Focused ultrasound ablation improves motor function in Parkinson’s

Patients with Parkinson’s disease (PD) who have undergone unilateral focused ultrasound ablation of the internal segment of globus pallidus show improved motor function or reduced dyskinesia over a period of 3 months, although the procedure comes with adverse events, according to a study.

A total of 94 patients with PD and dyskinesias or motor fluctuations and motor impairment in the off-medication state were randomly assigned to undergo either focused ultrasound ablation opposite the most symptomatic side of the body (active treatment, n=69) or a sham procedure (n=25).

The primary endpoint was a response at 3 months. Response defined as a decrease of at least 3 points from baseline either (1) in the score on the Movement Disorders Society–Unified Parkinson’s Disease Rating Scale part III (MDS-UPDRS III) for the treated side in the off-medication state or (2) in the score on the Unified Dyskinesia Rating Scale (UDysRS) in the on-medication state. Secondary endpoints were changes in the scores on various parts of the MDS-UPDRS at 3 months. After the 3-month blinded phase, an open-label phase was conducted until 12 months.

Of the patients, 65 in the active treatment group and 22 in the sham group completed the primary-endpoint assessment. Significantly more patients in the active treatment group than in the sham group achieved response (69 percent vs 32 percent; difference, 37 percentage points, 95 percent confidence interval, 15–60; p=0.003).

Among the responders in the active treatment group, 19 met the MDS-UPDRS III criterion only, eight met the UDysRS criterion only, and 18 met both criteria.

Results for secondary outcomes were generally consistent with the findings for the primary outcome. Of the 39 patients in the active treatment group who showed a response at 3 months and who were assessed at 12 months, 30 continued to have a response.

Pallidotomy-related adverse events included dysarthria, gait disturbance, loss of taste, visual disturbance, and facial weakness.