Comparing ventriculoatrial and ventriculopleural shunts in pediatric hydrocephalus: a Hydrocephalus Clinical Research Network study.

OBJECTIVE: When the peritoneal cavity cannot serve as the distal shunt terminus, nonperitoneal shunts, typically terminating in the atrium or pleural space, are used. The comparative effectiveness of these two terminus options has not been evaluated. The authors directly compared shunt survival and complication rates for ventriculoatrial (VA) and ventriculopleural (VPl) shunts in a pediatric cohort. METHODS: The Hydrocephalus Clinical Research Network Core Data Project was used to identify children ≤ 18 years of age who underwent either VA or VPl shunt insertion. The primary outcome was time to shunt failure. Secondary outcomes included distal site complications and frequency of shunt failure at 6, 12, and 24 months. RESULTS: The search criteria yielded 416 children from 14 centers with either a VA (n = 318) or VPl (n = 98) shunt, including those converted from ventriculoperitoneal shunts. Children with VA shunts had a lower median age at insertion (6.1 years vs 12.4 years, p < 0.001). Among those children with VA shunts, a hydrocephalus etiology of intraventricular hemorrhage (IVH) secondary to prematurity comprised a higher proportion (47.0% vs 31.2%) and myelomeningocele comprised a lower proportion (17.8% vs 27.3%) (p = 0.024) compared with those with VPl shunts. At 24 months, there was a higher cumulative number of revisions for VA shunts (48.6% vs 38.9%, p = 0.038). When stratified by patient age at shunt insertion, VA shunts in children < 6 years had the lowest shunt survival rate (p < 0.001, log-rank test). After controlling for age and etiology, multivariable analysis did not find that shunt type (VA vs VPl) was predictive of time to shunt failure. No differences were found in the cumulative frequency of complications (VA 6.0% vs VPl 9.2%, p = 0.257), but there was a higher rate of pneumothorax in the VPl cohort (3.1% vs 0%, p = 0.013). CONCLUSIONS: Shunt survival was similar between VA and VPl shunts, although VA shunts are used more often, particularly in younger patients. Children < 6 years with VA shunts appeared to have the shortest shunt survival, which may be a result of the VA group having more cases of IVH secondary to prematurity; however, when age and etiology were included in a multivariable model, shunt location (atrium vs pleural space) was not associated with time to failure. The baseline differences between children treated with a VA versus a VPl shunt likely explain current practice patterns.

The interictal suppression hypothesis is the dominant differentiator of seizure onset zones in focal epilepsy.

Successful surgical treatment of drug-resistant epilepsy traditionally relies on the identification of seizure onset zones (SOZs). Connectome-based analyses of electrographic data from stereo electroencephalography (SEEG) may empower improved detection of SOZs. Specifically, connectome-based analyses based on the Interictal Suppression Hypothesis (ISH) posit that when the patient is not having a seizure, SOZs are inhibited by non-SOZs through high inward connectivity and low outward connectivity. However, it is not clear whether there are other motifs that can better identify potential SOZs. Thus, we sought to use unsupervised machine learning to identify network motifs that elucidate SOZs and investigate if there is another motif that outperforms the ISH. Resting-state SEEG data from 81 patients with drug-resistant epilepsy undergoing a pre-surgical evaluation at Vanderbilt University Medical Center were collected. Directed connectivity matrices were computed using the alpha band (8-12Hz). Principal component analysis (PCA) was performed on each patient's connectivity matrix. Each patient's components were analyzed qualitatively to identify common patterns across patients. A quantitative definition was then used to identify the component that most closely matched the observed pattern in each patient. A motif characteristic of the Interictal Suppression Hypothesis (high-inward and low-outward connectivity) was present in all individuals and found to be the most robust motif for identification of SOZs in 64/81 (79%) patients. This principal component demonstrated significant differences in SOZs compared to non-SOZs. While other motifs for identifying SOZs were present in other patients, they differed for each patient, suggesting that seizure networks are patient specific, but the ISH is present in nearly all networks. We discovered that a potentially suppressive motif based on the Interictal Suppression Hypothesis was present in all patients, and it was the most robust motif for SOZs in 79% of patients. Each patient had additional motifs that further characterized SOZs, but these motifs were not common across all patients. This work has the potential to augment clinical identification of SOZs to improve epilepsy treatment.

Treatment of hydrocephalus following fetal repair of myelomeningocele: comparing endoscopic third ventriculostomy with choroid plexus cauterization to ventricular shunting.

OBJECTIVE: The aim of this study was to compare clinical and craniometric outcomes of patients treated for hydrocephalus following fetal myelomeningocele repair (fMMR) via a ventriculoperitoneal shunt (VPS) or endoscopic third ventriculostomy with choroid plexus cauterization (ETV/CPC). METHODS: This was a retrospective cohort study of children who were treated for hydrocephalus following fMMR via VPS or ETV with or without CPC (ETV ± CPC) at Vanderbilt between 2012 and 2021. The primary outcomes were treatment failure and time to failure (TTF). Secondary outcomes included changes in hydrocephalus metrics (fronto-occipital horn ratio [FOHR] and head circumference measurements) and healthcare resource utilization (number of hospital admissions, clinic visits, and neuroimaging findings). RESULTS: Among 88 patients who underwent fMMR, 37 (42%) required permanent CSF diversion, of whom 19 received treatment at the authors' institution. Twelve patients underwent ETV ± CPC, and 7 underwent VPS placement at a median corrected age of 23 weeks versus 1 week (p = 0.002). The preoperative median head circumference percentiles and z-scores for patients in the ETV ± CPC cohort were similar to those of the VPS cohort (percentiles: 98.5 vs 94.0, p = 0.064; z-scores: 2.32 vs 1.60, p = 0.111). There was no difference in preoperative median FOHR measurements between the two cohorts (0.57 vs 0.59, p = 0.53). At 6 months postoperatively, the median head circumference percentile and z-score for the ETV ± CPC cohort remained similar between the two cohorts (percentiles: 98.0 vs 67.5, p = 0.315; z-scores: 2.12 vs 0.52, p = 0.307). There was no difference in the change in FOHR (-0.06 vs -0.09, p = 0.37) and change in head circumference percentile (-1.33 vs -28.6, p = 0.058) between the cohorts 6 months after the index CSF diversion procedure. One patient in the ETV ± CPC cohort experienced a seizure and a nonoperative subdural hemorrhage postoperatively; no other complications were observed. Six of the 7 patients in the VPS cohort required shunt revision with a median TTF of 9.8 months while 2 of the 12 ETV ± CPC patients required a repeat ETV at a median of 17.5 months (86% vs 17%, p = 0.013). The median number of hydrocephalus-related hospital readmissions was significantly lower in the ETV ± CPC cohort than in the VPS cohort (0 vs 1, p = 0.006). The ETV ± CPC cohort had fewer CT scans (0 vs 2, p = 0.004) and radiographs (0 vs 2, p < 0.001) than the VPS cohort. CONCLUSIONS: In a single-center cohort, hydrocephalic fMMR patients treated via ETV ± CPC remained shunt free, while a majority of patients receiving an upfront shunt required revision. This is the first study comparing ETV ± CPC with VPS in the fMMR hydrocephalus population. While larger, multicenter studies are needed, these results suggest that ETV/CPC may be a preferred means of CSF diversion following fMMR.

Treatment of hydrocephalus following posterior fossa tumor resection: a multicenter collaboration from the Hydrocephalus Clinical Research Network.

OBJECTIVE: Persistent hydrocephalus following posterior fossa brain tumor (PFBT) resection is a common cause of morbidity in pediatric brain tumor patients, for which the optimal treatment is debated. The purpose of this study was to compare treatment outcomes between VPS and ETV in patients with persistent hydrocephalus following surgical resection of a PFBT. METHODS: A post-hoc analysis was performed of the Hydrocephalus Clinical Research Network (HCRN) prospective observational study evaluating VPS and ETV for pediatric patients. Children who experienced hydrocephalus secondary to PFBT from 2008 to 2021 were included. Primary outcomes were VPS/ETV treatment failure and time-to-failure (TTF). RESULTS: Among 241 patients, the VPS (183) and ETV (58) groups were similar in age, extent of tumor resection, and preoperative ETV Success Score. There was no difference in overall treatment failure between VPS and ETV (33.9% vs 31.0%, p = 0.751). However, mean TTF was shorter for ETV than VPS (0.45 years vs 1.30 years, p = 0.001). While major complication profiles were similar, compared to VPS, ETV patients had relatively higher incidence of minor CSF leak (10.3% vs. 1.1%, p = 0.003) and pseudomeningocele (12.1% vs 3.3%, p = 0.02). No ETV failures were identified beyond 3 years, while shunt failures occurred beyond 5 years. Shunt infections occurred in 5.5% of the VPS cohort. CONCLUSIONS: ETV and VPS offer similar overall success rates for PFBT-related postoperative hydrocephalus. ETV failure occurs earlier, while susceptibility to VPS failure persists beyond 5 years. Tumor histology and grade may be considered when selecting the optimal means of CSF diversion.

The Interictal Suppression Hypothesis in focal epilepsy: network-level supporting evidence.

Why are people with focal epilepsy not continuously having seizures? Previous neuronal signalling work has implicated gamma-aminobutyric acid balance as integral to seizure generation and termination, but is a high-level distributed brain network involved in suppressing seizures? Recent intracranial electrographic evidence has suggested that seizure-onset zones have increased inward connectivity that could be associated with interictal suppression of seizure activity. Accordingly, we hypothesize that seizure-onset zones are actively suppressed by the rest of the brain network during interictal states. Full testing of this hypothesis would require collaboration across multiple domains of neuroscience. We focused on partially testing this hypothesis at the electrographic network level within 81 individuals with drug-resistant focal epilepsy undergoing presurgical evaluation. We used intracranial electrographic resting-state and neurostimulation recordings to evaluate the network connectivity of seizure onset, early propagation and non-involved zones. We then used diffusion imaging to acquire estimates of white-matter connectivity to evaluate structure-function coupling effects on connectivity findings. Finally, we generated a resting-state classification model to assist clinicians in detecting seizure-onset and propagation zones without the need for multiple ictal recordings. Our findings indicate that seizure onset and early propagation zones demonstrate markedly increased inwards connectivity and decreased outwards connectivity using both resting-state (one-way ANOVA, P-value = 3.13 × 10-13) and neurostimulation analyses to evaluate evoked responses (one-way ANOVA, P-value = 2.5 × 10-3). When controlling for the distance between regions, the difference between inwards and outwards connectivity remained stable up to 80 mm between brain connections (two-way repeated measures ANOVA, group effect P-value of 2.6 × 10-12). Structure-function coupling analyses revealed that seizure-onset zones exhibit abnormally enhanced coupling (hypercoupling) of surrounding regions compared to presumably healthy tissue (two-way repeated measures ANOVA, interaction effect P-value of 9.76 × 10-21). Using these observations, our support vector classification models achieved a maximum held-out testing set accuracy of 92.0 ± 2.2% to classify early propagation and seizure-onset zones. These results suggest that seizure-onset zones are actively segregated and suppressed by a widespread brain network. Furthermore, this electrographically observed functional suppression is disproportionate to any observed structural connectivity alterations of the seizure-onset zones. These findings have implications for the identification of seizure-onset zones using only brief electrographic recordings to reduce patient morbidity and augment the presurgical evaluation of drug-resistant epilepsy. Further testing of the interictal suppression hypothesis can provide insight into potential new resective, ablative and neuromodulation approaches to improve surgical success rates in those suffering from drug-resistant focal epilepsy.

Multi-Center Validation of the McGovern Pediatric Blunt Cerebrovascular Injury Screening Score.

Blunt cerebrovascular injury (BCVI) is defined as blunt trauma to the head and neck leading to damage to the vertebral and/or carotid arteries; debate exists regarding which children are considered at high risk for BCVI and in need of angiographic/vessel imaging. We previously proposed a screening tool, the McGovern score, to identify pediatric trauma patients at high risk for BCVI, and we aim to validate the McGovern score by pooling data from multiple pediatric trauma centers. This is a multi-center, hospital-based, cohort study from all prospectively registered pediatric (<16 years of age) trauma patients who presented to the emergency department (ED) between 2003 and 2017 at six Level 1 pediatric trauma centers. The registry was retrospectively queried for patients who received a computed tomography angiogram (CTA) as a screening method for BCVI. Age, length of follow-up, mechanism of injury (MOI), arrival Glasgow Coma Scale (GCS) score, and focal neurological deficit were recorded. Radiological variables queried were the presence of a carotid canal fracture, petrous temporal bone fracture, and CT presence of infarction. Patients with BCVI were queried for mode of treatment, type of intracranial injury, artery damaged, and BCVI injury grade. The McGovern score was calculated for all patients who underwent CTA across all data groups. A total of 1012 patients underwent CTA; 72 of these patients were found to have BCVI, 51 of which were in the validation cohort. Across all data groups, the McGovern score has a >80% sensitivity (SN) and >98% negative predictive value (NPV). The McGovern score for pediatric BCVI is an effective, generalizable screening tool.

Endoscopic third ventriculostomy in previously shunt-treated patients.

OBJECTIVE: Endoscopic third ventriculostomy (ETV) is an option for treatment of hydrocephalus, including for patients who have a history of previous treatment with CSF shunt insertion. The purpose of this study was to report the success of postshunt ETV by using data from a multicenter prospective registry. METHODS: Prospectively collected data in the Hydrocephalus Clinical Research Network (HCRN) Core Data Project (i.e., HCRN Registry) were reviewed. Children who underwent ETV between 2008 and 2019 and had a history of previous treatment with a CSF shunt were included. A Kaplan-Meier survival curve was created for the primary outcome: time from postshunt ETV to subsequent CSF shunt placement or revision. Univariable Cox proportional hazards models were created to evaluate for an association between clinical and demographic variables and subsequent shunt surgery. Postshunt ETV complications were also identified and categorized. RESULTS: A total of 203 children were included: 57% male and 43% female; 74% White, 23% Black, and 4% other race. The most common hydrocephalus etiologies were postintraventricular hemorrhage secondary to prematurity (56, 28%) and aqueductal stenosis (42, 21%). The ETV Success Score ranged from 10 to 80. The median patient age was 4.1 years. The overall success of postshunt ETV at 6 months was 41%. Only the surgeon's report of a clear view of the basilar artery was associated with a lower likelihood of postshunt ETV failure (HR 0.43, 95% CI 0.23-0.82, p = 0.009). None of the following variables were associated with postshunt ETV success: age at the time of postshunt ETV, etiology of hydrocephalus, sex, race, ventricle size, number of previous shunt operations, ETV performed at time of shunt infection, and use of external ventricular drainage. Overall, complications were reported in 22% of patients, with CSF leak (8.6%) being the most common complication. CONCLUSIONS: Postshunt ETV was successful in treating hydrocephalus, without subsequent need for a CSF shunt, in 41% of patients, with a clear view of the basilar artery being the only variable significantly associated with success. Complications occurred in 22% of patients. ETV is an option for treatment of hydrocephalus in children who have previously undergone shunt placement, but with a lower than expected likelihood of success.

Endoscopic third ventriculostomy revision after failure of initial endoscopic third ventriculostomy and choroid plexus cauterization.

OBJECTIVE: Primary treatment of hydrocephalus with endoscopic third ventriculostomy (ETV) and choroid plexus cauterization (CPC) is well described in the neurosurgical literature, with wide reported ranges of success and complication rates. The purpose of this study was to describe the safety and efficacy of ETV revision after initial ETV+CPC failure. METHODS: Prospectively collected data in the Hydrocephalus Clinical Research Network Core Data Project registry were reviewed. Children who underwent ETV+CPC as the initial treatment for hydrocephalus between 2013 and 2019 and in whom the initial ETV+CPC was completed (i.e., not abandoned) were included. Log-rank survival analysis (the primary analysis) was used to compare time to failure (defined as any other surgical treatment for hydrocephalus or death related to hydrocephalus) of initial ETV+CPC versus that of ETV revision by using random-effects modeling to account for the inclusion of patients in both the initial and revision groups. Secondary analysis compared ETV revision to shunt placement after failure of initial ETV+CPC by using the log-rank test, as well as shunt failure after ETV+CPC to that after ETV revision. Cox regression analysis was used to identify predictors of failure among children treated with ETV revision. RESULTS: The authors identified 521 ETV+CPC procedures that met their inclusion criteria. Ninety-one children underwent ETV revision after ETV+CPC failure. ETV revision had a lower 1-year success rate than initial ETV+CPC (29.5% vs 45%, p < 0.001). ETV revision after initial ETV+CPC failure had a lower success rate than shunting (29.5% vs 77.8%, p < 0.001). Shunt survival after initial ETV+CPC failure was not significantly different from shunt survival after ETV revision failure (p = 0.963). Complication rates were similar for all examined surgical procedures (initial ETV+CPC, ETV revision, ventriculoperitoneal shunt [VPS] placement after ETV+CPC, and VPS placement after ETV revision). Only young age was predictive of ETV revision failure (p = 0.02). CONCLUSIONS: ETV revision had a significantly lower 1-year success rate than initial ETV+CPC and VPS placement after ETV+CPC. Complication rates were similar for all studied procedures. Younger age, but not time since initial ETV+CPC, was a risk factor for ETV revision failure.

The Hydrocephalus Clinical Research Network quality improvement initiative: the role of antibiotic-impregnated catheters and vancomycin wound irrigation.

OBJECTIVE: Two previous Hydrocephalus Clinical Research Network (HCRN) studies have demonstrated that compliance with a standardized CSF shunt infection protocol reduces shunt infections. In this third iteration, a simplified protocol consisting of 5 steps was implemented. This analysis provides an updated evaluation of protocol compliance and evaluates modifiable shunt infection risk factors. METHODS: The new simplified protocol was implemented at HCRN centers on November 1, 2016, for all shunt procedures, excluding external ventricular drains, ventricular reservoirs, and subgaleal shunts. Procedures performed through December 31, 2019, were included (38 months). Compliance with the protocol, use of antibiotic-impregnated catheters (AICs), and other variables of interest were collected at the index operation. Outcome events for a minimum of 6 months postoperatively were recorded. The definition of infection was unchanged from the authors' previous report. RESULTS: A total of 4913 procedures were performed at 13 HCRN centers. The overall infection rate was 5.1%. Surgeons were compliant with all 5 steps of the protocol in 79.4% of procedures. The infection rate for the protocol alone was 8.1% and dropped to 4.9% when AICs were added. Multivariate analysis identified having ≥ 2 complex chronic conditions (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.26-2.44, p = 0.01) and a history of prior shunt surgery within 12 weeks (OR 1.84, 95% CI 1.37-2.47, p < 0.01) as independent risk factors for shunt infection. The use of AICs (OR 0.70, 95% CI 0.50-0.97, p = 0.05) and vancomycin irrigation (OR 0.36, 95% CI 0.21-0.62, p < 0.01) were identified as independent factors protective against shunt infection. CONCLUSIONS: The authors report the third iteration of their quality improvement protocol to reduce the risk of shunt infection. Compliance with the protocol was high. These updated data suggest that the incorporation of AICs is an important, modifiable infection prevention measure. Vancomycin irrigation was also identified as a protective factor but requires further study to better understand its role in preventing shunt infection.

SEEG Functional Connectivity Measures to Identify Epileptogenic Zones: Stability, Medication Influence, and Recording Condition.

BACKGROUND AND OBJECTIVES: Functional connectivity (FC) measures can be used to differentiate epileptogenic zones (EZs) from non-EZs in patients with medically refractory epilepsy. Little work has been done to evaluate the stability of stereo-EEG (SEEG) FC measures over time and their relationship with antiseizure medication (ASM) use, a critical confounder in epilepsy FC studies. We aimed to answer the following questions: Are SEEG FC measures stable over time? Are they influenced by ASMs? Are they affected by patient data collection state? METHODS: In 32 patients with medically refractory focal epilepsy, we collected a single 2-minute prospective SEEG resting-state (awake, eyes closed) data set and consecutive 2-minute retrospective pseudo-rest (awake, eyes open) data sets for days 1-7 postimplantation. ASM dosages were recorded for days 1-7 postimplantation and drug load score (DLS) per day was calculated to standardize and compare across patients. FC was evaluated using directed and nondirected measures. Standard clinical interpretation of ictal SEEG was used to classify brain regions as EZs and non-EZs. RESULTS: Over 7 days, presumed EZs consistently had higher FC than non-EZs when using between imaginary coherence (ImCoh) and partial directed coherence (PDC) inward strength, without accounting for DLS. These measures were demonstrated to be stable over a short-term period of 3 consecutive days with the same DLS. Between ImCoh FC differences between EZs and non-EZs were reduced with DLS decreases, whereas other measures were not affected by DLS. FC differences between EZs and non-EZs were seen during both resting-state and pseudo-rest conditions; ImCoh values were strongly correlated between the 2 conditions, whereas PDC values were not. DISCUSSION: Inward and nondirected SEEG FC is higher in presumed EZs vs non-EZs and measures are stable over time. However, certain measures may be affected by ASM dose, as between ImCoh differences between EZs and non-EZs are less pronounced with lower doses, and other measures such as PDC are poorly correlated across recording conditions. These findings allow novel insight into how SEEG FC measures may aid surgical localization and how they are influenced by ASMs and other factors.

Anterior versus posterior entry site for ventriculoperitoneal shunt insertion: a randomized controlled trial by the Hydrocephalus Clinical Research Network.

OBJECTIVE: The primary objective of this trial was to determine if shunt entry site affects the risk of shunt failure. METHODS: The authors performed a parallel-design randomized controlled trial with an equal allocation of patients who received shunt placement via the anterior entry site and patients who received shunt placement via the posterior entry site. All patients were children with symptoms or signs of hydrocephalus and ventriculomegaly. Patients were ineligible if they had a prior history of shunt insertion. Patients received a ventriculoperitoneal shunt after randomization; randomization was stratified by surgeon. The primary outcome was shunt failure. The planned minimum follow-up was 18 months. The trial was designed to achieve high power to detect a 10% or greater absolute difference in the shunt failure rate at 1 year. An independent, blinded adjudication committee determined eligibility and the primary outcome. The study was conducted by the Hydrocephalus Clinical Research Network. RESULTS: The study randomized 467 pediatric patients at 14 tertiary care pediatric hospitals in North America from April 2015 to January 2019. The adjudication committee, blinded to intervention, excluded 7 patients in each group for not meeting the study inclusion criteria. For the primary analysis, there were 229 patients in the posterior group and 224 patients in the anterior group. The median patient age was 1.3 months, and the most common etiologies of hydrocephalus were postintraventricular hemorrhage secondary to prematurity (32.7%), myelomeningocele (16.8%), and aqueductal stenosis (10.8%). There was no significant difference in the time to shunt failure between the entry sites (log-rank test, stratified by age < 6 months and ≥ 6 months; p = 0.061). The hazard ratio (HR) of a posterior shunt relative to an anterior shunt was calculated using a univariable Cox regression model and was nonsignificant (HR 1.35, 95% CI, 0.98-1.85; p = 0.062). No significant difference was found between entry sites for the surgery duration, number of ventricular catheter passes, ventricular catheter location, and hospital length of stay. There were no significant differences between entry sites for intraoperative complications, postoperative CSF leaks, pseudomeningoceles, shunt infections, skull fractures, postoperative seizures, new-onset epilepsy, or intracranial hemorrhages. CONCLUSIONS: This randomized controlled trial comparing the anterior and posterior shunt entry sites has demonstrated no significant difference in the time to shunt failure. Anterior and posterior entry site surgeries were found to have similar outcomes and similar complication rates.

Measuring the effects of institutional pediatric traumatic brain injury volume on outcomes for rural-dwelling children.

OBJECTIVE: Rural-dwelling children may suffer worse pediatric traumatic brain injury (TBI) outcomes due to distance from and accessibility to high-volume trauma centers. This study aimed to compare the impacts of institutional TBI volume and sociodemographics on outcomes between rural- and urban-dwelling children. METHODS: This retrospective study identified patients 0-19 years of age with ICD-9 codes for TBI in the 2012-2015 National Inpatient Sample database. Patients were characterized as rural- or urban-dwelling using United States Census classification. Logistic and linear (in log scale) regressions were performed to measure the effects of institutional characteristics, patient sociodemographics, and mechanism/severity of injury on occurrence of medical complications, mortality, length of stay (LOS), and costs. Separate models were built for rural- and urban-dwelling patients. RESULTS: A total of 19,736 patients were identified (median age 11 years, interquartile range [IQR] 2-16 years, 66% male, 55% Caucasian). Overall, rural-dwelling patients had higher All Patient Refined Diagnosis Related Groups injury severity (median 2 [IQR 1-3] vs 1 [IQR 1-2], p < 0.001) and more intracranial monitoring (6% vs 4%, p < 0.001). Univariate analysis showed that overall, rural-dwelling patients suffered increased medical complications (6% vs 4%, p < 0.001), mortality (6% vs 4%, p < 0.001), and LOS (median 2 days [IQR 1-4 days ] vs 2 days [IQR 1-3 days], p < 0.001), but multivariate analysis showed rural-dwelling status was not associated with these outcomes after adjusting for injury severity, mechanism, and hospital characteristics. Institutional TBI volume was not associated with medical complications, disposition, or mortality for either population but was associated with LOS for urban-dwelling patients (nonlinear beta, p = 0.008) and cost for both rural-dwelling (nonlinear beta, p < 0.001) and urban-dwelling (nonlinear beta, p < 0.001) patients. CONCLUSIONS: Overall, rural-dwelling pediatric patients with TBI have worsened injury severity, mortality, and in-hospital complications, but these disparities disappear after adjusting for injury severity and mechanism. Institutional TBI volume does not impact clinical outcomes for rural- or urban-dwelling children after adjusting for these covariates. Addressing the root causes of the increased injury severity at hospital arrival may be a useful path to improve TBI outcomes for rural-dwelling children.

Genome-Wide Association Study Identifies Genetic Risk Factors for Spastic Cerebral Palsy.

BACKGROUND: Although many clinical risk factors of spastic cerebral palsy (CP) have been identified, the genetic basis of spastic CP is largely unknown. Here, using whole-genome genetic information linked to a deidentified electronic health record (BioVU) with replication in the UK Biobank and FinnGen, we perform the first genome-wide association study (GWAS) for spastic CP. OBJECTIVE: To define the genetic basis of spastic CP. METHODS: Whole-genome data were obtained using the multi-ethnic genotyping array (MEGA) genotyping array capturing single-nucleotide polymorphisms (SNPs), minor allele frequency (MAF) > 0.01, and imputation quality score (r2) > 0.3, imputed based on the 1000 genomes phase 3 reference panel. Threshold for genome-wide significance was defined after Bonferroni correction for the total number of SNPs tested (P < 5.0 × 10-8). Replication analysis (defined as P < .05) was performed in the UK Biobank and FinnGen. RESULTS: We identify 1 SNP (rs78686911) reaching genome-wide significance with spastic CP. Expression quantitative trait loci (eQTL) analysis suggests that rs78686911 decreases expression of GRIK4, a gene that encodes a high-affinity kainate glutamatergic receptor of largely unknown function. Replication analysis in the UK Biobank and FinnGen reveals additional SNPs in the GRIK4 loci associated with CP. CONCLUSION: To our knowledge, we perform the first GWAS of spastic CP. Our study indicates that genetic variation contributes to CP risk.

Choice and Trade-offs: Parent Decision Making for Neurotechnologies for Pediatric Drug-Resistant Epilepsy.

This qualitative study investigated factors that guide caregiver decision making and ethical trade-offs for advanced neurotechnologies used to treat children with drug-resistant epilepsy. Caregivers with affected children were recruited to semi-structured focus groups or interviews at one of 4 major epilepsy centers in Eastern and Western Canada and the USA (n = 22). Discussions were transcribed and qualitative analytic methods applied to examine values and priorities (eg, risks, benefits, adherence, invasiveness, reversibility) of caregivers pertaining to novel technologies to treat drug-resistant epilepsy. Discussions revealed 3 major thematic branches for decision making: (1) features of the intervention-risks and benefits, with an emphasis on an aversion to perceived invasiveness; (2) decision drivers-trust in the clinical team, treatment costs; and (3) quality of available information about neurotechnological options. Overall, caregivers' definition of treatment success is more expansive than seizure freedom. The full involvement of their values and priorities must be considered in the decision-making process.

Longitudinal CSF Iron Pathway Proteins in Posthemorrhagic Hydrocephalus: Associations with Ventricle Size and Neurodevelopmental Outcomes.

OBJECTIVE: Iron has been implicated in the pathogenesis of brain injury and hydrocephalus after preterm germinal matrix hemorrhage-intraventricular hemorrhage, however, it is unknown how external or endogenous intraventricular clearance of iron pathway proteins affect the outcome in this group. METHODS: This prospective multicenter cohort included patients with posthemorrhagic hydrocephalus (PHH) who underwent (1) temporary and permanent cerebrospinal fluid (CSF) diversion and (2) Bayley Scales of Infant Development-III testing around 2 years of age. CSF proteins in the iron handling pathway were analyzed longitudinally and compared to ventricle size and neurodevelopmental outcomes. RESULTS: Thirty-seven patients met inclusion criteria with a median estimated gestational age at birth of 25 weeks; 65% were boys. Ventricular CSF levels of hemoglobin, iron, total bilirubin, and ferritin decreased between temporary and permanent CSF diversion with no change in CSF levels of ceruloplasmin, transferrin, haptoglobin, and hepcidin. There was an increase in CSF hemopexin during this interval. Larger ventricle size at permanent CSF diversion was associated with elevated CSF ferritin (p = 0.015) and decreased CSF hemopexin (p = 0.007). CSF levels of proteins at temporary CSF diversion were not associated with outcome, however, higher CSF transferrin at permanent CSF diversion was associated with improved cognitive outcome (p = 0.015). Importantly, longitudinal change in CSF iron pathway proteins, ferritin (decrease), and transferrin (increase) were associated with improved cognitive (p = 0.04) and motor (p = 0.03) scores and improved cognitive (p = 0.04), language (p = 0.035), and motor (p = 0.008) scores, respectively. INTERPRETATION: Longitudinal changes in CSF transferrin (increase) and ferritin (decrease) are associated with improved neurodevelopmental outcomes in neonatal PHH, with implications for understanding the pathogenesis of poor outcomes in PHH. ANN NEUROL 2021;90:217-226.

Pediatric Intrathecal Baclofen Pumps: A Descriptive Analysis of Hospital Course and Associated Costs.

INTRODUCTION: The purpose of this study was to identify predictors of increased cost and postoperative length-of-stay (LOS) following intrathecal baclofen pump (ITBP) placement. METHODS: Patients were derived from the 2009/2012 kids' inpatient database. Inclusion criteria were selected for patients with ICD-9 codes 343.X (infantile cerebral palsy), 86.06 (infusion pump insertion), 03.90 (spinal catheter insertion), and elective hospitalizations. Nonparametric univariate analysis and subsequent gamma log-link general linear modeling were used to identify significant predictors of cost/LOS (p < 0.05). RESULTS: 529 unweighted patients (787 with survey weights applied) met criteria. Median LOS was 3.00 days, and median cost was USD 23,284. Following multivariate modeling, predictors of increased LOS (in days) included increased hospital ITBP volume (p = 0.027), small hospital size (+0.55, p = 0.004), device complications (+0.95, p < 0.001), procedural complications (+1.40, p < 0.001), additional procedures (+0.86, p < 0.001), electrolyte abnormalities (+3.74, p < 0.001), and neurological comorbidities (+1.60, p < 0.001). Factors associated with decreased LOS were paralysis (-0.53, p < 0.001), Northeastern hospital region (-0.55, p = 0.018), and investor-owned hospital status (-0.75, p = 0.001). Similarly, predictors of increased cost included race of Hispanic (+USD 1,156, p = 0.033) or "other" (+USD 2,158, p = 0.001), Northeast hospital region (+USD 4,120, p < 0.001), small (+USD 4,139, p < 0.001) or medium (+USD 3,368, p < 0.001) hospital sizes, additional procedures (+USD 1,649, p < 0.001), neurological comorbidities (+USD 3,222, p = 0.003), and increased LOS (p < 0.001). Factors associated with decreased cost included Western hospital region (-USD 1,594, p = 0.001), government hospitals (-USD 1,391, p = 0.019), and investor-owned hospitals (-USD 2,057, p = 0.021). CONCLUSION: This study found multiple variables associated with increased cost/LOS following ITBP placement. Broadly, this analysis demonstrates national trends associated with increased cost following ITBP placement.

Treatment strategies for hydrocephalus related to Dandy-Walker syndrome: evaluating procedure selection and success within the Hydrocephalus Clinical Research Network.

OBJECTIVE: Treating Dandy-Walker syndrome-related hydrocephalus (DWSH) involves either a CSF shunt-based or endoscopic third ventriculostomy (ETV)-based procedure. However, comparative investigations are lacking. This study aimed to compare shunt-based and ETV-based treatment strategies utilizing archival data from the Hydrocephalus Clinical Research Network (HCRN) registry. METHODS: A retrospective review of prospectively collected and maintained data on children with DWSH, available from the HCRN registry (14 sites, 2008-2018), was performed. The primary outcome was revision-free survival of the initial surgical intervention. The primary exposure was either shunt-based (i.e., cystoperitoneal shunt [CPS], ventriculoperitoneal shunt [VPS], and/or dual-compartment) or ETV-based (i.e., ETV alone or with choroid plexus cauterization [CPC]) initial surgical treatment. Primary analysis included multivariable Cox proportional hazards models. RESULTS: Of 8400 HCRN patients, 151 (1.8%) had DWSH. Among these, the 102 patients who underwent shunt placement (79 VPSs, 16 CPSs, 3 other, and 4 multiple proximal catheter) were younger (6.6 vs 18.8 months, p < 0.001) and more frequently had 1 or more comorbidities (37.3% vs 14.3%, p = 0.005) than the 49 ETV-treated children (28 ETV-CPC). Fifty percent of the shunt-based and 51% of the ETV-based treatments failed. Notably, 100% (4/4) of the dual-compartment shunts failed. Adjusting for age, baseline ventricular size, and comorbidities, ETV-based treatment was not significantly associated with earlier failure compared with shunt-based treatment (HR for failure 1.32, 95% CI 0.77-2.26; p = 0.321). Complication rates were low: 4.9% and 6.1% (p = 0.715) for shunt- and ETV-based procedures, respectively. There was no difference in survival between ETV-CPC- and ETV-based treatment when adjusting for age (HR for failure 0.86, 95% CI 0.29-2.55, p = 0.783). CONCLUSIONS: In this North American, multicenter, prospective database review, shunt-based and ETV-based primary treatment strategies of DWSH appear similarly durable. Pediatric neurosurgeons can reasonably consider ETV-based initial treatment given the similar durability and the low complication rate. However, given the observational nature of this study, the treating surgeon might need to consider subgroups that were too small for a separate analysis. Very young children with comorbidities were more commonly treated with shunts, and older children with fewer comorbidities were offered ETV-based treatment. Future studies may determine preoperative characteristics associated with ETV treatment success in this population.

Cerebrospinal fluid NCAM-1 concentration is associated with neurodevelopmental outcome in post-hemorrhagic hydrocephalus of prematurity.

OBJECTIVE: Efforts directed at mitigating neurological disability in preterm infants with intraventricular hemorrhage (IVH) and post hemorrhagic hydrocephalus (PHH) are limited by a dearth of quantifiable metrics capable of predicting long-term outcome. The objective of this study was to examine the relationships between candidate cerebrospinal fluid (CSF) biomarkers of PHH and neurodevelopmental outcomes in infants undergoing neurosurgical treatment for PHH. STUDY DESIGN: Preterm infants with PHH were enrolled across the Hydrocephalus Clinical Research Network. CSF samples were collected at the time of temporizing neurosurgical procedure (n = 98). Amyloid precursor protein (APP), L1CAM, NCAM-1, and total protein (TP) were compared in PHH versus control CSF. Fifty-four of these PHH subjects underwent Bayley Scales of Infant Development-III (Bayley-III) testing at 15-30 months corrected age. Controlling for false discovery rate (FDR) and adjusting for post-menstrual age (PMA) and IVH grade, Pearson's partial correlation coefficients were used to examine relationships between CSF proteins and Bayley-III composite cognitive, language, and motor scores. RESULTS: CSF APP, L1CAM, NCAM-1, and TP were elevated in PHH over control at temporizing surgery. CSF NCAM-1 was associated with Bayley-III motor score (R = -0.422, p = 0.007, FDR Q = 0.089), with modest relationships noted with cognition (R = -0.335, p = 0.030, FDR Q = 0.182) and language (R = -0.314, p = 0.048, FDR Q = 0.194) scores. No relationships were observed between CSF APP, L1CAM, or TP and Bayley-III scores. FOHR at the time of temporization did not correlate with Bayley-III scores, though trends were observed with Bayley-III motor (p = 0.0647 and R = -0.2912) and cognitive scores (p = 0.0506 and R = -0.2966). CONCLUSION: CSF NCAM-1 was associated with neurodevelopment in this multi-institutional PHH cohort. This is the first report relating a specific CSF protein, NCAM-1, to neurodevelopment in PHH. Future work will further investigate a possible role for NCAM-1 as a biomarker of PHH-associated neurological disability.

The survival of reimplanted shunts following externalization: a single-institution cohort study.

OBJECTIVE: The failure-free survival of ventriculoperitoneal shunts (VPSs) following externalization for distal catheter infection or malfunction has not been adequately explored. Conversion to a ventriculoatrial shunt (VAS) may allow earlier reinternalization in lieu of waiting for the peritoneum to be suitable for reimplantation. This option is tempered by historical concerns regarding high rates of VAS failure, and the risks of rare complications are rampant. METHODS: In this retrospective cohort study, all patients undergoing externalization of a VPS at a single institution between 2005 and 2020 were grouped according to the new distal catheter terminus location at the time of reinternalization (VPS vs VAS). The primary outcomes were failure-free shunt survival and duration of shunt externalization. Secondary outcomes included early (< 6 months) shunt failure. RESULTS: Among 36 patients, 43 shunt externalization procedures were performed. Shunts were reinternalized as VPSs in 25 cases and VASs in 18 cases. The median failure-free survival was 1002 (interquartile range [IQR] 161-3449) days for VPSs and 1163 (IQR 360-2927) days for VASs. There was no significant difference in shunt survival according to the new distal catheter terminus (log-rank, p = 0.73). Conversion to a VAS was not associated with shorter duration of shunt externalization (Wilcoxon rank-sum, p = 0.64); the median duration was 7 (IQR 5-11) days for VPSs and 8 (IQR 6-15) days for VASs. No rare complications occurred in the VAS group. CONCLUSIONS: Shunt failure-free survival rates following externalization are similar to published survival rates for nonexternalized shunts. There was no significant difference in survival between reinternalized VPSs and VASs. Although the VAS was not associated with a shortened duration of externalization, this finding is confounded by strong institutional preference for the VPS over the VAS. Early conversion to the VAS may be a viable treatment option in light of reassuring modern VAS survival data.

Machine learning predicts risk of cerebrospinal fluid shunt failure in children: a study from the hydrocephalus clinical research network.

PURPOSE: While conventional statistical approaches have been used to identify risk factors for cerebrospinal fluid (CSF) shunt failure, these methods may not fully capture the complex contribution of clinical, radiologic, surgical, and shunt-specific variables influencing this outcome. Using prospectively collected data from the Hydrocephalus Clinical Research Network (HCRN) patient registry, we applied machine learning (ML) approaches to create a predictive model of CSF shunt failure. METHODS: Pediatric patients (age < 19 years) undergoing first-time CSF shunt placement at six HCRN centers were included. CSF shunt failure was defined as a composite outcome including requirement for shunt revision, endoscopic third ventriculostomy, or shunt infection within 5 years of initial surgery. Performance of conventional statistical and 4 ML models were compared. RESULTS: Our cohort consisted of 1036 children undergoing CSF shunt placement, of whom 344 (33.2%) experienced shunt failure. Thirty-eight clinical, radiologic, surgical, and shunt-design variables were included in the ML analyses. Of all ML algorithms tested, the artificial neural network (ANN) had the strongest performance with an area under the receiver operator curve (AUC) of 0.71. The ANN had a specificity of 90% and a sensitivity of 68%, meaning that the ANN can effectively rule-in patients most likely to experience CSF shunt failure (i.e., high specificity) and moderately effective as a tool to rule-out patients at high risk of CSF shunt failure (i.e., moderately sensitive). The ANN was independently validated in 155 patients (prospectively collected, retrospectively analyzed). CONCLUSION: These data suggest that the ANN, or future iterations thereof, can provide an evidence-based tool to assist in prognostication and patient-counseling immediately after CSF shunt placement.