Morphological and ultrastructural investigation of the posterior atlanto-occipital membrane: Comparing children with Chiari malformation type I and controls.

INTRODUCTION: The fibrous posterior atlanto-occipital membrane (PAOM) at the craniocervical junction is typically removed during decompression surgery for Chiari malformation type I (CM-I); however, its importance and ultrastructural architecture have not been investigated in children. We hypothesized that there are structural differences in the PAOM of patients with CM-I and those without. METHODS: In this prospective study, blinded pathological analysis was performed on PAOM specimens from children who had surgery for CM-I and children who had surgery for posterior fossa tumors (controls). Clinical and radiographic data were collected. Statistical analysis included comparisons between the CM-I and control cohorts and correlations with imaging measures. RESULTS: A total of 35 children (mean age at surgery 10.7 years; 94.3% white) with viable specimens for evaluation were enrolled: 24 with CM-I and 11 controls. There were no statistical demographic differences between the two cohorts. Four children had a family history of CM-I and five had a syndromic condition. The cohorts had similar measurements of tonsillar descent, syringomyelia, basion to C2, and condylar-to-C2 vertical axis (all p>0.05). The clival-axial angle was lower in patients with CM-I (138.1 vs. 149.3 degrees, p = 0.016). Morphologically, the PAOM demonstrated statistically higher proportions of disorganized architecture in patients with CM-I (75.0% vs. 36.4%, p = 0.012). There were no differences in PAOM fat, elastin, or collagen percentages overall and no differences in imaging or ultrastructural findings between male and female patients. Posterior fossa volume was lower in children with CM-I (163,234 mm3 vs. 218,305 mm3, p<0.001), a difference that persisted after normalizing for patient height (129.9 vs. 160.9, p = 0.028). CONCLUSIONS: In patients with CM-I, the PAOM demonstrates disorganized architecture compared with that of control patients. This likely represents an anatomic adaptation in the presence of CM-I rather than a pathologic contribution.

Development of an online calculator for the prediction of seizure freedom following pediatric hemispherectomy using the Hemispherectomy Outcome Prediction Scale (HOPS).

OBJECTIVES: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy. METHODS: Retrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time-to-seizure recurrence. A multivariate Cox proportional-hazards regression model was developed to predict the likelihood of post-hemispheric surgery seizure freedom at three time points (1-, 2- and 5- years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops-calculator.com/). RESULTS: The selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non-hemispheric resective surgery, and contralateral fluorodeoxyglucose-positron emission tomography [FDG-PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time-to-seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG-PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non-lesional MRI, non-stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%. SIGNIFICANCE: Online calculators are useful, cost-free tools that can assist physicians in risk estimation and inform joint decision-making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.

Added value of corpus callosotomy following vagus nerve stimulation in children with Lennox-Gastaut syndrome: A multicenter, multinational study.

OBJECTIVE: Lennox-Gastaut syndrome (LGS) is a severe form of epileptic encephalopathy, presenting during the first years of life, and is very resistant to treatment. Once medical therapy has failed, palliative surgeries such as vagus nerve stimulation (VNS) or corpus callosotomy (CC) are considered. Although CC is more effective than VNS as the primary neurosurgical treatment for LGS-associated drop attacks, there are limited data regarding the added value of CC following VNS. This study aimed to assess the effectiveness of CC preceded by VNS. METHODS: This multinational, multicenter retrospective study focuses on LGS children who underwent CC before the age of 18 years, following prior VNS, which failed to achieve satisfactory seizure control. Collected data included epilepsy characteristics, surgical details, epilepsy outcomes, and complications. The primary outcome of this study was a 50% reduction in drop attacks. RESULTS: A total of 127 cases were reviewed (80 males). The median age at epilepsy onset was 6 months (interquartile range [IQR] = 3.12-22.75). The median age at VNS surgery was 7 years (IQR = 4-10), and CC was performed at a median age of 11 years (IQR = 8.76-15). The dominant seizure type was drop attacks (tonic or atonic) in 102 patients. Eighty-six patients underwent a single-stage complete CC, and 41 an anterior callosotomy. Ten patients who did not initially have a complete CC underwent a second surgery for completion of CC due to seizure persistence. Overall, there was at least a 50% reduction in drop attacks and other seizures in 83% and 60%, respectively. Permanent morbidity occurred in 1.5%, with no mortality. SIGNIFICANCE: CC is vital in seizure control in children with LGS in whom VNS has failed. Surgical risks are low. A complete CC has a tendency toward better effectiveness than anterior CC for some seizure types.

Machine learning models for predicting seizure outcome after MR-guided laser interstitial thermal therapy in children.

OBJECTIVE: MR-guided laser interstitial thermal therapy (MRgLITT) is associated with lower seizure-free outcome but better safety profile compared to open surgery. However, the predictors of seizure freedom following MRgLITT remain uncertain. This study aimed to use machine learning to predict seizure-free outcome following MRgLITT and to identify important predictors of seizure freedom in children with drug-resistant epilepsy. METHODS: This multicenter study included children treated with MRgLITT for drug-resistant epilepsy at 13 epilepsy centers. The authors used clinical data, diagnostic investigations, and ablation features to predict seizure-free outcome at 1 year post-MRgLITT. Patients from 12 centers formed the training cohort, and patients in the remaining center formed the testing cohort. Five machine learning algorithms were developed on the training data by using 10-fold cross-validation, and model performance was measured on the testing cohort. The models were developed and tested on the complete feature set. Subsequently, 3 feature selection methods were used to identify important predictors. The authors then assessed performance of the parsimonious models based on these important variables. RESULTS: This study included 268 patients who underwent MRgLITT, of whom 44.4% had achieved seizure freedom at 1 year post-MRgLITT. A gradient-boosting machine algorithm using the complete feature set yielded the highest area under the curve (AUC) on the testing set (AUC 0.67 [95% CI 0.50-0.82], sensitivity 0.71 [95% CI 0.47-0.88], and specificity 0.66 [95% CI 0.50-0.81]). Logistic regression, random forest, support vector machine, and neural network yielded lower AUCs (0.58-0.63) compared to the gradient-boosting machine but the findings were not statistically significant (all p > 0.05). The 3 feature selection methods identified video-EEG concordance, lesion size, preoperative seizure frequency, and number of antiseizure medications as good prognostic features for predicting seizure freedom. The parsimonious models based on important features identified by univariate feature selection slightly improved model performance compared to the complete feature set. CONCLUSIONS: Understanding the predictors of seizure freedom after MRgLITT will assist with prognostication.

Magnetic resonance imaging-guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study.

OBJECTIVE: The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children. METHODS: Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed. RESULTS: A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications. CONCLUSIONS: SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

A multicenter initiative to reduce intrathecal baclofen pump surgical site infection: a Cerebral Palsy Research Network quality improvement project.

OBJECTIVE: Intrathecal baclofen (ITB) therapy is an effective treatment for spasticity and dystonia in children with cerebral palsy (CP). However, ITB pump surgery is associated with one of the highest rates of surgical site infection (SSI) in medicine, leading to significant morbidity and expense. Surgical protocols have reduced the rate of SSI in children with other CNS implants, and single-center protocols have been effective in ITB surgery in pediatrics. The authors describe the first multicenter quality improvement (QI)-driven standardized protocol for ITB pump surgery in children with CP across the Cerebral Palsy Research Network (CPRN), implemented with the aim of reducing ITB-associated SSI. METHODS: SSI was defined as a culture-positive infection, ITB pump system removal for suspected infection, or wound dehiscence with exposed hardware. Each center reported historical infection rates for at least 3 years before initiating the SSI protocol (preintervention phase). After initiation of a 13-step surgical protocol, a consecutive series of 130 patients undergoing 149 surgical procedures for ITB at four CPRN tertiary pediatric neurosurgery centers were prospectively enrolled at surgery during a 2-year study period (intervention phase). QI methodology was used, including development of a key driver diagram and tracking performance using run and control charts. The primary process measure goal was documented compliance with 80% of the protocol steps, and the primary outcome measure goal was a 20% reduction in 90-day infection rate. Patient characteristics were collected from the CPRN Research Electronic Data Capture registry, including age at surgery, BMI, Gross Motor Function Classification System level, and pattern of spasticity. RESULTS: The aggregated preintervention 90-day ITB SSI rate was 4.9% (223 procedures) between 2014 and 2017. During the intervention phase, 136 of 149 ITB surgeries performed met inclusion criteria for analysis. The mean documented compliance rate with protocol steps was 75%, and the 90-day infection rate was 4.4%, with an average of 42 days from index surgery to infection. CONCLUSIONS: This is the first multicenter QI initiative designed to reduce SSI in ITB surgery in children with CP. Ongoing enrollment and expansion of the protocol to other CPRN centers will facilitate identification of patient- and procedure-specific risk factors for SSI, and iterative plan-do-study-act cycles incorporating these data will further decrease the risk of SSI for ITB surgery in children.

Treatment of a symptomatic thalamic pilocytic astrocytoma with reservoir placement and laser interstitial thermal therapy: illustrative case.

BACKGROUND: Treatment of pilocytic astrocytomas (PAs) in children can be challenging when they arise in deep midline structures because complete surgical resection may result in significant neurological injury. Laser interstitial thermal therapy (LITT) has provided an alternative treatment modality for lesions that may not be amenable to resection. However, many patients with PAs may be symptomatic from a compressive cyst associated with the PA, and LITT does not obviate the need for cystic decompression in these patients. OBSERVATIONS: A 12-year-old male presented with left-sided weakness. Magnetic resonance imaging (MRI) revealed an enhancing mass with a large cyst involving the right thalamus and basal ganglia. The patient underwent a reservoir placement for cyst drainage and biopsy of the mass, revealing a pilocytic astrocytoma. He then underwent LITT followed by adjuvant chemotherapy. Sixteen months after LITT, follow-up MRI of the brain revealed no tumor growth. LESSONS: This is the first case to describe reservoir placement to treat the cystic portion of a pilocytic astrocytoma followed by LITT and targeted chemotherapy. Reservoir placement reduced the cyst's mass effect and resolved the patient's symptoms, allowing for treatment options beyond resection.

Pediatric Traumatic Brain Injury in a Geographically Dispersed Population: A Relationship Between Distance to Definitive Neurosurgical Treatment and Outcome.

BACKGROUND: There are limited data on the association between transport distance and outcomes in pediatric patients with severe traumatic brain injuries (sTBIs), despite children having to travel further to pediatric trauma centers (PTCs). OBJECTIVE: To assess whether distance from a PTC is associated with outcomes in children who undergo cranial surgery after sTBI. METHODS: Children with sTBI who underwent craniectomy/craniotomy at our PTC between 2010 and 2019 were identified retrospectively. Of these 92 patients, 83 sustained blunt injury and underwent surgery within 24 hours. The distance from injury location to PTC was based on injury zip code and calculated as Euclidean distance. Variables associated with transport, including distance, time, and rural-urban disparity, were analyzed for correlation with poor outcome. RESULTS: Of the 83 patients identified, 81 had injury location information. Forty patients were injured within 30 miles and 41 were injured ≥30 miles from the PTC. Injury severity and pediatric trauma scores were not significantly different between groups. Sixty-eight children (82%) had a satisfactory outcome and 10 children (12%) died. There was a nonsignificant association between distance traveled and poor outcome, even when the cohort was stratified into those with subdural hematomas and those with nonabusive injuries. CONCLUSIONS: Regardless of the distance from the PTC at which their injury occurred, most children in this cohort made a moderate to good recovery. Children injured at greater distances from the PTC did not have worse outcomes; however, studies with larger cohorts are needed to more definitively assess prehospital pediatric transport systems in this population.

Stereotactic electroencephalography is associated with reduced opioid and nonsteroidal anti-inflammatory drug use when compared with subdural grids: a pediatric case series.

Patients undergoing surgical intervention for epilepsy mapping are typically administered opioids for pain control. The use of opioids is demonstrably lower after other procedures when a minimally invasive surgery (MIS) technique is used. Our objective was to determine whether using MIS for stereoelectroencephalography (SEEG) resulted in lower opioid requirement by pediatric patients when compared with subdural grid placement after craniotomy (ECoG). A retrospective chart review was conducted to identify patients < 18 years who underwent epilepsy mapping surgery using SEEG or ECoG in 2015-2019. The hospital stay was divided into four time periods, and the total amounts of opioids (converted into morphine milligram equivalents (MMEs)) and nonsteroidal anti-inflammatory drugs (NSAIDs) and pain scores (on numerical rating scale (NRS)) were calculated for each time interval. The two groups were then compared statistically. The study included 31 patients in the SEEG group and 9 in the ECoG group. The SEEG group consumed significantly fewer opioids during the hospital stay than the ECoG group (23.6 vs. 61.7 MMEs; p = 0.041). There were also significant differences in the length of stay (6.9 vs. 12.2 days; p = 0.002), rate of complications (0% vs. 20%; p = 0.006), and total NSAIDs consumed (3,264.8 vs. 12,730.2 mg; p = 0.002). Opioid and NSAID consumption were significantly lower and hospital stays were shorter in pediatric patients who underwent epilepsy mapping via SEEG compared with ECoG. These results suggest that MIS for epilepsy mapping may decrease the overall pain medication use and expedite patient discharge.

Transverse Rectus Abdominis Muscle Flow-Through to Free Fibula Flap for Lumbar Spinal Reconstruction in a Pediatric Patient: A Case Report.

CASE: A 7-week-old girl presented with a recurrent primitive myxoid mesenchymal tumor of infancy requiring extensive resection of lower back musculature, L3-S2 vertebral bodies, and left L5 nerve root. Reconstruction consisted of transverse rectus abdominis muscle (TRAM) flow-through to free fibular flap to reconstruct the bony defect and fill the soft-tissue void. One-year postoperative imaging revealed a well-incorporated fibula graft. At the 30-month follow-up, the patient can bear weight on the autograft while sitting upright, allowing for efficient ambulation with a wheelchair. CONCLUSION: TRAM flow-through to free fibular flap is an efficacious reconstructive method for a multilevel vertebral spinal defect in a pediatric patient.

Postoperative magnetic resonance imaging may predict poor outcome in children with severe traumatic brain injuries who undergo cranial surgery.

OBJECTIVE: Multiple studies have evaluated the use of MRI for prognostication in pediatric patients with severe traumatic brain injury (TBI) and have found a correlation between diffuse axonal injury (DAI)-type lesions and outcome. However, there remains a limited understanding about the use of MRI for prognostication after severe TBI in children who have undergone cranial surgery. METHODS: Children with severe TBI who underwent craniectomy or craniotomy at Primary Children's Hospital in Salt Lake City, Utah, between 2010 and 2019 were identified retrospectively. Of these 92 patients, 43 underwent postoperative brain MRI within 4 months of surgery. Susceptibility-weighted imaging (SWI) and FLAIR sequences were used to designate areas of hemorrhagic and nonhemorrhagic cerebral lesions related to DAI. Patients were then stratified based on the location of the DAI as read by a neuroradiologist as superficial, deep, or brainstem. The location of the DAI and other variables associated with poor outcome, including Glasgow Coma Scale (GCS) score, pediatric trauma score, mechanism of injury, and time to surgery, were analyzed for correlation with poor outcome. Outcomes were reported using the King's Outcome Scale for Childhood Head Injury (KOSCHI). RESULTS: In the 43 children with severe TBI who underwent postoperative brain MRI, the median GCS score on arrival was 4. The most common cause of injury was falls (14 patients, 33%). The most common primary intracranial pathology was subdural hematoma in 26 patients (60%), followed by epidural hematoma in 9 (21%). Fifteen patients (35%) had cerebral herniation and 31 (72%) had evidence of contusion. Variables associated with poor outcome included cerebral herniation (r = 0.338, p = 0.027) and location of DAI (r = 0.319, p = 0.037). In a separate analysis, brainstem DAI was shown to predict poor outcome, whereas location (no, superficial, or deep DAI) did not. Logistic regression showed that brainstem DAI (OR 22.3, p = 0.020) had a higher odds ratio than cerebral herniation (OR 10.5, p = 0.044) for poor outcome. Thirty-six children (84%) had a satisfactory outcome at last follow-up; 3 (7%) children died. CONCLUSIONS: The majority of children in this series who presented with a severe TBI and underwent craniectomy or craniotomy made a satisfactory recovery. In patients in whom there is a concern for poor outcome, the location of DAI-type lesions with SWI and FLAIR may assist in prognostication. The authors' results revealed that DAI-type lesions in the brainstem and evidence of cerebral herniation may indicate a poorer prognosis; however, more studies with larger cohorts are needed to make definitive conclusions.

Pediatric thalamic incidentalomas: an international retrospective multicenter study.

OBJECTIVE: Widespread use of modern neuroimaging has led to a surge in diagnosing pediatric brain incidentalomas. Thalamic lesions have unique characteristics such as deep location, surgical complexity, and proximity to eloquent neuronal structures. Currently, the natural course of incidental thalamic lesions is unknown. Therefore, the authors present their experience in treating such lesions. METHODS: A retrospective, international multicenter study was carried out in 8 tertiary pediatric centers from 5 countries. Patients were included if they had an incidental thalamic lesion suspected of being a tumor and were diagnosed before the age of 20 years. Treatment strategy, imaging characteristics, pathology, and the outcome of operated and unoperated cases were analyzed. RESULTS: Overall, 58 children (23 females and 35 males) with a mean age of 10.8 ± 4.0 years were included. The two most common indications for imaging were nonspecific reasons (n = 19; e.g., research and developmental delay) and headache unrelated to small thalamic lesions (n = 14). Eleven patients (19%) underwent early surgery and 47 were followed, of whom 10 underwent surgery due to radiological changes at a mean of 11.4 ± 9.5 months after diagnosis. Of the 21 patients who underwent surgery, 9 patients underwent resection and 12 underwent biopsy. The two most frequent pathologies were pilocytic astrocytoma and WHO grade II astrocytoma (n = 6 and n = 5, respectively). Three lesions were high-grade gliomas. CONCLUSIONS: The results of this study indicate that pediatric incidental thalamic lesions include both low- and high-grade tumors. Close and long-term radiological follow-up is warranted in patients who do not undergo immediate surgery, as tumor progression may occur.

Neurological and clinical outcomes in infants and children with a fetal diagnosis of asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum.

OBJECTIVE: Advances in prenatal imaging have facilitated improvements in the fetal diagnosis of congenital anomalies. Asymmetric ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum (AVID) is a constellation of congenital anomalies reported in fetal imaging. However, few data are available regarding postnatal outcomes of infants and children with a fetal diagnosis of AVID. The authors sought to report the neurodevelopmental outcomes of patients diagnosed with AVID before birth at a single institution. METHODS: An institutional fetal imaging database was queried to identify cases with ventriculomegaly, interhemispheric cyst, and dysgenesis of the corpus callosum over a 10-year study period from 2000 to 2019. Overall, 41 maternal-infant dyads who met imaging criteria for AVID were identified; medical records were reviewed for prenatal variables including gestational age at birth, perinatal complications including fetal demise, and postnatal variables including demographics, mortality, hydrocephalus diagnosis and management, epilepsy, and neurodevelopmental outcomes at 2 years or the last follow-up. RESULTS: Among 41 patients, 25 (61%) were male. A slight majority of patients (55%) were born before 36 weeks of gestational age, and 27 patients (68%) were delivered via cesarean section because their head size precluded vaginal delivery. There were 8 incidences of fetal demise, 1 pregnancy was terminated, and 32 patients were born alive. Neonatal or early infant death occurred in 5 patients. Two children died during follow-up after the neonatal period (ages 7 months and 7 years). Twenty-six children survived to at least the 2-year follow-up, all of whom required treatment for hydrocephalus. Of those 26 children, 12 (46%) had a diagnosis of epilepsy, 14 (54%) could sit independently, 4 (16%) were in mainstream school, 16 (62%) had expressive language, and 7 (28%) had near-normal development without seizures. CONCLUSIONS: Among 41 maternal-fetal dyads with AVID, a majority of children survived to the 2-year follow-up, although all developed hydrocephalus. Many continued to have seizures, but expressive language use, attendance at mainstream school, and near-normal development without seizures were not infrequent. These data are critical for prenatal counseling and to establish the natural history of a diagnosis with limited outcome data.

Comparison of the real-world effectiveness of vertical versus lateral functional hemispherotomy techniques for pediatric drug-resistant epilepsy: A post hoc analysis of the HOPS study.

OBJECTIVE: This study was undertaken to determine whether the vertical parasagittal approach or the lateral peri-insular/peri-Sylvian approach to hemispheric surgery is the superior technique in achieving long-term seizure freedom. METHODS: We conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri-insular/peri-Sylvian, or lateral trans-Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time-to-event method and calculated using the Kaplan-Meier survival method. RESULTS: Data for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittal hemispherotomy and 600 (89.3%) underwent lateral peri-insular/peri-Sylvian or trans-Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI] = 53.5%-70.2%) of the entire cohort at 10-year follow-up. Seizure freedom was 88.8% (95% CI = 78.9%-94.3%) at 1-year follow-up and persisted at 85.5% (95% CI = 74.7%-92.0%) across 5- and 10-year follow-up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI = 86.3%-91.5%) at 1-year to 72.1% (95% CI = 66.9%-76.7%) at 5-year to 57.2% (95% CI = 46.6%-66.4%) at 10-year follow-up for the lateral subgroup. Log-rank test found that vertical hemispherotomy was associated with durable seizure-free progression compared to the lateral approach (p = .01). Patients undergoing the lateral hemispherotomy technique had a shorter time-to-seizure recurrence (hazard ratio = 2.56, 95% CI = 1.08-6.04, p = .03) and increased seizure recurrence odds (odds ratio = 3.67, 95% CI = 1.05-12.86, p = .04) compared to those undergoing the vertical hemispherotomy technique. SIGNIFICANCE: This pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise-based observational studies or a randomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long-term seizure outcomes.

Epilepsy surgery in infants up to 3 months of age: Safety, feasibility, and outcomes: A multicenter, multinational study.

OBJECTIVE: Drug-resistant epilepsy (DRE) during the first few months of life is challenging and necessitates aggressive treatment, including surgery. Because the most common causes of DRE in infancy are related to extensive developmental anomalies, surgery often entails extensive tissue resections or disconnection. The literature on "ultra-early" epilepsy surgery is sparse, with limited data concerning efficacy controlling the seizures, and safety. The current study's goal is to review the safety and efficacy of ultra-early epilepsy surgery performed before the age of 3 months. METHODS: To achieve a large sample size and external validity, a multinational, multicenter retrospective study was performed, focusing on epilepsy surgery for infants younger than 3 months of age. Collected data included epilepsy characteristics, surgical details, epilepsy outcome, and complications. RESULTS: Sixty-four patients underwent 69 surgeries before the age of 3 months. The most common pathologies were cortical dysplasia (28), hemimegalencephaly (17), and tubers (5). The most common procedures were hemispheric surgeries (48 procedures). Two cases were intentionally staged, and one was unexpectedly aborted. Nearly all patients received blood products. There were no perioperative deaths and no major unexpected permanent morbidities. Twenty-five percent of patients undergoing hemispheric surgeries developed hydrocephalus. Excellent epilepsy outcome (International League Against Epilepsy [ILAE] grade I) was achieved in 66% of cases over a median follow-up of 41 months (19-104 interquartile range [IQR]). The number of antiseizure medications was significantly reduced (median 2 drugs, 1-3 IQR, p < .0001). Outcome was not significantly associated with the type of surgery (hemispheric or more limited resections). SIGNIFICANCE: Epilepsy surgery during the first few months of life is associated with excellent seizure control, and when performed by highly experienced teams, is not associated with more permanent morbidity than surgery in older infants. Thus surgical treatment should not be postponed to treat DRE in very young infants based on their age.

Hemispherectomy Outcome Prediction Scale: Development and validation of a seizure freedom prediction tool.

OBJECTIVE: To develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug-resistant epilepsy. METHODS: We analyzed 1267 hemispheric surgeries performed in pediatric participants across 32 centers and 12 countries to identify predictors of seizure freedom at 3 months after surgery. A multivariate logistic regression model was developed based on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). Missing data were handled using multiple imputation techniques. RESULTS: Overall, 817 of 1237 (66%) hemispheric surgeries led to seizure freedom (median follow-up = 24 months), and 1050 of 1237 (85%) were seizure-free at 12 months after surgery. A simple regression model containing age at seizure onset, presence of generalized seizure semiology, presence of contralateral 18-fluoro-2-deoxyglucose-positron emission tomography hypometabolism, etiologic substrate, and previous nonhemispheric resective surgery is predictive of seizure freedom (area under the curve = .72). A Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised that can be used to predict seizure freedom. SIGNIFICANCE: Children most likely to benefit from hemispheric surgery can be selected and counseled through the implementation of a scale derived from a multiple regression model. Importantly, children who are unlikely to experience seizure control can be spared from the complications and deficits associated with this surgery. The HOPS score is likely to help physicians in clinical decision-making.

Stereotactic laser interstitial thermal therapy for brainstem cavernous malformations: two preliminary cases.

Brainstem cavernous malformations (CMs) often have high hemorrhage rates and significant posthemorrhage morbidity. The authors present two cases in which magnetic resonance thermography-guided laser interstitial therapy was used for treatment of pontine CMs after recurrent hemorrhage. Both patients showed significant symptomatic improvement and were hemorrhage-free at 12- and 6-month follow-up, respectively. Each had radiographic evidence of lesion involution on serial follow-up imaging. These early results demonstrate this treatment modality may be technically safe; however, larger case numbers and longer follow-up are needed to demonstrate efficacy.

A comparison of the accuracy of fetal MRI and prenatal ultrasonography at predicting lesion level and perinatal motor outcome in patients with myelomeningocele.

OBJECTIVE: Prenatal imaging has several critical roles in the diagnosis and management of myelomeningocele, including specific family counseling and the selection of fetal surgery or postnatal repair. In this study, the authors compared the accuracy of fetal MRI and prenatal ultrasonography (US) in predicting the spinal lesion level and assessed the correlation between imaging findings and motor function as independently evaluated by a physical therapist (PT) after birth. METHODS: A retrospective review of demographic and clinical data was performed to identify children who had been treated with postnatal myelomeningocele closure at a single institution between March 2013 and December 2018. Patients were eligible for inclusion if they had all of the following: prenatal US identifying the neural tube defect level, fetal MRI identifying the neural tube defect level, and postoperative PT evaluation identifying the motor deficit level. Statistical analysis was performed using Cohen's kappa coefficient to compare the US- and MRI-demonstrated lesion level and correlate these findings with the motor level assigned postnatally by a PT via manual muscle testing. RESULTS: Thirty-four patients met the inclusion criteria. The mean gestational age at US was 23.0 ± 4.7 weeks, whereas the mean gestational age at MRI was 24.0 ± 4.1 weeks. The mean time from surgery to the PT evaluation was 2.9 ± 1.9 days. Prenatal US and MRI were in agreement within one spinal level in 74% of cases (25/34, k = 0.43). When comparing the US-demonstrated spinal level with the PT-assigned motor level, the two were in agreement within one level in 65% of cases (22/34, k = 0.40). When comparing MRI-demonstrated spinal level with the PT motor level, the two were in agreement within one level in 59% of cases (20/34, k = 0.37). MRI and US were within two spinal levels of the PT evaluation in 79.4% and 85.3% of cases, respectively. MRI and US agreed within two levels in 97.1% of cases. Prenatal US and MRI were equivalent when comparing the difference between the imaged level and the postnatal motor deficit level (mean level difference: 1.12 ± 1.16 vs 1.17 ± 1.11, p = 0.86). CONCLUSIONS: Prenatal US and MRI equivalently predicted the postnatal motor deficit level in children with myelomeningocele. These data may be valuable in prenatal prognostication.

Care management and contemporary challenges in spina bifida: a practice preference survey of the American Society of Pediatric Neurosurgeons.

OBJECTIVE: Neurosurgical management preferences related to myelomeningocele (MMC) care demonstrate significant variability. The authors sought to evaluate variability in practice patterns across a group of senior pediatric neurosurgeons. The purpose of this study was to identify the extent of variability and of consensus with regard to neurosurgical management of MMC and associated hydrocephalus, Chiari II malformation, and tethered spinal cord. METHODS: A 43-question survey was distributed electronically to the members of the American Society of Pediatric Neurosurgeons (ASPN). The survey covered domains such as clinic case volume, newborn management, hydrocephalus management, transition to adulthood, clinical indications for shunt revision, Chiari II malformation decompression (C2MD), and tethered cord release (TCR). Ninety responses were received from 200 active ASPN members, for an overall response rate of 45%. RESULTS: The majority (58%) of respondents closed 5-15 new cases of open MMC per year. Nearly all (98%) respondents perform back closure within 48 hours of birth, with the majority imbricating the placode and striving for a 3- to 4-layer closure. The most consistent indications for surgical intervention in early hydrocephalus were CSF leak from the back (92%), progressive ventricular enlargement (89%), and brainstem symptoms, including apnea/bradycardia (81%), stridor (81%), and dysphagia (81%). Eighty percent of respondents indicated that spina bifida care is delivered through multidisciplinary clinics, with neurosurgery, orthopedic surgery, urology, physical therapy, and social work as the most common disciplines included. One-third of clinics see both pediatric and adult patients, one-third offer a formal transition program to adult care, and one-third have no transition program. The vast majority of respondents offer prenatal counseling (95%), referral for in utero closure (66%), and endoscopic third ventriculostomy/choroid plexus cauterization (72%). Respondents were more willing to perform shunt revision for symptoms alone than for image changes alone. An asymptomatic broken shunt without ventricular enlargement produced responses evenly divided between observation, intervention, and further investigation. Operative shunt exploration was always performed before C2MD by 56% of respondents and performed sometimes by 40% of respondents. Symptoms of brainstem dysfunction were the strongest clinical triggers reported for C2MD, while declines in urinary continence, leg strength or sensation, or ambulation were the most consistent thresholds for TCR. CONCLUSIONS: Significant disparities exist surrounding key areas of decision making regarding treatment for patients with MMC, though there are central areas of agreement among ASPN members. Additionally, there is significant variation in the clinical management of chronic hydrocephalus, C2MD, and TCR, underscoring the need for further research into these specific areas.

A national analysis of 9655 pediatric cerebrovascular malformations: effect of hospital volume on outcomes.

OBJECTIVE: Comprehensive multicenter data on the surgical treatment of pediatric cerebrovascular malformations (CVMs) in the US are lacking. The goal of this study was to identify national trends in patient demographics and assess the effect of hospital case volume on outcomes. METHODS: Admissions for CVMs (1997-2012) were identified from the nationwide Kids' Inpatient Database. Admissions with and without craniotomy were reviewed separately. Patients were categorized by whether they were treated at low-, medium-, or high-volume centers (< 10, 10-40, > 40 cases/year, respectively). A generalized linear model was used to evaluate the association of hospital pediatric CVM case volume and clinical variables assessing outcomes. RESULTS: Among the 9655 patients, 1828 underwent craniotomy and 7827 did not. Patient age and race differed in the two groups, as did the rate of private medical payers. High-volume hospitals had fewer nonroutine discharges (11.2% [high] vs 16.4% [medium] vs 22.3% [low], p = 0.0001). For admissions requiring craniotomy, total charges ($106,282 [high] vs $126,215 [medium] vs $134,978 [low], p < 0.001) and complication rates (0.09% [high] vs 0.11% [medium] vs 0.16% [low], p = 0.001) were lower in high-volume centers. CONCLUSIONS: This study revealed that further investigation may be needed regarding barriers to surgical treatment of pediatric CVMs. The authors found that surgical treatment of pediatric CVM at high-volume centers is associated with significantly fewer complications, better dispositions, and lower costs, but for noncraniotomy patients, low-volume centers had lower rates of complications and death and lower costs. These findings may support the consideration of appropriate referral of CVM patients requiring surgery or with intracranial hemorrhage toward high-volume, specialized centers.