ultrasound chronic pain

Could Non-Invasive Brain Procedure Help Solve Chronic Pain?

/ Thomas Cohn, MD

ultrasound brainResearchers out of Virginia Tech are exploring the possibility of using targeted soundwaves to put an end to chronic pain sensations.

According to the research published in the journal PAIN on Feb. 5, researchers believe that low-intensity soundwaves aimed at a place deep in the brain called the insula could positively impact the perception of pain as well as some of the bodily effects of chronic pain, like heart rate variability.

““This is a proof-of-principle study,” said study lead author Wynn Legon, an assistant professor at the Fralin Biolmedical Research Institute at Virginia Tech. “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?”

Harnessing Ultrasound Technology

Ultrasound technology is commonly associated with the ability to view a baby inside a mother’s womb, but it has plenty of other helpful medical uses. High intensity ultrasound can ablate tissues, while low intensity soundwaves can alter electrical activity within a nerve. The latter was the idea behind Legon’s latest study.

For the study involving 23 patients, researchers applied heat to the back of their hands to induce discomfort. At the same time, a wearable headpiece delivered focused ultrasound waves to a specific spot in their brain that was guided by magnetic resonance imaging. Participants were asked to rate their pain perception during each application from zero to nine. At the same time, researchers monitored a person’s heart and heart rate variability, which can help to interpret the body’s reaction to painful stimulus.

When the soundwaves were administered, 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. “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.”

The study also found that the ultrasound application reduced the measured physical responses to the stress of pain – heart rate and heart rate variability.

“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.”

Although the research is in its infancy, it presents a new angle for tackling the issue of chronic pain. Hopefully future studies will find similar results, as a non-invasive and non-addictive treatment is the ideal answer to the problem of chronic pain.

For now, if you’re looking for a more traditional way to overcome your chronic pain condition, sync up with Dr. Cohn and his team. For more information, or for help with a specific chronic pain issue, reach out to Dr. Cohn’s office today at (952) 738-4580.

Burning the Brain to Eliminate Pain

/ Thomas Cohn, MD

ultrasound brainYears ago as an engineer, I learned about using ultrasound to evaluate structures in the body. Ultrasound uses tuned sound waves and their reflections from structures to study a variety of things. In the body, one can look at various soft tissues from the heart, to the unborn infant, to nerves, muscles and a variety of tissues using ultrasound technology. In physical therapy, ultrasound can be used to provide deep tissue heating. Outside of the body, it is used in non-invasive testing of many materials including airplanes, looking for stress fractures and locations of potential failure. The overall unique feature is that sound waves are being used safely, without radiation to look at the body.

Going on to the next level of thinking, sound waves are interesting since they act like any other wave. That means waves that are exact opposites of each other can cancel each other out when they meet; this process is used in noise cancelling headphones. Combining waves from several sources can also enlarge sound waves. Sophisticated computer techniques then can focus a number of beams in one point and at this location all the energy could cause the area to heat up. For years I thought about the potential of being able to focus ultrasound beams. Now with some very sophisticated equipment, this is finally beginning to be tried on an experimental basis.

Concentrated Ultrasound and Pain

A medical trial has begun at the University of Maryland to focus beams of ultrasound to a small area in the brain in order to treat certain conditions, including neuropathic pain. Other conditions being treated are movement disorders like the tremors caused by Parkinson’s Disease. The specific pains being treated are suppose to be caused by central damage to the nervous system and must include problems in the central processing of sensory signals in the brain. The pain must be from documented damage to nerves, the spinal cord, or into the neurons in the brain. Furthermore, all people in the study currently must have failed conventional techniques, it will be given only to five patients, and they must have had phantom limb pain from an amputation, a spinal cord injury or pain that does not respond to neurosurgery.

For now, the patients are placed in a special apparatus within an MRI scanner, and over 1,000 elements focus ultrasound beams to a discreet 5-6 millimeter area of brain that is then burned and destroyed. This treatment of pain is pretty unique. At this time we have not clearly identified a region in the brain that is definitely responsible for ongoing difficulties with chronic neuropathic pain. In the past, physicians have tried to cut out various areas in the brain and even place electrodes in the brain to pace out possibly abnormal signals causing pain. Surgeons have cut nerves in all kinds of places to prevent people from having painful sensations and have even cut off body parts in attempt to solve pain problems.

However all these solutions have found very limited use and usually failed over time to be successful. The main reason is pain is a extremely complex event far beyond just electrical signals from a damaged location in the body. Pain is a perceptual event involving an emotional response to some sort of signal that can be very diffuse in the body. Destroying a part of the brain is not a reversible event especially since we have no definite way to determine if a specific location in the brain just controls all the pain signals.  

The concept of focusing an ultrasound beam to one place in the brain to stop chronic neuropathic pain is intriguing. Pausing for a second and realizing that the process destroys a segment of brain makes one review our history of other tissue destroying attempts to cure pain. Chronic pain is extremely complex. Pain physicians know from experience that there is rarely a simple solution for most patients. We have a long history of failed destructive techniques to treat pain. No matter how intriguing this may sound, until we can absolutely determine that there is an definitive correlation to pain and a specific area in the brain and that this area is causing the pain, destroying parts of the brain appears to be ill-advised. Often the less we do as physicians, the better off it is for the patient. Or as part of the Hippocratic Oath says, “do no harm.”