Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA.
Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA.
Epilepsia. 2023 Nov;64(11):3025-3035. doi: 10.1111/epi.17758. Epub 2023 Sep 11.
Thalamic deep brain stimulation (DBS) is an effective therapeutic option in patients with drug-resistant epilepsy. Recent DBS devices with sensing capabilities enable chronic, outpatient local field potential (LFP) recordings. Whereas beta oscillations have been demonstrated to be a useful biomarker in movement disorders, the clinical utility of DBS sensing in epilepsy remains unclear. Our aim was to determine LFP features that distinguish ictal from inter-ictal states, which may aid in tracking seizure outcomes with DBS.
Electrophysiology data were obtained from DBS devices implanted in the anterior nucleus (N = 12) or centromedian nucleus (N = 2) of the thalamus. Power spectra recorded during patient/caregiver-marked seizure events were analyzed with a method that quantitatively separates the oscillatory and non-oscillatory/aperiodic components of the LFP using non-parametric statistics, without the need for pre-specification of the frequency bands of interest. Features of the LFP parameterized using this algorithm were compared with those from inter-ictal power spectra recorded in clinic.
Oscillatory activity in multiple canonical frequency bands was identified from the power spectra in 86.48% of patient-marked seizure events. Delta oscillations were present in all patients, followed by theta (N = 10) and beta (N = 9). Although there were no differences in oscillatory LFP features between the ictal and inter-ictal states, there was a steeper decline in the 1/f slope of the aperiodic component of the LFP during seizures.
Our work highlights the potential and shortcomings of chronic LFP recordings in thalamic DBS for epilepsy. Findings suggest that no single frequency band in isolation clearly differentiates seizures, and that features of aperiodic LFP activity may be clinically-relevant biomarkers of seizures.
丘脑深部脑刺激（DBS）是耐药性癫痫患者的有效治疗选择。最近具有感应功能的 DBS 设备可实现慢性门诊局部场电位（LFP）记录。虽然β振荡已被证明是运动障碍的有用生物标志物，但 DBS 感应在癫痫中的临床应用尚不清楚。我们的目的是确定区分发作期和发作间期状态的 LFP 特征，这可能有助于通过 DBS 跟踪癫痫发作结果。
从植入丘脑前核（N=12）或中央核（N=2）的 DBS 设备中获取电生理学数据。使用一种方法分析患者/护理人员标记的癫痫发作事件期间记录的功率谱，该方法使用非参数统计量定量分离 LFP 的振荡和非振荡/无节律成分，而无需预先指定感兴趣的频带。使用该算法参数化的 LFP 特征与在诊所记录的发作间期功率谱进行比较。
在 86.48%的患者标记的癫痫发作事件中，从功率谱中识别出多个典型频率带的振荡活动。所有患者均存在δ振荡，其次是θ（N=10）和β（N=9）。尽管在发作期和发作间期状态之间，LFP 的振荡特征没有差异，但在癫痫发作期间，LFP 的 1/f 斜率的非周期性成分下降更为陡峭。
我们的工作强调了慢性丘脑 DBS 中 LFP 记录在癫痫中的潜力和局限性。研究结果表明，没有单个单独的频率带能清楚地区分癫痫发作，并且 LFP 非周期性活动的特征可能是癫痫发作的临床相关生物标志物。
