Chronic adaptive versus conventional deep brain stimulation in Parkinson's disease: a blinded randomized pilot trial

BackgroundAdaptive deep brain stimulation (aDBS) is becoming a feasible therapeutic option in patients who are candidates for DBS, and implantable devices are now commercially available. We present the results of a blinded, randomized, crossover pilot trial aimed at comparing aDBS with conventional DBS (cDBS). MethodsFifteen patients were implanted with the AlphaDBS device (Newronika SpA, Milan, Italy, NCT04681534). The device replaced a previous Medtronic Activa PC at battery depletion in 11 patients, while the other four were first-time implant patients. Patients underwent two study phases: 1) a two-day, short-term follow-up in the hospital, in which patients received aDBS and cDBS for one day each (in random order); 2) a one-month, long-term follow-up at home, with patients receiving both DBS modes, each for two weeks. Safety endpoints were the occurrence of stimulation-related adverse events and the total electrical energy delivered to the tissue. The clinical endpoints were the Unified Parkinsons (part III) and Dyskinesia Disease Rating Scales used for in-clinic evaluation, and a three-day diary used for home assessment to estimate good on time without troublesome dyskinesia. At the end of the study, patients blindly decided their preferred stimulation mode. FindingsNo related adverse events were reported. The AlphaDBS device reliably recorded deep brain signals and applied a linear algorithm that changed the stimulation current every minute based on the average local field potential amplitude, calculated in a patient-specific beta frequency range. In the short-term follow-up, aDBS improved patients as much as cDBS, with lower UDysRS scores. In the long-term follow up, considering intra-patient differences, aDBS provided greater benefit than cDBS in 80% of patients. The same percentage of patients preferred and continued with aDBS (mean follow-up 316 days). InterpretationOur results suggest that aDBS is safe and effective and can be applied in a large population of parkinsonian patients who are candidates for DBS. The majority of patients improved more with aDBS than cDBS, who subjectively preferred aDBS in the long term. Further research is needed to better understand the profile of the best responders and the scheduling of aDBS.