By targeting the subthalamus, providers can help alleviate symptoms for patients whose Parkinson’s is not controlled with medication and who are not candidates for traditional brain surgery.
Focused ultrasound may be able to help relieve symptoms for patients who are more affected by Parkinson’s disease on one side of the body than the other, according to new research out of the University of Virginia Health System.
For patients who do not respond well to medication, but who do not wish to undergo traditional brain surgery, focused ultrasound, which creates therapeutic lesions in deep-brain structures, can be a good option by targeting the subthalamic nucleus, the preferred deep-brain stimulation target for treating the characteristic motor features associated with Parkinson’s.
“This small brain region, the subthalamic nucleus, had a very strong and potent effect on parkinsonian symptoms when we targeted it with precise, focused ultrasound energy,” said researcher Jeff Elias, M.D., a neurosurgeon at UVA Health. “The key for the ultimate adoption of this new procedure will be further refinements of the technology to ensure reliability and safety.”
He and his team published the results of their investigation into the efficacy of focused ultrasound in the Dec. 24 New England Journal of Medicine.
To test how well the technology and procedure works, Elias’s team enrolled 40 patients who had distinctly asymmetric Parkinson’s disease that was not fully controlled by medication and who were ineligible for deep-brain stimulation surgery in their study. They randomly assigned the group – at a 2-to-1 ratio – to either undergo focused ultrasound subthalamotomy on the side opposite from their main motor signs or a sham procedure – 27 underwent focused ultrasound and 13 received the sham surgery.
After the procedure, the team compared the Movement Disorder Society—Unified Parkinson’s Disease Rating Scale (MDS-UPDRS) motor score at baseline and after four months for both groups. The scores, which ranged from 0-to-44 with higher scores indicating worse disease, focused on the differences between the more affected side of the body when the patient was not taking medication.
Based on their assessment, among those patients who received focused ultrasound, their MDS-UPDRS scores dropped from 19.9 at baseline to 9.9 after 4 months. The control group saw a much smaller change, only decreasing from 18.7 to 17.1. The overall difference between the groups was 8.1, the team said.
Alongside the score improvement, some patients did experience adverse events, including impairment of voluntary movements, weakness on the treated side, speech disturbance, facial weakness, and gait disturbance. Most of these cases dissipated over time.
Even with these improvements, said Binit Shah, M.D., assistant professor of neurology at UVA, more research is needed with a large group of patients over a longer period of time.
“Parkinson’s disease affects patients in more way than just tremor,” he said. “The current FDA approval for focused ultrasound in Parkinson’s disease treats only tremor. Targeting this new area allows us to improve tremor but also get more overall benefit for our patients that we previously were able to achieve.”