Efficacy of Subthalamic Neural Closed-loop Deep Brain Stimulation for Bradykinesia in Parkinson’s Disease (P4.053)

Objective: Exaggerated neural synchrony in the beta band (13–30 Hz) in the subthalamic nucleus (STN) is a pathophysiological marker in Parkinson’s disease (PD), the attenuation of which is related to the improvement in bradykinesia. We compared the efficacy of neural closed-loop deep brain stimulation (NclDBS) for bradykinesia using whole- and sub-beta bands. Background: NclDBS for PD has shown promise over open-loop (ol)DBS paradigms in several studies. Various groups have succeeded in using beta frequency signals to drive NclDBS and in some cases, it has proved more effective than olDBS with respect to motor disability scores (UPDRS-III). Design/Methods: Six akinetic-rigid consenting PD subjects (8 STNs) off medication performed a repetitive wrist flexion-extension task (rWFE) during blinded presentations of 140 Hz contralateral STN NclDBS and olDBS. Synchronized wrist angular velocity and STN local field potentials (LFP) were recorded during the tasks. The Activa®PC+S-NexusD3 system (FDA-, IDE-, IRB- approved, Medtronic Inc.) was used to perform NclDBS through an external computer. Results: Contralateral rWFE data corresponding to 6/8 and 3/8 STNs has been collected during 20 minutes (driven by whole beta band) and 60 minutes (driven by patient specific band) of NclDBS respectively. The rWFE root mean square angular velocity (V rms ), movement frequency and coefficient of variation (CV) of frequency significantly improved during 20 minutes of NclDBS relative to OFF DBS (p=0.031, p=0.032 and p=0.044, respectively). For the 3 STNs with 1 hour NclDBS, V rms , CV of V rms , frequency and CV of frequency improved by 836 ± 687%, 53 ± 27%, 139 ± 52% and 67 ± 24% relative to OFF DBS, respectively. The total electrical energy delivered (TEED 1s ) decreased by 21 ± 32% during 1 hour NclDBS as compared to clinical olDBS. Conclusions: NclDBS using LFP power improved the velocity, frequency and regularity of progressive bradykinesia in akinetic-rigid PD subjects and was more efficacious than olDBS. Study Supported by: Not applicable Disclosure: Dr. Bronte-Stewart has nothing to disclose. Dr. Afzal has nothing to disclose. Dr. Velisar has nothing to disclose. Dr. Anidi has nothing to disclose.