Tamilia Eleonora, Madsen Joseph R, Grant Patricia Ellen, Pearl Phillip L, Papadelis Christos
Fetal-Neonatal Neuroimaging and Developmental Science Center, Division of Newborn Medicine, Department of Medicine, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA.
Division of Epilepsy Surgery, Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA.
Front Neurol. 2017 Jan 30;8:14. doi: 10.3389/fneur.2017.00014. eCollection 2017.
Up to one-third of patients with epilepsy are medically intractable and need resective surgery. To be successful, epilepsy surgery requires a comprehensive preoperative evaluation to define the epileptogenic zone (EZ), the brain area that should be resected to achieve seizure freedom. Due to lack of tools and methods that measure the EZ directly, this area is defined indirectly based on concordant data from a multitude of presurgical non-invasive tests and intracranial recordings. However, the results of these tests are often insufficiently concordant or inconclusive. Thus, the presurgical evaluation of surgical candidates is frequently challenging or unsuccessful. To improve the efficacy of the surgical treatment, there is an overriding need for reliable biomarkers that can delineate the EZ. High-frequency oscillations (HFOs) have emerged over the last decade as new potential biomarkers for the delineation of the EZ. Multiple studies have shown that HFOs are spatially associated with the EZ. Despite the encouraging findings, there are still significant challenges for the translation of HFOs as epileptogenic biomarkers to the clinical practice. One of the major barriers is the difficulty to detect and localize them with non-invasive techniques, such as magnetoencephalography (MEG) or scalp electroencephalography (EEG). Although most literature has studied HFOs using invasive recordings, recent studies have reported the detection and localization of HFOs using MEG or scalp EEG. MEG seems to be particularly advantageous compared to scalp EEG due to its inherent advantages of being less affected by skull conductivity and less susceptible to contamination from muscular activity. The detection and localization of HFOs with MEG would largely expand the clinical utility of these new promising biomarkers to an earlier stage in the diagnostic process and to a wider range of patients with epilepsy. Here, we conduct a thorough critical review of the recent MEG literature that investigates HFOs in patients with epilepsy, summarizing the different methodological approaches and the main findings. Our goal is to highlight the emerging potential of MEG in the non-invasive detection and localization of HFOs for the presurgical evaluation of patients with medically refractory epilepsy (MRE).
高达三分之一的癫痫患者药物治疗无效，需要进行切除性手术。要使癫痫手术成功，需要进行全面的术前评估以确定致痫区（EZ），即应切除以实现无癫痫发作的脑区。由于缺乏直接测量EZ的工具和方法，该区域是基于大量术前非侵入性检查和颅内记录的一致数据间接定义的。然而，这些检查的结果往往一致性不足或无定论。因此，手术候选者的术前评估常常具有挑战性或不成功。为了提高手术治疗的疗效，迫切需要能够描绘EZ的可靠生物标志物。高频振荡（HFOs）在过去十年中已成为描绘EZ的新的潜在生物标志物。多项研究表明，HFOs在空间上与EZ相关。尽管有这些令人鼓舞的发现，但将HFOs作为致痫生物标志物转化为临床实践仍面临重大挑战。主要障碍之一是难以使用非侵入性技术（如脑磁图（MEG）或头皮脑电图（EEG））检测和定位它们。虽然大多数文献使用侵入性记录研究HFOs，但最近的研究报告了使用MEG或头皮EEG检测和定位HFOs。与头皮EEG相比，MEG似乎特别具有优势，因为它具有受颅骨电导率影响较小且不易受肌肉活动污染的固有优势。用MEG检测和定位HFOs将在很大程度上把这些新的有前景的生物标志物的临床应用扩展到诊断过程的早期阶段，并应用于更广泛的癫痫患者。在此，我们对最近研究癫痫患者HFOs的MEG文献进行了全面的批判性综述，总结了不同的方法学方法和主要发现。我们的目标是突出MEG在难治性癫痫（MRE）患者术前评估中对HFOs进行非侵入性检测和定位的新兴潜力。
