Lead and Pulse Generator Migration After Spinal Cord Stimulation Implantation: Insights From an Analysis of 7322 Patients.

OBJECTIVES: Lead migration (LM) after spinal cord stimulation (SCS) implantation surgery is the most common device-related complication. Our study of lead and implantable pulse generator (IPG) migration using a large administrative claims data base aims to understand rates, risk factors, and outcomes after SCS implantation. MATERIALS AND METHODS: This retrospective cohort study used the IBM® MarketScan® (Armonk, NY) Commercial and Medicare Supplemental Databases from 2016 to 2018. Adult patients who underwent SCS surgical procedures with at least 90 days of follow-up were identified using Current Procedural Terminology (CPT®) codes. Patients with LM and IPG migration after SCS surgery were identified using the International Classification of Diseases, 10th Revision, Clinical Modification (ICD-10 CM) codes. Patients who underwent revision surgery after SCS implantation were identified using the CPT codes and ICD-10 CM codes. In addition, patient characteristics associated with LM or IPG migration, the temporal relationship of migration diagnosis, and revision surgery were evaluated in the cohort. Continuous outcomes were compared between groups using the two-sample Student t-test. The Fisher exact test was used to compare categorical outcomes between groups. RESULTS: A total of 7322 patients (64.4% percutaneous SCS) underwent SCS surgery during the study period. A total of 141 patients (1.9%) had LM or IPG migration. Of those, 116 patients (1.6%) had LM only; 18 patients (0.2%) had IPG migration; and seven patients (0.1%) had LM and IPG migration. The mean duration for migration diagnosis after initial SCS implantation was 168 (±163.1) days. The mean duration to revision surgery after the migration diagnosis was 12.3 (±35.2) days only. Most patients with migration (105, 74.5%) underwent revision surgery. Only younger age (p = 0.02) was associated with migration in this study. CONCLUSIONS: LM and pulse generator migration that required revision surgery occurred in a small proportion of patients who underwent SCS surgical procedures.

Evaluation of green light exposure on headache frequency and quality of life in migraine patients: A preliminary one-way cross-over clinical trial.

BACKGROUND: Pharmacological management of migraine can be ineffective for some patients. We previously demonstrated that exposure to green light resulted in antinociception and reversal of thermal and mechanical hypersensitivity in rodent pain models. Given the safety of green light emitting diodes, we evaluated green light as a potential therapy in patients with episodic or chronic migraine. MATERIAL AND METHODS: We recruited (29 total) patients, of whom seven had episodic migraine and 22 had chronic migraine. We used a one-way cross-over design consisting of exposure for 1-2 hours daily to white light emitting diodes for 10 weeks, followed by a 2-week washout period followed by exposure for 1-2 hours daily to green light emitting diodes for 10 weeks. Patients were allowed to continue current therapies and to initiate new treatments as directed by their physicians. Outcomes consisted of patient-reported surveys. The primary outcome measure was the number of headache days per month. Secondary outcome measures included patient-reported changes in the intensity and frequency of the headaches over a two-week period and other quality of life measures including ability to fall and stay asleep, and ability to perform work. Changes in pain medications were obtained to assess potential reduction. RESULTS: When seven episodic migraine and 22 chronic migraine patients were analyzed as separate cohorts, white light emitting diodes produced no significant change in headache days in either episodic migraine or chronic migraine patients. Combining data from the episodic migraine and chronic migraine groups showed that white light emitting diodes produced a small, but statistically significant reduction in headache days from (days ± SEM) 18.2 ± 1.8 to 16.5 ± 2.01 days. Green light emitting diodes resulted in a significant decrease in headache days from 7.9 ± 1.6 to 2.4 ± 1.1 and from 22.3 ± 1.2 to 9.4 ± 1.6 in episodic migraine and chronic migraine patients, respectively. While some improvement in secondary outcomes was observed with white light emitting diodes, more secondary outcomes with significantly greater magnitude including assessments of quality of life, Short-Form McGill Pain Questionnaire, Headache Impact Test-6, and Five-level version of the EuroQol five-dimensional survey without reported side effects were observed with green light emitting diodes. Conclusions regarding pain medications reduction with green light emitting diode exposure were not possible. No side effects of light therapy were reported. None of the patients in the study reported initiation of new therapies. DISCUSSION: Green light emitting diodes significantly reduced the number of headache days in people with episodic migraine or chronic migraine. Additionally, green light emitting diodes significantly improved multiple secondary outcome measures including quality of life and intensity and duration of the headache attacks. As no adverse events were reported, green light emitting diodes may provide a treatment option for those patients who prefer non-pharmacological therapies or may be considered in complementing other treatment strategies. Limitations of this study are the small number of patients evaluated. The positive data obtained support implementation of larger clinical trials to determine possible effects of green light emitting diode therapy.This study is registered with clinicaltrials.gov under NCT03677206.

Preresection intraoperative electrocorticography (ECoG) abnormalities predict seizure-onset zone and outcome in pediatric epilepsy surgery.

OBJECTIVE: The predictive value of intraoperative electrocorticography (ECoG) in pediatric epilepsy surgery is unknown. In a population of children undergoing ECoG followed typically by invasive extraoperative monitoring (IEM) and resection, we aimed to determine the relationship between frequent ECoG abnormalities and the seizure onset zone and outcome after resection. METHODS: We retrospectively identified 103 children with preresection ECoG of sufficient technical quality. ECoG records were scored based on electrode location and frequency, blinded to the seizure-onset zone and outcome. Electrographic seizure and spike locations were identified. Locations of seizures and spike populations were then compared to the location of seizure-onset zone defined by IEM using subdural electrodes and resection margin. RESULTS: Electrographic seizures were identified in 11 (11%) of 103 patients. A spike population of one or more was noted in 79 (77%) of 103 patients. In 50 (63%) of 79 patients, spike populations correlated with seizure-onset zone location. The overall surgical outcome was good (ILAE 1 to 3) in 53 (52%) of 101 patients. Outcome was good in seven (78%) of nine patients when electrographic seizure location was resected. The best outcomes were obtained with resection of both the seizure-onset zone and ECoG abnormalities to include seizures and spike locations (22/33 good outcome, 67%, p = 0.008). There was a significantly better outcome in children with complete resection of ECoG-identified spike populations (14/26, 62% good outcome) compared to when none were resected (4/14, 29%, p = 0.043). SIGNIFICANCE: Electrographic seizures and frequent spikes are frequently seen on pre-resection ECoG in children. The brain locations corresponding to these discharges are highly concordant with the seizure-onset zone; resection of these regions is correlated with good seizure outcome. Further research is needed to design interventions that increase the reliability of ECoG prediction of the epileptogenic zone and obviate the need for IEM.

Effects of epilepsy treatments on sleep architecture and daytime sleepiness: an evidence-based review of objective sleep metrics.

OBJECTIVE: Sleep is considered restorative, and good quantity and quality sleep is required for memory consolidation and synaptic plasticity. Sleep disorders are common in patients with epilepsy. Poor sleep quality or quantity may worsen seizure control. On the other end, seizures and epilepsy may worsen the sleep quality and set a vicious cycle. In addition, antiepileptic drugs have an effect on sleep architecture. We performed a systemic literature review with a goal to evaluate the effect of antiepileptic drugs and nondrug treatments for epilepsy on sleep architecture to help better understand treatment effects, especially in patients with epilepsy and sleep problems. METHODS: We searched PubMed and identified studies that evaluated objective sleep outcomes for an antiepileptic drug. We also searched for studies with objective sleep outcomes that evaluated other epilepsy treatments such as epilepsy surgery, vagus nerve stimulation, and ketogenic diet. RESULTS: The studies were categorized based on evidence class and study population for an individual antiepileptic drug or treatment. We identified that most antiepileptic drugs and nondrug treatments for epilepsy affect sleep architecture. SIGNIFICANCE: We identified that gabapentin, tiagabine, pregabalin, clobazam, and carbamazepine reduce sleep latency and/or improve sleep efficiency. Phenobarbital, valproic acid, and higher-dose levetiracetam aggravate daytime sleepiness, whereas topiramate and zonisamide do not. Vagus nerve stimulation reduces daytime sleepiness, and ketogenic diet improves slow-wave sleep. Epilepsy surgery may improve nocturnal sleep only in a subgroup of patients with improved seizure frequency. Further studies are needed to evaluate the dose-dependent sleep effects of antiepileptic drugs and nondrug treatments independent of the improvement of epilepsy, and to identify if these changes are clinically significant.

Value of combined video EEG and polysomnography in clinical management of children with epilepsy and daytime or nocturnal spells.

PURPOSE: Sleep disorders are common in epilepsy. Additionally, events of staring, jerking, or nocturnal behaviors are common presentations in neurology or sleep practice. Moreover, sleepiness and nocturnal awakenings are common symptoms in children with epilepsy and differentiation form ongoing seizures and sleep disorders is needed. However, limited data exist for the best evaluation methods. This study evaluated the usefulness of combined video electroencephalography (EEG) and polysomnography (PSG) studies (vEEG/PSG). METHODS: Polysomnography custom database was searched for combined vEEG/PSG studies, performed from July 2010 to April 2014, which identified 240 studies. From chart review, data were collected for presenting symptoms, sleep disorder and epilepsy/neurology diagnoses, and EEG and PSG results. RESULTS: Most common indications for performing combined vEEG/PSG were correlating sleep events with seizure occurrence, evaluating sleepiness, nocturnal awakenings and nocturnal events. Sleep physician evaluation and/or PSG were abnormal in 94% of the studies. The EEG was abnormal in 53% and events or seizures were recorded in 40% of the studies. Hence, vEEG/PSG addressed the diagnostic questions. Additionally, as compared to children with epilepsy, a significantly larger number of children with spells/parasomnia had a normal sleep evaluation including a normal PSG (9 Vs 37%, p = 0.00003). CONCLUSIONS: This study demonstrates that combined video EEG and polysomnography is useful in addressing the common management questions in children with epilepsy and suspicious nocturnal events. Additionally, sleep disorders are more common in children with epilepsy than parasomnia. Hence sleep evaluation is important in children with epilepsy. Further prospective studies are needed.

Ischemic stroke and excellent recovery after administration of intravenous tissue plasminogen activator.

Intravenous tissue plasminogen activator has become a mainstream treatment for ischemic hyperacute stroke in the adult population. Its safety and efficacy remain undetermined in the pediatric population. We present a teenager who was hospitalized with left-sided paralysis, and with decreased sensations on the left side. Head computed tomography indicated hyperdensity in the middle cerebral artery region, which confirmed the diagnosis of acute ischemic stroke. Her score on the National Institutes of Health stroke scale was 11. She received intravenous tissue plasminogen activator without any complications. At a follow-up visit 5 months after the stroke, the patient manifested mild apraxia in her left hand and mild expressive amusia. This case underscores the need for emergency head imaging in the pediatric population to establish a diagnosis. The excellent recovery in our patient indicates the need to establish thrombolytic treatment as an option for acute stroke in pediatric populations. It also suggests that tissue plasminogen activator can be used safely and effectively, even in pediatric populations. However, further studies are needed to establish the adequate dosage and adverse-effect profile in pediatric populations.

Outcomes of long-term iron supplementation in pediatric restless legs syndrome/periodic limb movement disorder (RLS/PLMD).

OBJECTIVES: Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are thought to center around a genetically mediated sensitivity to iron insufficiency. Previous studies have shown the effectiveness of short-term iron therapy in children with low iron storage. Little is known, however, about long-term iron treatment in children with RLS and PLMD. Therefore, we performed this study to assess the long-term effect of iron therapy in children with RLS and PLMD. METHODS: A retrospective chart review was performed for children who met the following criteria: A) diagnosed as having either RLS or PLMD, B) started on iron supplementation, C) followed up for >2 years in a sleep clinic. Baseline values for iron, ferritin, and periodic limb movement of sleep index (PLMS index) were defined in the three months leading up to the initiation of iron therapy. Values were also computed for follow-up periods of 3-6 months, 1-2 years, and >2 years. Serum iron and ferritin levels and PLMS index were compared between baseline and all subsequent follow-ups. RESULTS: In total, 105 patients met inclusion criteria, of whom 64 were diagnosed with PLMD alone, seven with RLS alone, and 35 with both RLS and PLMD. The average age was 10.2 ± 5.3 years. Compared to the baseline (27.4 ± 12.1 ng/ml), the average ferritin values at 3-6 months (45.62 ± 21.2 ng/ml, p < 0.001, n = 34), 1-2 years (52.0 ± 48.3 ng/ml, p <0.001, n = 63), and >2 years (54.7 ± 40.5 ng/ml, p <0.001, n = 67) were all significantly increased. Inversely, compared to baseline (21 ± 27.0/h, n = 66), PLMS index values at 3-6 months (7.5 ± 9.5/h p < 0.05, n = 11), 1-2 years (6.9 ± 8.9/h, p <0.001, n = 29), and >2 years (10 ± 14.5/h, p <0.001, n = 31) were all significantly decreased. No significant change in serum iron levels was noted at any time point. CONCLUSION: While retrospective in nature, this study demonstrates a sustained improvement in PLMS index and maintenance of adequate ferritin levels >2 years after iron therapy initiation in our RLS/PLMD cohort with a long-term follow-up. Iron therapy appears to lead to long-lasting improvements in children with RLS/PLMD.

Should spikes on post-resection ECoG guide pediatric epilepsy surgery?

PURPOSE: There is wide variation in clinical practice regarding the role of electrocorticography immediately after resection (post-resection ECoG) for pediatric epilepsy surgery. Results can guide further resection of potentially epileptogenic tissue. We hypothesized that post-resection ECoG spiking represents a biomarker of the epileptogenic zone and predicts seizure outcome in children undergoing epilepsy surgery. METHODS: We retrospectively identified 124 children with post-resection ECoG performed on the margins of resection. ECoG records were scored in a blinded fashion based on presence of frequent spiking. For patients identified as having additional resection based on clinical post-resection ECoG interpretation, these "second-look" ECoG results were re-reviewed for ongoing discharges or completeness of resection. Frequent spike populations were grouped using a standard scoring system into three ranges: 0.1-0.5Hz, 0.5-1Hz, >1Hz. Seizure outcomes were determined at minimum 12-month followup. RESULTS: Of 124 patients who met inclusion criteria, 60 (48%) had an identified spike population on post-resection ECoG. Thirty (50%) of these had further resection based on clinical interpretation. Overall, good outcome (ILAE 1) was seen in 56/124 (45%). Completeness of resection of spiking (absence of spiking on initial post-resection ECoG or resolution of spiking after further resection) showed a trend toward good outcome (OR 2.03, p=0.099). Patients with completeness of resection had good outcome in 41/80 (51%) of cases; patients with continued spikes had good outcome in 15/44 (35%) of cases. CONCLUSIONS: Post-resection ECoG identifies residual epileptogenic tissue in a significant number of children. Lower frequency or absence of discharges on initial recording showed a trend toward good outcome. Completeness of resection demonstrated on final ECoG recording did not show a significant difference in outcome. This suggests that post-resection discharges represent a prognostic marker rather than a remediable biomarker of the epileptogenic zone in all patients. Resecting residual spike-generating cortex may be beneficial in selected patients, including children with tumors.

Clinical factors predict surgical outcomes in pediatric MRI-negative drug-resistant epilepsy.

PURPOSE: Lack of a potentially epileptogenic lesion on brain magnetic resonance imaging (MRI) is a poor prognostic marker for epilepsy surgery. We present a single-center series of childhood-onset MRI-negative drug-resistant epilepsy (DRE) and analyze surgical outcomes and predictors. METHODS: Children with MRI-negative DRE who had resective surgery from January 2007 to December 2013 were identified using an institutional database. Relevant clinical, neurophysiological, imaging, and surgical data was extracted. The primary outcome measure was seizure freedom. Predictors of seizure freedom were obtained using multivariate logistic regression. RESULTS: Out of 47 children with MRI-negative DRE, 12 (25.5%) were seizure free (International League Against Epilepsy [ILAE] outcome class I), after mean follow-up of 2.75 (±1.72) years. Seizure-free proportion was significantly higher in patients with single seizure semiology and concordant ictal EEG (50.0% vs. 15.2%, p=0.025). Multivariate analysis using only non-invasive pre-surgical data showed that children with daily seizures (OR 0.02, 95% CI<0.001-0.55), and earlier onset of seizures (OR 0.72, 95% CI 0.52-0.99) were less likely to be seizure-free. Also, each additional anti-epileptic drug (AED) tried before surgery decreased the probability of seizure-free outcome (OR 0.16, 95% CI 0.04-0.63). Repeat multivariate analysis after including surgical variables found no additional significant predictors of seizure-freedom. Cortical dysplasia (ILAE type IB) was the commonest histopathology. CONCLUSION: Surgical outcomes in children with MRI-negative DRE are determined by clinical factors including seizure frequency, age of onset of seizures, and number of failed AEDs.

Sleep and Epilepsy.

Sleep and epilepsy are common bedfellows. Sleep can affect frequency and occurrence of interictal spikes and occurrence, timing, and threshold of seizure. Epilepsy can worsen sleep architecture and severity of sleep disorders. Thus, a vicious cycle is set. Certain epilepsy syndromes are so intertwined with sleep that they are considered sleep-related epilepsies. Poor sleep in epilepsy is multifactorial and is worsened by poorly controlled seizures. On the contrary, poor sleep is associated with worsened quality of life, psychological function, and memory. Improving sleep has been noted to improve seizure frequency and an overall well-being in patients with epilepsy. Hence, an emphasis should be given to address sleep in patients with epilepsy. These interactions are discussed in detail in this review.

Central Hypersomnia.

Sleepiness is not uncommon in the pediatric population. Although the etiology can be multifactorial, sleepiness due to increased sleep drive, also called central hypersomnia, is a common cause. The third edition of the International Classification of Sleep Disorders updated the diagnostic criteria for several of the central disorders of hypersomnolence, most notably narcolepsy. Although the International Classification Of Sleep Disorders-3 is not specific to pediatric patients, the peak incidence for many of the included disorders occurs during childhood or adolescence. As a result, recognition of these lifelong and potentially debilitating disorders is imperative for providers who evaluate pediatric patients. This review provides an update on recent advances in the field and highlights some of the diagnostic dilemmas, unique clinical features, and variable presentations associated with central disorders of hypersomnolence within the pediatric population.

Melatonin improves sleep in children with epilepsy: a randomized, double-blind, crossover study.

OBJECTIVE: Insomnia, especially maintenance insomnia, is widely prevalent in epilepsy. Although melatonin is commonly used, limited data address its efficacy. We performed a randomized, double-blind, placebo-controlled, crossover study to identify the effects of melatonin on sleep and seizure control in children with epilepsy. METHODS: Eleven prepubertal, developmentally normal children aged 6-11 years with epilepsy were randomized by a software algorithm to receive placebo or a 9-mg sustained release (SR) melatonin formulation for four weeks, followed by a one-week washout and a four-week crossover condition. The pharmacy performed blinding; patients, parents, and study staff other than a statistician were blinded. The primary outcomes were sleep onset latency and wakefulness after sleep onset (WASO) measured on polysomnography. The secondary outcomes included seizure frequency, epileptiform spike density per hour of sleep on electroencephalogram (EEG), and reaction time (RT) measures on psychomotor vigilance task (PVT). Statistical tests appropriate for crossover designs were used for the analysis. RESULTS: Data were analyzed from 10 subjects who completed the study. Melatonin decreased sleep latency (mean difference, MD, of 11.4 min and p = 0.02) and WASO (MD of 22 min and p = 0.04) as compared to placebo. No worsening of spike density or seizure frequency was seen. Additionally, slow-wave sleep duration and rapid eye movement (REM) latency were increased with melatonin and REM sleep duration was decreased. These changes were statistically significant. Worsening of headache was noted in one subject with migraine on melatonin. CONCLUSION: SR melatonin resulted in statistically significant decreases in sleep latency and WASO. No clear effects on seizures were observed, but the study was too small to allow any conclusions to be drawn in this regard.

Absence Epilepsy: Older vs Newer AEDs.

OPINION STATEMENT: Over the last one to two decades, several new antiepileptic drugs (AEDs) have become available. These medications have different mechanisms of action, metabolism, efficacy, and side effect profiles. Hence, it has become possible to customize medications for a particular patient. It has also become possible to use various combinations of treatments for refractory epilepsies. As medication options have increased, our goal has shifted to not only to maximize seizure control but also to minimize side effects. However, the older AEDs are still widely used. So the question arises-are newer medications better than older AEDs for the treatment of absence epilepsy? Based on a large multicenter class I study, older AEDs-ethosuximide and valproic acid-are more efficacious than newer AEDs. Due to reduced side effects, ethosuximide remains the first line treatment for childhood absence epilepsy.

Central sleep apnea: does stabilizing sleep improve it?

Central sleep apnea is not uncommon in children with neurologic disorders. The mechanisms include increased ventilatory chemosensitivity to carbon dioxide level. Conventional treatments include oxygen, noninvasive ventilation, and in patients with heart failure, improving cardiac output. Here, we present a case of a 9-year-old male with Angelman syndrome, epilepsy, insomnia, and central sleep apnea. The patient was initially evaluated for nighttime awakenings and pauses in breathing. Sustained-release melatonin was used to improve his nighttime awakenings. A polysomnography confirmed central sleep apnea. We saw a reduction in arousals and improvement in insomnia with sustained-release melatonin. On a repeat study, central sleep apnea was improved. We hypothesize that sustained-release melatonin, by improving sleep continuity and reducing arousals, might improve central sleep apnea. Studies are needed to test the hypothesis.

Provider practices impact adequate diagnosis of sleep disorders in children with epilepsy.

Sleep disorders significantly affect the lives of children with epilepsy. Limited data exist about provider practices concerning detection and correct diagnosis of sleep problems in epilepsy. The authors conducted this study to identify and correlate sleep screening methods, referral practices, referral reasons and final sleep diagnoses. They identified that 94% of the providers who had referred patients to the sleep center of a major children's hospital used routine screening and 70% of them used 2 to 3 screening questions. This method, however, underidentified the patients at risk for sleep disorders. Moreover, in 40% of the children, sleep disorder was incorrectly anticipated, based on the initial symptoms. Of these children, 10% had no sleep disorder and 30% had unexpected sleep disorder. The authors conclude that better screening methods should be used for sleep disorders. Once identified, these patients should have formal sleep evaluation and management. Further studies are needed to develop screening questionnaires.

Obstructive sleep apnea and primary snoring in children with epilepsy.

Sleep-related breathing disruptions in children with epilepsy are common and can range from primary snoring to obstructive sleep apnea. Untreated obstructive sleep apnea can lead to significant morbidity. This study aimed to identify factors associated with its occurrence and severity in children with epilepsy. Children with epilepsy and sleep disruption were evaluated with polysomnography and diagnosed with obstructive sleep apnea or primary snoring. Statistical analyses were done to identify differences within both the groups and among the subjects in the obstructive sleep apnea group. Uncontrolled epilepsy was a risk factor for obstructive sleep apnea (80%) compared with primary snoring (47%, P = .02). Obstructive index increased with increasing number of antiepileptic drugs. In children with epilepsy and disturbed sleep, obstructive sleep apnea is associated with uncontrolled epilepsy and is more severe with polytherapy use. Children with uncontrolled seizures on antiepileptic polytherapy should be routinely screened for obstructive sleep apnea.

Narcolepsy-cataplexy: is streptococcal infection a trigger?

Narcolepsy-cataplexy is an uncommon sleep disorder which may present in childhood. We report a case of an 8-year-old presenting with narcolepsy-cataplexy following a streptococcal infection. Autoimmune etiology for narcolepsy has been suggested. In our patient increased anti-streptolysin O and anti-DNAse B titers were noted. As suggested by recent cases, the streptococcal infection was likely a trigger for narcolepsy onset in this genetically predisposed child. The patient was initially diagnosed as having Sydenham chorea due to motor movements. However, these transient movements may be due to the narcolepsy onset. Narcolepsy in childhood may present with atypical symptoms; it might be difficult to obtain accurate history and can be misdiagnosed as in the reported case. A high index of clinical suspicion is needed to diagnose these patients.

Ictal MEG onset source localization compared to intracranial EEG and outcome: improved epilepsy presurgical evaluation in pediatrics.

PURPOSE: Magnetoencephalography (MEG) has been shown a useful diagnostic tool for presurgical evaluation of pediatric medically intractable partial epilepsy as MEG source localization has been shown to improve the likelihood of seizure onset zone (SOZ) sampling during subsequent evaluation with intracranial EEG (ICEEG). We investigated whether ictal MEG onset source localization further improves results of interictal MEG in defining the SOZ. METHODS: We identified 20 pediatric patients with one habitual seizure during MEG recordings between October 2007 and April 2011. MEG was recorded with sampling rates of 600Hz and 4000Hz for 10 and 2min respectively. Continuous head localization (CHL) was applied. Source localization analyses were applied using multiple algorithms, both at the beginning of ictal onset and for interictal MEG discharges. Ictal MEG onsets were identified by visual inspection and power spectrum using short-time Fourier transform (STFT). Source localizations were compared with ICEEG, surgical procedure and outcome. KEY FINDINGS: Eight patients met all inclusion criteria. Five of the 8 patients (63%) had concordant ictal MEG onset source localization and interictal MEG discharge source localizations in the same lobe, but the source of ictal MEG onset was closer to the SOZ defined by ICEEG. SIGNIFICANCE: Although the capture of seizures during MEG recording is challenging, the source localization for ictal MEG onset proved to be a useful tool for presurgical evaluation in our pediatric population with medically intractable epilepsy.