Magnetoencephalographic detection of high-frequency activity in epilepsy patients

癫痫患者高频活动的脑磁图检测

• 批准号: 7998889
• 负责人: Manu Hegde
• 金额: $ 4.85万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7998889
• 关键词: Affect; Archives; Brain; Clinical; Detection; Disease; Electrocorticogram; Electrodes; Epilepsy; Epileptogenesis; Excision; Freedom; Frequencies; Human; Implant; Lead; Location; Magnetoencephalography; Methods; Neurons; Operative Surgical Procedures; Outcome; Pathology; Patients; Pharmaceutical Preparations; Phase; Population; Quality of life; Recurrence; Refractory; Resected; Scientific Advances and Accomplishments; Seizures; Source; Techniques; Tissues; brain tissue; improved; magnetic field; magnetoencephalogram; prospective; public health relevance; success; voltage

DESCRIPTION (provided by applicant): We propose to identify unusual types of electrical activity in the human brain that lead to seizures. Epilepsy, a tendency toward recurrent seizures, affects 0.5% of the population. While many patients with epilepsy respond to medication, 10% are medically refractory. If the source of seizures can be localized in the brain (the epileptogenic zone, EZ), surgical removal of that tissue may be possible. In straightforward cases, 80% of patients become seizure-free after such surgery, leading to significant improvements in quality-of-life. However, localizing the EZ is challenging. When traditional techniques fail, subdural electrodes may be surgically implanted to find the seizure onset or interictal spikes. In these cases, only 50% of patients receiving subsequent surgery become seizure-free. To improve EZ localization and surgical outcomes for these patients, we propose studying high-frequency low-voltage activity (HFLV), instead of the current practice of localizing interictal spikes. HFLV is a type of electrical cortical activity that has recently been associated with the EZ, both interictally and at seizure onset. While others have detected HFLV using surgically implanted subdural electrodes (electrocorticography, ECoG), we will attempt to identify HFLV using noninvasive methods. Specifically, we will use the magnetoencephalogram (MEG), which detects extracranial magnetic fields produced by neuronal current flow. In the retrospective phase of our study, we will identify HFLV in archived ECoG and MEG recordings, and determine the spatial concordance between these methods. We will then determine if removal of HFLV- associated tissue in subsequent surgery correlated with seizure freedom. We will thereby determine whether MEG is an adequate noninvasive alternative to ECoG for HFLV identification, and also validate HFLV's clinical importance. In the prospective phase, we will use MEG and ECoG systematically in patients eligible for epilepsy surgery, and determine which HFLV frequency bands (subtypes) best correlate with the epileptogenic zone. We will also study surgical outcomes and pathology of resected tissue in this prospective phase, to better understand the importance of HFLV. We believe completion of this project will advance the scientific understanding of epileptogenesis, and more importantly, improve the efficacy of epilepsy surgery for patients with this disease. PUBLIC HEALTH RELEVANCE: Localizing brain tissue responsible for seizures is challenging, but can lead to surgery that may reduce - or even eliminate - seizures for patients with epilepsy. To help identify this tissue, we will study high- frequency low-voltage electrical activity in the brain, whose importance in generating seizures was only recently recognized. We will use invasive (electrocorticography) and noninvasive (magnetoencephalography) techniques to identify this activity, and determine if its presence and location impacts the success of epilepsy surgeries.

描述（由申请人提供）：我们建议识别导致癫痫发作的人类大脑中不寻常类型的电活动。癫痫是一种倾向于反复发作的疾病，影响0.5%的人口。虽然许多癫痫患者对药物有反应，但10%的患者是医学难治性的。如果癫痫发作的来源可以定位在大脑中（致痫区，EZ），手术切除该组织可能是可能的。在简单的病例中，80%的患者在手术后没有并发症，从而显著改善了生活质量。 然而，将经济区本地化是一项挑战。当传统技术失败时，可以通过手术植入硬膜下电极来发现癫痫发作或发作间期棘波。在这些情况下，只有50%的接受后续手术的患者没有复发。为了改善这些患者的EZ定位和手术效果，我们建议研究高频低电压活动（HFLV），而不是目前的定位发作间期棘波的做法。HFLV是一种皮层电活动，最近被认为与EZ相关，在发作间期和癫痫发作时。虽然其他人已经检测到HFLV使用手术植入硬膜下电极（皮层电图，ECoG），我们将尝试识别HFLV使用非侵入性的方法。具体来说，我们将使用脑磁图（MEG），它检测由神经元电流产生的颅外磁场。 在我们研究的回顾性阶段，我们将在存档的ECoG和MEG记录中识别HFLV，并确定这些方法之间的空间一致性。然后我们将确定在随后的手术中切除HFLV相关组织是否与癫痫发作无关。因此，我们将确定MEG是否是一个足够的非侵入性替代ECoG HFLV识别，并验证HFLV的临床重要性。在前瞻性研究阶段，我们将在符合癫痫手术条件的患者中系统地使用MEG和ECoG，并确定哪些HFLV频带（亚型）与致痫区最相关。我们还将在这个前瞻性阶段研究手术结果和切除组织的病理学，以更好地了解HFLV的重要性。我们相信该项目的完成将促进对癫痫发生的科学认识，更重要的是，提高癫痫手术治疗该病的疗效。 公共卫生相关性：定位负责癫痫发作的脑组织具有挑战性，但可以导致手术，可能会减少-甚至消除-癫痫患者的癫痫发作。为了帮助识别这种组织，我们将研究大脑中的高频低压电活动，其在产生癫痫发作中的重要性直到最近才被认识到。我们将使用侵入性（皮层脑电图）和非侵入性（脑磁图）技术来识别这种活动，并确定其存在和位置是否影响癫痫手术的成功。