Gogia Angad S, Martin Del Campo-Vera Roberto, Chen Kuang-Hsuan, Sebastian Rinu, Nune George, Kramer Daniel R, Lee Morgan B, Tafreshi Ali R, Barbaro Michael F, Liu Charles Y, Kellis Spencer, Lee Brian
Departments of1Neurological Surgery and.
2Neurology and.
Neurosurg Focus. 2020 Jul;49(1):E4. doi: 10.3171/2020.4.FOCUS20179.
Motor brain-computer interface (BCI) represents a new frontier in neurological surgery that could provide significant benefits for patients living with motor deficits. Both the primary motor cortex and posterior parietal cortex have successfully been used as a neural source for human motor BCI, leading to interest in exploring other brain areas involved in motor control. The amygdala is one area that has been shown to have functional connectivity to the motor system; however, its role in movement execution is not well studied. Gamma oscillations (30-200 Hz) are known to be prokinetic in the human cortex, but their role is poorly understood in subcortical structures. Here, the authors use direct electrophysiological recordings and the classic "center-out" direct-reach experiment to study amygdaloid gamma-band modulation in 8 patients with medically refractory epilepsy.
The study population consisted of 8 epilepsy patients (2 men; age range 21-62 years) who underwent implantation of micro-macro depth electrodes for seizure localization and EEG monitoring. Data from the macro contacts sampled at 2000 Hz were used for analysis. The classic center-out direct-reach experiment was used, which consists of an intertrial interval phase, a fixation phase, and a response phase. The authors assessed the statistical significance of neural modulation by inspecting for nonoverlapping areas in the 95% confidence intervals of spectral power for the response and fixation phases.
In 5 of the 8 patients, power spectral analysis showed a statistically significant increase in power within regions of the gamma band during the response phase compared with the fixation phase. In these 5 patients, the 95% bootstrapped confidence intervals of trial-averaged power in contiguous frequencies of the gamma band during the response phase were above, and did not overlap with, the confidence intervals of trial-averaged power during the fixation phase.
To the authors' knowledge, this is the first time that direct neural recordings have been used to show gamma-band modulation in the human amygdala during the execution of voluntary movement. This work indicates that gamma-band modulation in the amygdala could be a contributing source of neural signals for use in a motor BCI system.
运动脑机接口（BCI）是神经外科领域的一个新前沿，可为患有运动功能障碍的患者带来显著益处。初级运动皮层和顶叶后皮质均已成功用作人类运动BCI的神经源，这引发了人们对探索其他参与运动控制的脑区的兴趣。杏仁核是一个已被证明与运动系统存在功能连接的区域；然而，其在运动执行中的作用尚未得到充分研究。伽马振荡（30 - 200赫兹）在人类皮层中已知具有促运动作用，但其在皮层下结构中的作用却知之甚少。在此，作者使用直接电生理记录和经典的“中心外”直接伸手实验，对8例药物难治性癫痫患者的杏仁核伽马波段调制进行研究。
研究人群包括8例癫痫患者（2名男性；年龄范围21 - 62岁），他们接受了微 - 宏深度电极植入以进行癫痫灶定位和脑电图监测。以2000赫兹采样的宏接触数据用于分析。采用经典的中心外直接伸手实验，该实验包括试间间隔期、注视期和反应期。作者通过检查反应期和注视期频谱功率的95%置信区间内的非重叠区域，评估神经调制的统计学意义。
在8例患者中的5例中，功率谱分析显示，与注视期相比，反应期伽马波段区域内的功率在统计学上显著增加。在这5例患者中，反应期伽马波段相邻频率的试平均功率的95%自展置信区间高于注视期试平均功率的置信区间，且不与之重叠。
据作者所知，这是首次使用直接神经记录来显示人类杏仁核在自主运动执行过程中的伽马波段调制。这项工作表明，杏仁核中的伽马波段调制可能是用于运动BCI系统的神经信号的一个贡献源。
