Staged bilateral FUS-STN safely improves motor features in Parkinsonism: JAMA

Unilateral magnetic resonance imaging (MRI)–guided focused ultrasound subthalamotomy (FUS-STN) improves cardinal motor features among patients with asymmetrical Parkinson's disease (PD). The feasibility of bilateral FUS-STN is as yet unexplored. A study was done to assess the safety and effectiveness of staged bilateral FUS-STN to treat Parkinson's disease. This prospective, open-label, case series study was conducted between June 18, 2019, and November 7, 2023, at HM-CINAC, Puerta del Sur University Hospital, Madrid, Spain, and included 6 patients with Parkinson's disease who had been treated with unilateral FUS-STN contralateral to their most affected body side and whose parkinsonism on the untreated side had progressed and was not optimally controlled with medication.

Primary outcomes were assessed 6 months after the second treatment and included safety (incidence and severity of adverse events after the second treatment) and effectiveness in terms of motor change (measured with the Movement Disorders Society Unified Parkinson’s Disease Rating Scale part III [MDS-UPDRS III]) in the off-medication state (ie, after at least 12 hours of antiparkinsonian drug withdrawal) compared with baseline (ie, prior to the first side ablation). Secondary outcomes included motor change in patients in the on-medication state (ie, after usual antiparkinsonian medication intake), motor complications (measured with the MDS-UPDRS IV), daily living activities (measured with the MDS-UPDRS I-II), quality of life (measured with the 39-item Parkinson’s Disease Questionnaire), change in dopaminergic treatment, patient’s global impression of change (measured with the Global Impression of Change [PGI-C] scale), and long-term (24-month) follow-up. Results: Of 45 patients previously treated with unilateral FUS-STN, 7 were lost to follow-up, and 4 were excluded due to adverse events. Of the remaining 34 patients, 6 (median age at first FUS-STN, 52.6 years [IQR, 49.0-57.3 years]; 3 women [50%]) experienced progression of parkinsonism on the untreated body side and were included. At the time of the first FUS-STN, patients’ median duration of disease was 5.7 years (IQR, 4.7-7.3 years).