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OBJECTIVE Periventricular nodular heterotopia (PVNH) is a result of disrupted neuronal migration from the ventricular system and can be a rare cause of refractory focal epilepsy. The goal of this case series was to describe the treatment of pediatric PVNH-related epilepsy with MR-guided laser interstitial thermal ablation. METHODS Patients treated at a single institution with MR-guided laser interstitial thermal therapy (MRgLITT) for PVNH-related epilepsy were identified. Preoperative and postoperative seizure outcomes and procedural information were evaluated. RESULTS Five children with PVNH treated with MRgLITT were reviewed; 1 child was treated twice. Three patients were female; the median age was 10.9 years. Five of 6 treatments were preceded by stereoelectroencephalography phase II monitoring. Three children experienced unilateral PVNH, and 2 had bilateral seizures. The median number of seizures recorded during phase II monitoring was 2; the median number of ablation targets was 2 (range 1–4). All patients experienced a decrease in seizure frequency; 4 patients (80%) had an Engel class ≤ III at the last follow-up (range I–IV). One child experienced right hemianopia posttreatment. CONCLUSIONS This case series investigation has illustrated a novel, minimally invasive approach for treating pediatric PVNH-related epilepsy. Further study of this technique with comparison with other surgical techniques is warranted.

Ependymomas comprise approximately 10 percent of childhood CNS malignancies and are associated with dismal outcomes if metastatic, incompletely resected, or recurrent.1 Standard therapy consists of maximal safe surgical resection followed by focal irradiation.2 Recurrent fusion genes involving C11orf95-RELA or YAP1 have been identified in supratentorial ependymomas, but targetable molecular lesions are rare.3,4 Here, we report a sustained response to larotrectinib in a pediatric patient with a histologic diagnosis of recurrent metastatic anaplastic ependymoma, whose molecular testing unexpectedly revealed a KANK1-NTRK2 fusion and methylation profile most consistent with pleomorphic xanthoastrocytoma (PXA). This case highlights the potentially profound clinical implications of integrating genomic profiling into the diagnostic evaluation of pediatric CNS tumors.

OBJECTIVE Several small series have described stereotactic MRI-guided laser interstitial thermal therapy for partial callosotomy of astatic and generalized tonic-clonic (GTC) seizures, especially in association with Lennox-Gastaut syndrome. Larger case series and comparison of distinct stereotactic methods for stereotactic laser corpus callosotomy (SLCC), however, are currently lacking. The objective of this study was to report seizure outcomes in a series of adult patients with epilepsy following anterior, posterior, and complete SLCC procedures and to compare the results achieved with a frameless stereotactic surgical robot versus direct MRI guidance frames. METHODS The authors retrospectively reviewed sequential adult epilepsy surgery patients who underwent SLCC procedures at a single institution. They describe workflows, stereotactic errors, percentage disconnection, hospitalization durations, adverse events, and seizure outcomes after performing anterior, posterior, and complete SLCC procedures using a frameless stereotactic surgical robot versus direct MRI guidance platforms. RESULTS Thirteen patients underwent 15 SLCC procedures. The median age at surgery was 29 years (range 20–49 years), the median duration of epilepsy was 21 years (range 9–48 years), and median postablation follow-up was 20 months (range 4–44 months). Ten patients underwent anterior SLCC with a median 73% (range 33%–80%) midsagittal length of callosum acutely ablated. Following anterior SLCC, 6 of 10 patients achieved meaningful (> 50%) reduction of target seizures. Four patients underwent posterior (completion) SLCC following prior anterior callosotomy, and 1 patient underwent complete SLCC as a single procedure; 3 of these 5 patients experienced meaningful reduction of target seizures. Overall, 8 of 10 patients in whom astatic seizures were targeted and treated by anterior and/or posterior SLCC experienced meaningful improvement. SLCC procedures with direct MRI guidance (n = 7) versus a frameless surgical robot (n = 8) yielded median radial accuracies of 1.1 mm (range 0.2–2.0 mm) versus 2.4 mm (range 0.6–6.1 mm; p = 0.0011). The most serious adverse event was a clinically significant intraparenchymal hemorrhage in a patient who underwent the robotic technique. CONCLUSIONS This is the largest reported series of SLCC for epilepsy to date. SLCC provides seizure outcomes comparable to open surgery outcomes reported in the literature. Direct MRI guidance is more accurate, which has the potential to reduce the risks of SLCC. Methodological advancements and larger studies are needed.

Zusammenfassung Einleitung Die stereotaktische Laserthermoablation (SLTA) stellt eine minimal-invasive Behandlung für therapierefraktäre Epilepsien auf dem Boden eines hypothalamischen Hamartoms (HH) dar. Durch die weitreichenden Folgen einer therapierefraktären Epilepsie können hohe direkte Kosten entstehen, die durch eine zu erzielende Anfallsfreiheit gesenkt werden können. Methoden Anhand einer Patientin mit einem HH sollen die Auswirkungen einer solchen Erkrankung beleuchtet und der Krankheitsverlauf nach erfolgter SLTA dargestellt werden. Zur Beurteilung der Kosteneffizienz der SLTA wurden die direkten Kosten, basierend auf den Krankenversicherungsdaten der Patientin, über die Versicherungsjahre 2017 bis 2020 analysiert. Ergebnisse Bei der Patientin bestand eine hochaktive, medikamentenrefraktäre Epilepsie mit erhöhtem Verletzungsrisiko und zunehmender Verschlechterung der schulischen Leistung und der psychischen Verfassung. Begleitend bestand durch das HH eine Pubertas praecox. Nach SLTA entwickelte die Patientin mit einem Follow-up von 26 Monaten eine vollständige Anfallsfreiheit sowie eine endokrinologische Stabilisierung, sodass die antikonvulsive als auch die hormonelle Medikation im Verlauf beendet werden konnten. Relevante persistierende Komplikationen wurden nicht beobachtet. Die direkten jährlichen Kosten (stationär [ausschließlich der SLTA selbst]/ambulant/Medikamente) reduzierten sich von € 6603 in 2017 und € 12.903 in 2018 auf € 3609 in 2019 und zuletzt € 617 in 2020, was einer Reduktion von bis zu 95 % (2018 gegenüber 2020) entsprach. Zusätzlich konnten die Kosten einer geplanten Integrationsassistenz von schätzungsweise € 18.000/Jahr eingespart werden. Schlussfolgerung Die SLTA stellt eine effektive und risikoarme Behandlung von HH dar und führt bereits nach 2 Jahren zu einer relevanten Einsparung der direkten Kosten, was bei der Kosten-Nutzen-Abwägung der SLTA einzubeziehen ist.

Introduction: Hypothalamic hamartoma is rarely associated with epileptic spasms. We describe epileptic spasms in a large cohort of hypothalamic hamartoma patients. Methods: We performed a retrospective chart review between March 2011 and March 2020 to identify patients with hypothalamic hamartoma and epilepsy. Results: We identified 114 patients with hypothalamic hamartoma and epilepsy, only 3 male patients (2.6%) also had epileptic spasms. The epileptic spasms developed between 6 and 18 months of age. Epileptic spasms resolved with oral prednisolone in 1 and with vigabatrin in the second patient. The third patient continued epileptic spasms despite multiple antiepileptic drugs and partial resection of hypothalamic hamartoma. All 3 patients underwent laser-ablation of hypothalamic hamartoma at the age of 14, 29, and 63 months. The seizure burden decreased by 100%, 84%, and 93% at follow-up (3-47 months). Conclusions: Epileptic spasms are rare in hypothalamic hamartoma patients and early laser-ablation could potentially treat epileptic spasms and all other seizure types associated with hypothalamic hamartoma.

Epilepsy occurs in nearly all patients with tuberous sclerosis and is often refractory to medical treatment. The definition of surgical candidacy in these patients has broadened in recent years due to philosophical and technological advances. The goals of surgery have shifted to focusing on quality of life and maximizing neurodevelopmental potential in patients unable to obtain seizure freedom. Novel diagnostic, ablative, and neuromodulatory techniques have been developed that may help patients that were previously considered inoperable to have an improved quality of life. In the coming years, it is expected that these techniques will be further refined and lead to an improvement of neurological prognosis in patients with tuberous sclerosis.

This article overviews the surgical options for hypertonia management in cerebral palsy, both spasticity and dystonia. We review the history and use of intrathecal baclofen. We contrast its use with the indications for selective dorsal rhizotomy and review how it is the optimal technique to lower tone in the ambulatory spastic diplegic patient with cerebral palsy. This article reviews the advent of deep brain stimulation, with an emphasis on selection criteria and expected outcomes in this population. The article reviews the principles and use of selective peripheral neurotomy as it is applied to focal spasticity not requiring systemic tone reduction.

Background and Purpose The current tools available for localization of expressive language, including functional magnetic resonance imaging (fMRI) and cortical stimulation mapping (CSM), require that the patient remain stationary and follow language commands with precise timing. Many pediatric epilepsy patients, however, have intact language skills but are unable to participate in these tasks due to cognitive impairments or young age. In adult subjects, there is evidence that language laterality can be determined by resting state (RS) fMRI activity, however there are few studies on the use of RS to accurately predict language laterality in children. Methods A retrospective review of pediatric patients at Texas Children's Hospital was performed to identify patients who have undergone epilepsy surgical planning over 3 years with language localization using traditional methods of Wada testing, CSM, or task-based fMRI with calculated laterality index, as well as a 7-minute RS scan available without excessive motion or noise. We found the correlation between each subject's left and right Broca's region activity and each of 68 cortical regions. Results A group of nine patients with left-lateralized language were found to have greater voxel-wise correlations than a group of six patients with right-lateralized language between a left hemispheric Broca's region seed and the following six cortical regions: left inferior temporal, left lateral orbitofrontal, left pars triangularis, right lateral orbitofrontal, right pars orbitalis and right superior frontal regions. Conclusions In a cohort of children with epilepsy, we found that patients with left- and right-hemispheric language lateralization have different RS networks.

Background Hypothalamic hamartomas (HH) are a challenging pathology that cause gelastic seizures. Magnetic Resonance Imaging-guided Laser Interstitial Thermal Therapy (MRgLITT) offers a safe and effective treatment for HHs via a minimally invasive technique. Objective To determine how clinical outcome correlates to residual tumor volume and surgical strategy by analyzing radiographic data and reconstructing volumetric imaging. Methods Clinical and radiographic information of 58 pediatric patients who underwent MRgLITT for HH with at least 6 mo of follow-up were retrospectively reviewed. MR imaging was volumetrically reconstructed to analyze the impact of hamartoma and ablation volumes on outcome. Primary outcome measure was freedom from gelastic seizures. Results Eighty-one percent of patients were completely free of gelastic seizures at last follow-up; of 22 patients with secondary nongelastic epilepsy, 15 were free of additional seizures. Postoperative complication rate was low. There was no significant difference in gelastic seizure outcome related to pre- or postoperative hamartoma size. Residual hamartoma percentage in those free of gelastic seizures was 43% compared to 71% in those with continued seizures (P = .021). Larger hamartomas required multiple ablations to achieve seizure freedom. Conclusion This large series of patients confirms the safety and efficacy of MRgLITT for pediatric HH and describes morphological considerations that predict success. Our data suggest that complete ablation of the lesion is not necessary, and that the focus should be on appropriate disconnection of the epileptogenic network. We have found that a staged approach to hamartoma ablation allows adequate disconnection of the hamartoma while mitigating risk to surrounding structures.

OBJECTIVEThe indication for and timing of surgery for epilepsy associated with low-grade mixed neuronal-glial tumors may be controversial. The purpose of this study was to evaluate the effect of resection and associated variables on epilepsy and on progression-free survival (PFS).METHODSA retrospective chart review of patients treated between 1992 and 2016 was conducted to identify individuals with epilepsy and low-grade gliomas or neuronal-glial tumors who underwent resective surgery. Data analyzed included age at epilepsy onset, age at surgery, extent of resection, use of electrocorticography, the number of antiepileptic drugs (AEDs) before and after surgery, the presence of dysplasia, Engel class, histological findings, and PFS. The institutional review board protocol was specifically approved to conduct this study.RESULTSA total of 107 patients were identified. The median follow-up was 4.9 years. The most common pathology was dysembryoplastic neuroepithelial tumor (36.4%), followed by ganglioglioma (31.8%). Eighty-four percent of patients had Engel class I outcomes following surgery. Gross-total resection was associated with a higher likelihood of an Engel class I outcome (90%) as compared to subtotal resection (58%) (p = 0.0005). Surgery reduced the AED burden, with 40% of patients requiring no AEDs after surgery (p < 0.0001). Children with neurodevelopmental comorbidities (n = 5) uniformly did not experience seizure improvement following resection (0% vs 83% overall; p < 0.0001). Electrocorticography was used in 33% of cases and did not significantly increase class I outcomes. PFS was 90% at 5 years. Eleven percent of tumors recurred, with subtotal resection more likely to result in recurrence (hazard ratio 5.3, p = 0.02). Histological subtype showed no significant impact on recurrence.CONCLUSIONSGross-total resection was strongly associated with Engel class I outcome and longer PFS. Further studies are needed to elucidate the suitable time for surgery and to identify factors associated with oncological transformation.

Texas Children’s Hospital opened its doors in 1954, and since that time the institution has remained dedicated to a three-part mission: patient care, education, and research. Dr. William R. Cheek developed an early interest in pediatric neurosurgery, which led to his efforts in building and developing a service at Texas Children’s Hospital at a time when the field was just emerging. His work with other early pioneers in the field led to the establishment of organized societies, educational texts, and governing bodies that have led to significant advances in the field over the past 50 years.

OBJECTIVE The grid-based orthogonal placement of depth electrodes (DEs), initially defined by Jean Talairach and Jean Bancaud, is known as stereo-electroencephalography (sEEG). Although acceptance in the United States was initially slow, advances in imaging and technology have spawned a proliferation of North American epilepsy centers offering sEEG. Despite publications highlighting minimal access techniques and varied indications, standard work for phase I targeted DE has not been defined. In this article, the authors propose the term “dynamic sEEG” and define standard work tools and related common data elements to promote uniformity in the field. METHODS A multidisciplinary approach from July to August 2016 resulted in the production of 4 standard work tools for dynamic sEEG using ROSA: 1) a 34-page illustrated manual depicting a detailed workflow; 2) a planning form to collocate all the phase I data; 3) a naming convention for DEs that encodes the data defining it; and 4) a reusable portable perioperative planning and documentation board. A retrospective review of sEEG case efficiency was performed comparing those using standard work tools (between July 2016 and April 2017) with historical controls (between March 2015 and June 2016). The standard work tools were then instituted at another epilepsy surgery center, and the results were recorded. RESULTS The process for dynamic sEEG was formally reviewed, including anesthesia, positioning, perioperative nursing guidelines, surgical steps, and postoperative care for the workflow using cranial fixation and ROSA-guided placement. There was a 40% improvement in time per electrode, from 44.7 ± 9.0 minutes to 26.9 ± 6.5 minutes (p = 0.0007) following the development and use of the manual, the naming convention, and the reusable portable perioperative planning and documentation board. This standardized protocol was implemented at another institution and yielded a time per electrode of 22.3 ± 4.4 minutes. CONCLUSIONS The authors propose the term dynamic sEEG for stereotactic depth electrodes placed according to phase I workup data with the intention of converting to ablation. This workflow efficiency can be optimized using the standard work tools presented. The authors also propose a novel naming convention that encodes critical data and allows portability among providers. Use of a planning form for common data elements optimizes research, and global adoption could facilitate multicenter studies correlating phase I modality and seizure onset zone identification.

MRgLITT was first used for treatment of epilepsy in a child in 2010. Since that initial case, the technique has been applied to many pediatric epileptogenic targets such as tuberous sclerosis, mesial temporal lobe epilepsy, focal cortical dysplasia, periventricular nodular heterotopia, insular epilepsy, cavernous malformation, and, most efficiently, hypothalamic hamartoma. The combination of instant thermal ablation and peri-operative steroids to combat edema has resulted in an 83% 1-year seizure freedom rate with 1.5% rate of memory impairment, making it a profound improvement on open surgery. The technique has also been applied in disconnection, such as in corpus callosotomy, both in de novo and in salvage cases. In the treatment of drop attacks, three to four lasers can be employed to achieve the disconnection minimally invasively, obviating the need for a craniotomy. Outside of hypothalamic hamartoma, there have been few large pathology-based series, and long-term cognitive data is not available. MRgLITT in pediatric epilepsy holds the promise of less morbidity and shorter hospital stays, steps that may narrow the treatment gap in pediatric epilepsy surgery from anxiety and morbidity avoidance.

ObjectiveTo describe the findings of histopathology and genotyping studies in affected brain tissue from an individual with phacomatosis pigmentovascularis (PPV).MethodsA retrospective chart review of a 2-year 10-month-old male with a clinical diagnosis of PPV cesiomarmorata (or type V) was performed. Clinical features, brain imaging and histopathology findings, and genotyping studies in his affected brain tissue are summarized.ResultsThe proband had a clinically severe neurologic phenotype characterized by global developmental delay, generalized hypotonia, and recurrent episodes of cardiac asystole in the setting of status epilepticus. A somatic pathogenic variant in GNA11 (c.547C>T, p.Arg183Cys) was detected in his skin tissue but not in blood (previously published). He underwent an urgent left posterior quadrantectomy for his life-threatening seizures. Histopathology of resected brain tissue showed an increase in leptomeningeal melanocytes and abnormal vasculature, and the exact pathogenic variant in GNA11 (c.547C>T, p.Arg183Cys), previously isolated from his skin tissue but not blood, was detected in his resected brain tissue.ConclusionsThe finding of this variant in affected skin and brain tissue of our patient with PPV supports a unifying genetic diagnosis of his neurocutaneous features.

BACKGROUND Patients with metastatic pediatric ependymoma have limited therapeutic options and poor outcomes. Approximately ¾ of supratentorial ependymomas are driven by C11ORF95-RELA fusions, and the remaining by a heterogeneous group of fusion events. We present a six year-old male diagnosed with supratentorial ependymoma with leptomeningeal carcinomatosis harboring an NTRK2-fusion. Local and distant multifocal, intracranial and intraspinal tumor recurrence occurred seven months following gross total resection of the primary lesion and proton beam craniospinal irradiation. METHODS DNA and RNA from FFPE tumor were used for targeted sequencing using an 81-gene fusion panel and 124-gene mutation panel. Separately, capture transcriptome sequencing, exome sequencing, and copy number array were performed as part of the Texas KidsCanSeq study, an NHGRI/NCI-funded Clinical Sequencing Evidence-Generating Research (CSER) consortium project. All sequencing was carried out in CLIA-certified laboratories. RESULTS An in-frame fusion between 5’ exons 1–3 of KANK1 and 3’ exons 16–21 of NTRK2, predicted to retain the kinase domain, was identified. At tumor recurrence, therapy was initiated with Larotrectinib, an FDA-approved pan-TRK inhibitor. Clinical improvement in cognitive speed, motor strength, and coordination was observed at two weeks with significant tumor response on MRI at two and four months. CONCLUSION TRK gene fusions have not previously been reported in ependymoma. Further tumor characterization by methylation profiling is underway and will be of diagnostic interest given the apparent discordance between tumor histology and molecular findings. This case highlights the potential impact of clinical genomic analysis for children with CNS tumors.

In selected children with tuberous sclerosis complex, epilepsy surgery leads to seizure freedom or seizure reduction. The current standard involves a multimodal pre-surgical workup followed by invasive electrocorticographic monitoring and resective surgery. Recent insights in the disorder and novel technologies are changing the approach to pediatric epilepsy surgery in tuberous sclerosis complex. New evidence suggests tubers are poorly delineated, and epileptogenic activity may originate in the perituber tissue. Novel imaging modalities relevant to surgical planning include high-resolution MRI, α-methyl-l-tryptophan or fluorodeoxyglucose PET with diffusion tensor imaging. Advanced neurophysiological techniques have improved identification of the surgical target, including magnetoencephalography, electrical source imaging of high-density electroencephalograph data, and high-frequency oscillations in electrocorticography data. Simultaneously, novel surgical tools including stereo-electroencephalography and laser-induced thermal therapy have become available for children. This article reviews the literature in the light of these rapidly changing technologies.

Summary Epilepsy associated with cavernous malformation (CM) often requires surgical resection of seizure focus to achieve seizure‐free outcome. High‐frequency oscillations (HFOs) in intracranial electroencephalogram (EEG) are reported as potential biomarkers of epileptogenic regions, but to our knowledge there are no data on the existence of HFOs in CM‐caused epilepsy. Here we report our experience of the identification of the seizure focus in a 3‐year‐old pediatric patient with intractable epilepsy associated with CM. The electrocorticographic recordings were obtained from a 64‐contact grid over 2 days in the epilepsy monitoring unit (EMU). The spatial distribution of HFOs and epileptic spikes were estimated from recording segments right after the electrode placement, during sleep and awake states separately. The HFO distribution showed consistency with the perilesional region; the location of spikes varied over days and did not correlate with the lesion. The HFO spatial distribution was more compact in sleep state and pinpointed the contacts sitting on the CM border. Following the resection of the CM and the hemosiderin ring, the patient became seizure‐free. This is the first report describing HFOs in a pediatric patient with intractable epilepsy associated with CM and shows their potential in identifying the seizure focus.

Hypothalamic hamartoma (HH) is a congenital intracranial lesion associated with precocious puberty and gelastic epilepsy in children. Surgical management of HH to treat refractory epilepsy is a mainstay of treatment. Our aim was to compare the demographic characteristics and perioperative costs associated with resection by craniotomy and stereotactic laser ablation (SLA) by reviewing our institutional experience with SLA and comparing these data to a national database for craniotomy and resection. Retrospective chart review was conducted for the Texas Children's Hospital cohort of patients who underwent SLA for HH between 2011 and 2013. Information about the craniotomy cohort representing historical cases of craniotomy was obtained from the Kids' Inpatient Database for years 2003, 2006, and 2009. The cohort definition for patients undergoing craniotomy for HH was modified from published adult literature to identify pediatric patients with refractory epilepsy secondary to HH. Our study has shown that children undergoing SLA for HH have a shorter length of stay and lower cost of hospitalization compared with those who underwent craniotomy and resection for the same diagnosis. Together with previous findings from our institution regarding the safety and efficacy of SLA, our findings suggest that SLA may represent an attractive alternative to craniotomy for the treatment of refractory epilepsy secondary to HH.

OBJECTIVE Postoperative resting-state functional magnetic resonance imaging (MRI) in children with intractable epilepsy has not been quantified in relation to seizure outcome. Therefore, its value as a biomarker for epileptogenic pathology is not well understood. METHODS In a sample of children with intractable epilepsy who underwent prospective resting-state seizure onset zone (SOZ)-targeted epilepsy surgery, postoperative resting-state functional MRI (rs-fMRI) was performed 6 to 12 months later. Graded normalization of the postoperative resting-state SOZ was compared to seizure outcomes, patient, surgery, and anatomical MRI characteristics. RESULTS A total of 64 cases were evaluated. Network-targeted surgery, followed by postoperative rs-fMRI normalization was significantly (p < 0.001) correlated with seizure reduction, with a Spearman rank correlation coefficient of 0.83. Of 39 cases with postoperative rs-fMRI SOZ normalization, 38 (97%) became completely seizure free. In contrast, of the 25 cases without complete rs-fMRI SOZ normalization, only 3 (5%) became seizure free. The accuracy of rs-fMRI as a biomarker predicting seizure freedom is 94%, with 96% sensitivity and 93% specificity. INTERPRETATION Among seizure localization techniques in pediatric epilepsy, network-targeted surgery, followed by postoperative rs-fMRI normalization, has high correlation with seizure freedom. This study shows that rs-fMRI SOZ can be used as a biomarker of the epileptogenic zone, and postoperative rs-fMRI normalization is a biomarker for SOZ quiescence. ANN NEUROL 2019;86:344-356.

Background Tethered cord syndrome (TCS) refers to a clinical constellation of signs and symptoms associated with tension in the spinal cord and associated with pathologies related to abnormally low-lying conus medullaris. As minimally invasive spinal operations have become more prevalent in the past decade, we applied expanding indications to selected intradural procedures, such as tethered cord release (TCR). We present the first series of minimally invasive muscle-sparing TCR in the pediatric population. Methods A retrospective review of the Texas Children's Hospital, Houston, neurosurgical database was conducted for patients who underwent TCR between 2010 and 2017. Charts were reviewed to determine the source of TCS and whether surgery was conducted in a minimally invasive fashion. To establish a cohort of control population, age-matched cases of open TCR were selected in the same. Exclusion criterion was non-fatty filum sources of TCS. The length of stay, operative time, estimated blood loss, and postoperative complications were recorded. Results Eleven patients underwent minimally invasive TCR. Mean age of the patients was 10.1 years. All patients underwent L4-5 tubular laminotomy and cord detethering by 2 pediatric neurosurgeons at Texas Children's Hospital. The average length of stay in the hospital was 2.6 days. The average operative time was 167 minutes and average estimated blood loss was 8.2 mL. Ten patients reported clinical improvement and 1 patient was lost to follow-up. Conclusions Minimally invasive TCR is a safe and represents a viable alternative to the open approach with advantages such as minimal estimated blood loss, shortened length of stay, and postoperative pain control.

The vagus nerve stimulator (VNS) has been shown to provide a safe, albeit costly, treatment for intractable epilepsy. We aimed to analyze the incidence, timing, and clinical/demographic associations of revision surgery post-VNS implantation in epilepsy patients. The Thomson Reuters MarketScan database, containing data from 23-50million individuals, was used. Epilepsy patients receiving VNS implantations from 2003 to 2009 were identified by Current Procedural Terminology and International Classification Of Diseases Ninth Revision codes. Incidence and timing of subsequent implant-related surgeries were recorded. Events were described using time-to-event methodology, with Kaplan-Meier failure estimation/Cox proportional hazard models adjusted for clinical/demographic factors. In 1234 patients, average incidence of revision surgeries over 6years of follow-up were

Deep brain stimulation (DBS) has improved the prospects for many individuals with diseases affecting motor control, and recently it has shown promise for improving cognitive function as well. Several studies in individuals with Alzheimer disease and in amnesic rats have demonstrated that DBS targeted to the fimbria-fornix, the region that appears to regulate hippocampal activity, can mitigate defects in hippocampus-dependent memory. Despite these promising results, DBS has not been tested for its ability to improve cognition in any childhood intellectual disability disorder. Such disorders are a pressing concern: they affect as much as 3% of the population and involve hundreds of different genes. We proposed that stimulating the neural circuits that underlie learning and memory might provide a more promising route to treating these otherwise intractable disorders than seeking to adjust levels of one molecule at a time. We therefore studied the effects of forniceal DBS in a well-characterized mouse model of Rett syndrome (RTT), which is a leading cause of intellectual disability in females. Caused by mutations that impair the function of MeCP2 (ref. 6), RTT appears by the second year of life in humans, causing profound impairment in cognitive, motor and social skills, along with an array of neurological features. RTT mice, which reproduce the broad phenotype of this disorder, also show clear deficits in hippocampus-dependent learning and memory and hippocampal synaptic plasticity. Here we show that forniceal DBS in RTT mice rescues contextual fear memory as well as spatial learning and memory. In parallel, forniceal DBS restores in vivo hippocampal long-term potentiation and hippocampal neurogenesis. These results indicate that forniceal DBS might mitigate cognitive dysfunction in RTT.

OBJECTIVE The purpose of this study is to investigate the outcomes of epilepsy surgery targeting the subcentimeter-sized resting state functional magnetic resonance imaging (rs-fMRI) epileptogenic onset zone (EZ) in hypothalamic hamartoma (HH). METHODS Fifty-one children with HH-related intractable epilepsy received anatomical MRI-guided stereotactic laser ablation (SLA) procedures. Fifteen of these children were control subjects (CS) not guided by rs-fMRI. Thirty-six had been preoperatively guided by rs-fMRI (RS) to determine EZs, which were subsequently targeted by SLA. The primary outcome measure for the study was a predetermined goal of 30% reduction in seizure frequency and improvement in class I Engel outcomes 1 year postoperatively. Quantitative and qualitative volumetric analyses of total HH and ablated tissue were also assessed. RESULTS In the RS group, the EZ target within the HH was ablated with high accuracy (>87.5% of target ablated in 83% of subjects). There was no difference between the groups in percentage of ablated hamartoma volume (P = 0.137). Overall seizure reduction was higher in the rs-fMRI group: 85% RS versus 49% CS (P = 0.0006, adjusted). The Engel Epilepsy Surgery Outcome Scale demonstrated significant differences in those with freedom from disabling seizures (class I), 92% RS versus 47% CS, a 45% improvement (P = 0.001). Compared to prior studies, there was improvement in class I outcomes (92% vs 76%-81%). No postoperative morbidity or mortality occurred. SIGNIFICANCE For the first time, surgical SLA targeting of subcentimeter-sized EZs, located by rs-fMRI, guided surgery for intractable epilepsy. Our outcomes demonstrated the highest seizure freedom rate without surgical complications and are a significant improvement over prior reports. The approach improved freedom from seizures by 45% compared to conventional ablation, regardless of hamartoma size or anatomical classification. This technique showed the same or reduced morbidity (0%) compared to recent non-rs-fMRI-guided SLA studies with as high as 20% permanent significant morbidity.

OBJECTIVEDetermining language laterality in patients with intractable epilepsy is important in operative planning. Wada testing is the gold standard, but it has a risk of stroke. Both Wada and task-based functional MRI (tb-fMRI) require patient cooperation. Recently, resting-state fMRI (rs-fMRI) has been explored for language lateralization. In the present study, the correlation between rs-fMRI and tb-fMRI in language lateralization is estimated in a pediatric population with intractable epilepsy.METHODSrs-fMRI and tb-fMRI language lateralization testing performed as part of epilepsy surgery evaluation was retrospectively reviewed.RESULTSTwenty-nine patients underwent rs-fMRI and tb-fMRI; a total of 38 rs-fMRI studies and 30 tb-fMRI studies were obtained. tb-fMRI suggested left dominance in 25 of 30 cases (83%), right in 3 (10%), and in 2 (7%) the studies were nondiagnostic. In rs-fMRI, 26 of 38 studies (68%) suggested left dominance, 3 (8%) right dominance, 6 (16%) bilateral, and 3 (8%) were nondiagnostic. When tb-fMRI lateralized to the left hemisphere (25 cases), rs-fMRI was lateralized to the left in 23 patients (92%) and it was bilateral/equal in 2 (8%). When tb-fMRI lateralized to the right (3 cases), rs-fMRI lateralized to the right in all cases (100%). The overall concordance rate was 0.93 (95% CI 0.76–0.99) when considering cases with tb-fMRI and rs-fMRI performed within 6 months of each other, and tb-fMRI results were not nondiagnostic.CONCLUSIONSrs-fMRI significantly correlated with tb-fMRI in lateralizing language and suggests the potential role for identifying hemispheric dominance via rs-fMRI. Further investigation and validation studies are warranted.

Hypothalamic hamartoma is an archetypal example of subcortical epilepsy that can be associated with intractable gelastic epilepsy, secondary epilepsy, and epileptic encephalopathy. The history of its surgical treatment is fraught with mislocalization of the seizure focus, modest efficacy and a high complication rate. Many minimally invasive techniques have been described to mitigate this high complication profile of which MR-guided laser ablation is one. The technology combines instant effect of thermal coagulation with stereotactic precision and guidance with real time MR thermography. This article presents a series of 71 hypothalamic hamartoma patients operated with laser ablation. Ninety-three percent (93%) were free of gelastic seizures at one year with 23% of the patients requiring more than one ablation. One patient experienced a significant memory deficit and one patient experienced worsening diabetes insipidus. Stereotactic laser ablation appears to be a safe and effective surgical option in the treatment of hypothalamic hamartoma.

MRI-guided laser interstitial thermal therapy for epilepsy (LITT-E) has become an established, minimally invasive alternative to traditional epilepsy surgery. LITT-E is particularly valuable in cases in which open surgery poses unacceptably high morbidity or patient preference precludes craniotomy. Here we present a focused review of technical details and application of LITT to both focal and generalized epilepsy.

Resting-state functional magnetic resonance imaging (rsfMRI) is emerging as a useful tool in the multimodal assessment of patients with epilepsy. In pediatric patients who cannot perform task-based fMRI, rsfMRI may present an adjunct and alternative. Although changes in brain activation during task-based fMRI have been described after surgery for epilepsy, there is limited data on the role of postoperative rsfMRI. In this short review, we discuss the role of postoperative rsfMRI after laser ablation of seizure foci. By establishing standardized anesthesia protocols and imaging parameters, we have been able to perform serial rsfMRI at postoperative follow-up. The development of in-house software that can merge rsfMRI images to surgical navigation systems has allowed us to enhance the clinical applications of this technique. Resting-state fMRI after laser ablation has the potential to identify changes in connectivity, localize new seizure foci, and guide antiepileptic therapy. In our experience, rsfMRI complements conventional MR imaging and task-based fMRI for the evaluation of patients with seizure recurrence after laser ablation, and represents a potential noninvasive biomarker for functional connectivity.

Preoperative antibiosis contributes up to one third of total antibiotic use in major hospitals. Choice of antibiotic is not uniformly standardized, and polypharmacy regimens may be used without knowing the effect on rates of surgical site infection, nonsurgical infections, or antibiotic resistance. Careful examination of trends in surgical prophylaxis is warranted. In this study, we aimed to examine our institution’s experience with vagus nerve stimulator (VNS) implantation, focusing on association between perioperative antibiotic practices and postoperative infectious outcomes. We conducted a single-center case-control study using a retrospective chart review of 50 consecutively operated patients undergoing VNS implantation over 24 months by two experienced surgeons at our institution from April 2014 to March 2016. In each surgery, the technical procedure, operating room, and surgical team were the same, while surgeon’s preference in antibiotic prophylaxis differed. Group 1 received a single dose of intravenous (IV) cefazolin (n = 26), and Group 2 received IV cefazolin, paired with one or both of gentamicin/vancomycin, in addition to a 10-day outpatient oral course of clindamycin (n = 24). Patient demographics, perioperative details, and minimum 3-month follow-up for infection and healthcare utilization were recorded. Student t tests were computed for significance. Group 1 patients on average were older than group 2 patients (10.2, 7.1 years, p = 0.01), and length of surgery was longer (115.5, 91.9 min, p = 0.007). There were no differences in number of surgeons gowned (p = 0.11), presence of tracheostomy (p = 0.43) or gastrostomy (p = 0.20) tube, nonsurgical infections (p = 0.32), and number of postoperative emergency department (ED) visits (p = 0.22) or readmissions (p = 0.23). Neither group had VNS infections in the follow-up period. Single preoperative dosing of one antibiotic appropriately chosen to cover typical skin flora conferred equal benefit to perioperative prophylactic polypharmacy in this study. There were no differences in postoperative infection events or ED visits/readmissions. Restraint with preoperative antibiosis shows equipoise in postoperative infection and overall resource utilization.

Object Deep brain stimulation (DBS) has become accepted therapy for intractable dystonia and other movement disorders. The accurate placement of DBS electrodes into the globus pallidus internus is assisted by unimpaired microelectrode recordings (MERs). Many anesthetic and sedative drugs interfere with MERs, requiring the patient to be awake for target localization and neurological testing during the procedure. In this study, a novel anesthetic technique was investigated in pediatric DBS to preserve MERs. Methods In this paper, the authors describe a sedative/anesthetic technique using ketamine, remifentanil, dexmedetomidine, and nicardipine in 6 pediatric patients, in whom the avoidance of GABAergic stimulating drugs permitted excellent surgical conditions with no detrimental effects on intraoperative MERs. The quality of the MERs, and the frequency of its use in making electrode placement decisions, was reviewed. Results All 6 patients had good-quality MERs. The data were of sufficient quality to make a total of 9 trajectory adjustments. Conclusions Microelectrode recordings in pediatric DBS can be preserved with a combination of dexmedetomidine and ketamine, remifentanil, and nicardipine. This preservation of MERs is particularly crucial in electrode placement in children.

Resting-state functional MRI (rs-fMRI) identifies resting-state networks (RSN) in the human brain by analyzing the connectivity of anatomically remote neuronal populations with synchronous low-frequency fluctuation in blood oxygen level-dependent (BOLD) signal. Network analysis has informed the understanding of functional brain organization and is beginning to reveal the impact that neurological disorders such as epilepsy may have on the developing cerebral cortex. Among children undergoing epilepsy surgery, mapping the brain networks supporting language, sensorimotor and visual function is a critical part of the preoperative evaluation. However, task-based functional mapping techniques are particularly difficult in immature patients and those with severe impairment. Functional mapping of RSN is a promising tool that may help circumvent the challenges of adequate cooperation and limited abilities of developmentally disabled children to perform age-appropriate functions. We discuss the current methodology of rs-fMRI in the pediatric population, review the literature of rs-fMRI in pediatric epilepsy and present our experience of using rs-fMRI for functional network mapping in children undergoing epilepsy surgery.

Object The most common cause of cervical spine arthrodesis in the pediatric population is instability related to congenital or traumatic pathology. Instrumenting the cervical spine can be challenging given smaller anatomical structures, less ossified bone, and future growth potential and development. Studies in adult patients have suggested that using screw constructs results in improved outcomes with lower rates of instrumentation failure. However, the pediatric literature is limited to small retrospective series. Based on a review of the literature and their own patient series, the authors report that instrumenting the pediatric cervical spine with screw constructs may be safer and more effective than using wiring techniques. Methods The authors reviewed the existing pediatric cervical spine arthrodesis literature and contributed 31 of their own cases from September 1, 2007, to January 1, 2011. They reviewed 204 abstracts from January 1, 1966, to December 31, 2010, and 80 manuscripts with 883 total patients were included in the review. They recorded demographic, radiographic, and outcomes data—as well as surgical details—with a focus on fusion rates and complications. Patients were then grouped into categories based upon the procedure performed: 1) patients who underwent fusions bridging the occipitocervical junction and 2) patients who underwent fusion of the cervical spine that did not include the occiput, thus including atlantoaxial and subaxial fusions. Patients were further subdivided according to the type of instrumentation used—some had posterior cervical fusion with wiring (with or without rod implantation); others had posterior cervical fusion with screws. Results The entire series comprised 914 patients with a mean age of 8.30 years. Congenital abnormalities were encountered most often (in 55% of cases), and patients had a mean follow-up of 32.5 months. From the entire cohort, 242 patients (26%) experienced postsurgical complications, and 50 patients (5%) had multiple complications. The overall fusion rate was 94.4%. For occipitocervical fusions (N = 285), both screw and wiring groups had very high fusion rates (99% and 95%, respectively, p = 0.08). However, wiring was associated with a higher complication rate. From a sample of 252 patients, 14% of those treated with screw instrumentation had complications, compared with 50% of patients treated with wiring (p < 0.05). In cervical fusions not involving the occipitocervical junction (N = 181), screw constructs had a 99% fusion rate, whereas wire instrumentation only had an 83% fusion rate (p < 0.05). Similarly, patients who underwent screw fixation had a lower complication profile (15%) when compared with those treated with wiring constructs (54%, p < 0.05). Conclusions The results of this study are limited by variations in construct design, use of orthoses, follow-up duration, and newer adjuvant products promoting fusions. However, a literature review and the authors' own series of pediatric cases suggest that instrumentation of the cervical spine in children may be safer and more efficacious using screw constructs rather than wiring techniques.

Object Over 85% of patients with myelomeningoceles require placement of a ventriculoperitoneal shunt for hydrocephalus, and between 25% and 85% of these patients develop scoliosis. Although most patients undergo repeated shunt series radiography to evaluate for device malfunction, scoliosis radiographs are less consistently obtained. The authors sought to determine if a correlation exists between these 2 radiographic techniques for a given patient, as shunt series are obtained with the patient supine, whereas scoliosis radiographs are acquired with the patient standing upright. The authors also endeavored to study if shunt series radiographs can reliably detect significant scoliosis. Methods The authors retrospectively reviewed a single institution's series of 593 patients with myelomeningoceles and identified all patients in whom a shunt series and scoliosis radiographs were obtained within a 6-month period. They reviewed the medical records and radiographs of these patients for demographic and radiographic parameters. They then applied a linear regression model and determined shunt series curve cutoffs to detect scoliotic curves greater than 20° and 50°. Results Of the 593 patients identified, 116 did not have radiographs available for interpretation. Of the remaining 477 patients, 201 had radiographic evidence of scoliosis (42%), and 66 had both a shunt series and a scoliosis radiographs acquired within a 6-month interval. In 4 patients, both end vertebrae of the scoliotic curve could not be visualized on a single radiograph. The mean age of the remaining cohort was 10.6 ± 5.2 years and the mean curve magnitude was 58° ± 37°. Using identical end vertebrae, the mean shunt series curve magnitude was 49° ± 35°. The mean interval between both radiographs was 2.3 ± 3.3 months. The regression model showed a strong linear association between shunt series and scoliosis series curves. A curve greater than 19° on shunt series radiographs would detect significant curves of greater than 20° on scoliosis series with 91% sensitivity and 78% specificity. A shunt series curve greater than 37° had 100% sensitivity and 93% specificity in identifying significant scoliotic curves greater than 50°. Conclusions Although shunt series radiographs may not precisely depict scoliotic curve magnitude because the impact of gravity is negated, they may be useful in helping to confirm clinical suspicion of scoliosis. The authors' results suggest a strong correlation between both types of radiographs.

Object Left ventricular assist devices (LVADs) are continuous or pulsatile flow devices that could potentially be life-saving measures for patients with end-stage heart failure. These devices have clear advantages over extracorporeal membrane oxygenation (ECMO) and are often used in adults. They are only recently being commonly used in the pediatric age group. As the use of LVADs becomes more mainstream in children, it is important to determine the complication profile associated with these devices. Furthermore, with the increasing application of LVADs in children, pediatric neurosurgeons are seeing a correlative increase in associated neurological complications. In this study, the authors reviewed the incidence of neurological complications due to LVAD use in the pediatric age group and the role of neurosurgery in treatment. Methods The authors examined data regarding patients with LVADs from the Texas Children's Hospital Heart Center database (July 01, 2007, to June 30, 2011) and recorded neurological complications requiring neurosurgical consultation. They identified 2 children who underwent craniotomies during LVAD treatment. Results Intracranial hemorrhage occurred in 3 (6.5%) of the 46 patients treated with an LVAD at the authors' institution. Of these patients, 2 were treated with craniotomies for life-threatening intracranial hemorrhages. The 3 patients in the neurosurgical cohort presented with cerebral infarction, decreased level of consciousness, and/or seizure. At the last follow-up (286, 503, and 550 days), 1 patient (Case 2) had no decline in neurological status, underwent a successful heart transplant, and was discharged home; 1 patient (Case 1) died of refractory cardiac failure; and 1 patient (Case 3) was on an LVAD for destination therapy (that is, the LVAD is not a bridge to transplantation but rather the final treatment). This patient was discharged from the hospital, but he died of overwhelming fungemia at 286 days while on VAD support. Conclusions Intracranial hemorrhage is a serious and feared complication of LVAD treatment. While the surgical risk is substantial due to systemic anticoagulation and significant medical comorbidities, neurosurgical evacuation of hemorrhage plays an important life-saving role that can yield successful and acceptable outcomes.

Intracranial cerebral aneurysms in the pediatric population are infrequent, and those occurring in infants less than 1 year old are extremely rare. Of intracranial aneurysms in children, dissecting aneurysms are the most common type seen. While spontaneous dissecting aneurysms usually present with ischemia, hemorrhage can also occur. A retrospective review of our patients revealed that from July 1, 2007 to June 30, 2012, four infants were treated for ruptured distal dissecting intracranial aneurysms at Texas Children’s Hospital. Mycotic aneurysms and collagen vascular disorder were excluded in all four cases. All patients presented in our series presented with subarachnoid hemorrhage, and three had intraventricular hemorrhage. All patients underwent conventional catheter angiography for diagnosis. All patients in this series were managed in the acute or subacute period with surgical or endovascular trapping without distal bypass procedures. All four patients tolerated sacrifice of the parent vessels feeding these distal aneurysms well. We describe the presentation and management of these rare cases and then review the current literature on the management of these dissecting aneurysms in infants.

Congenital long QT syndrome (LQTS) is a rare genetic ion transmembrane disorder that has been associated with multiple various genetic mutations including life-threatening cardiac arrhythmias and sudden death. Left thorascopic sympathectomy is an effective treatment for patients who are refractory to medical therapy or who need frequent epicardial internal cardiodefibrillator intervention. Although there is substantial literature about this therapy in adults, few reports detail the outcomes in children who undergo left thorascopic sympathectomies to treat LQTS. The authors report the successful use of a left thoracic sympathectomy for the treatment of an 11-year-old girl who had persistently symptomatic LQTS, even after implantation of an automatic cardioverter-defibrillator. The patient remained clinically stable without arrhythmias through 6 months' of follow-up. The authors also reviewed the relevant literature and found that it suggests that 77% of patients will have immediate resolution of their symptoms/arrhythmias after the procedure. When the outcome definition was broadened to include patients who had only 1 or 2 cardiac episodes in the follow-up period, 88% of cases were considered successful. The results of this case study and literature review suggest that left thorascopic sympathectomy is a safe and effective approach for treating pediatric patients with LQTS.

Endoscopic third ventriculostomy (ETV) is an accepted option in the treatment of obstructive hydrocephalus in children and is considered by many pediatric neurosurgeons to be the treatment of choice in this population. The procedure involves perforation of the floor of the third ventricle, specifically, the tuber cinereum, which is part of the hypothalamic-pituitary axis of cerebral endocrine regulation. Endocrine dysfunction, such as amenorrhea, weight gain, and precocious puberty, which are recognized only months to years after the procedure, may be underreported because patients and physicians may not relate the endocrine sequelae to the ETV. Few detailed reports of endocrinerelated complications following ETV exist to better understand these issues. In this study, the authors add to the literature with case descriptions of and correlative laboratory findings in 2 adolescent girls who underwent ETV for obstructive hydrocephalus and in whom amenorrhea subsequently developed.

Object Significant lumbar kyphosis is frequently observed in patients with myelomeningocele and has been associated with increasing functional impairment, decreased abdominal volume, respiratory impairment, discomfort, and skin ulcerations overlying the prominent gibbus. Treatment of severe kyphotic deformities can include kyphectomy, with or without ligation of the thecal sac, with posterior spinal fixation. However, most series have reported a high rate of morbidity and complications associated with surgical intervention for correction of kyphosis in patients with myelomeningocele. The authors describe a technique in which pedicle screw (PS)–only constructs are used without transection of the thecal sac to treat severe kyphosis successfully, with minimal morbidity. Methods The authors retrospectively reviewed medical records and radiographic images in 2 patients with myelomeningoceles in whom kyphectomies had been performed at the authors' institution between January 2007 and July 2010. They also reviewed the existing literature for case reports or published series of patients with myelomeningocele treated with kyphectomies, to evaluate the outcomes. Results Both patients were male and had thoracic-level myelomeningoceles that had been repaired at birth, with associated paraplegia. Neither patient had any significant scoliotic deformity associated with the kyphosis, and both had fixation from T-9 to the ilium, which was performed using PS constructs, along with L1–2 kyphectomies. The patient in Case 1 was 20 years old and was treated for progressive kyphosis and an ulcerated nonhealing wound over the gibbus. The patient in Case 2 was 10 years old and was treated for progressive pain and functional impairment. The 2 patients had a mean correction of 63%, with a mean correction of kyphotic deformity from 136° to 51°. Neither patient developed any complication in the short term postoperatively, whereas published series have reported high complication rates, including wound infection, poor wound healing, CSF leakage, pseudarthrosis, and shunt malfunction. Conclusions Severe kyphotic deformities in patients with myelomeningocele can be safely treated using PS-only constructs without ligation of the thecal sac. Further evaluation with a larger sample and longer follow-up are needed to detect any associated complications, such as proximal junctional kyphosis. Further evaluation may also validate whether PS-only constructs permit successful outcomes with a shorter construct and fewer instrumented levels.

Object Lumbar disc herniation is rare in the pediatric age group, but may still cause a significant amount of pain and disability. Whereas minimally invasive surgery (MIS) for lumbar disc herniation is routinely performed in adults, it has not yet been described in the pediatric population. The purpose of this study was to describe the surgical results of pediatric MIS-treated lumbar disc disease. Methods The authors retrospectively reviewed a series of 6 consecutive cases of lumbar microdiscectomy performed using MIS techniques between April 2008 and July 2010. Presenting symptoms, physical examination findings, and preoperative MR imaging results were obtained from medical records. Perioperative results, including blood loss, length of hospital stay, and complications were assessed. Findings at latest follow-up evaluation were also recorded. Results This report represents the first surgical series regarding pediatric lumbar microdiscectomies performed using MIS. The mean patient age was 16 years (range 14–17 years); there were 4 girls and 2 boys. Preoperative signs and symptoms of radiculopathic pain were notable in 100% of patients, and myotomal weakness was noted in 33% of patients. The first line of treatment in all patients was a period of conservative management lasting an average of 11.5 months (range 6–12 months). The mean intraoperative blood loss was 10.8 ml, and the mean postoperative length of stay was 1.3 days. There were no complications in this small series. Conclusions The treatment of pediatric lumbar disc herniation by using MIS techniques can be safe and efficacious. However, further study with a larger number of patients and longer follow-up is needed to compare outcomes between MIS and open microdiscectomies.

Study design A retrospective review of coronal spine balance after tethered cord release for children with tight filum terminale. Objective To understand the effects of untethering on coronal spine balance for these patients. Summary of background data In patients with tight filum terminale, the spinal cord is tethered by a thickened filum with a low conus medullaris but without other forms of spinal dysraphism. There have not been studies examining the effects of spinal cord untethering on coronal spinal alignment in children with tight filum terminale. Methods Forty-five consecutive pediatric patients with tight filum terminale who had undergone untethering were evaluated. Their presenting signs and symptoms, pre- and postsurgery imagings, and clinical courses were reviewed for scoliosis progression. Results Twenty-six girls and 19 boys underwent tethered cord release at a mean age of 4.5 years. The prevalence of coronal spinal malalignment, manifesting as scoliosis, before the untethering procedure was 31% (14 of 45). During the follow-up period, nine patients had coronal spinal alignment that worsened>10° (five patients eventually underwent surgical fusion), two patients had spinal alignment that improved, and five patients' curves stabilized after untethering surgery. Therefore, at the end of the follow-up period, 9 of 45 patients (20%) had worsened coronal spinal alignment. In the multivariate analysis, patients who presented with a Cobb angle greater than 35° were most likely to progress (P=0.002, odds ratio=21). There was no operative morbidity or mortality associated with scoliosis surgery. Conclusion A significant number of children with tight filum terminale were found to present with scoliosis. In patients with less severe curves, tethered cord release may halt scoliosis progression.

Object Neurophysiological monitoring of motor evoked potentials (MEPs) during complex spine procedures may reduce the risk of injury by providing feedback to the operating surgeon. While this tool is a well-established surgical adjunct in adults, clinical data in children are sparse. The purpose of this study was to determine the reliability and safety of MEP monitoring in a group of children younger than 3 years of age undergoing neurosurgical spine procedures. Methods A total of 10 consecutive spinal procedures in 10 children younger than 3 years of age (range 5–31 months, mean 16.8 months) were analyzed between January 1, 2008, and May 1, 2010. Motor evoked potentials were elicited by transcranial electric stimulation. A standardized anesthesia protocol for monitoring consisted of a titrated propofol drip combined with bolus dosing of fentanyl or sufentanil. Results Motor evoked potentials were documented at the beginning and end of the procedure in all 10 patients. A mean baseline stimulation threshold of 533 ± 124 V (range 321–746 V) was used. Six patients maintained MEP signals ≥ 50% of baseline amplitude throughout the surgery. There was a greater than 50% decrease in intraoperative MEP amplitude in at least 1 extremity in 4 patients. Two of these patients returned to baseline status by the end of the case. Two patients had a persistent decrement or variability in MEP signals at the end of the procedure; this correlated with postoperative weakness. There were no complications related to the technique of monitoring MEPs. Conclusions A transcranial electric stimulation protocol monitoring corticospinal motor pathways during neurosurgical procedures in children younger than 3 years of age was reliably and safely implemented. A persistent intraoperative decrease of greater than 50% in this small series of 10 pediatric patients younger than 3 years of age predicted a postoperative neurological deficit. The authors advocate routine monitoring of MEPs in this pediatric age group undergoing neurosurgical spine procedures.

Object Translaminar screw (TLS) fixation can be used safely and efficaciously for upper cervical fusion in children. No published studies have evaluated this technique in the thoracic spine of the pediatric population, and thus the authors undertook such an analysis. Methods The upper thoracic spines (T1–4) of 130 patients, consisting of 70 boys and 60 girls, were studied using CT scans. Laminar height and thickness, screw length, and screw angle were measured. Exclusion criteria included the following: patients older than 18 years of age, trauma or congenital abnormalities of the thoracic spine, or absent demographic information or imaging studies through T-4. Statistical analysis was performed using paired or unpaired Student t-tests (p < 0.05) and linear regression analysis. Results The mean laminar heights for T-1, T-2, T-3, and T-4 were as follows: 12.3 ± 3.4, 13.0 ± 3.5, 13.4 ± 3.8, and 14.7 ± 4.1 mm, respectively. The mean laminar widths were 6.5 ± 1.3, 6.6 ± 1.3, 6.6 ± 1.3, and 6.6 ± 1.4 mm, respectively. The mean screw lengths were 29.9 ± 4.1, 25.2 ± 3.5, 22.7 ± 3.2, and 21.6 ± 3.1 mm, respectively. The mean screw angles were 47° ± 4°, 48° ± 4°, 51° ± 4°, and 53° ± 5°, respectively. There were no significant differences between the right and left sides. However, significant differences were found when comparing patients younger than 8 years with those who were 8 years or older, and when comparing boys and girls. Conclusions Careful preoperative thin-cut CT with sagittal reconstruction is mandatory to determine if the placement of TLSs is feasible in the pediatric population. Based on CT analysis, the insertion of TLSs in the pediatric thoracic spine is possible in all patients older than 8 years and in many patients younger than 8 years. Boys could accept longer screws in the upper thoracic spine compared with girls.

BACKGROUND: Previous studies using recombinant human bone morphogenetic protein-2 (rhBMP-2) in the adult lumbar spine have shown consistently good results, There have been no pediatric case series. OBJECTIVE: To determine the safety and efficacy of rhBMP-2 use in posterior instrumented fusions of the pediatric population. METHODS: A retrospective review of 19 consecutive pediatric patients who underwent posterior occiptocervical, cervical, thoracic, lumbar, or lumbosacral spine fusion from October 1, 2007, to June 30, 2008, at Texas Children's Hospital was performed. The average age was approximately 12 years old (range, 9 months to 20 years). The minimum follow-up was 17 months (average of 19 months, range: 17-25 months), with computed tomography (CT) evaluation and grading of fusion by an independent radiologist at 3 months after surgery. RESULTS: The average CT grade was 3, indicating bilateral bridging bone. No pseudoarthroses or loss of correction was identified clinically or radiographically at 3 months and latest follow-up. There was one complication of bony overgrowth and restenosis of the spinal canal necessitating reoperation, and two superficial wound infections. There were no deep wound infections. CONCLUSION: Early outcomes using rhBMP-2 in the pediatric population show that it is a safe and efficacious adjunct to posterior spine fusions of the occipitocervical, cervical, thoracic, lumbar, and lumbosacral spine. It dependably results in the development of stable bridging bone at 3 months after surgery with good maintenance of correction and stability in long-term follow-up. Lessons learned from the case of unexpected bony overgrowth are discussed.

Object Patients with CSF shunts often present to the emergency department (ED) with suspected shunt malfunction. Timely assessment and treatment are important factors affecting patient outcomes. A protocol was implemented at a tertiary children's hospital ED to expedite the care of these patients. This study evaluated the effectiveness of this protocol. Methods The protocol assigned all patients with CSF shunts into 1 of 3 pathways. If a patient presented with altered mental status, the Cushing triad, acute focal neurological deficit, ongoing seizure activity, or severe dehydration due to emesis, an ED physician was immediately notified (emergency pathway). If a patient presented with emesis, headache, increasing frequency of seizure, or parental concern for shunt malfunction, the patient entered the expedited pathway, and imaging studies were ordered prior to physician evaluation. All other patients entered the default pathway, in which a physician would evaluate the patient before deciding on further workup. Outcomes of interest included measures of timeliness in the ED and clinical outcomes. Comparisons were made between preprotocol and protocol periods and among the 3 pathways. Results The total time to complete both ED physician evaluation and to initiate imaging studies was significantly shorter in the protocol period than in the preprotocol period (104 vs 147 minutes). Similar time saving over the 2 processes was demonstrated comparing expedited and default pathways during the protocol period (95 vs 134 minutes, a 29% difference). Clinically, more patients underwent surgery in the expedited pathway than the default pathway (36% vs 17%), and patients in the expedited pathway had a shorter hospital stay (3.4 ± 0.9 days vs 5.7 ± 4.0 days; p = 0.02). Conclusions An ED-based protocol helped identify patients at risk for shunt failure early in the triage process and shortened the assessment process prior to neurosurgical intervention. Improving the timeliness of care for patients with shunt failure is important because morbidity and mortality associated with shunt failure are time dependent.

Posterior reversible encephalopathy syndrome (PRES) has been described in the setting of malignant hypertension, renal disease, eclampsia, and immunosuppression. In addition, a single case of intraoperative (posterior fossa craniotomy) PRES has been reported; however, this case occurred in an adult. The authors present a clinically and radiographically documented case of intraoperative PRES complicating the resection of a posterior fossa tumor in a 6-year-old child. During tumor resection, untoward force was used to circumferentially dissect the tumor, and excessive manipulation of the brainstem led to severe hypertension for a 10-minute period. An immediate postoperative MR image was obtained to rule out residual tumor, but instead the image showed findings consistent with PRES. Moreover, the patient's postoperative clinical findings were consistent with PRES. Aggressive postoperative management of blood pressure and the institution of anticonvulsant therapy were undertaken. The patient made a good recovery; however, he required a temporary tracheostomy and tube feedings for prolonged lower cranial nerve dysfunction. Posterior reversible encephalopathy syndrome can occur as a result of severe hypertension during surgery, even among young children. With prompt treatment, the patient in the featured case experienced significant clinical and radiographic recovery.

Study Design. Technical report. Objective. To describe a minimally invasive surgical approach for the obliteration of a subarachnoid-pleural fistula in a 4-year-old child after resection of an intrathoracic ganglioneuroma. Summary of Background Data. Development of a subarachnoid-pleural fistula has been reported after thoracotomy for lung, chest wall, and spinal tumors, when an iatrogenic meningeal laceration results in establishing communication between the spinal subarachnoid space and the pleural cavity. Methods. Review of a single case in which video-assisted thorascopic surgery (VATS) was used to deposit fibrin glue and to suture a pleural allograft. Literature review was performed to document other options to treat subarachnoid-pleural cerebrospinal fluid (CSF) fistula. Results. At 10 months after VATS repair, the CSF fistula has remained closed. Conclusion. VATS technique should be considered for a safe, efficacious, and durable CSF leak repair and as an alternative to open thoracotomy in the pediatric age group.