Nine out of 19 genes encoding GABAA receptor subunits have been linked to monogenic syndromes characterized by seizures and developmental disorders. Previously, we reported the de novo variant p.(Thr300Ile) in GABRA4 in a patient with epilepsy and neurodevelopmental abnormalities. However, no new cases have been reported since then. Through an international collaboration, we collected molecular and phenotype data of individuals carrying de novo variants in GABRA4. Patients and their parents were investigated either by exome or genome sequencing, followed by targeted Sanger sequencing in some cases. All variants within the transmembrane domain, including the previously reported p.(Thr300Ile) variant, were characterized in silico and analyzed by molecular dynamics (MD) simulation studies. We identified three novel de novo missense variants in GABRA4 (NM_000809.4): c.797 C > T, p.(Pro266Leu), c.899 C > A, p.(Thr300Asn), and c.634 G > A, p.(Val212Ile). The p.(Thr300Asn) variant impacts the same codon as the previously reported variant p.(Thr300Ile) and likely arose post-zygotically as evidenced by sequencing oral mucosal cells. Overlapping phenotypes among affected individuals included developmental delay (4/4), epileptiform EEG abnormalities (3/4), attention deficits (3/4), seizures (2/4), autistic features (2/4) and structural brain abnormalities (2/4). MD simulations of the three variants within the transmembrane domain of the receptor indicate that sub-microsecond scale dynamics differ between wild-type and mutated subunits. Taken together, our findings further corroborate an association between GABRA4 and a neurological phenotype including variable neurodevelopmental, behavioral and epileptic abnormalities.

The aim of this study was to describe the turnaround time, diagnostic yield, and clinical impact of rapid whole-genomic sequencing (rWGS). We conducted a prospective observational study in acutely ill children (0-21 years) with an undiagnosed, potentially genetic abnormality in a children's hospital. A phenotype-prioritized analysis approach for rWGS was utilized. The turnaround times, diagnostic yield, number of genes detected, inheritance pattern, zygosity, and the clinical impact of positive or negative tests were analyzed. Out of a total of 109 children, 92 abnormal (pathogenic or likely pathogenic) gene variants were detected in 60 (55%) patients. There were 45 neonates, 35 infants, and 29 children. The admission location was 49.5, 34.9, and 15.6% in the pediatric intensive care unit (PICU), neonatal intensive care unit (NICU), and cardiac intensive care unit (CICU), respectively. The median (interquartile range [IQR]) times for the return of preliminary and final results were 3 (2-5) and 10 (6-14) days, respectively. With ultra-rapid processing, the median time to final results was shorter (5 [3-7] vs. 12 [7.75-15] days). Neurologic issues were the most common underlying admission diagnoses. The diagnostic yield for a causative gene was 47.7%. The diagnostic yield was not different based on age group or location of admission but higher in metabolic issues (78.6 vs. 43.2%; odds ratio [OR]: 4.8; 95% confidence interval [CI]: 1.3-18.4). There was a change in clinical management in 39.4%. In acutely ill children with undiagnosed conditions and with clinical suspicion of a genetic disorder, rWGS detected gene variants in 55% with a diagnostic yield of 47.7% and resulted in a change in the management in 39.4%. The diagnostic yield in patients with metabolic conditions was the highest.

ObjectiveMulti-center implementation of rapid whole genome sequencing with assessment of the clinical utility of rapid whole genome sequencing (rWGS), including positive, negative and uncertain results, in admitted infants with a suspected genetic disease.Study designrWGS tests were ordered at eight hospitals between November 2017 and April 2020. Investigators completed a survey of demographic data, Human Phenotype Ontology (HPO) terms, test results and impacts of results on clinical care.ResultsA total of 188 patients, on general hospital floors and intensive care unit (ICU) settings, underwent rWGS testing. Racial and ethnic characteristics of the tested infants were broadly representative of births in the country at large. 35% of infants received a diagnostic result in a median of 6 days. The most common HPO terms for tested infants indicated an abnormality of the nervous system, followed by the cardiovascular system, the digestive system, the respiratory system and the head and neck. Providers indicated a major change in clinical management because of rWGS for 32% of infants tested overall and 70% of those with a diagnostic result. Also, 7% of infants with a negative rWGS result and 23% with a variant of unknown significance (VUS) had a major change in management due to testing.ConclusionsOur study demonstrates that the implementation of rWGS is feasible across diverse institutions, and provides additional evidence to support the clinical utility of rWGS in a demographically representative sample of admitted infants and includes assessment of the clinical impact of uncertain rWGS results in addition to both positive and negative results.

Spike detection in epileptic neonates is a challenging task since the recorded electroencephalography (EEG) data are often fraught with artifacts and noise. This study aims to enhance the clarity of epileptic spikes by separating them from background activity using an integrated method based on the independent component analysis (ICA). We analyzed spikes of 12 epileptic neonates as marked in their EEG scalp recordings by a clinical expert. The proposed method makes use of the ICA method to isolate the source of the spikes and then apply a power frequency analysis and template matching to validate the performance of the ICA. Isolating a spike is achieved by choosing the component that should correspond to its defining characteristics, followed by signal reconstruction using that component. To evaluate the accuracy of our spike isolation method, we first check if the power spectrum of the separated spikes aligns with the typical power spectral density observed in neonates. Subsequently, we measured the degree of similarity between the extracted spike and a predefined spike template, comparing it against the original spike segment. With this integrated method, the results show the successful extraction of 29 out of the 37 marked spikes (i.e., 79 percent), which signifies that ICA can serve as a promising approach in the initial isolation process of spikes in EEG records of neonates. This could lead to further investigation into those subtle features or changes missed on those EEG records of the marked spikes that were not separated. Determining such features and subtle changes, if indeed inherent to spikes, could lead to the development of enhanced spike detection methods in neonates. It should be noted that in 5 out of the 37 epochs, we could not identify any independent component as a spike source, and 3 out of 32 remaining cases showed unsuccessful separation in validation, possibly due to the source not being statistically independent or being Gaussian in nature. In such cases, the expert clinician(s) could review or reconsider marking such spikes.

Introduction: We describe 5 children with GFAP astrocytopathy with the goal of further characterizing this rare form of meningoencephalomyelitis. Methods: Retrospective chart review of patients diagnosed with GFAP astrocytopathy between 2019 and 2021. Results: Patients were 8-17 years old, and all were male. Fever, headache, and vomiting were common presenting symptoms, and weakness, tremor, and ataxia were common initial examination findings. Initial magnetic resonance imaging (MRI) showed spinal cord abnormalities in 2 patients and leptomeningeal enhancement in 1. Most patients had cerebral spinal fluid pleocytosis, and all screened negative for malignancy. Three patients progressed to coma, and all were treated with immunosuppressant therapy. By discharge, all patients had improved over their clinical nadir, although none had returned to baseline. Discussion: GFAP astrocytopathy is a recently recognized cause of meningoencephalomyelitis in children. Here, we expand our understanding of this entity with the goal of aiding those treating children with GFAP astrocytopathy.

Developmental and epileptic encephalopathy 35 (DEE 35) is a severe neurological condition caused by biallelic variants in ITPA, encoding inosine triphosphate pyrophosphatase, an essential enzyme in purine metabolism. We delineate the genotypic and phenotypic spectrum of DEE 35, analyzing possible predictors for adverse clinical outcomes. We investigated a cohort of 28 new patients and reviewed previously described cases, providing a comprehensive characterization of 40 subjects. Exome sequencing was performed to identify underlying ITPA pathogenic variants. Brain MRI (magnetic resonance imaging) scans were systematically analyzed to delineate the neuroradiological spectrum. Survival curves according to the Kaplan-Meier method and log-rank test were used to investigate outcome predictors in different subgroups of patients. We identified 18 distinct ITPA pathogenic variants, including 14 novel variants, and two deletions. All subjects showed profound developmental delay, microcephaly, and refractory epilepsy followed by neurodevelopmental regression. Brain MRI revision revealed a recurrent pattern of delayed myelination and restricted diffusion of early myelinating structures. Congenital microcephaly and cardiac involvement were statistically significant novel clinical predictors of adverse outcomes. We refined the molecular, clinical, and neuroradiological characterization of ITPase deficiency, and identified new clinical predictors which may have a potentially important impact on diagnosis, counseling, and follow-up of affected individuals.

Background Neuromonitoring is the use of continuous measures of brain physiology to detect clinically important events in real-time. Neuromonitoring devices can be invasive or non-invasive and are typically used on patients with acute brain injury or at high risk for brain injury. The goal of this study was to characterize neuromonitoring infrastructure and practices in North American pediatric intensive care units (PICUs). Methods An electronic, web-based survey was distributed to 70 North American institutions participating in the Pediatric Neurocritical Care Research Group. Questions related to the clinical use of neuromonitoring devices, integrative multimodality neuromonitoring capabilities, and neuromonitoring infrastructure were included. Survey results were presented using descriptive statistics. Results The survey was completed by faculty at 74% (52 of 70) of institutions. All 52 institutions measure intracranial pressure and have electroencephalography capability, whereas 87% (45 of 52) use near-infrared spectroscopy and 40% (21/52) use transcranial Doppler. Individual patient monitoring decisions were driven by institutional protocols and collaboration between critical care, neurology, and neurosurgery attendings. Reported device utilization varied by brain injury etiology. Only 15% (eight of 52) of institutions utilized a multimodality neuromonitoring platform to integrate and synchronize data from multiple devices. A database of neuromonitoring patients was maintained at 35% (18 of 52) of institutions. Funding for neuromonitoring programs was variable with contributions from hospitals (19%, 10 of 52), private donations (12%, six of 52), and research funds (12%, six of 52), although 73% (40 of 52) have no dedicated funds. Conclusions Neuromonitoring indications, devices, and infrastructure vary by institution in North American pediatric critical care units. Noninvasive modalities were utilized more liberally, although not uniformly, than invasive monitoring. Further studies are needed to standardize the acquisition, interpretation, and reporting of clinical neuromonitoring data, and to determine whether neuromonitoring systems impact neurological outcomes.

There is an increasing demand for supporting the adoption of rapid whole-genome sequencing (rWGS) by demonstrating its real-world value. We aimed to assess the cost-effectiveness of rWGS in critically ill pediatric patients with diseases of unknown cause. Data were collected prospectively of patients admitted to the Nicklaus Children’s Hospital’s intensive care units from March 2018 to September 2020, with rWGS (N = 65). Comparative data were collected in a matched retrospective cohort with standard diagnostic genetic testing. We determined total costs, diagnostic yield (DY), and incremental cost-effectiveness ratio (ICER) adjusted for selection bias and right censoring. Sensitivity analyses explored the robustness of ICER through bootstrapping. rWGS resulted in a diagnosis in 39.8% while standard testing in 13.5% (p = 0.026). rWGS resulted in a mean saving per person of $100,440 (SE = 26,497, p < 0.001) and a total of $6.53 M for 65 patients. rWGS in critically ill pediatric patients is cost-effective, cost-saving, shortens diagnostic odyssey, and triples the DY of traditional approaches.

OBJECTIVE:To describe the characteristics of pediatric intensive care neurologists and their practice in the United States and Canada.METHODS:We performed a survey-based study of child neurologists who self-identify as 'intensive care neurologists'. The survey included questions about demographics, training, pediatric neurocritical care service and job structure, teaching, academics, challenges, and views on the future of pediatric neurocritical care.RESULTS:We analyzed 55 surveys. Most respondents were 31-50 years of age with ≤10 years of practice experience. Fifty-four percent identified as female. Most completed subspecialty training after child neurology residency. The majority practice at highly resourced centers with >45 intensive care unit beds. Respondents cover a variety of inpatient (critical and noncritical care) services, at times simultaneously, for a median of 19.5 weeks/y and work >70 hours/wk when on service for pediatric neurocritical care. The top 3 challenges reported were competing demands for time, excess volume, and communication with critical care medicine. Top priorities for the "ideal pediatric neurocritical care service" were attendings with training in pediatric neurocritical care or a related field and joint rounding with critical care medicine.CONCLUSION:We report a survey-based analysis of the demographics and scope of practice of pediatric critical care neurologists. We highlight challenges faced and provide a framework for the further development of this rapidly growing field.

OBJECTIVE:To describe existing pediatric acute stroke protocols to better understand how pediatric centers might implement such pathways within the context of institution-specific structures.STUDY DESIGN:We administered an Internet-based survey of pediatric stroke specialists. The survey included questions about hospital demographics, child neurology and pediatric stroke demographics, acute stroke response, imaging, and hyperacute treatment.RESULTS:Forty-seven surveys were analyzed. Most respondents practiced at a large, freestanding children's hospital with a moderate-sized neurology department and at least 1 neurologist with expertise in pediatric stroke. Although there was variability in how the hospitals deployed stroke protocols, particularly in regard to staffing, the majority of institutions had an acute stroke pathway, and almost all included activation of a stroke alert page. Most institutions preferred magnetic resonance imaging (MRI) over computed tomography (CT) and used abbreviated MRI protocols for acute stroke imaging. Most institutions also had either CT-based or magnetic resonance-based perfusion imaging available. At least 1 patient was treated with intravenous tissue plasminogen activator (IV-tPA) or mechanical thrombectomy at the majority of institutions during the year before our survey.CONCLUSIONS:An acute stroke protocol is utilized in at least 41 pediatric centers in the US and Canada. Most acute stroke response teams are multidisciplinary, prefer abbreviated MRI over CT for diagnosis, and have experience providing IV-tPA and mechanical thrombectomy. Further studies are needed to standardize practices of pediatric acute stroke diagnosis and hyperacute management.

Laor, Leanna; Korumilli, Ritesh; Jayakar, Anuj; Ladd, Hugh; Meyer, Keith; Totapally, Balagangadhar Author Information

The generalized form of UDP-galactose-4′-epimerase (GALE) deficiency causes hypotonia, failure to thrive, cataracts, and liver failure. Individuals with non-generalized forms may remain asymptomatic with uncertain long-term outcomes. We report a 2-year-old child compound heterozygous for GALE p.R51W/p.G237D who never developed symptoms of classic galactosemia but has a history of congenital combined mitral and tricuspid valve malformation and pyloric stenosis, and presented with pancytopenia. Variant pathogenicity was supported by predictive computational tools and decreased GALE activity measured in erythrocytes. GALE function extends to the biosynthesis of glycans by epimerization of UDP-N-acetyl-galactosamine and -glucosamine. Interrogation of the Gene Ontology consortium database revealed several putative proteins involved in normal hematopoiesis and atrioventricular valve morphogenesis, requiring N-glycosylation for adequate functionality. We hypothesize that by limiting substrate supply due to GALE deficiency, alterations in N-linked protein glycosylation can explain the patient’s phenotype.

Objective: We aimed to investigate the current practices guiding surgical resection strategies involving epileptogenic zones (EZs) near or in eloquent cortex (EC) at pediatric epilepsy surgery centers worldwide. Methods: A survey was conducted among 40 respondents from 33 pediatric epilepsy surgery centers worldwide on the weight assigned to diagnostic tests used to define the EZ and EC, how EC is viewed, and how surgeries are planned for foci near or in eloquent cortex. Results: A descriptive analysis was performed that revealed considerable variation in the use of diagnostic tests and resective strategies toward EZ and EC. Significance: The wide variation in strategies may contribute to undesirable outcomes characterized by poor seizure control with added deficits and underscores the need to establish best practices in pediatric epilepsy surgery. The survey data were used to formulate a set of recommendations to help minimize deficits and to report them consistently.

Near-infrared spectroscopy (NIRS) monitors changes in the regional cerebral oxygenation (rSO) and has been used to study cerebral physiologic functions in normal states and during epileptic seizures. Yet, the limitations and pitfalls of the technique are not fully understood. The authors evaluated NIRS changes over the frontal lobes during language tasks known to be associated with the integrity of the dominant frontal lobe in 17 normal adults (handedness: 14 right, 3 left). Recording protocol involved a baseline (3 minutes) with the subject relaxed and thinking of a blue sky and a second baseline during voluntary mouth movements mimicking speech. Two standardized neuropsychological word-generation tasks (controlled word-association tests: CFL and Animals) were then administered (4 minutes total) followed again by the two baseline procedures. Mouth movement without verbalization increased rSO values in excess of 2 SD of baseline fluctuations in 70% of the subjects. A t-test comparison of these baseline measurements was statistically significant (P < 0.0001). A general linear model repeated-measures procedure was then used to statistically examine NIRS increments during the cognitive tasks above and beyond the contribution produced by mouth movements during the second baseline. Compared to the second baseline, rSO further increased significantly during the word generation tasks (left frontal F value = 21.4, P < 0.0001; right frontal F value = 15.2, P < 0.001), confirming the utility of the technique. There was no apparent difference related to handedness. These findings corroborate the usefulness of NIRS to demonstrate focal cerebral activation during an "executive" language task. However, interpretation of changes can be confounded by extracerebral factors such as mouth movement, a finding of particular relevance in NIRS clinical applications.