The most significant side effects reported were mild weakness on one side of the body in two patients, which later improved, and numbness of the face and finger, which were persistent. Side effects occur if the focused ultrasound affects adjacent brain circuits, Elias said.

The procedure is simple: The ultrasound transducer looks like an old-timey helmet hairdryer, Elias said, and it is turned on while patients are undergoing an MRI. Researchers can watch the effects of the ultrasound in real-time and target it to sub-millimeter precision.

However, the treatment does not affect the progression of Parkinson’s, and has only been tested by UVa on patients with tremor-dominant presentation of the disease.

“The idea is that the tremors are just one less problem,” Elias said. “We’re not altering the course of the disease, but it’s a quality-of-life improvement.”

Now that the pilot study has concluded, researchers hope to begin a large, multicenter study to define the role of focused ultrasound in managing Parkinson’s.