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Children and adults with genetic generalized epilepsy may have focal clinical seizure symptoms as well as electroencephalographic (EEG) findings. This may pose a diagnostic challenge to clinicians, especially when concomitant focal neuroimaging findings exist and the epilepsy is medically refractory. We sought to highlight the challenges that clinicians may face through the description of 2 children with suspected genetic generalized epilepsy who had both focal seizure symptoms and EEG/neuroimaging findings and underwent invasive EEG monitoring. Ultimately, invasive monitoring failed to demonstrate a focal origin for the seizures in both cases, and instead confirmed the presence of genetic generalized epilepsy. We demonstrate that ≥3-Hz generalized monomorphic spike and waves are less likely to represent secondary bilateral synchrony, that focal neuroimaging findings may not always be causal and that repeated hyperventilation is an essential activation procedure for genetic generalized epilepsy. [ABSTRACT FROM AUTHOR]

Aim: To determine whether epilepsy surgery improved health-related quality of life (HRQoL) and whether seizure freedom after surgery mediated the improvement in HRQoL.Method: This multicenter cohort study compared HRQoL after epilepsy surgery to pharmacological management in children with drug-resistant epilepsy (DRE). HRQoL was measured using the Quality of Life in Childhood Epilepsy (QOLCE) questionnaire at baseline and 1-year follow-up. The mediator between treatment type and HRQoL was seizure freedom.Results: Two hundred and thirty-seven patients were recruited (surgery group: n=147 [92 males, 45 females]; pharmacological group: n=90 [53 males, 37 females]). Mean age at seizure onset was 6 years (SD 4y 4mo) in the surgical group and 6 years 1 month (SD 4y) in the pharmacological group. The odds ratio of seizure freedom was higher for the surgery versus pharmacological group (β=4.24 [95% confidence interval {CI}: 2.26-7.93], p<0.001). Surgery had no direct effect on total QOLCE score at 1-year (β=0.24 [95% CI -2.04 to 2.51], p=0.839) compared to pharmacological management, but had an indirect effect on total QOLCE that was mediated by seizure freedom (β=0.92 [95% CI 0.19-1.65], p=0.013), adjusting for baseline total QOLCE score. Surgery had a direct effect on improving social function (p=0.043), and an indirect effect on improving physical function (p=0.016), cognition (p=0.042), social function (p=0.012) and behavior (p=0.032), mediated by seizure freedom.Interpretation: Greater seizure freedom achieved through epilepsy surgery mediated the improvement in HRQoL compared to pharmacological management in children with DRE.What This Paper Adds: Seizure freedom is higher after pediatric epilepsy surgery compared to pharmacologically managed epilepsy. Surgery indirectly improves health-related quality of life (HRQoL) mediated by seizure freedom compared to pharmacological management. Surgery has a direct effect on improving social function relative to pharmacological management. Baseline HRQoL was an important predictor of HRQoL after treatment. [ABSTRACT FROM AUTHOR]

Background: The safety of hemispherectomy between staged cardiac procedures is unknown and not previously reported. Method: Retrospective review of a case with drug-resistant epilepsy due to stroke following bidirectional cavopulmonary connection (BDCPC). Results: This report describes the first case of a successful pediatric peri-insular functional hemispherectomy in the setting of a BDCPC. A discussion of the complex preoperative planning from both a cardiac and neurological perspective is presented. Considerations regarding hemispherectomy and its effects on the cardiac physiology, and perioperative considerations are emphasized in clinical decision making. Conclusions: A multidisciplinary approach was critical in this child which led to a successful outcome. [ABSTRACT FROM AUTHOR]

Highlights • Extra-operative mapping (penfield technique) frequently leads to after-discharges and seizures. • Intra-operative motor-mapping (IODCS-SDG) using "train of five" provided more mapping information. • No stimulation-provoked seizures were noted during IODCS-SDG. Abstract Objectives The objective of this study was to review our experience with intra-operative "train of five" stimulation using subdural grid for motor mapping in children undergoing epilepsy surgery evaluation. Methods Twenty consecutive children below 18-years of age with drug-refractory epilepsy who underwent invasive-EEG monitoring using subdural-grid placement and intra-operative motor mapping using direct cortical stimulation by sub-dural grid electrodes (IODCS-SDG) at our institution between January-2016 and June-2017 were reviewed. Stimulation was delivered through the subdural-grid electrodes using a train-of-five pulses and muscle responses were recorded by motor-evoked-potentials (MEPs). Intra-operative direct cortical stimulation delivered through a ball-tipped probe (IODCS-probe) and extra-operative motor-mapping (EODCS-SDG) were also performed. Results IODCS-SDG was completed in 20 patients and subsequent EODCS-SDG was done in 17/20 patients. MEP responses were more commonly obtained in the deltoid (19/20), extensor-digitorum-communis (20/20) and first-dorsal-interosseus (19/20). The median thresholds varied between 40 V and 60 V for the six muscle groups. The respective IODCS-probe thresholds tended to be similar. No stimulation-provoked seizures or anaesthesia-related complications were noted during IODCS-SDG. EODCS-SDG could not be completed in 4/17 children and mapping data obtained was frequently inadequate. Nine patients demonstrated 100% concordance between IODCS-SDG and EODCS-SDG for the common mapped body regions. Stimulation-provoked seizures during EODCS-SDG were seen in 6/17 (35.3%) and after-discharges in 7/17 (41.2%) children. Conclusions IODCS-SDG could be performed safely in children with drug refractory epilepsy undergoing invasive EEG monitoring. Significance IODCS-SDG may be a useful adjunct to EODCS-SDG in motor mapping for children. [ABSTRACT FROM AUTHOR]

• 26.7 % patients showed ≥1 McHugh class improvement after replacement with cardiac-based VNS device. • 50 % patients maintained their McHugh class at last follow up. • 36.7 % Patients showed >50 % seizure reduction after replacement. • 4 patients showed deterioration in behaviour after replacement. This study evaluated the seizure outcomes in children with drug-resistant epilepsy (DRE), having a pre-existing VNS device, after generator replacement with cardiac-based VNS device. This retrospective study enrolled 30 children with DRE from 2 centers with an existing VNS device nearing end-of-service who underwent generator replacement with cardiac-based VNS device and had at least 1 year follow up. Seizure outcomes and adverse effects were studied. The mean age at insertion of cardiac-based VNS device was 15.03 years. 26.7 % patients showed at least one class improvement at last follow up (mean 2.08 years) and half of the patients maintained their McHugh seizure-outcome class. Thirty-six percent of patients had > 50 % seizure reduction at last follow up. Ten patients reported improvement in ictal severity. Most of the patients tolerated the replacement well. Nearly one-third of patients with DRE showed additional improvement after replacement with cardiac based VNS device. Half of the patients maintained their seizure control. [ABSTRACT FROM AUTHOR]

• The EST lateralized language to one hemisphere in almost 80.9% cases. • Contralateral EEG slowing was noted in 73.7% patients, mostly transient which did not affect the overall interpretation. • The EST was unsuccessful in two cases because of persistent diffuse EEG slowing. • The EST was well tolerated in this pediatric population. To review our experience with the Etomidate speech test (EST) for lateralizing language in children undergoing epilepsy surgery evaluation This retrospective study included children (<18 years) with drug refractory focal epilepsy undergoing EST for bilateral or poorly reliable language representation on functional MRI. Data for consecutive children who underwent EST between January 2013 to June 2017 were reviewed. Twenty-one children (mean age at EST, 13.1 ± 4.4 years) were studied, with 19-right hemispheric and 20 left hemispheric injections. Six patients had neurological co-morbidities. Duration of ipsilateral EEG slowing was sufficient for speech testing in all children with a single bolus of Etomidate per carotid artery. Language was lateralized to one hemisphere in 17 (80.9%) and bilateral in two cases. EST was unsuccessful in two patients because of diffuse EEG slowing. Contralateral transient frontal EEG slowing was seen in 14 (73.7%) cases. EST was well tolerated in all the patients. The EST was found to be successful and safe in lateralizing language in most of our drug refractory pediatric epilepsy cohort. [ABSTRACT FROM AUTHOR]

Background: Infantile epileptic spasms syndrome is an epileptic encephalopathy, characterized by spasms, hypsarrhythmia, and developmental regression. Appropriately selected patients with infantile epileptic spasms syndrome may be candidates for epilepsy surgery. Methods: This is a single-center retrospective case series of children 0-18 years with a current or previous diagnosis of infantile epileptic spasms syndrome with a lesion on magnetic resonance imaging (MRI) and/or positron emission tomography scan who underwent epilepsy surgery at The Hospital for Sick Children (HSC) in Toronto, Canada. The records of 223 patients seen in the infantile epileptic spasms syndrome clinic were reviewed. Results: Nineteen patients met inclusion criteria. The etiology of infantile epileptic spasms syndrome was encephalomalacia in 6 patients (32%), malformations of cortical development in 12 patients (63%), and atypical hypoglycemic injury in 1 patient (5%). Nine patients (47%) underwent hemispherectomy, and 10 patients (53%) underwent lobectomy/lesionectomy. Three patients (16%) underwent a second epilepsy surgery. Fifteen patients (79%) were considered ILAE seizure outcome class 1 (completely seizure free; no auras) at their most recent follow-up visit. The percentage of patients who were ILAE class 1 at most recent follow-up decreased with increasing duration of epilepsy prior to surgery. Developmental outcome after surgery was improved in 14 of 19 (74%) and stable in 5 of 19 (26%) patients. Conclusions: Our study found excellent seizure freedom rates and improved developmental outcomes following epilepsy surgery in patients with a history of infantile epileptic spasms syndrome with a structural lesion detected on MRI brain. Patients who undergo surgery earlier have improved seizure freedom rates and improved developmental outcomes. [ABSTRACT FROM AUTHOR]

Hippocampal sclerosis (HS) is a common surgical substrate in adult epilepsy surgery cohorts but variably reported in various pediatric cohorts. We aimed to study the epilepsy phenotype, radiological and pathological variability, seizure and neurocognitive outcomes in children with drug-resistant epilepsy and hippocampal sclerosis (HS) with or without additional subtle signal changes in anterior temporal lobe who underwent surgery. This retrospective study enrolled children with drug-resistant focal epilepsy and hippocampal sclerosis with or without additional subtle T2-Fluid Attenuated Inversion Recovery (FLAR)/Proton Density (PD) signal changes in anterior temporal lobe who underwent anterior temporal lobectomy with amygdalohippocampectomy. Their clinical, EEG, neuropsychological, radiological and pathological data were reviewed and summarized. Thirty-six eligible patients were identified. The mean age at seizure onset was 3.7 years; 25% had daily seizures at time of surgery. Isolated HS was noted in 22 (61.1%) cases and additional subtle signal changes in ipsilateral temporal lobe in 14 (38.9%) cases. Compared to the normative population, the group mean performance in intellectual functioning and most auditory and visual memory tasks were significantly lower than the normative sample. The mean age at surgery was 12.3 years; 22 patients (61.1%) had left hemispheric surgeries. ILAE class 1 outcomes was seen in 28 (77.8%) patients after a mean follow up duration of 2.3 years. Hippocampal sclerosis was noted pathologically in 32 (88.9%) cases; type 2 (54.5%) was predominant subtype where further classification was possible. Additional pathological abnormalities were seen in 11 cases (30.6%); these had had similar rates of seizure freedom as compared to children with isolated hippocampal sclerosis/gliosis (63.6% vs 84%, p=0.21). Significant reliable changes were observed across auditory and visual memory tasks at an individual level post surgery. Favourable seizure outcomes were seen in most children with isolated radiological hippocampal sclerosis. Patients with additional pathological abnormalities had similar rates of seizure freedom as compared to children with isolated hippocampal sclerosis/gliosis. • Subtle anterior temporal signal changes were noted in 38.9% children with hippocampal sclerosis (HS). • 77.8% children became seizure free after anterior temporal lobectomy with amygdalohippocampectomy. • Overall, 30.6% cases had additional pathological abnormalities. • Seizure freedom rates of children with additional pathological abnormalities similar to those with isolated HS. [ABSTRACT FROM AUTHOR]

Decelerated resting cortical oscillations, high-frequency activity, and enhanced cross-frequency interactions are features of focal epilepsy. The association between electrophysiological signal properties and neurocognitive function, particularly following resective surgery, is, however, unclear. In the current report, we studied intraoperative recordings from intracranial electrodes implanted in seven children with focal epilepsy and analyzed the spectral dynamics both before and after surgical resection of the hypothesized seizure focus. The associations between electrophysiological spectral signatures and each child’s neurocognitive profiles were characterized using a partial least squares analysis. We find that extent of spectral alteration at the periphery of surgical resection, as indexed by slowed resting frequency and its acceleration following surgery, is associated with baseline cognitive deficits in children. The current report provides evidence supporting the relationship between altered spectral properties in focal epilepsy and neuropsychological deficits in children. In particular, these findings suggest a critical role of disrupted thalamocortical rhythms, which are believed to underlie the spectral alterations we describe, in both epileptogenicity and neurocognitive function. [ABSTRACT FROM AUTHOR]

Summary: Objective: Polymicrogyria (PMG) is a common malformation of cortical development. Many patients with PMG will have medically refractory epilepsy but the role of epilepsy surgery is unclear. The objective of this study was to assess the efficacy of surgical resection/disconnection in achieving seizure control in pediatric patients with PMG. Methods: A retrospective review of children undergoing epilepsy surgery for PMG between 2002 and 2017 at The Hospital for Sick Children in Toronto, Canada, was performed. Results: A total of 12 children aged 6 months to 17.8 years (median 8.8 years) underwent resective surgery (7 children) or functional hemispherectomy (5 children). Gross total resection or complete disconnection of PMG was carried out in 7 of 12 children. Follow‐up duration was between 1 and 9 years (median 2.1 years). Nine children remained seizure‐free at last follow‐up. Complete resection or disconnection of PMG led to seizure freedom in 6 of 7 patients (86%), whereas subtotal resection produced seizure freedom in 3 of 5 patients (60%). Significance: We present one of the largest surgical series of pediatric PMG patients. Seizure outcomes were best with complete resection/disconnection of PMG. However, tailored resections based on electroclinical and neuroradiologic data can produce good outcomes and remain an appropriate strategy for patients with extensive PMG. [ABSTRACT FROM AUTHOR]