MRC Brain Network Dynamics Unit, University of Oxford, Oxford, UK.
Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
Mov Disord. 2021 Apr;36(4):863-873. doi: 10.1002/mds.28513. Epub 2021 Feb 6.
High-frequency thalamic stimulation is an effective therapy for essential tremor, which mainly affects voluntary movements and/or sustained postures. However, continuous stimulation may deliver unnecessary current to the brain due to the intermittent nature of the tremor.
We proposed to close the loop of thalamic stimulation by detecting tremor-provoking movement states using local field potentials recorded from the same electrodes implanted for stimulation, so that the stimulation is only delivered when necessary.
Eight patients with essential tremor participated in this study. Patient-specific support vector machine classifiers were first trained using data recorded while the patient performed tremor-provoking movements. Then, the trained models were applied in real-time to detect these movements and triggered the delivery of stimulation.
Using the proposed method, stimulation was switched on for 80.37 ± 7.06% of the time when tremor-evoking movements were present. In comparison, the stimulation was switched on for 12.71 ± 7.06% of the time when the patients were at rest and tremor-free. Compared with continuous stimulation, a similar amount of tremor suppression was achieved while only delivering 36.62 ± 13.49% of the energy used in continuous stimulation.
The results suggest that responsive thalamic stimulation for essential tremor based on tremor-provoking movement detection can be achieved without any requirement for external sensors or additional electrocorticography strips. Further research is required to investigate whether the decoding model is stable across time and generalizable to the variety of activities patients may engage with in everyday life. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
高频丘脑刺激是治疗原发性震颤的有效方法，主要影响随意运动和/或持续姿势。然而，由于震颤的间歇性，连续刺激可能会向大脑输送不必要的电流。
我们通过使用从植入刺激的相同电极记录的局部场电位来检测震颤诱发的运动状态，从而提出闭环丘脑刺激，以便仅在必要时才提供刺激。
8 名原发性震颤患者参与了这项研究。首先使用患者在进行震颤诱发运动时记录的数据来训练针对患者的支持向量机分类器。然后，将训练有素的模型实时应用于检测这些运动并触发刺激的传递。
使用所提出的方法，当存在震颤诱发运动时，刺激开启了 80.37±7.06%的时间。相比之下，当患者处于休息且无震颤状态时，刺激开启了 12.71±7.06%的时间。与连续刺激相比，在仅输送连续刺激所用能量的 36.62±13.49%的情况下，实现了类似的震颤抑制效果。
结果表明，基于震颤诱发运动检测的原发性震颤反应性丘脑刺激可以在不依赖外部传感器或额外脑电图带的情况下实现。需要进一步研究来研究解码模型是否随时间稳定且可推广到患者在日常生活中可能参与的各种活动。©2021 作者。运动障碍由 Wiley Periodicals LLC 代表国际帕金森病和运动障碍学会出版。
