Pediatric Epilepsy Surgery Research Articles

Novel tonometer device distinguishes brain stiffness in epilepsy surgery

Complete surgical resection of abnormal brain tissue is the most important predictor of seizure freedom following surgery for cortical dysplasia. While lesional tissue is often visually indiscernible from normal brain, anecdotally, it is subjectively stiffer. We report the first experience of the use of a digital tonometer to understand the biomechanical properties of epilepsy tissue and to guide the conduct of epilepsy surgery. Consecutive epilepsy surgery patients (n = 24) from UCLA Mattel Children’s Hospital were recruited to undergo intraoperative brain tonometry at the time of open craniotomy for epilepsy surgery. Brain stiffness measurements were corrected with abnormalities on neuroimaging and histopathology using mixed-effects multivariable linear regression. We collected 249 measurements across 30 operations involving 24 patients through the pediatric epilepsy surgery program at UCLA Mattel Children’s Hospital. On multivariable mixed-effects regression, brain stiffness was significantly associated with the presence of MRI lesion (β = 32.3, 95%CI 16.3–48.2; p < 0.001), severity of cortical disorganization (β = 19.8, 95%CI 9.4–30.2; p = 0.001), and recent subdural grid implantation (β = 42.8, 95%CI 11.8–73.8; p = 0.009). Brain tonometry offers the potential of real-time intraoperative feedback to identify abnormal brain tissue with millimeter spatial resolution. We present the first experience with this novel intraoperative tool for the conduct of epilepsy surgery. A carefully designed prospective study is required to elucidate whether the clinical application of brain tonometry during resective procedures could guide the area of resection and improve seizure outcomes.

A needs assessment of pediatric epilepsy surgery in Haiti.

Epilepsy disproportionately affects low- and/or middle-income countries (LMICs). Surgical treatments for epilepsy are potentially curative and cost-effective and may improve quality of life and reduce social stigmas. In the current study, the authors estimate the potential need for a surgical epilepsy program in Haiti by applying contemporary epilepsy surgery referral guidelines to a population of children assessed at the Clinique d'Épilepsie de Port-au-Prince (CLIDEP). The authors reviewed 812 pediatric patient records from the CLIDEP, the only pediatric epilepsy referral center in Haiti. Clinical covariates and seizure outcomes were extracted from digitized charts. Electroencephalography (EEG) and neuroimaging reports were further analyzed to determine the prevalence of focal epilepsy or surgically amenable syndromes and to assess the lesional causes of epilepsy in Haiti. Lastly, the toolsforepilepsy instrument was applied to determine the proportion of patients who met the criteria for epilepsy surgery referral. Two-thirds of the patients at CLIDEP (543/812) were determined to have epilepsy based on clinical and diagnostic evaluations. Most of them (82%, 444/543) had been evaluated with interictal EEG, 88% of whom (391/444) had abnormal findings. The most common finding was a unilateral focal abnormality (32%, 125/391). Neuroimaging, a prerequisite for applying the epilepsy surgery referral criteria, had been performed in only 58 patients in the entire CLIDEP cohort, 39 of whom were eventually diagnosed with epilepsy. Two-thirds (26/39) of those patients had abnormal findings on neuroimaging. Most patients (55%, 18/33) assessed with the toolsforepilepsy application met the criteria for epilepsy surgery referral. The authors' findings suggest that many children with epilepsy in Haiti could benefit from being evaluated at a center with the capacity to perform basic brain imaging and neurosurgical treatments.

Establishing criteria for pediatric epilepsy surgery center levels of care: Report from the ILAE Pediatric Epilepsy Surgery Task Force.

Presurgical evaluation and surgery in the pediatric age group are unique in challenges related to caring for the very young, range of etiologies, choice of appropriate investigations, and surgical procedures. Accepted standards that define the criteria for levels of presurgical evaluation and epilepsy surgery care do not exist. Through a modified Delphi process involving 61 centers with experience in pediatric epilepsy surgery across 20 countries, including low-middle- to high-income countries, we established consensus for two levels of care. Levels were based on age, etiology, complexity of presurgical evaluation, and surgical procedure. Competencies were assigned to the levels of care relating to personnel, technology, and facilities. Criteria were established when consensus was reached (≥75% agreement). Level 1 care consists of children age 9 years and older, with discrete lesions including hippocampal sclerosis, undergoing lobectomy or lesionectomy, preferably on the cerebral convexity and not close to eloquent cortex, by a team including a pediatric epileptologist, pediatric neurosurgeon, and pediatric neuroradiologist with access to video-electroencephalography and 1.5-T magnetic resonance imaging (MRI). Level 2 care, also encompassing Level 1 care, occurs across the age span and range of etiologies (including tuberous sclerosis complex, Sturge-Weber syndrome, hypothalamic hamartoma) associated with MRI lesions that may be ill-defined, multilobar, hemispheric, or multifocal, and includes children with normal MRI or foci in/abutting eloquent cortex. Available Level 2 technologies includes 3-T MRI, other advanced magnetic resonance technology including functional MRI and diffusion tensor imaging (tractography), positron emission tomography and/or single photon emission computed tomography, source localization with electroencephalography or magnetoencephalography, and the ability to perform intra- or extraoperative invasive monitoring and functional mapping, by a large multidisciplinary team with pediatric expertise in epilepsy, neurophysiology, neuroradiology, epilepsy neurosurgery, neuropsychology, anesthesia, neurocritical care, psychiatry, and nursing. Levels of care will improve safety and outcomes for pediatric epilepsy surgery and provide standards for personnel and technology to achieve these levels.

Sacrificing one visual hemifield during pediatric epilepsy surgery: Effects on visual search.

To investigate early and late effects of planned surgically acquired homonymous hemianopias on visual search in children and adolescents. This prospective study included five patients (5y 5m-18y 0m; 2 girls) with pharmaco-refractory epilepsies in whom one visual hemifield was sacrificed as part of the surgical strategy, and, as controls, seven patients (5y 11m-18y 0m; 6 girls) undergoing epilepsy surgeries not affecting the visual fields. Visual search was studied using the "TableTest", which is an everyday life-like visual search test. General processing speed was studied using a standard IQ subtest. All five patients with newly acquired homonymous hemianopias showed a relative disadvantage of visual search times for objects in their newly blind hemifields immediately after the surgery. Six months later, this relative disadvantage had recovered completely in all patients. Nevertheless, compared with the preoperative situation, overall search times were still prolonged in the hemianopic patients, but this effect could be mitigated or even overcompensated by improvements in processing speed. Children with homonymous hemianopias inflicted by epilepsy surgery develop effective compensation strategies to minimize the relative disadvantage of visual search in their blind hemifields. For changes in overall visual search times between the preoperative and the six-month follow-up examination, we could demonstrate overlapping effects of (a) deterioration by hemianopia and (b) amelioration by improved processing speed as part of the cognitive improvements achieved by amelioration of the epilepsy.

Surgery for drug refractory pediatric epilepsy: Saving and nurturing the developing brain

The drug refractory epilepsy in the pediatric age group can wreak havoc on the developing brain affecting all the important developmental milestones. This not only affects the child but also creates a socioeconomic burden to the family. Pediatric epilepsy poses a special challenge in not only the diagnosis of focal drug refractory epilepsy but also in the selection of surgical candidate. Awareness about the myriad numbers of focal epilepsies, current standard in pre-surgical evaluation, and the available minimally invasive surgical options are important in raising the standard of both the primary epilepsy care and a timely referral to a specialized center. Authors have made an attempt to emphasize the importance of early recognition and intervention along with the reviewing of the current evidences on the surgical management so that any treating pediatrician are informed well enough for a better clinical judgment.

The Role of Inpatient Rehabilitation After Pediatric Epilepsy Surgery for Refractory Epilepsy

Epilepsy surgery reduces seizure burden and antiepileptic use while improving quality of life. Neuroplasticity and rehabilitation aid in recovery after epilepsy surgery. We aimed to examine the impact and role of inpatient rehabilitation after epilepsy surgery in pediatric patients with refractory epilepsy. A retrospective chart review examined patients aged 0–18 years old undergoing epilepsy surgery for refractory epilepsy at our institution between 2012 and 2018, with subsequent admission to inpatient rehabilitation. Demographic, clinical, neurocognitive, and functional outcomes were measured. Thirty-six patients were included: 17 male (47.2%) and 19 female (52.8%). Mean age was 9.3 years (SD 5.2, range 1.1–18.9). The most common procedures were hemispherectomy (13, 36.1%) and lobectomy (12, 33.3%). The mean duration of rehabilitation was 16.2 days (SD 9.2, range 6–42). WeeFIMR scores improved after rehabilitation (65.6 vs. 49.3, p 0.05), and procedure type (p < 0.02), with more independent patients undergoing lobectomy compared with hemispherectomy. Admission and discharge WeeFIMR scores were higher in those functionally independent compared with those functionally dependent at last follow-up (p < 0.01 for all subscores). No difference in change in WeeFIMR was seen between those functionally independent vs. dependent at last follow-up (p < 0.11). Postoperative inpatient rehabilitation after pediatric epilepsy surgery is associated with functional improvement in self-care, mobility, and cognition, but may be influenced by age or procedure type.

Responsive neurostimulation for refractory epilepsy in the pediatric population: A single-center experience

Drug-resistant focal epilepsy (DRFE) in children can impair cognition and behavior, and lead to premature death. Increased pediatric epilepsy surgery numbers reflect the improvements in seizure control and long-term developmental outcomes. Yet, many children with DRFE are not candidates for surgical resection due to overlap of the seizure network with eloquent cortex or multiple seizure-onset zones, making surgery dangerous or ineffective. In adults, responsive neurostimulation (RNS System) therapy is safe and effective treatment for DRFE with one or two seizure foci, especially when the seizure focus is in eloquent cortex.We present six pediatric patients with DRFE who underwent RNS implantation. Our outcomes demonstrate safety, decreased clinical seizure frequency, as well as improved functional status and quality of life. Changes in the clinical seizure semiology and frequency occurred in conjunction with adjustments to the stimulation parameters, supporting the efficacy of responsive neuromodulation in children.

Book Review: Pediatric Epilepsy Surgery: Preoperative Assessment and Surgical Treatment, Second Edition

Book Review: Pediatric Epilepsy Surgery: Preoperative Assessment and Surgical Treatment, Second Edition

Memory outcomes following hemispherectomy in children

ObjectiveA vast proportion of children with epilepsy exhibit memory impairments. Although numerous studies have examined memory performance following pediatric resective epilepsy surgery, little is known about the memory outcomes following hemispherectomy. The few studies that report on memory performance typically include restricted measures, consist of case reports, or do not report on preoperative performance. Given the current limitations, the aim of this study was to delineate pre- and postoperative memory functioning in youth who underwent a hemispherectomy. MethodParticipants included patients who had undergone a hemispherectomy at the Hospital for Sick Children, between 1999 and 2016. Standardized neuropsychological assessments of verbal (digit span, word list recall, word pair recall, stories) and visual (faces, dot locations) memory abilities prior to and after surgery were reviewed. A Wilcoxon signed rank test and effect sizes was completed to compare patients' memory performance to population norms and to assess pre- to postoperative difference scores. ResultsThirteen participants were included in the study: five patients completed preoperative assessments only and eight patients completed pre- and postoperative assessments. Preoperatively, patients performed substantially worse relative to population norms as indicated by large effect sizes (r: 0.5–0.9). Postoperatively, effect sizes were large for the majority of the memory tests, demonstrating considerable differences in patients' memory scores over time. When clinically meaningful changes were examined, stable performance was evident on 63% of the memory tasks. ConclusionOverall, the results highlight that youth who are eligible for hemispherectomy demonstrate profound memory deficits prior to surgery. In addition, undergoing hemispherectomy was not necessarily associated with declined memory performance, with the majority of patients showing stable scores.

Increase in cognitive function is seen in many single-operated pediatric patients after epilepsy surgery

PurposeThe recurrent seizures of pediatric drug-resistant epilepsy (DRE) are known to impair brain development and can lead to a loss in cognitive functioning. Surgery is increasingly being used to treat children with DRE. This study investigates the pre- and postoperative cognitive function in a pediatric epilepsy surgery cohort as well as predictive determinants of change in intelligence quotient (IQ) following surgery. MethodsA consecutive series of 91 Danish children who underwent focal resective epilepsy surgery between January 1996 and December 2016 were included. All underwent preoperative cognitive evaluation and were reevaluated at 1-year and/or 2-year follow-up. Single-operated and multi-operated patients were examined separately. Results79 of 91 patients were single-operated. Single-operated patients received less anti-epileptic drugs (AED) and experienced a decrease in seizure frequency postoperatively, p < 0.001. IQ increased postoperatively (IQ change ± standard deviation: 3.3 ± 14.0), p < 0.05. High preoperative seizure frequency was a significant predictor for decreased IQ, p < 0.01. Multi-operated patients did not experience a reduction in AED treatment. Surgery and continued AED treatment did, however, result in significantly better seizure control, p < 0.01. IQ remained unchanged in multi-operated patients. ConclusionEpilepsy surgery allowed for IQ gains in single-operated patients. Preoperative seizure frequency was a significant predictor of IQ change following surgery. Interactions between other, not included, possible predictors remain to be examined. Single-operated patients had the best cognitive outcome. The inclusion of a non-surgical control group is needed to assess the extent of the beneficial effects of surgery on cognitive ability.

An Initial Cost-Effectiveness Analysis of Magnetic Resonance-Guided Laser Interstitial Thermal Therapy in Pediatric Epilepsy Surgery

Introduction: Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a new technology that provides a clinically efficacious and minimally invasive alternative to conventional microsurgical resection. However, little data exist on how costs compare to traditional open surgery. The goal of this paper is to investigate the cost-effectiveness of MRgLITT in the treatment of pediatric epilepsy. Methods: We retrospectively analyzed the medical records of pediatric patients who underwent MRgLITT via the Visualase® thermal therapy system (Medtronic, Inc., Minneapolis, MN, USA) between December 2013 and September 2017. Direct costs associated with preoperative, operative, and follow-up care were extracted. Benefit was calculated in quality-adjusted life years (QALYs), and the cost-effectiveness was derived from the discounted total direct costs over QALY. Sensitivity analysis on 4 variables was utilized to assess the validity of our results. Results: Twelve consecutive pediatric patients with medically refractory epilepsy underwent MRgLITT procedures. At the last postoperative follow-up, 8 patients were seizure free (Engel I, 66.7%), 2 demonstrated significant improvement (Engel II, 16.7%), and 2 patients showed worthwhile improvement (Engel III, 16.7%). The average cumulative discounted QALY was 2.11 over the lifetime of a patient. Adjusting for inflation, MRgLITT procedures had a cost-effectiveness of USD 22,211 per QALY. Our sensitivity analysis of cost variables is robust and supports the procedure to be cost-­effective. Conclusion: Our data suggests that MRgLITT may be a cost-effective alternative to traditional surgical resection in pediatric epilepsy surgery.

Cognitive and developmental outcomes after pediatric insular epilepsy surgery for focal cortical dysplasia.

Cognitive risk associated with insular cortex resection is not well understood. The authors reviewed cognitive and developmental outcomes in pediatric patients who underwent resection of the epileptogenic zone involving the insula. A review was conducted of 15 patients who underwent resective epilepsy surgery involving the insular cortex for focal cortical dysplasia, with a minimum follow-up of 12 months. The median age at surgery was 5.6 years (range 0.3-13.6 years). Developmental/intelligence quotient (DQ/IQ) scores were evaluated before surgery, within 4 months after surgery, and at 12 months or more after surgery. Repeated measures multivariate ANOVA was used to evaluate the effects on outcomes of the within-subject factor (time) and between-subject factors (resection side, anterior insular resection, seizure control, and antiepileptic drug [AED] reduction). The mean preoperative DQ/IQ score was 60.7 ± 22.8. Left-side resection and anterior insular resection were performed in 9 patients each. Favorable seizure control (International League Against Epilepsy class 1-3) was achieved in 8 patients. Postoperative motor deficits were observed in 9 patients (permanent in 6, transient in 3). Within-subject changes in DQ/IQ were not significantly affected by insular resection (p = 0.13). Postoperative changes in DQ/IQ were not significantly affected by surgical side, anterior insular resection, AED reduction, or seizure outcome. Only verbal function showed no significant changes before and after surgery and no significant effects of within-subject factors. Resection involving the insula in children with impaired development or intelligence can be performed without significant reduction in DQ/IQ, but carries the risk of postoperative motor deficits.

Bleeding properties according to surgical sites during pediatric craniotomy: a retrospective study comparing the two stages of epilepsy surgery.

BackgroundDuring pediatric epilepsy surgery, due to low circulating blood volume, intraoperative bleeding can result in significant hemodynamic instability, thereby requiring meticulous hemodynamic and transfusion strategies. Knowing the source of bleeding during the procedure would allow medical staff to better prepare the perioperative protocols for these patients. We compared intraoperative bleeding between the first (involving skin to meninges) and second (involving brain parenchyma) stages of epilepsy surgery to investigate the differences between various anatomical sites.MethodsWe reviewed the electronic medical records of 102 pediatric patients < 14 years old who underwent two-stage epilepsy surgeries during January 2012–December 2016. Invasive subdural grids were placed via craniotomy during Stage 1 and the epileptogenic zone was removed during Stage 2 of the surgery. We compared the volume of intraoperative bleeding between these two surgeries and identified variables associated with bleeding using multivariate regression analysis.ResultsBoth surgeries resulted in similar intraoperative bleeding (24 vs. 26 ml/kg, P = 0.835), but Stage 2 required greater volumes of blood transfusion than Stage 1 (18.4 vs. 14.8 ml/kg, P = 0.011). Massive bleeding was associated with patients < 7 years of age in Stage 1 and weighing < 18 kg in Stage 2.ConclusionsThe volume of intraoperative bleeding was similar between the two stages of pediatric epilepsy surgery and was large enough to require blood transfusions. Thus, blood loss during pediatric epilepsy surgery occurred at both anatomic sites. This indicates the necessity of early preparation for blood transfusion in both stages of pediatric epilepsy surgery.

A methodological perspective on the cognitive outcome of epilepsy surgery in children and adolescents

PurposeThe purpose of the study was to explore the impact of timing and test specificity of cognitive outcome measures after pediatric epilepsy surgery. MethodsA consecutive national cohort of 114 children with medically resistant epilepsy having had resective epilepsy surgery were screened for children tested with a complete age-appropriate Wechsler Intelligence test at two or three time-points. This provided 43 children for analyses. Composite subscale scores were assessed in comparison to index and intelligence quotient (IQ) scores. ResultsWe found a main effect of time in seizure-free children for full-scale IQ (FSIQ); F(2, 42) = 6.49 with higher T2 measures compared with T1 (MDiff = 5.46, p = .006). There was a difference in FSIQ scores between seizure-free and nonseizure-free children at T2; M = 7.31, 95% confidence interval (CI) [0.05 to 14.57], t(38) = 2.04, p = .049, favoring seizure-free children. A statistical difference between composite scale scores and index scores was found with medium to large effect. The correlation of medical treatment (anti-epileptic drug (AED)) change and score differences in FSIQ outcome was significant (p = .041), with less AED correlated with a higher FSIQ. All children with left-temporal surgery had a stable or improved verbal comprehension composite subscale score outcome at T2 regardless of seizure status. ConclusionOur results correspond to some longitudinal studies with outcome measures >2 years, in contrast to short-term studies ≤2 years with a stable outcome. Our study supports the fact that the specificity of the used tests and the timing of assessments after pediatric epilepsy surgery are essential factors for the clinical validity of outcome measures. However, there are further needs of extensive longitudinal studies to provide a better understanding of life-long cognitive development and impact after childhood epilepsy surgery.

Neuropsychological outcomes after pediatric epilepsy surgery: Role of electrical stimulation language mapping

PurposeWe studied the association between electrical stimulation mapping (ESM) with a visual naming task and post-operative neuropsychological outcomes after pediatric epilepsy surgery. MethodsChildren who underwent epilepsy surgery, having pre- and 1-year post-surgery neuropsychological evaluation (NPE) available, were included. NPE scores were transformed using principal components (PC) analysis. The relationship between post-surgical PC scores, adjusted for pre-surgery PC scores, and ESM was analyzed. Clinical variables influencing this relationship were also sought. ResultsOne hundred and four children (89 patients >5 years-old, and 15 patients 3−5 years-old) were included. Among children >5 years-of-age, a significant effect of language ESM was observed on all 3 post-surgery PC scores adjusted for respective pre-surgery PC scores. Specifically, only 30 % patients who underwent language ESM had a decrease in PC1 scores ≥1-year after epilepsy surgery, compared to 68 % those who did not undergo language ESM (p = 0.001). Seizure outcomes, age at the time of surgery, predominant seizure type, and family history of epilepsy were other significant determinants of post-surgical PC scores including a change in PC scores from pre-surgery baseline. Combinations of pre-surgical variables were able to predict post-surgical PC scores with high specificity. In children aged 3−5 years, no significant effect of language ESM was seen on post-surgery PC scores adjusted for respective pre-surgery PC scores. ConclusionsSpeech/language ESM should be performed more widely in patients >5 years-of-age undergoing epilepsy surgery. Also, more efficient brain mapping techniques and language paradigms are needed for younger children.

Rigid Cranial Fixation for Robot-Assisted Stereoelectroencephalography in Toddlers: Technical Considerations.

Stereoelectroencephalography (sEEG) using depth electrodes has become a mainstay of pediatric epilepsy surgery. This technique relies on rigid cranial fixation using skull pins, which forms the basis for accurate stereotactic navigation. The use of cranial fixation pins poses the threat of traumatic skull injuries in young children because of inadequate cranial bone thickness. To describe a rigid cranial fixation technique involving the integrated Gel Head Ring from the DORO QR3 multipurpose skull clamp set (Pro Med Instruments) with superimposed pin fixation in children below the age of 36 mo undergoing sEEG. Patients were placed in the supine position and the head was fixed using a DORO skull clamp with 3 pediatric cranial pins. The head was supported on the integrated Gel Head Ring, and a pin pressure of 20 pounds was applied. The DORO skull clamp set was then attached to the ROSA neurosurgical robot support telescopic arm for stereotactic navigation. We present an illustrative series of 2 patients below the age of 3 yr with medicallyrefractory epilepsy who underwent sEEG using our modified cranial fixation technique. Head position and reference registration were stable throughout the surgeries. Postoperative volumetric computed tomography scans of the head showed accurate placement of sEEG depth electrodes and did not reveal any fractures or epidural hematoma. No other complications related to cranial fixation were noted. Concurrent use of rigid and nonrigid cranial fixation using the DORO skull clamp set provides safe and effective cranial fixation in infants and toddlers undergoing sEEG.

SUN-057 Endocrine Dysfunction After Pediatric Epilepsy Surgery: A Report from the Global Pediatric Epilepsy Surgery Registry

RATIONALE: Epilepsy surgery in children is no longer considered a last resort for drug-resistant seizures; however, there are no studies that address the impact of pediatric epilepsy surgery on endocrine function. We reviewed patients in the Global Pediatric Epilepsy Surgery Registry to assess the prevalence of various endocrinopathies after epilepsy surgery in childhood.METHODS: Retrospective data was collected for 122 patients, via parent proxy, who had epilepsy surgery before age 18. Data were collected on age, height, weight, seizure etiology, and surgery type, as well as reported endocrine diagnoses. Descriptive statistics were tabulated and group differences assessed.RESULTS: 22.7% of patients were followed by an endocrinologist after surgery, but not before. 9.8% of patients reported one diagnosed endocrine disorder post-operatively, including precocious puberty (5.7%) and diabetes insipidus (0.8%); 3.3% had more than one diagnosed endocrine disorder. A higher incidence of diagnosed endocrinopathies was found in children after hemispherectomy surgery (12.64%) or who acquired hydrocephalus after surgery (30%) than in other forms of surgery. 16.4% of parents report that the child had “excessive weight gain” after surgery and 9.8% report “excessive weight loss” after surgery.CONCLUSION: Endocrine dysfunction, including precocious puberty and disorders of water balance, appears to be common after epilepsy surgery in childhood, especially hemispherectomy. Longitudinal studies are needed to better understand the etiology and true prevalence of these disorders. The Global Pediatric Epilepsy Surgery Registry is the first longitudinal study with this aim.

Parents' and children's decision-making and experiences in pediatric epilepsy surgery

BackgroundIn pediatric epilepsy surgery, little research has been conducted on parents' decision-making for or against surgery, their satisfaction with the surgical outcome, as well as their children's personal experiences with the process. ObjectiveThis study explores (1) factors that may influence parents' decision-making, (2) factors associated with their postoperative satisfaction, and (3) their children's involvement in decision-making and their experiences with epilepsy surgery. MethodsSelf-developed questionnaires were provided to parents and their children in Germany, Switzerland, and Austria. Clinical and psychosocial differences between parents who decided for or against surgery, as well as associations between postoperative factors and the parents' satisfaction were statistically analyzed. ResultsFifty-one questionnaires (42 parent and nine patient questionnaires) were evaluated. Parents who decided for epilepsy surgery reported significantly more frequently to have received a good medical consultation and a consistent recommendation. They made significantly less use of information websites, internet forums, and patient organizations. Their children were classified as more intelligent and resisted surgery less. Most of the parents were satisfied with the surgical outcome (83%). Parents were significantly more satisfied when their children had fewer medication side effects, their memory or concentration had improved, their character or behavior had changed in a positive direction, or when their children were more independent or less excluded. They were also significantly more content when they had more free time to themselves and their professional situation or their relationship with their children, friends, or other family members had improved. However, no significant association was found between parental satisfaction and reduced number of medications or improved seizure outcome. Although the children were reported to have been minimally involved in the decision-making process, they were satisfied with their involvement. ConclusionsA good medical consultation that involves the children and considers the family's living conditions is a crucial factor for parents' decision-making on pediatric epilepsy surgery. For parents' satisfaction, a positive change in their child's character or behavior and an improved psychosocial situation of the family are more important than postoperative seizure frequency or number of antiepileptic drugs (AEDs). Therefore, the medical consultation should not only focus on clinical factors, but also point out psychosocial and behavioral changes that may occur after the surgical treatment.

A novel effective paradigm of intraoperative electrical stimulation mapping in children.

Resective epilepsy surgery is an established treatment method for children with focal intractable epilepsy, but the use of this method introduces the risk of postsurgical motor deficits. Electrical stimulation mapping (ESM), used to define motor areas and pathways, frequently fails in children. The authors developed and tested a novel ESM protocol in children of all age categories. The ESM protocol utilizes high-frequency electric cortical stimulation combined with continuous intraoperative motor-evoked potential (MEP) monitoring. The relationships between stimulation current intensity and selected presurgical and surgery-associated variables were analyzed in 66 children (aged 7 months to 18 years) undergoing 70 resective epilepsy surgeries in proximity to the motor cortex or corticospinal tracts. ESM elicited MEP responses in all children. Stimulation current intensity was associated with patient age at surgery and date of surgery (F value = 6.81, p < 0.001). Increase in stimulation current intensity predicted postsurgical motor deficits (F value = 44.5, p < 0.001) without effects on patient postsurgical seizure freedom (p > 0.05). The proposed ESM paradigm developed in our center represents a reliable method for preventing and predicting postsurgical motor deficits in all age groups of children. This novel ESM protocol may increase the safety and possibly also the completeness of epilepsy surgery. It could be adopted in pediatric epilepsy surgery centers.

Relative contribution of individual versus combined functional imaging studies in predicting seizure freedom in pediatric epilepsy surgery: an area under the curve analysis.

The goal of this study was to evaluate the predictive value and relative contribution of noninvasive presurgical functional imaging modalities based on the authors' institutional experience in pursuing seizure-free surgical outcomes in children with medically refractory epilepsy. This was a retrospective, single-institution, observational cohort study of pediatric patients who underwent evaluation and surgical treatment for medically refractory partial epilepsy between December 2003 and June 2016. During this interval, 108 children with medically refractory partial epilepsy underwent evaluation for localization and resective epilepsy surgery. Different noninvasive functional imaging modalities, including ictal SPECT, FDG-PET, and magnetoencephalography-magnetic source imaging, were utilized to augment a standardized paradigm (electroencephalography/semiology, MRI, and neuropsychology findings) for localization. Outcomes were evaluated at a minimum of 2 years (mean 7.5 years) utilizing area under the receiver operating characteristic curve analysis. Localizing modalities and other clinical covariates were examined in relation to long-term surgical outcomes. There was variation in the contribution of each test, and no single presurgical workup modality could singularly and reliably predict a seizure-free outcome. However, concordance of presurgical modalities yielded a high predictive value. No difference in long-term outcomes between inconclusive (normal or diffusely abnormal) and abnormal focal MRI results were found. Long-term survival analyses revealed a statistically significant association between seizure freedom and patients with focal ictal EEG, early surgical intervention, and no history of generalized convulsions. Comprehensive preoperative evaluation utilizing multiple noninvasive functional imaging modalities is not redundant and can improve pediatric epilepsy surgical outcomes.