrasound, which is thought to detect invasive nodules more accurately.

To track the prognosis of patients with and without invasive nodules between surgical and non-surgical groups, the researchers followed them for an average of about five years (ranging from 6 months to 24 years, depending on the patient).

The results showed that the presence or absence of invasive nodules had a significant impact on their survival. For patients with invasive nodules, undergoing surgery had a positive effect on improving their survival. On the other hand, most patients without invasive nodules had a favorable outcome even without surgery. 

Endoscopic ultrasound (EUS) enables differentiation between non-invasive and invasive nodules within IPMN, providing crucial information for surgical decision making. (Credit: Ryohei Kumano) 

In this study, a total of 21 patients who did not have invasive nodules opted for clinical monitoring instead of surgery. Notably, their five-year survival rates were 84.7% for overall survival and 100% for disease-specific survival.

In addition, in patients at higher risk for surgery, such as the elderly, there was little difference in survival rates between patients who underwent surgery and those who did not, if they had no invasive nodules. “Avoiding surgery, especially in such patients, seems to be a reasonable treatment strategy, given the fact that pancreatic surgery is highly invasive, carries a high risk of complications, and requires a long recovery period,” Kumano said.  

“We expect that our findings will contribute to future clinical guidelines for IPMNs, leading to more accurate cancer diagnosis and optimised treatment selection.”

Source: Nagoya University

Point-of-care Ultrasound Enhances Early Pregnancy Care, Cuts Emergency Visits by 81%

Photo by Mart Production on Pexels

Published in Annals of Family Medicine, a University of Minnesota Medical School research team found that implementing point-of-care ultrasounds (POCUS) to assess the viability and gestational age of pregnancies in the first trimester enhanced care for pregnant patients and cut emergency visits by 81% for non-miscarrying patients.

Previously, early pregnancy care was provided through separate appointments for ultrasound, risk assessment and patient education. This new integrated approach allows patients who are under 14 weeks pregnant to receive comprehensive care during a single visit. This includes ultrasound-based pregnancy dating, immediate assessment of pregnancy viability, risk evaluation and on-site counselling – all based on real-time ultrasound results.

“Our study demonstrates that the use of point-of-care ultrasound provides meaningful benefit to the patients we serve by addressing early pregnancy problems at the time they are identified,” said Allison Newman, MD, an assistant professor at the U of M Medical School and family medicine physician at M Health Fairview Clinic. “POCUS in early pregnancy helps clinicians more efficiently and accurately diagnose problems without compromising the quality of needed first trimester assessments – saving time, money and stress for patients.”

The research team introduced this integrated approach at M Health Fairview Clinic – Bethesda in autumn 2022, allowing the clinic to quickly identify high-risk cases and offer timely intervention for issues such as miscarriage or abnormal pregnancies. They found:

  • The clinic saw an 81% reduction in emergency visits, urgent clinic appointments and first-trimester phone inquiries for non-miscarrying patients. 
  • Clinic implementation led to more timely diagnosis of abnormal pregnancies and improved education and support for all patients, including those who experience miscarriage. 
  • For miscarriage cases, the time from initial concern to diagnosis decreased from an average of 5.8 days to 1.7 days.

Suggested next steps include rolling out the process more widely within other family medicine practices and performing a wider study across multiple sites.

Source: University of Michigan

Ultrasound Chronic Pain Relief Device Takes a Step Closer

Photo by Pawel Czerwinski on Unsplash

Chronic pain is often caused by faulty signals emerging deep within the brain, giving false alarms about a wound that has since healed, a limb that has since been amputated, or other intricate, hard-to-explain scenarios. Effective treatment options are sorely needed; now, a new device from the University of Utah may represent a practical long-sought solution, using ultrasound to target pain centres deep inside the brain.

Researchers at the University of Utah’s John and Marcia Price College of Engineering and Spencer Fox Eccles School of Medicine have published promising findings about an experimental therapy that has given many participants relief after a single treatment session.

At the core of this research is Diadem, a new biomedical device that uses ultrasound to noninvasively stimulate deep brain regions, potentially disrupting the faulty signals that lead to chronic pain.

The Diadem Device

The findings of a recent clinical trial are published in the journal PainThis study constitutes a translation of two previous studies, published in Nature Communications Engineering and IEEE Transactions on Biomedical Engineering, which describe the unique features and characteristics of the device.

The study was conducted by Jan Kubanek, professor in Price’s Department of Biomedical Engineering (BME), and Thomas Riis, a postdoctoral researcher in his lab, and other collaborators.

The randomised sham-controlled study recruited 20 participants with chronic pain, who each experienced two 40-minute sessions with Diadem, receiving either real or sham ultrasound stimulation. Patients described their pain a day and a week after their sessions, with 60% of the experimental group receiving real treatment reporting a clinical meaningful reduction in symptoms at both points.

“We were not expecting such strong and immediate effects from only one treatment,” says Riis.

“The rapid onset of the pain symptom improvements as well as their sustained nature are intriguing, and open doors for applying these noninvasive treatments to the many patients who are resistant to current treatments,” Kubanek says.

Diadem’s approach is based on neuromodulation, a therapeutic technique that seeks to directly regulate the activity of certain brain circuits. Other neuromodulation approaches are based on electric currents and magnetic fields, but those methods cannot selectively reach the brain structure investigated in the researchers’ recent trial: the anterior cingulate cortex.

After an initial functional MRI scan to map the target region, the researchers adjust Diadem’s ultrasound emitters to correct for the way the waves deflect off of the skull and other brain structures. This procedure was published in Nature Communications Engineering.

The team is now preparing for a Phase 3 clinical, trial which is the final step before FDA approval to use Diadem as a treatment for the general public.

Source: University of Utah

Most Accurate Ultrasound Test Could Detect 96% of Women with Ovarian Cancer

Photo by Mart Production on Pexels

An ultrasound test that detected 96% of ovarian cancers in postmenopausal women should replace current standard of care test in the UK according to a new study.

In a paper published in Lancet Oncology, research led by Professor Sudha Sundar from the University of Birmingham compared all currently available tests to diagnose ovarian cancer in postmenopausal women head-to-head in a high-quality diagnostic test accuracy study.

Of the six diagnostic tests investigated, the IOTA ADNEX model which looks at ultrasound features (how the lump looked like on ultrasound) had the best accuracy of all and could detect up to 96% of women with ovarian cancer.

The ultrasound test outperforms the current standard of care in the UK significantly and so the researchers recommend that the IOTA ultrasound ADNEX model should replace the current standard of care test called risk of malignancy (RMI1) test in the UK which identifies 83% of ovarian cancers.

Sudha Sundar, Professor of Gynaecological Cancer at the University of Birmingham and consultant in gynaecological cancer surgery at Sandwell and West Birmingham NHS Trust said:

“This is the first time that a head-to-head study of all available ovarian cancer tests have been done in the same population. Here we studied their use with symptomatic, postmenopausal women who are most at risk of this cancer. Our trial found that the IOTA ADNEX ultrasound protocol had highest sensitivity for detecting ovarian cancer compared to the standard of care and other test.

“The ultrasound test also performs well when delivered by a trained sonographer who have received specific training and certification and quality assurance, and as the vast majority of ultrasound scans are performed by sonographers it is important that a new standard is able to be delivered by as many clinical professionals as possible.

“We found that the higher sensitivity of the IOTA ADNEX model is likely to lead to some women who don’t have cancer also being flagged up as having a higher risk of cancer. We however did discuss this extensively with patients, cancer charity Target ovarian cancer and NHS experts who all agreed that in postmenopausal women who are at higher risk of ovarian cancer, picking up more women with cancer would benefit women overall.”

The research team note that the IOTA ADNEX model achieved 96% accuracy when delivered by NHS sonographers who were appropriately trained and received quality assurance. As most scans worldwide are carried out by sonographers rather than gynaecologists, introductory free online resources have been created by the researchers for NHS staff to undergo the specialist ultrasound training and get certification and quality assurance.

Source: University of Birmingham

Pushing Kidney-stone Fragments Reduces Stones’ Recurrence

Kidney and ureteral stones. Credit: Scientific Animations CC4.0

Sometimes all it takes is a little push. That is the conclusion of a study, published recently in the Journal of Urology, in which doctors used a handheld ultrasound device to nudge patients’ kidney-stone fragments.

As many as 50% of patients who have kidney stones removed surgically still have small fragments remaining in the kidneys afterward. Of those patients, about 25% find themselves returning for another operation within five years to remove the now-larger fragments.

UW Medicine researchers found, however, that patients who underwent the stone-moving ultrasound procedure had a 70% lower risk of such a recurrence.

“I think the main takeaways of this study are removing fragments reduces relapse and using a noninvasive, hand-held ultrasound device to help clear these kidney stone fragments,” said UW Medicine urologist Dr Jonathan Harper, the study’s senior author.

The multisite, randomised and controlled trial was conducted from May 2015 to April 2024. Almost all of the 82 participants were from the UW Medicine or the VA Puget Sound health systems. All had stone fragments that had persisted in their kidneys for months, and their ureters were free of stones and fragments.

In the study, 40 underwent ultrasound treatment to encourage fragments to clear from the kidneys, while 42 control-group members received no such treatment.

With patients awake in a clinic office setting, doctors used a wand that generated ultrasonic pulses through the skin to move the fragments closer to the ureter, where they could be naturally expelled, sometimes with the next urination, Harper noted.

Harper and his co-lead author on the paper, urologist Dr Mathew Sorensen, have worked on this technology and treatment for 15 years. They also use this technology, called burst wave lithotripsy, to blast larger stones into smaller pieces; those successes were published in 2022.

The pushing and breaking technologies are used with the same ultrasound platform.

Harper expressed hope that both clinical uses of the technology would become commonplace. A company, SonoMotion, is commercialising the technology, which was developed at the University of Washington, he added.

“I see a lot of potential in this It could become as common as getting your teeth cleaned. If you have a couple of small stones which could cause future problems, you make an office appointment and in 30 minutes you’re done.

“This could really revolutionise kidney stone treatment,” Harper said.

Source: University of Washington School of Medicine

Sonic ‘Tweezers’ can Manipulate Objects inside the Body

Photo by Pawel Czerwinski on Unsplash

In 2018, Arthur Ashkin won the Nobel Prize in Physics for inventing optical tweezers: laser beams that can be used to manipulate microscopic particles. While useful for many biological applications, optical tweezers require extremely controlled, static conditions to work properly.

“Optical tweezers work by creating a light ‘hotspot’ to trap particles, like a ball falling into a hole. But if there are other objects in the vicinity, this hole is difficult to create and move around,” says Romain Fleury, head of the Laboratory of Wave Engineering in EPFL’s School of Engineering.

Fleury and postdoctoral researchers Bakhtiyar Orazbayev and Matthieu Malléjac have spent the last four years trying to move objects in uncontrolled, dynamic environments using soundwaves. In fact, the team’s method – wave momentum shaping – is entirely indifferent to an object’s environment or even its physical properties. All the information that’s required is the object’s position, and the soundwaves do the rest.

“In our experiments, instead of trapping objects, we gently pushed them around, as you might guide a puck with a hockey stick,” Fleury explains.

The unconventional method, funded by the Swiss National Science Foundation (SNSF) Spark program, has been published in Nature Physics in collaboration with researchers from the University of Bordeaux in France, Nazarbayev University in Kazakhstan, and the Vienna University of Technology in Austria.

Very simple, very promising

If soundwaves are the hockey stick in Fleury’s analogy, then a floating object like a ping-pong ball is the puck. In the lab’s experiments, the ball was floating on the surface of a large tank of water, and its position was captured by an overhead camera. Audible soundwaves emitted from a speaker array at either end of the tank directed the ball along a pre-determined path, while a second array of microphones ‘listened’ to the feedback, called a scattering matrix, as it bounced off of the moving ball. This scattering matrix, combined with the camera’s positional data, allowed the researchers to calculate in real time the optimal momentum of the soundwaves as they nudged the ball along its path.

“The method is rooted in momentum conservation, which makes it extremely simple and general, and that’s why it’s so promising,” Fleury says.

He adds that wave momentum shaping is inspired by the optical technique of wavefront shaping, which is used to focus scattered light, but this is the first application of the concept to moving an object. What’s more, the team’s method is not limited to moving spherical objects along a path: they also used it to control rotations, and to move more complex floaters like an origami lotus.

Mimicking conditions inside the body

Once the scientists succeeded in guiding a ping-pong ball, they performed additional experiments with both stationary and moving obstacles designed to add inhomogeneity to the system. Successfully navigating the ball around these scattering objects demonstrated that wave momentum shaping could perform well even in dynamic, uncontrolled environments like a human body. Fleury adds that sound is a particularly promising tool for biomedical applications, as it is harmless and noninvasive.

“Some drug delivery methods already use soundwaves to release encapsulated drugs, so this technique is especially attractive for pushing a drug directly toward tumour cells, for example.”

Source: Ecole Polytechnique Fédérale de Lausanne

New Ultrasound and Genetics Combination Precisely Targets Neurons in Diseased Regions

McKelvey School of Engineering researchers have developed a noninvasive technology combining a holographic acoustic device with genetic engineering that allows them to precisely target affected neurons in the brain, creating the potential to precisely modulate selected cell types in multiple diseased brain regions. (Credit: Yaoheng Yang)

Brain diseases such as Parkinson’s disease involve damage in more than one region of the brain, requiring technology that could precisely and flexibly address all affected regions simultaneously. Researchers have developed a noninvasive technology combining a holographic acoustic device with genetic engineering that allows them to precisely target affected neurons in the brain. This has the potential to precisely modulate selected cell types in multiple diseased brain regions. 

Hong Chen, associate professor of biomedical engineering and neurosurgery at Washington University in St. Louis and her team created AhSonogenetics, or Airy-beam holographic sonogenetics, a technique that uses a noninvasive wearable ultrasound device to alter genetically selected neurons in the brains of mice. Results of the proof-of-concept study were published in Proceedings of the National Academy of Sciences

AhSonogenetics brings together several of Chen’s group’s recent advances into one technology. In 2021, she and her team launched Sonogenetics, a method that uses focused ultrasound to deliver a viral construct containing ultrasound-sensitive ion channels to genetically selected neurons in the brain. They use low-intensity focused ultrasound to deliver a small burst of warmth, which opens the ion channels and activates the neurons. Chen’s team was the first to show that sonogenetics could modulate the behaviour of freely moving mice.

In 2022, she and members of her lab designed and 3D-printed a flexible and versatile tool known as an Airy beam-enabled binary acoustic metasurface that allowed them to manipulate ultrasound beams. She also is developing Sonogenetics 2.0, which combines the advantage of ultrasound and genetic engineering to modulate defined neurons noninvasively and precisely in the brains of humans and animals. AhSonogenetics brings them together as a potential method to intervene in neurodegenerative diseases. 

“By enabling precise and flexible cell-type-specific neuromodulation without invasive procedures, AhSonogenetics provides a powerful tool for investigating intact neural circuits and offers promising interventions for neurological disorders,” Chen said. 

Sonogenetics gives researchers a way to precisely control the brains, while airy-beam technology allows researchers to bend or steer the sound waves to generate arbitrary beam patterns inside the brain with a high spatial resolution. Yaoheng (Mack) Yang, a postdoctoral research associate who earned a doctorate in biomedical engineering from McKelvey Engineering in 2022, said the technology gives the researchers three unique advantages.

“Airy beam is the technology that can give us precise targeting of a smaller region than conventional technology, the flexibility to steer to the targeted brain regions, and to target multiple brain regions simultaneously,” Yang said.

Chen and her team, including first authors Zhongtao Hu, a former postdoctoral research associate, and Yang, designed each Airy-beam metasurface individually as the foundation for wearable ultrasound devices that were tailored for different applications and for precise locations in the brain.

Chen’s team tested the technique on a mouse model of Parkinson’s disease. With AhSonogenetics, they were able to stimulate two brain regions simultaneously in a single mouse, eliminating the need for multiple implants or interventions. This stimulation alleviated Parkinson’s-related motor deficits in the mouse model, including slow movements, difficulty walking and freezing behaviours.

The team’s Airy-beam device overcomes some of the limits of sonogenetics, including tailoring the design of the device to target specific brain locations, as well as incorporating the flexibility to adjust target locations in a single brain.

Hu said the device, which costs roughly $50 to make, can be tailored in size to fit various brain sizes, expanding its potential applications. 

“This technology can be used as a research platform to speed neuroscience research because of the capability to flexibly target different brain regions,” Hu said. “The affordability and ease of fabrication lower the barriers to the widespread adoption of our proposed devices by the research community for neuromodulation applications.”

Source: Washington University in St. Louis

Spinal Surgeons can Now Monitor their Procedure’s Effects Mid-surgery

Photo by Natanael Melchor on Unsplash

With technology developed at UC Riverside, scientists can, for the first time, make high resolution images of the human spinal cord during surgery. The advancement could help bring real relief to millions suffering chronic back pain.

The technology, known as fUSI or functional ultrasound imaging, not only enables clinicians to see the spinal cord, but also enables them to map the cord’s response to various treatments in real time. A paper published today in the journal Neuron details how fUSI worked for six people undergoing electrical stimulation for chronic back pain treatment.

“The fUSI scanner is freely mobile across various settings and eliminates the requirement for the extensive infrastructure associated with classical neuroimaging techniques, such as functional magnetic resonance imaging (fMRI),” said Vasileios Christopoulos, assistant professor of bioengineering at UCR who helped develop the technology. “Additionally, it offers ten times the sensitivity for detecting neuroactivation compared to fMRI.”

Until now, it has been difficult to evaluate whether a back pain treatment is working since patients are under general anaesthesia, unable provide verbal feedback on their pain levels during treatment. “With ultrasound, we can monitor blood flow changes in the spinal cord induced by the electrical stimulation. This can be an indication that the treatment is working,” Christopoulos said.

The spinal cord is an “unfriendly area” for traditional imaging techniques due to significant motion artifacts, such as heart pulsation and breathing. “These movements introduce unwanted noise into the signal, making the spinal cord an unfavorable target for traditional neuroimaging techniques,” Christopoulos said.

By contrast, fUSI is less sensitive to motion artifacts, using echoes from red blood cells in the area of interest to generate a clear image. “It’s like submarine sonar, which uses sound to navigate and detect objects underwater,” Christopoulos said. “Based on the strength and speed of the echo, they can learn a lot about the objects nearby.”

Christopoulos partnered with the USC Neurorestoration Center at Keck Hospital to test the technology on six patients with chronic low back pain. These patients were already scheduled for the last-ditch pain surgery, as no other treatments, including drugs, had helped to ease their suffering. For this surgery, clinicians stimulated the spinal cord with electrodes, in the hopes that the voltage would alleviate the patient’s discomfort and improve their quality of life.

“If you bump your hand, instinctively, you rub it. Rubbing increases blood flow, stimulates sensory nerves, and sends a signal to your brain that masks the pain,” Christopoulos said. “We believe spinal cord stimulation may work the same way, but we needed a way to view the activation of the spinal cord induced by the stimulation.”

The Neuron paper details how fUSI can detect blood flow changes at unprecedented levels of less than 1mm/s. For comparison, fMRI is only able to detect changes of 2cm/s.

“We have big arteries and smaller branches, the capillaries. They are extremely thin, penetrating your brain and spinal cord, and bringing oxygen places so they can survive,” Christopoulos said. “With fUSI, we can measure these tiny but critical changes in blood flow.”

Generally, this type of surgery has a 50% success rate, which Christopoulos hopes will be dramatically increased with improved monitoring of the blood flow changes. “We needed to know how fast the blood is flowing, how strong, and how long it takes for blood flow to get back to baseline after spinal stimulation. Now, we will have these answers,” Christopoulos said.

Moving forward, the researchers are also hoping to show that fUSI can help optimise treatments for patients who have lost bladder control due to spinal cord injury or age. “We may be able to modulate the spinal cord neurons to improve bladder control,” Christopoulos said.

“With less risk of damage than older methods, fUSI will enable more effective pain treatments that are optimised for individual patients,” Christopoulos said. “It is a very exciting development.”

Source: University of California Riverside

Focused Ultrasound can Shut Down Pain Centre in Brain

Source: CC0

A new method has been developed that could non-invasively ease pain, avoiding the side effects of pain medication and the addiction problems associated with current opioid pain relievers.

This new study by Wynn Legon, assistant professor at the Fralin Biomedical Research Institute at Virginia Tech, and his team targets the insula, the location for pain reception deep within the brain. Their study, published in the journal PAIN, found that soundwaves from low-intensity focused ultrasound aimed at this spot can reduce both the perception of pain and other effects of pain, such as heart rate changes.

“This is a proof-of-principle study,” Legon said. “Can we get the focused ultrasound energy to that part of the brain, and does it do anything? Does it change the body’s reaction to a painful stimulus to reduce your perception of pain?”

Unlike ultrasound scans, focused ultrasound delivers a narrow band of sound waves to a tiny point. At high intensity, ultrasound can ablate tissue. At low-intensity, it can cause gentler, transient biological effects, such as altering nerve cell electrical activity

Neuroscientists have long studied how non-surgical techniques, such as transcranial magnetic stimulation, might be used to treat depression and other issues. Legon’s study, however, is the first to target the insula and show that focused ultrasound can reach deep into the brain to ease pain.

The study involved 23 healthy human participants. Heat was applied to the backs of their hands to induce pain. At the same time, they wore a device that delivered focused ultrasound waves to a spot in their brain guided by magnetic resonance imaging (MRI).

Participants rated their pain perception in each application on a scale of zero to nine. Participants reported an average reduction in pain of three-fourths of a point.

“That might seem like a small amount, but once you get to a full point, it verges on being clinically meaningful,” said Legon, also an assistant professor in the School of Neuroscience in Virginia Tech’s College of Science.

“It could make a significant difference in quality of life, or being able to manage chronic pain with over-the-counter medicines instead of prescription opioids.”

Researchers also monitored each participant’s heart rate and heart rate variability as a means to discern how ultrasound to the brain also affects the body’s reaction to a painful stimulus.

The study also found the ultrasound application reduced physical responses to the stress of pain – heart rate and heart rate variability, which are associated with better overall health.

“Your heart is not a metronome. The time between your heart beats is irregular, and that’s a good thing,” Legon said.

“Increasing the body’s ability to deal with and respond to pain may be an important means of reducing disease burden.”

The effect of focused ultrasound on those factors suggests a future direction for the Legon lab’s research – to explore the heart-brain axis, or how the heart and brain influence each other, and whether pain can be mitigated by reducing its cardiovascular stress effects.

Source: Virginia Tech