Edited by: Stefan Rampp, University Hospital Erlangen, Germany
Reviewed by: Elizabeth W. Pang, The Hospital for Sick Children, Canada; Masaki Iwasaki, National Center of Neurology and Psychiatry, Japan
This article was submitted to Brain Imaging and Stimulation, a section of the journal Frontiers in Human Neuroscience
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Magnetoencephalography (MEG) is recognized as a valuable non-invasive clinical method for localization of the epileptogenic zone and critical functional areas, as part of a pre-surgical evaluation for patients with pharmaco-resistant epilepsy. MEG is also useful in localizing functional areas as part of pre-surgical planning for tumor resection. MEG is usually performed in an outpatient setting, as one part of an evaluation that can include a variety of other testing modalities including 3-Tesla MRI and inpatient video-electroencephalography monitoring. In some clinical circumstances, however, completion of the MEG as an inpatient can provide crucial ictal or interictal localization data during an ongoing inpatient evaluation, in order to expedite medical or surgical planning. Despite well-established clinical indications for performing MEG in general, there are no current reports that discuss indications or considerations for completion of MEG on an inpatient basis. We conducted a retrospective institutional review of all pediatric MEGs performed between January 2012 and December 2020, and identified 34 cases where MEG was completed as an inpatient. We then reviewed all relevant medical records to determine clinical history, all associated diagnostic procedures, and subsequent treatment plans including epilepsy surgery and post-surgical outcomes. In doing so, we were able to identify five indications for completing the MEG on an inpatient basis: (1) super-refractory status epilepticus (SRSE), (2) intractable epilepsy with frequent electroclinical seizures, and/or frequent or repeated episodes of status epilepticus, (3) intractable epilepsy with infrequent epileptiform discharges on EEG or outpatient MEG, or other special circumstances necessitating inpatient monitoring for successful and safe MEG data acquisition, (4) MEG mapping of eloquent cortex or interictal spike localization in the setting of tumor resection or other urgent neurosurgical intervention, and (5) international or long-distance patients, where outpatient MEG is not possible or practical. MEG contributed to surgical decision-making in the majority of our cases (32 of 34). Our clinical experience suggests that MEG should be considered on an inpatient basis in certain clinical circumstances, where MEG data can provide essential information regarding the localization of epileptogenic activity or eloquent cortex, and be used to develop a treatment plan for surgical management of children with complicated or intractable epilepsy.
Magnetoencephalography (MEG) is a direct, non-invasive, neurophysiologic study that provides complimentary interictal and ictal data to electroencephalography (EEG) by recording and localizing the magnetic fields generated by brain activity in real time. MEG is particularly sensitive to epileptogenic sources that arise from the cerebral sulci and large cortical planes as they are of tangential orientation (
Magnetoencephalography is recognized as a valuable non-invasive clinical method for localization of the epileptogenic zone and critical functional areas in as part of a pre-surgical evaluation in patients with intractable epilepsy (
In most cases MEG is performed on an outpatient basis, as part of a pre-surgical evaluation that can include a variety of other testing modalities such as 3T MRI, positron emission tomography (PET), inpatient video-EEG monitoring, and single photon emission computed tomography (SPECT). This is reasonable practice given that most pre-surgical evaluations are in patients with epilepsy that is chronic but fairly stable, although intractable, and it is safe and convenient to plan the tests needed as an outpatient over a series of weeks or even months. The other reason MEG is routinely performed as an outpatient in the aforementioned group of patients is that, in the fee-for-service healthcare environment that currently exists in the U.S., insurance reimbursement for MEG that is not based on DRG (diagnosis related groups) is necessary to assure economic sustainability for most MEG centers (
All MEG studies performed at our MEG Center at Children’s Memorial Hermann Hospital in Houston, TX, United States between January 2012 and December 2020 were retrospectively reviewed. A total 34 children who had undergone inpatient MEG were identified. Relevant medical data, including hospitalizations and hospital course, epilepsy history, seizure semiology, scalp EEG data, neuroimaging studies, surgical procedures, and outpatient clinic notes were reviewed as appropriate, and for those who had subsequent neurosurgical procedures performed at our institution, post-surgical outcome and pathology were also reviewed. The seizure semiologies at the time of inpatient MEG were categorized according to the 2017 ILAE seizure-type classification (
Findings and characteristics of subjects. (Followed by the already existing explanation of abbreviations).
MEG recordings were performed in accordance with the ACMEGS clinical practice guidelines (
A total of 816 MEG studies were performed from 2012 to 2020, of which 478 (59%) were on children between 3 months and 18 years of age. Of this group, 444 (93%) of the studies were done as outpatient, and the remaining 34 (7%) were performed during hospitalization, as inpatient studies.
Overall, there were 16 females and 18 males, with a mean age of 7.3 years at the time of inpatient MEG. The most common etiology was malformation of cortical development (MCD) in 25 children (74%). Specific types of MCD findings, identified by imaging, pathology, or both, were focal cortical dysplasia (FCD) in 14 (41%), Tuberous Sclerosis Complex (TSC) in 7 (21%), polymicrogyria (PMG) in 3 (9%), and nodular grey matter heterotopia (NH) in 4 (11%), with some patients having multiple types. Three children (9%) had a vascular malformation, 2 children (6%) had hypoxic Ischemic encephalopathy from birth, 1 child (3%) had a tumor (DNET), and in 3 children (9%) etiology was unknown (see
In terms of MEG findings, interictal epileptiform localization showed a single focal cluster in 16 (47%), scattered regional in 4 (12%), scattered hemispheric in 4 (12%), bilateral multifocal in 6 (17%), and inconclusive in 4 (12%) (see
The reasons for performing inpatient MEG were determined by review of each subject’s available medical records, and five distinct indications were identified by consensus of the investigators. Relevant data for each case is presented in
The label
Three children had inpatient MEG due to ongoing pharmaco-resistant non-convulsive status epilepticus on continuous EEG monitoring. These children all had known intractable focal epilepsy, and due to an ongoing episode of SRSE, were being considered for emergent surgical intervention. In these cases, all had malformations of cortical development detectable on MRI, and focal or at least lateralized seizure activity on EEG. MEG results provided crucial localization data used in formulating a decisive plan for emergent surgical intervention that resulted in resolution of the SRSE in all three cases.
Case 1 was born at 28-weeks-gestation and had normal development until 5-years of age, when she developed intractable epilepsy with multiple seizure types including generalized tonic-clonic seizures, focal motor seizures, and head drop seizures, repeated episodes of status epilepticus, global developmental regression and progressive ataxia. Epilepsy evaluation revealed bi-frontal interictal epileptiform discharges and generalized or left-hemispheric seizure onset. High resolution epilepsy protocol MRI brain showed T2 white matter signal abnormality around the occipital horns extending to the subcortical white matter. A corpus callosotomy was performed, and immediately following the procedure she was noted to be in non-convulsive status epilepticus on EEG, with epileptiform discharges exhibiting a left hemisphere or left posterior quadrant predominance. All attempts to abort the activity with pharmacological treatment proved unsuccessful over multiple days. As she fit criteria for super-refractory status epilepticus and had lateralized EEG activity, an inpatient MEG was done emergently to explore the option of abortive epilepsy surgery. Performing the MEG evaluation required substantial coordinated planning, including use of a portable mechanical ventilator, supportive care from a respiratory therapist, PICU nurse, pediatric neurology physician, and two MEG technicians (see
Case 1
Fifteen children (44%) had inpatient MEG performed under this indication. When children with intractable epilepsy develop seizures that occur daily or become life-threatening, the usual pace of outpatient data gathering is sometimes not adequate to meet the needs of a more urgent pre-surgical evaluation. Frequent hospitalizations due to seizure exacerbations or prolonged seizures can result in missed outpatient testing appointments, or make outpatient testing unsafe or impractical. In these instances, performing the MEG during inpatient EMU admission provides a more reliable and safe way of completing the evaluation and often results in ictal MEG data acquisition, as it did in 5 children in this group (33%). Ictal localization on MEG is uncommon in most patients, but can vastly increase the helpfulness of MEG in identifying the seizure focus. The ability to gather all data in the pre-surgical evaluation as quickly as possible can also help to more efficiently finalize a plan for surgical intervention, and MEG localization can be invaluable in more precise surgical planning. Ictal MEG data can be helpful in obviating the need for invasive monitoring prior to definitive surgical intervention, be it laser ablation, resection or disconnection, corpus callosotomy, or hemispherotomy. In children with this indication, more timely surgical intervention can be life-saving, or result in vastly improved safety, quality of life, and/or developmental outcome.
Case 18 is a boy who was born at full-term with normal development and seizure onset at 18 months of age. Over the next 6 months, his epilepsy failed to respond to multiple trials of AEDs, and he started to have daily prolonged seizures and increasingly frequent episodes of status epilepticus requiring hospitalization and intubation. Seizures consisted of staring, variable head turning to either side, often followed by right greater than left clonic activity, or abrupt onset generalized clonic activity. Brain MRI showed subtle diffuse abnormal gyration and blurring of gray-white junction in multiple regions of the left hemisphere. Due to his frequent hospitalizations, outpatient MEG appointments were missed. Of note, a half-brother had undergone epilepsy surgery for intractable epilepsy as a child, which was initially successful, however, he later died from SUDEP. During an exacerbation with increased seizure frequency, the patient was admitted to the EMU. Video EEG showed frequent interictal epileptiform discharges in the left frontal and left centro-parietal region, with multiple seizures captured with left hemispheric or generalized onset. An inpatient MEG was performed and interictal and ictal epileptiform activity showed a scattered localization distributed over the left frontal and central regions (see
Case 18
In this clinical scenario, utilization of inpatient MEG helped to expedite the presurgical workup for this patient with intractable epilepsy who was experiencing daily seizures and repeated episodes of status epilepticus. Completion of the MEG as an inpatient allowed a more clear understanding of likelihood of success and risks of the various options for surgical intervention, while also providing a practical solution that allowed the patient to experience a notable improvement in overall seizure burden and consequently a significant improvement in overall quality of life. In less urgent circumstances, this MEG result would most likely have led our group to pursue a phase II evaluation with left hemispheric SEEG. However, given the risks of prolonging the time to definitive intervention, a corpus callosotomy was chosen as more appropriate, and the MEG provided crucial insight that eliminated the possibility of focal resection without phase II evaluation.
Case 7 is a girl born at full-term gestation with tuberous sclerosis complex and polycystic kidney disease caused by a deletion in 16p encompassing the TSC2 and PDK1 genes. Brain MRI revealed multiple cortical and subcortical tubers in both hemispheres and bilateral subependymal nodules. Epilepsy was diagnosed at 2 months of age when left occipital electrographic seizures with clinical correlate of intermittent eye deviation were detected on a screening scalp VEEG. These seizures continued despite multiple AED trials, and when she developed daily right-sided focal motor seizures with impaired awareness, focal epileptic spasms, and began demonstrating limitations in visual tracking and language development at 5 months of age, she was admitted to the EMU for pre-surgical evaluation. Video EEG captured multiple interictal epileptiform discharges in the left occipital region, with multiple seizures involving a left occipital onset and spread over the left posterior quadrant. Additionally, several episodes of focal epileptic spasms were captured arising from the left posterior quadrant. Due to the increasing frequency and severity of her seizures and onset of epileptic spasms, inpatient MEG was obtained during the admission. This revealed a focal cluster of interictal activity and seizure onsets in the left occipital region (see
Case 7
Magnetoencephalography was performed as an inpatient due to indication 3 in 7 of our cases (21%). Six of these children had either a previously inconclusive outpatient MEG (3), or demonstrated infrequent interictal epileptiform abnormalities on their EEGs (3). For two of the children with rare interictal abnormalities, seizures only occurred at night. Performing these MEGs in an inpatient setting allowed for more control of the conditions, such as reversing sleep-wake cycle, monitored sleep-deprivation, and reducing or holding AEDs in a safe and monitored environment. In the remaining case (case #19), social factors made outpatient preparation for testing too unpredictable, and so testing in an inpatient environment allowed for more optimal preparation of the patient.
Case 24 was adopted at 3 years of age and had unknown birth, neonatal, and early developmental history, as well as mild intellectual disability. Seizure onset was at 11 years old, with nightly nocturnal focal seizures with impaired awareness, head and body turning to the right and automatisms, which proved unresponsive to multiple AEDs. On prolonged scalp video EEG, rare interictal epileptiform discharges were seen from the left temporal region, with ictal onset that appeared generalized. Brain MRI was normal, and outpatient MEG was inconclusive due to lack of interictal discharges. MEG language testing (as an outpatient) revealed bilateral posterior temporal and inferior frontal involvement in receptive language processing. PET demonstrated hypometabolism in the left inferolateral temporal lobe. In order to obtain SPECT and maximize yield of MEG, she was admitted to EMU, antiepileptic medications were reduced, and the sleep-wake cycle was reversed using sleep deprivation. Ictal SPECT revealed increased uptake in the left frontal lobe and left insula with a lesser extent of uptake in the left temporal lobe. On the third day of admission, an inpatient MEG was done with the child asleep, and only interictal data were captured, with 70% of discharges localizing to the lateral temporal and posterior insular region, and 30% of discharges localizing to the right posterior temporal region (see
Case 24
For clinical situations in which urgent inpatient neurosurgical intervention is felt to be necessary, MEG can be performed pre-operatively as an inpatient for interictal localization or functional mapping to help guide surgical planning and decision-making. In our 2 cases, both were patients with epilepsy who were admitted when MRI detected an intracranial mass of unknown etiology, for urgent resection in the setting of a suspected malignancy.
Case 26 was an 11-year-old boy with epilepsy characterized by focal motor seizures with impaired awareness and auditory aura, with subsequent tonic-clonic generalization. Initial brain MRI had revealed a lesion in the left frontal operculum, and VEEG revealed left frontoparietal interictal epileptiform discharges. Epilepsy was initially well-controlled with AEDs, but the child was admitted when seizures became suddenly refractory to medications, and a follow-up MRI brain revealed interval growth of the lesion with caudate body, globus pallidus, and insular extension. Urgent neurosurgical intervention was recommended due to change in size of the mass and recent conversion to intractable epilepsy. Inpatient MEG was performed to localize interictal epileptiform activity and lateralize functional language activity, in relation to the mass. Receptive language processing was left hemispheric involving posterior and superior temporal and inferior parietal cortex. In an additional non-standard step, as seen in
Case 26
In 7 cases (21%), MEG was performed as an inpatient because the patient was traveling for evaluation from long distances, or internationally. In these cases, if there is no difference in reimbursement for services or cost to the family, the goal should be to make the evaluation as efficient, practical, and convenient as possible for the patient and their family.
Case 32 is a 15-year-old boy from Mexico, traveling to our institution for a second opinion regarding persistent focal seizures despite multiple surgical interventions. His seizure onset was at 7 years of age, with focal motor seizures with impaired awareness that became medically intractable; a pre-operative brain MRI had revealed focal cortical dysplasia of the left frontal lobe. Laser ablation of the left premotor area had been performed at 10 years of age, then left-sided subdural grids and subsequent left craniotomy for premotor and supplementary motor area resection at 11 years of age, followed by VNS placement at 13 years of age. As he was traveling from another country and was self-pay, all tests were performed as an inpatient as this made his evaluation faster and more efficient, with no change of cost for the family. In the EMU, VEEG revealed interictal epileptiform discharges that were left frontocentral and left temporal, as well as focal motor seizures with impaired awareness arising from the left frontal region. Inpatient MEG showed frequent ictal and interictal activity arising from the left frontal lobe, which overlapped with localization of tactile somato-sensory stimulation (see
Case 32
The most important and highest acuity indication in our cohort of cases was Indication 1: patients in super-refractory status epilepticus (SRSE) with focal or lateralized EEG. Status epilepticus (SE) is a common neurological emergency in both adults and children, with an annual incidence of 10–40 cases per 100,000 population (
In situations where pharmacologic treatments have failed in SRSE, and the EEG, semiology, or imaging suggests a potential underlying epileptic focality, considering neurosurgical treatment options is warranted (
However, there are a number of potential limitations to performing an inpatient MEG in unstable patients with SRSE, which must be taken into consideration. At present, in order for the infinitesimally small magnetic fields that are associated with epileptic discharges to be detected, MEG recordings must still be performed within a magnetically shielded room that deflects the external magnetic noise of the surrounding environment. These rooms can often be located at a distance from the intensive care unit, and it may require a coordinated team of physicians, nurses and technicians to plan and carry out successful transportation of the patient. Furthermore, a number of devices will typically accompany any patient requiring intensive care, including portable ventilators and other monitors that can be the source of considerable competing magnetic noise. Such artifacts must be adequately processed during and after recordings with the use of the tSSS method (
The preparation protocol for inpatient MEG recording in these three cases (see section “Indication 1”) was extensive, involving a step-by-step approach from the intensive care unit to the MEG recording room. As with all mobilization procedures of patients from the intensive care unit, patient transport relied on effective team communication and extensive pre-planning. To ensure safety during transport and MEG recording, the patients were transitioned from an in-room mechanical ventilator to a portable mechanical ventilator with a care team consisting of a Pediatric Transport Nurse, the Pediatric Neurologist on service, the MEG Technologist, and a Respiratory Therapist. The patient was maintained on portable mechanical ventilator support throughout the duration of MEG recording, with the care team present at bedside. The set-up involved in the magnetically shielded room is illustrated in
If medical equipment is placed a sufficient distance from the helmet, then its artifacts may be reduced to an acceptable level, such that it could be removed in signal processing. Shown here is a pediatric intensive care unit (PICU) patient during an MEG examination with an MRI-compatible ParaPAC ventilator positioned in the corner of the magnetically shielded room (red box at the lower right). It is positioned as far as possible away from the patient and the sensor helmet. The separate side table minimizes vibration artifacts. For situations where anesthesia of a patient is needed, then the suction, oxygen, intravenous lines, pulse oximetry fiber optics cable, electrocardiogram (ECG) leads, etc. can generally be brought through port tubes in the walls of the room.
Surgical management of SRSE has been successful when presurgical evaluation has identified a focal onset to seizures (
In children with severe intractable or catastrophic epilepsy (see section “Indication 2”), seizure frequency can be quite high, sometimes with many seizures occurring daily. In some patients, there is also tendency toward prolonged seizures or repeated episodes of status epilepticus, leading to frequent hospitalizations. Epilepsy in these children has severe psychological and social consequences, which imparts an increased risk of bodily injury, systemic complications, and SUDEP, all contributing to increased cumulative mortality (
In addition to the effect on mortality, frequent clinical or subclinical seizure activity can also have a negative impact on development and cognitive performance in children (
For children with intractable epilepsy who have frequent seizures or repeated episodes of SE, the impact on developmental and cognitive outcome and their high risk of morbidity and mortality adds additional urgency to completing pre-surgical evaluation and determining candidacy for epilepsy surgery. This indication was the most common one for inpatient MEG in our cohort, comprising 44% of the total. For these children, performing MEG on an inpatient basis expedited obtaining the critical mass of data required for decision-making regarding surgical candidacy and planning. Especially for children who are experiencing increased seizure frequency and unpredictable hospitalizations, inpatient testing avoids the delays and subsequent clinical deterioration that could occur during an outpatient workup.
Twelve of our 15 children in this indication group (#2) had epilepsy surgery, with time from inpatient MEG to surgery that ranged from 3 days to 8 months, and an average time to surgery of 2 months. We found that there were a variety of factors that contributed to this time lag, ranging from parental decision to further unexpected hospitalizations and scheduling delays (including those due to the COVID-19 pandemic). From the perspective of their high degree of intractability as a group, it is reassuring that 7 (58%) of the children were seizure-free after surgery, and that 75% had a surgical outcome of Engel class I or II.
Up to 26% of clinical MEG studies for epilepsy will have inconclusive results (
While the most frequent use of clinical MEG is for localization of epileptic foci in patients with intractable epilepsy, MEG is also used for pre-surgical mapping of various sensory modalities (
Although standard practice is to perform MEG as an outpatient test, the ease with which a MEG can be completed on an outpatient basis as part of a pre-surgical evaluation is heavily dependent upon the patient’s proximity to the MEG center, and to the referring Epilepsy Center. A recent Clinical MEG Survey indicated that there are currently 25 MEG centers in the United States that are considered to be actively engaged in providing significant clinical MEG services (
It is important to note that in our cohort of children in whom MEG was performed in the inpatient setting, only two children had MEG results that were non-contributory due to inconclusive data, and in one of these cases, the other testing modalities were also inconclusive, leading to the conclusion that the child was not a surgical candidate. In all the other cases, the MEG data contributed to the surgical decision-making process, even if surgery was not performed due to the family’s choice. In 15 cases (44%), the MEG provided data that was concordant with the other modalities of data, such as interictal and ictal EEG, semiology, MRI, PET, and SPECT, and provided unique information that was more specific in localization of the seizure onset zone. For 14 of these, this was due to finding a focal cluster of epileptiform discharges, and in one case a regional cluster of discharges. For this group of 15 children, nine had surgery, six of whom had Engel I outcome (77%), two had Engel II outcome (22%), and one had Engel III outcome. The only Engel III outcome was in the child with a regionally dispersed MEG cluster and a GABRG2 gene mutation. The six patients who did not have surgery either declined surgical intervention, or are scheduled for surgery at the time of this publication. In the other 17 cases where MEG contributed to the decision-making process for surgery, the MEG was concordant with other modality data in 11, and provided data that was classified as either supplementary (six cases) or confirmatory (five cases) in the decision-making process, based on review of our group’s Case Conference discussions that took place prior to surgical intervention. Of the “concordant and supplementary” classification cases, five of the six had surgery of which three had Engel I outcome and two had Engel II outcome, and one has surgery scheduled at the time of publication. In four of these, the MEG showed either hemispheric or regional localization, which extended the epileptogenic zone from that suggested by the other data alone, and resulted in decisions toward more extensive surgeries (three hemispherotomies and one POT). In the other two cases, supplementary MEG data also suggested more extensive epileptogenicity, leading to decision to recommend invasive Phase II intracranial monitoring, one of which was declined by family and the other leading to a corpus callosotomy (see section “Clinical Vignette 2”). In the five cases classified as “concordant and confirmatory,” the MEG data contributed by reinforcing data from other modalities. In Case 5, MEG findings confirmed hemispheric epileptogenicity and led to decision for hemispherotomy with an Engel I outcome. In Case 6, MEG findings confirmed bilateral and multifocal epileptogenicity, leading to decision for corpus callosotomy resulting in Engel I outcome. In Case 12, MEG results confirmed regional epileptogenicity resulting in decision for POT, which unfortunately resulted in Engel III outcome. This case then went on to have a hemispherotomy completed at another institution, which has resulted in subsequent seizure-freedom. The other two cases had MEG confirm bilateral multifocal epileptogenicity, leading to decision for VNS placement. Four cases of our cohort had MEG findings that were discordant with the other modality data. In three of these cases, the MEG findings were bilateral and multifocal, and led to decision in one to not recommend surgery (“no-go”). In the other two cases, focal surgeries were performed disregarding the MEG localization, resulting in less successful surgical outcome (Engel III). In the last case with discordant MEG data, MEG revealed a focal cluster concordant with MRI lesion but not EEG findings, which resulted in a decision to recommend Phase II invasive monitoring, subsequently refused by the family.
In this paper, we report our institutional experience with inpatient MEG in children over an 8-year period, and propose five indications for obtaining inpatient MEG. Clinical MEG is performed predominantly in an outpatient setting in the current United States healthcare environment. However, as seen in our single institution experience, there are clinical circumstances where performing MEG as an inpatient is instrumental in timely decision-making that can result in life-saving care, may increase significantly the likelihood of a successful study, or can contribute to more efficient and superior overall care of the patient. Although availability and circumstances may vary among clinical MEG centers within the United States and outside the United States, it is our hope that these indications can instruct a way of approaching children with intractable epilepsy that takes advantage of the intrinsic value of MEG in optimizing surgical decision-making and formulating more effective treatment plans, in one of the world’s most vulnerable groups of individuals with epilepsy. While further investigation is warranted to evaluate clinically significant long-term outcomes, our clinical experience demonstrates that MEG can be safely and effectively performed in inpatient settings, and can provide essential information regarding the localization of epileptogenic or functional activity that that aids in timely and informed clinical decision-making. In addition, our cohort confirms the usefulness of MEG in surgical decision-making. Our experience demonstrates that in cases with a focal cluster on MEG, more specific localizing data guides SEEG placement or focal resections that result in better surgical outcomes, and in cases with more extensive epileptogenic abnormalities, MEG can clarify the extent of epileptogenicity and thus contribute to decision-making that leads to more effective surgical choices for those children. Even discordant MEG findings can be helpful in decision-making, by leading to “no-go” decisions, Phase II evaluations, or choice of alternative treatments such as VNS or ketogenic diet, or by predicting less effective surgical outcome by indicating a more complex or extensive epileptogenic network.
The original contributions presented in the study are included in the article/supplementary files, further inquiries can be directed to the corresponding author.
The studies involving human participants were reviewed and approved by University of Texas Health Science Center Institutional Review Board: HSC-MS-17-0092, Surgical evaluation of Pediatric Epilepsy: Analysis of EEG, MEG, FDG-PET, SEEG, and ECoG in localization and seizure outcome after resective surgery. Written informed consent to participate in this study was provided by the participants’ legal guardian/next of kin. Written informed consent was obtained from the minor(s)’ legal guardian/next of kin for the publication of any potentially identifiable images or data included in this article.
GV, MF, and MW contributed to conception and design of the study. SG-T, ES, and MW organized the database. MW, GV, and ES wrote the first draft of the manuscript. MW, ES, GV, MF, and JM wrote sections of the manuscript. MF, CL, and ES designed figures and tables. All authors contributed to manuscript revision, read, and approved the submitted version.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
We would like to thank our two ABRET-certified MEG technologists, without whom this work would not be possible: Lisa Caballero, CMEG, and Wayne Mead, CMEG. They contributed to the paper not just by attending all our patients and ensuring the acquisition of high quality MEG/EEG data, but also by meticulously maintaining and updating the clinical MEG database and data server. We would also like to acknowledge Ai Sumida, MD, and Mohamed Hegazy, MD, both of whom contributed to the MEG data analysis of several of the cases, during their clinical MEG fellowships. Lastly, we would like to thank all of our epilepsy patients and their families, who honor us with their trust, and inspire us with their persistence in overcoming epilepsy.