Imaging

November 7, 2019

Device studied as non-addictive option for chronic pain

Vanderbilt researchers are developing a focused ultrasound neuromodulation device as a non-invasive and non-addictive method for treating chronic pain.

Researchers developing a focused ultrasound neuromodulation device for treating chronic pain include, from left, Charles Caskey, PhD, William Grissom, PhD, and Li Min Chen, MD, PhD.
Researchers developing a focused ultrasound neuromodulation device for treating chronic pain include, from left, Charles Caskey, PhD, William Grissom, PhD, and Li Min Chen, MD, PhD. (photo by Susan Urmy)

With $3.6 million in funding, researchers from the Vanderbilt University Institute of Imaging Science (VUIIS) are developing a focused ultrasound neuromodulation device as a non-invasive and non-addictive method for treating chronic pain.

The funding was awarded by the National Institutes of Health (NIH) as part of the Helping to End Addiction Long-term Initiative, also known as the NIH HEAL Initiative, which aims to improve treatments for chronic pain, curb the rates of opioid use disorder and overdose and achieve long-term recovery from opioid addiction.

The device, which will look like an MRI head coil, will combine functional MRI with ultrasound neuromodulation, allowing researchers to simultaneously alter neuronal activity in brain regions associated with pain while monitoring the response in real-time using functional MRI.

While other devices to treat pain exist, their efficacy is limited by inaccurate targeting of pain regions and circuits in the brain. The VUIIS research team, which includes Charles Caskey, PhD, William Grissom, PhD, Li Min Chen, MD, PhD, and John Gore, PhD, hypothesize that ultrasound neuromodulation technology will allow for accurate and reliable stimulation of specific pain targets through enhanced, image-guided control.

“Ultrasound neuromodulation is a pretty new and exciting area because it allows you to alter activity non-invasively, with fine spatial precision, in deep or superficial brain targets,” said Grissom, associate professor of Biomedical Engineering at Vanderbilt University. “We have done a lot of work with it in animals, but the purpose of this project is to scale it up to a human-sized device and specifically try to modulate pain circuits.”

According to the researchers, drug-based treatment plans for chronic pain are associated with negative consequences, such as addiction and drug diversion. In 2016, an estimated 50 million U.S. adults suffered from chronic pain, and in 2018, an estimated 10.3 million people 12 years and older in the U.S. misused opioids.

Device-based treatments offer an alternative that may eliminate these risks.

“Despite their benefits, device-based solutions, such as deep brain stimulation, are often avoided or considered last resort, partly because it is challenging to know prior to implantation whether the pain node being stimulated will alleviate chronic pain symptoms,” the researchers wrote in their project proposal. “Understanding how different neuromodulatory effects at various targets affect pain will improve the efficacy of existing methods and guide the development of individualized treatments in the future.”

The study will target three brain regions, each of which are currently targeted by deep brain stimulation and ablation procedures for pain relief in chronic pain conditions, including post-stroke pain, pain from limb loss and cancer pain. The device will also target nociceptive pain, or pain that occurs when body tissue is damaged during surgery or by an external force, such as torn muscles after excessive exercise.

The goal of the study is to test the device’s accuracy, efficacy and safety in animals to develop a clear path for IRB-approved use of the technology in humans.

The study’s design combines multidisciplinary expertise in ultrasound (Caskey), MRI and magnetic resonance-guided focused ultrasound (Grissom) and the physiology and imaging of pain circuits (Chen and Gore). The principal investigators are all housed in VUIIS, and device testing will occur in collaboration with the Vanderbilt Institute for Surgery and Engineering (VISE).

This research is supported by grant MH-111877.