Clinical Outcomes with Chronic Adaptive Versus Conventional DBS in Parkinson's Disease: A Pilot Randomized Crossover Trial.

BACKGROUND: Currently available adaptive deep brain stimulation (aDBS) modulates stimulation guided by real-time beta-band local field potential activity, potentially offering advantages over conventional DBS (cDBS). Clinical evidence under chronic stimulation remains limited. OBJECTIVES: To compare aDBS versus cDBS efficacy in patients with Parkinson's disease (PD) under chronic stimulation. METHODS: This was a double-blind, randomized crossover trial in nine PD patients with bilateral subthalamic nucleus DBS. Patients underwent consecutive one-month periods of cDBS and aDBS after a four-month postoperative interval. aDBS used dual-threshold algorithm adjusting amplitude based on subthalamic beta-band LFP power. Primary outcomes were daily ON/OFF durations and dyskinesia duration under optimized medication. Mixed-effects ANCOVA estimated treatment effects. Bayesian analyses integrated prior evidence to assess probabilities of clinically meaningful differences. RESULTS: No statistically significant differences emerged between treatments. Directional effects varied: ON duration favored cDBS, whereas troublesome dyskinesia and UPDRS scores favored aDBS. Bayesian analyses indicated low probabilities that these differences reached clinical importance (29.4% probability for cDBS advantage on ON time, 7.5% for aDBS advantage on UPDRS Part III). Moderate-to-substantial between-patient heterogeneity was observed in comparative treatment effects across outcomes. CONCLUSIONS: The current beta-band LFP-guided aDBS approach with dual-threshold algorithm showed efficacy comparable to cDBS in patients with PD. These findings both call for and provide a basis for appropriately powered follow-up studies to determine whether, for whom, and with which adaptive stimulation strategies aDBS offers greater benefit than cDBS-a key step in the further development of personalized aDBS.