Dyskinesias induced by focused ultrasound subthalamotomy in Parkinson's disease are associated with better patient impression of change.

BACKGROUND: Unilateral magnetic resonance-guided focused ultrasound (MRgFUS) subthalamotomy is an effective treatment for asymmetric Parkinson's disease (PD) although it may induce dyskinesias in some patients. OBJECTIVES: We aim to assess how post-treatment dyskinesias impact patient-reported outcomes, parkinsonian improvement, and quality of life (QoL). METHODS: Thirty-four PD patients underwent MRgFUS subthalamotomy in a randomized controlled trial. They were retrospectively divided into those who developed dyskinesias (PD-Dysk) and those who did not (PD-NoDysk). Outcomes included Patient's Global Impression of Change (PGI-C), MDS-UPDRS III, levodopa equivalent daily dose (LEDD) reduction, and QoL change (PDQ-39) through 30 months. RESULTS: At four months, PD-dysk patients (n = 13) reported greater PGI-C improvement (P = 0.027) and greater LEDD reduction (P = 0.015). At 30 months, the PGI-C was numerically more favorable in PD-dysk patients, but the difference was not statistically significant (P = 0.061). Total motor improvement did not differ significantly between groups, with greater treated-side off-medication improvement in PD-dysk patients at 4 and 12 months. QoL changes did not differ significantly. CONCLUSION: Post-MRgFUS dyskinesias were associated with better perceived improvement at four months, with no statistically significant between-group differences detected in QoL or other outcomes.