IEEE Trans Neural Syst Rehabil Eng. 2021;29:450-457. doi: 10.1109/TNSRE.2021.3056544. Epub 2021 Mar 2.
Excessive beta band (13-30 Hz) oscillations have been observed in the basal ganglia (BG) of patients with Parkinson's disease (PD). Understanding the origin and transmission of beta band oscillations are important to improve treatments of PD, such as closed-loop deep brain stimulation (DBS). This paper proposed a model-based closed-loop GPi stimulation system to suppress pathological beta band oscillations of BG. The feedback nucleus was selected through the analysis of GPi oscillations variation when different synaptic currents were blocked, mainly projections from globus pallidus external (GPe), the subthalamic nucleus (STN) and striatum. Since simulation results proved the important role of synaptic current from GPe in shaping the excessive GPi beta band oscillations, the local field potential (LFP) of GPe was chosen as the feedback signal. That is to say, the feedback nucleus was selected based on the origin analysis of the pathological GPi beta band oscillation. The closed-loop algorithm was the multiplication of linear delayed feedback of the filtered GPe-LFP and modeled synaptic dynamics from GPe to GPi. Thus, the formed stimulation waveform was synaptic current like shape, which was proved to be more energy efficient than open-loop continuous DBS in suppressing GPi beta band oscillation. With the development of DBS devices, the efficiency of this closed-loop stimulation could be testified in animal model and clinical.
过度的β波段（13-30Hz）振荡已在帕金森病（PD）患者的基底节（BG）中观察到。了解β波段振荡的起源和传播对于改善 PD 的治疗方法（如闭环深部脑刺激（DBS））非常重要。本文提出了一种基于模型的闭环 GPi 刺激系统，以抑制 BG 的病理性β波段振荡。通过分析不同突触电流阻断时 GPi 振荡变化来选择反馈核，主要是苍白球外部（GPe）、丘脑底核（STN）和纹状体的投射。由于模拟结果证明了 GPe 中的突触电流在形成过度 GPiβ波段振荡中的重要作用，因此选择了 GPe 的局部场电位（LFP）作为反馈信号。也就是说，根据病理性 GPiβ波段振荡的起源分析选择了反馈核。闭环算法是滤波后的 GPe-LFP 的线性延迟反馈与 GPe 到 GPi 的模型化突触动力学的乘法。因此，形成的刺激波形具有类似于突触电流的形状，已被证明在抑制 GPiβ波段振荡方面比开环连续 DBS 更节能。随着 DBS 设备的发展，这种闭环刺激的效率可以在动物模型和临床中得到验证。
