Using ultrasound to stimulate a specific part of the brain could offer a non-invasive therapy that benefits those experiencing chronic pain, a new study has suggested.
The research, published in the journal Nature Communications, was conducted by experts from the University of Plymouth's Brain Research and Imaging Centre and the University of Exeter Medical School.
They invited participants to sessions where transcranial ultrasound stimulation (TUS) - a safe low-intensity and targeted neuromodulation technique - was applied to the dorsal anterior cingulate cortex (dACC), a region of the brain implicated in those experiencing chronic pain.
Dr Sam Hughes, of the University of Exeter Medical School, was involved in the study and said: "Our study represents an important first step in understanding how this technology can non-invasively stimulate deep brain regions involved in pain processing. We found that targeting a specific brain region involved in pain processing can alter how pain is perceived and change how this area communicates with other parts of the brain's pain network. The next stage of our research will be to test whether this approach can help people living with chronic pain."
During the stimulation, participants' right hand was placed in a cold gel to illicit pain sensations, and they were asked a series of questions to rate the severity of any pain they were feeling.
They also underwent MRI and magnetic resonance spectroscopy (MRS) scans throughout the same period, which researchers used to monitor any functional and biochemical changes within the participants' brain.
The results showed that while TUS had no immediate effect on the pain intensity people were feeling, they reported a significantly greater reduction in pain from 28 to 55 minutes after the TUS application, suggesting it may have a delayed analgesic effect.
The researchers say the study extends current understanding of the effects of TUS on the dorsal anterior cingulate cortex by demonstrating it can bring about functionally meaningful changes in pain perception and brain connectivity.
The also believe the findings lay important groundwork for exploring the therapeutic use of TUS in people experiencing chronic pain through conditions including fibromyalgia, back pain and arthritis, or while they are recovering after cancer treatment.
Dr Sophie Clarke, Post Doctoral Research Fellow at the University of Plymouth and the study's lead author, said: "The study aimed to characterise how transcranial ultrasound stimulation interacts with - and potentially also alters - the brain's processing of pain. Understanding these mechanisms will be very important to support the next steps in understanding whether the stimulation can be effective in helping patients with chronic pain."
Professor Elsa Fouragnan, Director of the University of Plymouth's Brain Research and Imaging Centre and CENTUS, said: "Having shown the use of ultrasound can yield positive results for people with a variety of neurological conditions, we wanted to explore what it could mean for those living with chronic pain. Most of us know someone experiencing chronic pain, and there are very few treatments that deliver any form of long-term benefit. The findings of this new work are really promising, and we are already building on it to assess whether TUS could be a beneficial and non-invasive therapeutic treatment."
