Kumaravelu Karthik, Schmidt Stephen L, Zhao Yi, Vittert Allison, Swan Brandon D, Oza Chintan S, Peters Jennifer J, Mitchell Kyle T, Turner Dennis A, Grill Warren M
Department of Biomedical Engineering, Duke University, Durham, NC, USA.
Department of Neurology, Duke University Medical Center, Durham, NC, USA.
Brain Stimul. 2025 Aug 11;18(5):1479-1489. doi: 10.1016/j.brs.2025.08.006.
Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus (TH) is an effective therapy for suppressing tremor. One of the critical challenges to optimizing VIM-DBS therapy is the lack of robust neural biomarkers that correlate well with tremor.
To quantify biomarkers for tremor using intraoperative TH local field potential (LFP) recorded from DBS electrodes. Further, we used computational modeling to understand the biophysical basis of the recorded LFP signal.
We simultaneously recorded intraoperative TH LFP and tremor from the hand dorsum (32 participants) and during DBS at different frequencies (16 participants). Then, we simulated the effects of DBS and spatial distribution of tremor cells on calculated LFPs in a TH model.
There was a moderate correlation between tremor and LFP spectral power in the theta and alpha bands (r = 0.445 and 0.389, respectively). There was a strong correlation between tremor and peak coherence between LFP and tremor signal (r = 0.559). Postural tremor was decoded from the LFP signal with an area under the curve of ∼0.7. High frequency DBS reduced spectral power in the theta and alpha bands and tremor could be decoded from the LFP spectral power in the presence of DBS (0.429 goodness of fit R). The theta power in the simulated LFP signal varied substantially with the specific location of the bipolar contact pair of the DBS electrode used for the LFP recordings as well as the spatial distribution of tremor cells.
Theta power alone was not sufficient for prediction of tremor control. Simulations indicated that the number and distribution of tremor cells surrounding the DBS lead may explain the lack of a strong correlation between tremor and theta power.
丘脑腹中间核（VIM）的深部脑刺激（DBS）是抑制震颤的有效疗法。优化VIM-DBS治疗的关键挑战之一是缺乏与震颤密切相关的可靠神经生物标志物。
使用从DBS电极记录的术中丘脑局部场电位（LFP）来量化震颤的生物标志物。此外，我们使用计算模型来理解记录的LFP信号的生物物理基础。
我们同时记录了术中丘脑LFP和手背部的震颤（32名参与者），以及在不同频率进行DBS期间的震颤（16名参与者）。然后，我们在丘脑模型中模拟了DBS的效果以及震颤细胞的空间分布对计算出的LFP的影响。
震颤与θ和α波段的LFP频谱功率之间存在中等程度的相关性（分别为r = 0.445和0.389）。震颤与LFP和震颤信号之间的峰值相干性之间存在很强的相关性（r = 0.559）。姿势性震颤可从LFP信号中解码出来，曲线下面积约为0.7。高频DBS降低了θ和α波段的频谱功率，并且在存在DBS的情况下可以从LFP频谱功率中解码出震颤（拟合优度R为0.429）。模拟的LFP信号中的θ功率随用于LFP记录的DBS电极双极接触对的特定位置以及震颤细胞的空间分布而有很大变化。
仅θ功率不足以预测震颤控制。模拟表明，DBS导线周围震颤细胞的数量和分布可能解释了震颤与θ功率之间缺乏强相关性的原因。
