Huang Yongzhi, Cheeran Binith, Green Alexander L, Denison Timothy J, Aziz Tipu Z
Oxford Functional Neurosurgery Group, Nuffield Departments of Surgical Sciences, University of Oxford, Oxford OX3 9DU, UK.
Institute of Biomedical Engineering, University of Oxford, Oxford OX3 7DQ, UK.
Brain Sci. 2019 Jun 26;9(7):150. doi: 10.3390/brainsci9070150.
Deep brain stimulation (DBS) of the anterior cingulate cortex (ACC) was offered to chronic pain patients who had exhausted medical and surgical options. However, several patients developed recurrent seizures. This work was conducted to assess the effect of ACC stimulation on the brain activity and to guide safe DBS programming. A sensing-enabled neurostimulator (Activa PC + S) allowing wireless recording through the stimulating electrodes was chronically implanted in three patients. Stimulation patterns with different amplitude levels and variable ramping rates were tested to investigate whether these patterns could provide pain relief without triggering after-discharges (ADs) within local field potentials (LFPs) recorded in the ACC. In the absence of ramping, AD activity was detected following stimulation at amplitude levels below those used in chronic therapy. Adjustment of stimulus cycling patterns, by slowly ramping on/off (8-s ramp duration), was able to prevent ADs at higher amplitude levels while maintaining effective pain relief. The absence of AD activity confirmed from the implant was correlated with the absence of clinical seizures. We propose that AD activity in the ACC could be a biomarker for the likelihood of seizures in these patients, and the application of sensing-enabled techniques has the potential to advance safer brain stimulation therapies, especially in novel targets.
对于那些已经用尽药物和手术治疗方案的慢性疼痛患者，采用了前扣带回皮质（ACC）深部脑刺激（DBS）疗法。然而，有几名患者出现了复发性癫痫发作。开展这项工作是为了评估ACC刺激对大脑活动的影响，并指导安全的DBS编程。将一种能够通过刺激电极进行无线记录的具备传感功能的神经刺激器（Activa PC + S）长期植入三名患者体内。测试了具有不同振幅水平和可变斜坡率的刺激模式，以研究这些模式是否能够在不触发ACC记录的局部场电位（LFP）中的后放电（AD）的情况下缓解疼痛。在没有斜坡的情况下，在低于慢性治疗所用振幅水平的刺激后检测到了AD活动。通过缓慢开启/关闭斜坡（斜坡持续时间为8秒）来调整刺激循环模式，能够在更高振幅水平下防止AD，同时保持有效的疼痛缓解。植入物确认没有AD活动与没有临床癫痫发作相关。我们提出，ACC中的AD活动可能是这些患者癫痫发作可能性的生物标志物，并且具备传感功能的技术的应用有可能推动更安全的脑刺激疗法的发展，尤其是在新的靶点方面。
