Research from the UNC School of Medicine, published Tuesday in the New England Journal of Medicine, has demonstrated that a new method of treating Parkinson’s disease, focused ultrasound, was effective at reducing dyskinesia (involuntary movements) and motor impairment. Originally approved as a treatment by the FDA in 2016 for patients with essential tremor in 2016, data from the new pivotal trial has led to its approval to also treat dyskinesia and motor impairment.
“Focused ultrasound is an exciting new treatment for patients with certain neurological disorders,” said Vibhor Krishna, is vice chair of inpatient operations in the UNC Department of Neurosurgery and co-author of the study. “The procedure is incisionless, eliminating the risks associated with surgery. Using focused ultrasound, we can target a specific area of the brain and safely ablate the diseased tissue.”
Parkinson’s disease is a common neurological disorder, with approximately 500,000 people diagnosed with the disease in the U.S. alone. Characterized by loss of dopamine neurons in the brain, the most commonly prescribed medication for treating Parkinson’s is levodopa a central nervous system agent that is converted to dopamine in the brain. However, some patients who are treated long-term with levodopa develop dyskinesia and motor impairment characterized as a return of debilitating disease symptoms as the effectiveness of the medication decline.
For these patients, an alternative treatment such as focused ultrasound can be an important next line of treatment to counter the decline in effective oral medications.
In this pivotal trial, the investigators enrolled 94 patients with Parkinson’s disease. Of those enrolled, 69 were assigned to undergo ultrasound ablation, while the remaining 35 would receive a “sham” procedure and comprise the control group. Primary outcome was defined as response to the therapy at three months as measured by a decrease of at least three points from baseline either in the score on the Movement Disorders Society–Unified Parkinson’s Disease Rating Scale, part III (off medication state), or in the score on the Unified Dyskinesia Rating Scale (on medication state). Secondary outcomes included changes from baseline to month three in the scores on various parts of the Movement Disorders Society–Unified Parkinson’s Disease Rating Scale.
Results of the study showed that 65 patients completed the primary outcome assessment in the focused ultrasound group and 22 completed it in the control group. In the focused ultrasound group, 45 patients (69%) had a response, compared with 7 (32%) in the control group. Results for secondary outcomes were generally in the same direction as those for the primary outcome. Of the 39 patients in the active-treatment group who had had a response at three months and who were assessed at 12 months, 30 continued to have a response.
“Our research aims to optimize focused ultrasound treatment to minimize risks and maximize improvements,” Krishna said. “We observed that clinical outcomes after focused ultrasound ablation can be site-specific. Specifically, we observed two distinct hotspots in the globus pallidus that correlated with improvements in dyskinesia and motor impairment respectively. In the future, we aim to investigate whether these findings can lead to a personalized approach to treating Parkinson’s disease with focused ultrasound.”
Adverse effects related to ablation of the globus pallidus were infrequent. These included speech difficulty, visual disturbance, and gait difficulty, each one observed in only one patient, and only one serious adverse event documented one week after the treatment in one patient.