The study, which was published in the most recent issue of Brain Stimulation, was the first of its kind on humans.1 Stavros Zanos, MD, PhD, associate professor in the Institute of Bioelectronic Medicine at Northwell Health's Feinstein Institutes for Medical Research, and his colleagues attempted to elicit an anti-inflammatory response using either focused ultrasound neuromodulation of the spleen (sFUS) or sham stimulations.
The findings were encouraging: those who received the sFUS demonstrated an anti-inflammatory effect and reduced the production of a key inflammatory protein known as tumor necrosis factor (TNF) for more than two hours after treatment.
Verywell spoke with Zanos about the experiments and their potential for future treatment options. The fact that sFUS is noninvasive is one of its most important features.
Similar results have been obtained in the past, according to Zanos, but they always required an implanted electrical device, making treatment very invasive and costly. For about 20 years, scientists have known that electrical stimulation activates the autonomic nervous system, first in mice and then in humans.
"The problem with this approach is that it involves an implant, either in the vagus nerve or in other nerves in the abdomen," Zanos explained. "Ultrasound comes into play here." We discovered that when the ultrasound parameters are set correctly, it also activates nerves."
Zanos' research focused on the spleen because the blood supply to the body passes through that organ. The spleen regulates blood levels and searches for pathogens as well as old or damaged red blood cells. The spleen contains immune cells that can affect a variety of conditions.
"A lot of very common diseases—from hypertension and obesity to heart failure and cardiac arrhythmias—are associated with chronic inflammation, and the spleen is a part of that response," he explained.
The study made use of existing ultrasound technology, but for a longer period of time than is required for basic imaging. Even after a longer period of time, Zanos reported few, if any, side effects. In fact, even the extended treatment stayed within the FDA's guidelines for a safe amount of ultrasound.
According to Stuart D. Kaplan, MD, chief of rheumatology at Mount Sinai South Nassau, inflammation can be a symptom of a variety of conditions, but it is inherently linked to autoimmune diseases. Current treatment options begin with over-the-counter anti-inflammatory medications such as ibuprofen or naproxen, but as inflammation increases beyond the benefits of these medications, so do the side effects.
The new research is promising, but human trials are still in the works. Because most inflammatory diseases are chronic, potential treatment plans could include multiple sessions of ultrasound therapy per week.
"The chronic nature of inflammation poses some difficulties." How do you go about doing this? Is it a walk-in clinic? A machine that they can use at home to self-administer the therapy?" Zanos stated. "There are some very important things we need to address in the future."
According to Zanos, future applications will use a customized ultrasound for this purpose only, removing most of the other diagnostic functionality of existing hospital ultrasound machines.