Dual threshold neural closed loop deep brain stimulation in Parkinson disease patients

Area of Science:

• Neuroscience and Neurology
• Biomedical Engineering

Background:

• Closed-loop deep brain stimulation (clDBS) in Parkinson's disease (PD) has shown efficacy primarily in acute post-operative settings with externalized equipment.
• Current limitations necessitate exploring the feasibility of chronic, implanted systems for sustained therapeutic benefits in PD management.

Purpose of the Study:

• To assess the feasibility of using an implanted neurostimulator with a novel beta dual threshold algorithm for neural closed-loop deep brain stimulation (NclDBS).
• To evaluate the efficacy of NclDBS in patients with tremor and bradykinesia dominant Parkinson's disease on chronic deep brain stimulation (DBS).

Main Methods:

• Thirteen Parkinson's disease subjects with existing open-loop DBS underwent NclDBS using an implanted clinical neurostimulator and a dual threshold algorithm targeting beta band power (13-30 Hz).
• Therapeutic voltage windows were customized per patient.
• Tremor was monitored continuously, and bradykinesia was assessed using a repetitive wrist flexion-extension task (rWFE) after 20 minutes of NclDBS. Total electrical energy delivered (TEED) was compared to open-loop DBS (olDBS).

Main Results:

• NclDBS was well-tolerated for an average of 21.67 minutes, with measurable resting beta band power.
• NclDBS demonstrated significant improvements in bradykinesia (increased rWFE velocity and frequency) and tremor control (95.4% of trial below 0.15 rad/sec).
• NclDBS achieved these benefits while using only 56.86% of the TEED compared to olDBS.

Conclusions:

• This study establishes the feasibility and efficacy of subthalamic nucleus (STN) NclDBS in Parkinson's disease patients with tremor and bradykinesia.
• Utilizing an implanted clinical neurostimulator and a novel beta power-driven dual threshold algorithm, NclDBS proved more energy-efficient than conventional olDBS in the long-term.
• These findings support the potential of NclDBS as an advanced therapeutic strategy for managing Parkinson's disease symptoms.