Key Points
- A clinical study conducted in Toronto enrolled participants with previously implanted DBS leads.
- Researchers applied low-intensity focused ultrasound neuromodulation to the globus pallidus internus (GPi) region of the brain.
Source: Darmani, G., Ramezanpour, H., Sarica, C. et al. Individualized non-invasive deep brain stimulation of the basal ganglia using transcranial ultrasound stimulation. Nat Commun 16, 2693 (2025). https://doi.org/10.1038/s41467-025-57883-7
Robert Chen, MA, MBBChir, MSc, professor of medicine (neurology) at the University of Toronto and senior scientist at Krembil Research Institute (a part of University Health Network) together with postdoctoral researcher Ghazaleh Darmani, PhD, and neurosurgeon Andres Lozano, MD, PhD, enrolled 10 patients who were previously implanted with GPi DBS leads into a low-intensity focused ultrasound neuromodulation clinical trial (NCT 06232629). Nine of the participants had DBS leads to treat Parkinson’s disease, and one had DBS for treating dystonia. The results were recently published in the journal Nature Communications.
The goal of the research study was to provide evidence of transcranial ultrasound (TUS) target engagement and specificity in deep brain structures. The research team used the GPi DBS electrodes to record local field potentials before, during, and up to one hour after the focused ultrasound neuromodulation was applied.
“Our goal was to demonstrate that TUS could meaningfully modulate signals recorded from deep brain targets, confirming target engagement with current methodologies,” said Dr. Chen. “Now that we have achieved reliable signal modulation, the next step is to evaluate the clinical benefits of TUS in deep brain targets for patients with movement disorders. With ongoing developments in TUS, patients may be able to experience the benefits of DBS noninvasively and without the need for surgery.”
Under MRI neuronavigation, the team used the Brainbox neuromodulation system to apply bilateral TUS to the GPi with either a two-minute theta-burst protocol (20 ms pulse duration, 200 ms pulse repetition interval) or a 40-second, 10-Hertz protocol (30 ms pulse duration, 100 ms pulse repetition interval) per hemisphere. The order of the protocols was assigned in random order and spaced at least one week apart. The intensity, as measured in water, was 30 Watts per square centimeter (ISPPA or spatial peak pulse average intensity) for both protocols. The left side was targeted first, then the right side underwent the same procedure. All participants also underwent a sham procedure protocol.
Interestingly, the GPi sonications were individualized to account for variations in skull density and morphology.
The electrophysiological findings collected in the clinical study suggested that focused ultrasound could be an effective and noninvasive tool for treating GPi-based neurological and psychiatric disorders.