Adaptive deep brain stimulation in a freely moving parkinsonian patient

The future of deep brain stimulation (DBS) for Parkinson's disease (PD) lies in new closed‐loop systems that continuously supply the implanted stimulator with new settings obtained by analyzing a feedback signal related to the patient's current clinical condition.1 The most suitable feedback for PD is subthalamic local field potential (LFP) activity recorded from the stimulating electrode itself.2, 3, 4 This closed‐loop technology known as adaptive DBS (aDBS) recently proved superior to conventional open‐loop DBS (cDBS) in patients with PD.2 No studies have yet tested aDBS in freely moving humans for a prolonged time. This information is an essential prerequisite for developing new implantable aDBS devices for chronic PD treatment. In this single‐case study, we tested whether a portable DBS device we developed is suitable to compare the clinical benefit in a freely moving PD patient induced by either aDBS or cDBS. To do so, after a first experimental session for extracting patient settings to personalize the aDBS algorithm, we treated a blinded patient (51 y old, male, 8 y PD history) with cDBS and aDBS in two separate experimental sessions each lasting 120 min, 5 and 6 d, respectively, after DBS electrode implant. To ensure reliable results, the patient underwent repeated clinical assessments every 20 min (T1‐T5) by two independent blinded neurologists through Unified Parkinson's Disease Rating Scale (UPDRS) III subsections and Rush Dyskinesia Rating Scale (see Supplemental Data for details).