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.

Vasospasm and subsequent stroke from paraneoplastic syndrome in a pediatric patient with an intracranial mature teratoma: a case report.

Teratomas account for 18-20% of all intracranial germ cell tumors and mostly occur in the pineal region with only a few cases of pediatric sellar and suprasellar teratomas described in the literature. Here, we present a case of a child with an intracranial mature teratoma with pancreatic features causing vasospasm and subsequent stroke, found to be positive for CDKN2A-an independent variant associated with malignancy and small vessel disease leading to stroke.

MRI and pathology comparisons in Rasmussen's encephalitis: a multi-institutional examination of hemispherotomy outcomes relative to imaging and histological severity.

PURPOSE: Rasmussen encephalitis (RE) is a very rare chronic neurological disorder of unilateral inflammation of the cerebral cortex. Hemispherotomy provides the best chance at achieving seizure freedom in RE patients, but with significant risks and variable long-term outcomes. The goal of this study is to utilize our multicenter pediatric cohort to characterize if differences in pathology and/or imaging characterization of RE may provide a window into post-operative seizure outcomes, which in turn could guide decision-making for parents and healthcare providers. METHODS: This multi-institutional retrospective review of medical record, imaging, and pathology samples was approved by each individual institution's review board. Data was collected from all known pediatric cases of peri-insular functional hemispherotomy from the earliest available electronic medical records. Mean follow-up time was 4.9 years. Clinical outcomes were measured by last follow-up visit using both Engel and ILAE scoring systems. Relationships between categorical and continuous variables were analyzed with Pearson correlation values. RESULTS: Twenty-seven patients met study criteria. No statistically significant correlations existed between patient imaging and pathology data. Pathology stage, MRI brain imaging stages, and a combined assessment of pathology and imaging stages showed no statistically significant correlation to post-operative seizure freedom rates. Hemispherectomy Outcome Prediction Scale scoring demonstrated seizure freedom in only 71% of patients receiving a score of 1 and 36% of patients receiving a score of 2 which were substantially lower than predicted. CONCLUSIONS: Our analysis did not find evidence for either independent or combined analysis of imaging and pathology staging being predictive for post peri-insular hemispherotomy seizure outcomes, prompting the need for other biomarkers to be explored. Our data stands in contrast to the recently proposed Hemispherectomy Outcome Prediction Scale and does not externally validate this metric for an RE cohort.

Surgical outcomes of open and laser interstitial thermal therapy approaches for corpus callosotomy in pediatric epilepsy.

OBJECTIVE: Corpus callosotomy (CC) is a palliative surgical intervention for patients with medically refractory epilepsy that has evolved in recent years to include a less-invasive alternative with the use of laser interstitial thermal therapy (LITT). LITT works by heating a stereotactically placed laser fiber to ablative temperatures under real-time magnetic resonance imaging (MRI) thermometry. This study aims to (1) describe the surgical outcomes of CC in a large cohort of children with medically refractory epilepsy, (2) compare anterior and complete CC, and (3) review LITT as a surgical alternative to open craniotomy for CC. METHODS: This retrospective cohort study included 103 patients <21 years of age with at least 1 year follow-up at a single institution between 2003 and 2021. Surgical outcomes and the comparative effectiveness of anterior vs complete and open versus LITT surgical approaches were assessed. RESULTS: CC was the most common surgical disconnection (65%, n = 67) followed by anterior two-thirds (35%, n = 36), with a portion proceeding to posterior completion (28%, n = 10). The overall surgical complication rate was 6% (n = 6/103). Open craniotomy was the most common approach (87%, n = 90), with LITT used increasingly in recent years (13%, n = 13). Compared to open, LITT had shorter hospital stay (3 days [interquartile range (IQR) 2-5] vs 5 days [IQR 3-7]; p < .05). Modified Engel class I, II, III, and IV outcomes at last follow-up were 19.8% (n = 17/86), 19.8% (n = 17/86), 40.2% (n = 35/86), and 19.8% (n = 17/86). Of the 70 patients with preoperative drop seizures, 75% resolved postoperatively (n = 52/69). SIGNIFICANCE: No significant differences in seizure outcome between patients who underwent only anterior CC and complete CC were observed. LITT is a less-invasive surgical alternative to open craniotomy for CC, associated with similar seizure outcomes, lower blood loss, shorter hospital stays, and lower complication rates, but with longer operative times, when compared with the open craniotomy approach.

Design and Validation of a 3D Printed Cranio-Facial Simulator: A Novel Tool for Surgical Education.

OBJECTIVE: To assess the ability of current 3D printing technology to generate a craniofacial bony and soft tissue anatomical model for use in simulating the performance of a fronto-orbital advancement (FOA) osteotomy and then to further assess the value of the model as an educational tool. DESIGN: Anatomic models were designed with a process of serial anatomic segmentation/design, 3D printing, dissection, and device refinement. A validation study was conducted with 5 junior and 5 senior plastic surgery residents. The validation study incorporated a multiple-choice Knowledge Assessment test (KA), an Objective Structured Assessment of Technical skills (OSATs), a Global Rating Scale (GRS) and a Michigan Standard Simulation Experience Scale (MiSSES). We compared the scores of both the junior and senior residents and compared junior resident scores, before and after viewing a lecture/demonstration. RESULTS: MiSSES showed high face validity with a score of 85.1/90, signifying high satisfaction with the simulator learning experience. Simulation and the lecture/demonstration improved the junior resident average KA score from 5.6/10 to 9.6/10 (P = .02), OSATs score from 32.4/66 to 64.4/66 (P < .001) and GRS score from 13.9/35 to 27.5/35 (P < .001). The senior residents OSATs score of 56.3/66 was higher than the pre-lecture juniors (32.4/66) (P < .001), but lower than the post-lecture juniors (64.4/66) (P < .001). CONCLUSION: We have successfully fabricated a 3D printed craniofacial simulator capable of being used as an educational tool alongside traditional surgical training. Next steps would be improving soft tissue realism, inclusion of patient and disease specific anatomy and creation of models for other surgical specialties.

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.

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.

The Role of SPECT and PET in Epilepsy.

OBJECTIVE. The purpose of this article is to summarize the role of molecular imaging of the brain by use of SPECT, FDG PET, and non-FDG PET radiotracers in epilepsy. CONCLUSION. Quantitative image analysis with PET and SPECT has increased the diagnostic utility of these modalities in localizing epileptogenic onset zones. A multi-modal platform approach integrating the functional imaging of PET and SPECT with the morphologic information from MRI in presurgical evaluation of epilepsy can greatly improve outcomes.

Management of sagittal synostosis in the Synostosis Research Group: baseline data and early outcomes.

OBJECTIVE: Sagittal synostosis is the most common form of isolated craniosynostosis. Although some centers have reported extensive experience with this condition, most reports have focused on a single center. In 2017, the Synostosis Research Group (SynRG), a multicenter collaborative network, was formed to study craniosynostosis. Here, the authors report their early experience with treating sagittal synostosis in the network. The goals were to describe practice patterns, identify variations, and generate hypotheses for future research. METHODS: All patients with a clinical diagnosis of isolated sagittal synostosis who presented to a SynRG center between March 1, 2017, and October 31, 2019, were included. Follow-up information through October 31, 2020, was included. Data extracted from the prospectively maintained SynRG registry included baseline parameters, surgical adjuncts and techniques, complications prior to discharge, and indications for reoperation. Data analysis was descriptive, using frequencies for categorical variables and means and medians for continuous variables. RESULTS: Two hundred five patients had treatment for sagittal synostosis at 5 different sites. One hundred twenty-six patients were treated with strip craniectomy and 79 patients with total cranial vault remodeling. The most common strip craniectomy was wide craniectomy with parietal wedge osteotomies (44%), and the most common cranial vault remodeling procedure was total vault remodeling without forehead remodeling (63%). Preoperative mean cephalic indices (CIs) were similar between treatment groups: 0.69 for strip craniectomy and 0.68 for cranial vault remodeling. Thirteen percent of patients had other health problems. In the cranial vault cohort, 81% of patients who received tranexamic acid required a transfusion compared with 94% of patients who did not receive tranexamic acid. The rates of complication were low in all treatment groups. Five patients (2%) had an unintended reoperation. The mean change in CI was 0.09 for strip craniectomy and 0.06 for cranial vault remodeling; wide craniectomy resulted in a greater change in CI in the strip craniectomy group. CONCLUSIONS: The baseline severity of scaphocephaly was similar across procedures and sites. Treatment methods varied, but cranial vault remodeling and strip craniectomy both resulted in satisfactory postoperative CIs. Use of tranexamic acid may reduce the need for transfusion in cranial vault cases. The wide craniectomy technique for strip craniectomy seemed to be associated with change in CI. Both findings seem amenable to testing in a randomized controlled trial.

Morphologic Severity of Craniosynostosis: Implications for Speech and Neurodevelopment.

BACKGROUND: Single-suture craniosynostosis (SSC) can be associated with neurodevelopmental deficits. We examined the correlation between morphologic severity and incidence of speech-language or psychological concerns. METHODS: In 62 patients (33 sagittal, 17 metopic, and 12 unicoronal), morphologic severity was determined via preoperative computed tomography (CT). Severity metrics for sagittal, metopic, and unicoronal synostosis were adjusted cephalic index (aCI), interfrontal angle (IFA), and anterior cranial fossa area ratio (ACFR), respectively. Speech-language and psychological concerns were assessed at age ≥4.5 years and defined as recommendation for therapy or monitoring. RESULTS: Mean assessment age was 5.7 years; 32% had a speech-language concern and 44% had a psychological concern; 44% had neither. Sagittal: Mean aCI of those with a speech-language concern (0.62) and those without (0.62) were equivalent (P = .580), as were mean aCI of those with a psychological concern (0.62) and those without (0.62; P = .572). Metopic: Mean IFA with (117.9) and without (125.2) a speech-language concern were equivalent (P = .326), as were mean IFA with (120.2) and without (123.2) a psychological concern (P = .711). Unicoronal: Mean ACFR with (0.65) and without (0.69) a psychological concern (P = .423) were equivalent. However, mean ACFR with (0.74) and without (0.63) a speech-language concern were not (P = .022*). Bivariate rank correlation showed significant association between morphologic severity and speech-language score only for unicoronal synostosis (ρ = .722; P = .008*). CONCLUSION: A significant portion of patients with SSC had speech-language or psychological concerns. We found no correlation between morphologic severity and incidence of speech-language or psychological concerns for patients with sagittal or metopic synostosis. Morphological severity did correlate with speech concerns in patients with unicoronal synostosis.

Comparison of 2 Sagittal Craniosynostosis Repair Techniques: Spring-Assisted Surgery Versus Endoscope-Assisted Craniectomy With Helmet Molding Therapy.

INTRODUCTION: This study compares anthropometric outcomes of 2 sagittal synostosis repair techniques: spring-assisted surgery and endoscope-assisted craniectomy with molding helmet therapy. METHODS: Patients undergoing spring-assisted surgery (n = 27) or endoscope-assisted craniectomy with helmet therapy (n = 40) at separate institutions were retrospectively reviewed. Pre- and 1-year postoperative computed tomography (CT) or laser scans were analyzed for traditional cranial index (CI), adjusted cranial index (aCI), and cranial vault volume (CVV). Nine patient-matched scans were analyzed for measurement consistency. RESULTS: The spring-assisted group was older at both time points (P < .050) and spring-assisted group CVV was larger preoperatively and postoperatively (P < .01). However, the change in CVV did not differ between the groups (P = .210). There was no difference in preoperative CI (helmet vs spring: 70.1 vs 71.2, P = .368) between the groups. Postoperatively, helmet group CI (77.0 vs 74.3, P = .008) was greater. The helmet group also demonstrated a greater increase in CI (6.9 vs 3.1, P < .001). The proportion of patients achieving CI of 75 or greater was not significantly different between the groups (helmet vs spring: CI, 65% vs 52%, P = .370). There was no detectable bias in CI between matched CT and laser scans. Differences were identified between scan types in aCI and CVV measurements; subsequent analyses used corrected CVV and aCI measures for laser scan measures. CONCLUSIONS: Both techniques had equivalent proportions of patients achieving normal CI, comparable effects on cranial volume, and similar operative characteristics. The study suggests that there may be greater improvement in CI in the helmet group. However, further research should be performed.

On the role of the corpus callosum in interhemispheric functional connectivity in humans.

Resting state functional connectivity is defined in terms of temporal correlations between physiologic signals, most commonly studied using functional magnetic resonance imaging. Major features of functional connectivity correspond to structural (axonal) connectivity. However, this relation is not one-to-one. Interhemispheric functional connectivity in relation to the corpus callosum presents a case in point. Specifically, several reports have documented nearly intact interhemispheric functional connectivity in individuals in whom the corpus callosum (the major commissure between the hemispheres) never develops. To investigate this question, we assessed functional connectivity before and after surgical section of the corpus callosum in 22 patients with medically refractory epilepsy. Section of the corpus callosum markedly reduced interhemispheric functional connectivity. This effect was more profound in multimodal associative areas in the frontal and parietal lobe than primary regions of sensorimotor and visual function. Moreover, no evidence of recovery was observed in a limited sample in which multiyear, longitudinal follow-up was obtained. Comparison of partial vs. complete callosotomy revealed several effects implying the existence of polysynaptic functional connectivity between remote brain regions. Thus, our results demonstrate that callosal as well as extracallosal anatomical connections play a role in the maintenance of interhemispheric functional connectivity.

Evaluation of the Patient-Practitioner Consultation on Surgical Treatment Options for Patients With Craniosynostosis.

INTRODUCTION: Endoscope-assisted craniectomy and spring-assisted cranioplasty with post-surgical helmet molding are minimally invasive alternatives to the traditional craniosynostosis treatment of open cranial vault remodeling. Families are often faced with deciding between techniques. This study aimed to understand providers' practice patterns in consulting families about surgical options. METHODS: An online survey was developed and distributed to 31 providers. The response rate was 84% (26/31). RESULTS: Twenty-six (100%) respondents offer a minimally invasive surgical option for sagittal craniosynostosis, 21 (81%) for coronal, 20 (77%) for metopic, 18 (69%) for lambdoid, and 12 (46%) for multi-suture. Social issues considered in determining whether to offer a minimally invasive option include anticipated likelihood of compliance (23 = 88%), distance traveled for care (16 = 62%) and financial considerations (6 = 23%). Common tools to explain options include verbal discussion (25 = 96%), 3D reconstructed CT scans (17 = 65%), handouts (13 = 50%), 3D models (12 = 46%), hand drawings (11 = 42%) and slides (10 = 38%). Some respondents strongly (7 = 27%) or somewhat (3 = 12%) encourage a minimally invasive option over open repair. Others indicate they remain neutral (7 = 27%) or tailor their approach to meet perceived needs (8 = 31%). One (4%) somewhat encourages open repair. Despite this variation, all completely (17 = 65%), strongly (5 = 19%) or somewhat agree (4 = 15%) they use shared decision making in presenting surgical options. CONCLUSION: This survey highlights the range of practice patterns in presenting surgical options to families and reveals possible discrepancies in the extent providers believe they use shared decision making and the extent it is actually used.

Role of resting state MRI temporal latency in refractory pediatric extratemporal epilepsy lateralization.

BACKGROUND: Pediatric epilepsy affects 0.5-1% of children, with 10-30% of these children refractory to medical anticonvulsant therapy and potentially requiring surgical intervention. Analysis of resting state functional MRI (rsMRI) signal temporal differences (latency) has been proposed to study the pathological cognitive processes. PURPOSE/HYPOTHESIS: To quantitatively and qualitatively analyze the correlation of rsMRI signal latency to pediatric refractory extratemporal epilepsy seizure foci lateralization. STUDY TYPE: Retrospective review. POPULATION: With Institutional Review Board approval, rsMRI and anatomical MRI scans were obtained from 38 registered pediatric epilepsy surgery patients from Washington University and 259 healthy control patients from the ADHD-200 dataset. FIELD STRENGTH/SEQUENCE: 3 T echo planar imaging (EPI) blood oxygenation level-dependent (BOLD) sequence. ASSESSMENT: The images were transformed to pediatric atlases in Talairach space. Preoperative voxelwise latency maps were generated with parabolic interpolation of the rsMRI signal lateness or earliness when compared with the global mean signal (GMS) using cross-covariance analysis. STATISTICAL TESTS: Latency z-score maps were created for each epilepsy patient by voxelwise calculation using healthy control mean and standard deviation maps. Voxelwise hypothesis testing was performed via multiple comparisons corrected (false discovery and familywise error rate) and uncorrected methods to determine significantly late and early voxels. Significantly late and/or early voxels were counted for the right and left hemisphere separately. The hemisphere with the greater proportion of significantly late and/or early voxels was hypothesized to contain the seizure focus. Preoperative rsMRI latency analysis hypotheses were compared with postoperative seizure foci lateralization determined by resection images. RESULTS: Preoperative rsMRI latency analysis correctly identified seizure foci lateralization of 64-85% of postoperative epilepsy resections with the proposed methods. RsMRI latency lateralization analysis was 77-100% sensitive and 58-79% specific. In some patients, qualitative analysis yielded preoperative rsMRI latency patterns specific to procedure performed. DATA CONCLUSION: Preoperative rsMRI signal latency of pediatric epilepsy patients was correlated with seizure foci lateralization. J. Magn. Reson. Imaging 2019;49:1347-1355.

Evaluation of pediatric glioma outcomes using intraoperative MRI: a multicenter cohort study.

BACKGROUND: The use of intraoperative MRI (iMRI) during treatment of gliomas may increase extent of resection (EOR), decrease need for early reoperation, and increase progression-free and overall survival, but has not been fully validated, particularly in the pediatric population. OBJECTIVE: To assess the accuracy of iMRI to identify residual tumor in pediatric patients with glioma and determine the effect of iMRI on decisions for resection, complication rates, and other outcomes. METHODS: We retrospectively analyzed a multicenter database of pediatric patients (age ≤ 18 years) who underwent resection of pathologically confirmed gliomas. RESULTS: We identified 314 patients (mean age 9.7 ± 4.6 years) with mean follow-up of 48.3 ± 33.6 months (range 0.03-182.07 months) who underwent surgery with iMRI. There were 201 (64.0%) WHO grade I tumors, 57 (18.2%) grade II, 24 (7.6%) grade III, 9 (2.9%) grade IV, and 23 (7.3%) not classified. Among 280 patients who underwent resection using iMRI, 131 (46.8%) had some residual tumor and underwent additional resection after the first iMRI. Of the 33 tissue specimens sent for pathological analysis after iMRI, 29 (87.9%) showed positive tumor pathology. Gross total resection was identified in 156 patients (55.7%), but this was limited by 69 (24.6%) patients with unknown EOR. CONCLUSIONS: Analysis of the largest multicenter database of pediatric gliomas resected using iMRI demonstrated additional tumor resection in a substantial portion of cases. However, determining the impact of iMRI on EOR and outcomes remains challenging because iMRI use varies among providers nationally. Continued refinement of iMRI techniques for use in pediatric patients with glioma may improve outcomes.

Onyx embolization of a ruptured anterior inferior cerebellar artery in a neonate.

Aneurysmal subarachnoid hemorrhage (SAH) is rare in neonates. The authors present a unique report of a neonate with SAH from anterior inferior cerebellar artery (AICA) aneurysm rupture that was successfully treated with Onyx embolization. This case report demonstrates the utility of Onyx embolization for posterior circulation aneurysms in neonates and the successful management of SAH in this population.

Long-Term Characterization of Cranial Defects After Surgical Correction for Single-Suture Craniosynostosis.

INTRODUCTION: Craniosynostosis is typically corrected surgically within the first year of life through cranial vault reconstruction. These procedures often leave open calvarial defects at the time of surgery, which are anticipated to close over time in a large proportion of cases. However, residual calvarial defects may result as long-term sequelae from cranial vault remodeling. When larger defects are present, they may necessitate further reconstruction for closure.Better understanding of the calvarial osseous healing process may help to identify which defects will resolve or shrink to acceptable size and which will require further surgery. Our study aims to assess the long-term changes in defect size after cranial vault reconstruction for craniosynostosis. METHODS: One-year postoperative and long-term computed tomography scans were retrieved from the craniofacial anomalies archive. Analysis used custom software. All defects above the size of 1 cm were analyzed and tracked for calvarial location, surface area, and circularity. Monte Carlo simulation was performed to model the effect of initial defect size on the rate of defect closure. RESULTS: We analyzed a total of 74 defects. The mean ± SD initial defect surface area was 3.27 ± 3.40 cm. The mean ± SD final defect surface area was 1.71 ± 2.54 cm. The mean ± SD percent decrease was 55.06% ± 28.99%. There was a significant difference in the percentage decrease of defects in the parietal and frontoparietal locations: 68.4% and 43.7%, respectively (P = 0.001). Monte Carlo simulation results suggest that less than 10% of defects above the size of 9 cm will close to the size of 2.5 cm or less. CONCLUSIONS: We describe and make available a novel validated method of measuring cranial defects. We find that the large majority of initial defects greater than 9 cm remain at least 1 in in size (2.5 cm) 1 year postoperatively. In addition, there appear to be regional differences in closure rates across the cranium, with frontoparietal defects closing more slowly than those in the parietal region. This information will aid surgeons in the decision-making process regarding cranioplasty after craniosynostosis correction.

Postsurgical Changes in Osseous Dysmorphology of the Midface and Mandible in Unilateral Coronal Craniosynostosis.

BACKGROUND: Early management of unilateral coronal synostosis (UCS) aims to treat the cranial abnormality with the hope of improving middle and lower facial morphology. This study analyzed osseous volume and 3-dimensional distances in the midface and mandible of patients with UCS to assess changes in facial symmetry following a cranial vault procedure. METHODS: Patients who underwent fronto-orbital advancement for UCS repair between 1981 and 2012 with follow-up of at least 3 years were included. Computed tomography-based 3-dimensional reconstructions of the mandible and LeFort III midface were divided by 3 midline osseous landmarks and measured for volume. Distances between 11 osseous landmarks were measured in the midface and mandible. Ratios between the measurements on synostotic and nonsynostotic sides were calculated. Presurgical to postsurgical changes were evaluated with paired samples t tests. The study was powered to detect differences between preoperative and postoperative ratios of at least 3%. RESULTS: Eleven patients were included. Mean age at initial imaging was 4.7 ± 3.2 months (range, 0.4-9.2 months) with postoperative follow-up of 9.0 ±â€Š5.3 years (range, 3.3-17.0 years). Midfacial symmetry of osseous volume improved following surgery (synostotic to nonsynostotic ratio, 94.1% vs 98.9%, P = 0.044). The width (P < 0.001), height (P = 0.039), and anterior-posterior depth of the midface (P = 0.011) also became more symmetric. In the mandible, however, volumetric and linear symmetry did not improve. CONCLUSIONS: Symmetry of the midface, but not the mandible, improves significantly following the cranial procedure in patients with UCS.

Evaluation of Direct Surgical Remodeling of Frontal Bossing in Patients With Sagittal Synostosis.

BACKGROUND: The need for surgical correction of frontal bossing in patients with sagittal synostosis is currently debated. The authors retrospectively analyzed frontal bossing in patients with isolated, nonsyndromic sagittal synostosis who underwent calvarial remodeling with and without frontal craniotomy and compared with control subjects. METHODS: The authors analyzed computed tomography (CT) scans of patients with sagittal synostosis <9 months of age (6.2 ±â€Š1.6 months) who underwent modified-pi procedure either with frontal craniotomy (FC, n = 15) or without frontal craniotomy (NFC, n = 10). Only patients treated with both pre-operative and 1-year post-operative CT scans were included. Non-synostotic age-matched control scans were also analyzed. Cephalic index (CI), 3 previously validated measures of frontal bossing (bossing angle, horizontal bossing ratio, and vertical bossing ratio), and pre-nasion volume ratio were obtained. Additionally, three-dimensional photographs of 10 FC patients were evaluated for frontal bossing between 1 and 8 years post-operatively. RESULTS: Pre-operatively, no significant differences were found between the 2 groups (.064

Evaluation of Endoscopic Strip Craniectomy and Orthotic Therapy for Bilateral Coronal Craniosynostosis.

BACKGROUND: Bilateral coronal craniosynostosis is the premature fusion of both coronal sutures. Traditionally, this condition is treated by frontal-orbital advancement (FOA). Endoscopic strip craniectomy with cranial orthotic therapy, which has gained popularity in treating single suture craniosynostosis, has recently been adapted for the treatment of bicoronal synostosis. There have been few studies documenting the outcomes of this treatment. The objective of this study is to compare the morphological outcomes of endoscopic strip craniectomy and FOA in patients with bicoronal synostosis. METHODS: A retrospective case series was done on 24 patients with bilateral coronal synostosis treated with endoscopic strip craniectomy or FOA at 2 institutions. Patients with preoperative and 1-year postoperative computed tomography scans were included. Multiple measures of cranial shape and size were assessed: cephalic index, turricephaly index, basofrontal angle, circumference Z-score, and cranial vault volume Z-score. RESULTS: The 2 groups were similar statistically in terms of morphology at preoperative scan. There were no statistical differences between the FOA group and endoscopic group at postoperative scan in any of the morphologic outcomes measured. Cranial vault volume Z-scores increased postoperatively in both the endoscopic (P < 0.001) and FOA (P = 0.034) groups. CONCLUSIONS: One year after repair there were no significant morphological difference between patients with bicoronal synostosis treated with the endoscopic approach and those treated by FOA.