Kamali Golnoosh, Smith Rachel J, Hays Mark, Coogan Christopher, Crone Nathan E, Sarma Sridevi V, Kang Joon Y
Annu Int Conf IEEE Eng Med Biol Soc. 2020 Jul;2020:2524-2527. doi: 10.1109/EMBC44109.2020.9175954.
Surgical resection of the seizure onset zone (SOZ) could potentially lead to seizure-freedom in medically refractory epilepsy patients. However, localizing the SOZ can be a time consuming and tedious process involving visual inspection of intracranial electroencephalographic (iEEG) recordings captured during passive patient monitoring. Single pulse electrical stimulation (SPES) is currently performed on patients undergoing invasive EEG monitoring for the main purposes of mapping functional brain networks such as language and motor networks. We hypothesize that evoked responses from SPES can also be used to localize the SOZ as they may express the natural frequencies and connectivity of the iEEG network. To test our hypothesis, we construct patient specific single-input multi-output transfer function models from the evoked responses recorded from five epilepsy patients that underwent SPES evaluation and iEEG monitoring. Our preliminary results suggest that the stimulation electrodes that produced the highest gain transfer functions, as measured by the ${\mathcal{H}_\infty }$ norm, correspond to those electrodes clinically defined in the SOZ in successfully treated patients.Clinical Relevance- This study creates an innovative tool that allows clinicians to identify the seizure onset zone in medically refractory epilepsy patients using quantitative metrics thereby increasing surgical success outcomes, mitigating patient risks, and decreasing costs.
手术切除癫痫发作起始区(SOZ)可能会使药物难治性癫痫患者实现无癫痫发作。然而,定位SOZ可能是一个耗时且繁琐的过程,需要目视检查在患者被动监测期间采集的颅内脑电图(iEEG)记录。目前,单脉冲电刺激(SPES)主要用于接受侵入性脑电图监测的患者,以绘制诸如语言和运动网络等功能性脑网络。我们假设,SPES诱发的反应也可用于定位SOZ,因为它们可能反映iEEG网络的固有频率和连通性。为了验证我们的假设,我们根据五名接受SPES评估和iEEG监测的癫痫患者记录的诱发反应,构建了患者特异性单输入多输出传递函数模型。我们的初步结果表明,以${\mathcal{H}_\infty }$范数衡量,产生最高增益传递函数的刺激电极与成功治疗患者中临床定义的SOZ电极相对应。临床意义——本研究创建了一种创新工具,使临床医生能够使用定量指标识别药物难治性癫痫患者的癫痫发作起始区,从而提高手术成功率、降低患者风险并降低成本。