Laparotomy-assisted, two-port fetoscopic myelomeningocele repair: infant to preschool outcomes.

OBJECTIVE: This study reports the infant to preschool outcomes of a laparotomy-assisted, two-port fetoscopic myelomeningocele (MMC) repair and compares the results with those of a contemporary, same-center cohort that underwent either fetal MMC surgery via hysterotomy or postnatal MMC repair. METHODS: All MMC closures between December 2011 and July 2021 were screened. Singleton pregnancies with hindbrain herniation and MMC between T1 and S1 were included. Fetuses were excluded for genetic abnormalities, severe kyphosis, and other congenital anomalies. The pregnant woman determined the method of MMC repair (fetoscopic, hysterotomy, or postnatal repair). RESULTS: Two hundred MMC closures met the study criteria (100 fetoscopic, 41 hysterotomy, and 59 postnatal). The median length of follow-up was beyond 46 months for all groups. The median gestational age at delivery was 38.1 weeks (IQR 35.1, 39.1 weeks) for the fetoscopic group, 35.7 weeks (IQR 33.6, 37.0 weeks) for the hysterotomy group, and 38.6 weeks (IQR 37.7, 39.0 weeks) for the postnatal group. Vaginal delivery occurred in 51% of the fetoscopic cases, and there were no instances of uterine dehiscence or rupture. Treatment for hydrocephalus in the 1st year occurred in 35% (95% CI 27%-50%) of fetoscopic, 33% (95% CI 20%-50%) of hysterotomy, and 81% (95% CI 70%-90%) of postnatal repair cases. At 30 months, patients who underwent fetal intervention were twice as likely to be community ambulators (with or without devices) as those who underwent postnatal repair (52% [95% CI 42%-62%] of fetoscopic, 54% [95% CI 39%-68%] of hysterotomy, and 24% [95% CI 14%-36%] of postnatal cases). Surgery for symptomatic tethered cord occurred in 12% (95% CI 7%-19%) of fetoscopic, 17% (95% CI 8%-31%) of hysterotomy, and 2% (95% CI 1%-8%) of postnatal repair cases. Surgery for symptomatic spinal inclusion cysts was required in 4% (95% CI 1%-9%) of fetoscopic, 7% (95% CI 2%-18%) of hysterotomy, and none (95% CI 0%-8%) of the postnatal cases. CONCLUSIONS: Laparotomy-assisted, two-port fetoscopic repair provides significant benefits for maternal health. It negates the risk of uterine rupture for the index pregnancy and subsequent pregnancies and allows for vaginal delivery. The benefits to the fetus are the same as those of hysterotomy repairs, with a lower risk of prematurity. There was no difference in the rate of surgery for tethered cord or spinal inclusion cysts between fetoscopic and hysterotomy procedures. Overall, laparotomy-assisted, two-port fetoscopic repair is safer for the fetus and the mother than fetal MMC surgery via hysterotomy.

Cerebral Sinus Venous Thrombosis in Pediatric Acute Lymphoblastic Leukemia: Incidence, Clinical Characteristics, and Long-term Neurologic Outcomes.

OBJECTIVE: To describe the incidence, clinical characteristics, and long-term outcomes of cerebral sinus venous thrombosis in children with acute lymphoblastic leukemia. METHODS: This was a retrospective cohort study comprising pediatric patients with newly diagnosed or first-relapse acute lymphoblastic leukemia who developed cerebral sinus venous thrombosis at Texas Children's Hospital from 2002 to 2019. RESULTS: Nineteen cases (1.7%) with cerebral sinus venous thrombosis were identified in all pediatric patients with acute lymphoblastic leukemia (n = 1129). Increased risk of cerebral sinus venous thrombosis was observed with age >10 years (P = .006). Twelve cases (63%) occurred during the induction, 4 (21%) during maintenance, and 3 (16%) during the consolidation phases of leukemia therapy. Seizures (10/19) and headaches (9/19) were the most common presenting symptoms. After treatment with anticoagulation therapy, we observed full resolution of thrombosis in 10 (53%) and partial resolution in 8 patients (42%). Long-term neurologic outcomes at follow-up in the 14 patients who survived included normal neurologic examinations (n = 10), epilepsy (n = 3), and focal neurologic deficits (n = 2). The death occurred in 5 individuals. CONCLUSION: Cerebral sinus venous thrombosis is a notable complication of pediatric acute lymphoblastic leukemia therapy. Older age (>10 years) was a risk factor for developing cerebral sinus venous thrombosis. Despite variable patient presentations and treatment durations, favorable clinical outcomes were observed in most patients after the treatment with anticoagulation for a minimum of 3 months.

Neuroimaging of Vermiform Giant Arachnoid Granulations in Children.

Arachnoid granulations (AGs) are generally benign structures within the subarachnoid space that extend into the dural sinuses and calvarial bone. They can present in a variety of sizes but are termed 'giant' arachnoid granulations (GAGs) when they are larger than 1 cm in diameter or take up a significant portion of the dural sinus' lumen. Vermiform giant arachnoid granulations are a specific type of GAG that are known for their worm-like appearance. Specifically, these vermiform GAGs can be challenging to diagnose as they can mimic other pathologies like dural sinus thrombosis, sinus cavernomas, or brain tumors. In this case series, we present two cases of vermiform giant arachnoid granulations, discuss their imaging characteristics and highlight the diagnostic challenges to improve identification and prevent misdiagnoses.

Clinical and Radiologic Findings in Children with Anomalous Pontine Cranial Nerves.

We retrospectively reviewed the clinical and radiologic findings in 17 children with an aberrant cisternal cranial nerve 7 (CN7), and found that these patients had additional anomalies involving other pontine cranial nerves (CNs). The hallmark imaging feature identified in all patients was an aberrant cisternal segment of an enlarged-appearing CN7. The abnormal nerve coursed anteriorly toward the Gasserian ganglion, where it fanned out toward the internal auditory canal, Meckel cave, or both. This finding was accompanied by a small cisternal CN5, which often had a lateral bowed appearance. CN5 and CN7 were abnormally close to each other. Meckel's cave appeared widened posteriorly and often was close to or merged with the internal auditory canal. Other abnormalities in the pontine CNs included CN8 deficiency in most children and variable CN6 deficiency. This constellation of findings was most often discovered in children having an MR evaluation for sensorineural hearing loss, and most patients had preserved facial nerve function. In patients with available genetic testing, no pathogenic variants were observed. Interestingly, in 13 children with an available birth history, 9 were notable for maternal or gestational diabetes (69%), suggesting a possible early intrauterine insult to the developing nerves.

Evaluating functional connectivity differences between DBS ON/OFF states in essential tremor.

Deep brain stimulation (DBS) targeting the ventral intermediate (Vim) nucleus of the thalamus is an effective treatment for essential tremor (ET). We studied 15 â€‹ET patients undergoing DBS to a major input/output tract of the Vim, the dentato-rubro-thalamic tract (DRTt), using resting state functional MRI (rsfMRI) to evaluate connectivity differences between DBS ON and OFF and elucidate significant regions most influential in impacting tremor control and/or concomitant gait ataxia. Anatomical/functional 1.5T MRIs were acquired and replicated for each DBS state. Tremor severity and gait ataxia severity were scored with DBS ON at optimal stimulation parameters and immediately upon DBS OFF. Whole brain analysis was performed using dual regression analysis followed by randomized permutation testing for multiple correction comparison. Regions of interest (ROI) analysis was also performed. All 15 patients had tremor improvement between DBS ON/OFF (p â€‹< â€‹0.001). Whole brain analysis revealed significant connectivity changes between states in the left pre-central gyrus and left supplemental motor area. Group analysis of ROIs revealed that, with threshold p â€‹< â€‹0.05, in DBS ON vs. OFF both tremor duration and tremor improvement were significantly correlated to changes in connectivity. A sub-group analysis of patients with greater ataxia had significantly decreased functional connectivity between multiple ROIs in the cortex and cerebellum when DBS was ON compared to OFF. Stimulation of the DRTt and concordant improvement of tremor resulted in connectivity changes seen in multiple regions outside the motor network; when combined with both structural and electrophysiologic connectivity, this may help to serve as a biomarker to improve DBS targeting and possibly predict outcome.

Incidence and Characteristics of Cerebellar Atrophy/Volume Loss in Children with Confirmed Diagnosis of Tuberous Sclerosis Complex.

Objectives: The goal of our study was to determine the incidence of cerebellar atrophy, assess the imaging findings in the posterior fossa and determine the incidence of hippocampal sclerosis in a cohort of pediatric patients with confirmed tuberous sclerosis complex (TSC). Material and methods: MRI studies of 98 TSC pediatric patients (mean age 7.67 years) were evaluated for cerebellar atrophy, cerebral/cerebellar tubers, white matter lesions, subependymal nodules, subependymal giant cell astrocytomas, ventriculomegaly, and hippocampal sclerosis. Clinical charts were revisited for clinical symptoms suggesting cerebellar involvement, for seizures and treatment for seizures, behavioral disorders and autism. Results: Cerebral tubers were present in 97/98 cases. In total, 97/98 had subependymal nodules, 15/98 had SEGA, 8/98 had ventriculomegaly and 4/98 had hippocampal sclerosis. Cerebellar tubers were found in 8/98 patients (8.2%), whereas cerebellar atrophy was described in 38/98 cases (38.8%). In 37/38 patients, cerebellar volume loss was mild and diffuse, and only one case presented with left hemi-atrophy. Briefly, 32/38 presented with seizures and were treated with anti-seizure drugs. In total, 8/38 (21%) presented with behavioral disorders, 10/38 had autism and 2/38 presented with seizures and behavioral disorders and autism. Conclusions: Several studies have demonstrated cerebellar involvement in patients with TSC. Cerebellar tubers differ in shape compared with cerebral tubers and are associated with cerebellar volume loss. Cerebellar atrophy may be focal and diffuse and one of the primary cerebellar manifestations of TSC, especially if a TSC2 mutation is present. Cerebellar degeneration may, however, also be secondary/acquired due to cellular damage resulting from seizure activity, the effects of anti-seizure drugs and anoxic-ischemic injury from severe seizure activity/status epilepticus. Further, prospective studies are required to identify and establish the pathogenic mechanism of cerebellar atrophy in patients with TSC.

A Comprehensive Examination of Clinical Characteristics and Determinants of Long-Term Outcomes in Pediatric Cerebral Sinus Venous Thrombosis.

BACKGROUND: To analyze the clinical and neuroimaging features, risk factors, treatment choices, and long-term clinical outcomes in children with cerebral sinus venous thrombosis (CSVT). METHODS: This is a retrospective cohort study of children diagnosed with CSVT between 2002 and 2018 at Texas Children's Hospital. RESULTS: A total of 183 children (male: 62.3%) with CSVT were included. The average presenting age was 7.7 years (S.D.: 5.6). The mean follow-up duration was 33.7 months (S.D.: 38.6). The most common presenting clinical feature was headache (36.6%). Head and neck infections other than meningitis (36.6%) were the most common risk factors. Prevalent neurological examination findings included motor deficit (21.3%) and altered mental status (AMS, 20.2%). Neuroimaging features included hemorrhagic infarction (19.6%), ischemic infarction (8.2%), and intracranial hemorrhage without infarction (5.5%). The most common site of thrombosis was the superior sagittal sinus (37.2%), with 78.2% of patients demonstrating involvement of multiple sinuses. Treatment of choice was low-molecular-weight heparin in 69.4% of patients. Factors associated with worse clinical outcomes included head and neck infections, malignancy (other than hematologic), cardiac disease, and recent surgery; seizure and dehydration on initial presentation; motor abnormalities and AMS on initial examination; ischemic infarct only; and involvement of vein of Trolard on neuroimaging. Thrombus condition on repeat imaging, receiving any anticoagulant/antithrombotic treatment, treatment duration, or follow-up duration was not associated with severity of long-term outcome. CONCLUSIONS: CSVT may lead to unfavorable long-term outcomes in a remarkable portion of pediatric patients. Thus, a high index of suspicion and early and appropriate management of pediatric CSVT is imperative.

Expanded clinical phenotype and untargeted metabolomics analysis in RARS2-related mitochondrial disorder: a case report.

BACKGROUND: RARS2-related mitochondrial disorder is an autosomal recessive mitochondrial encephalopathy caused by biallelic pathogenic variants in the gene encoding the mitochondrial arginyl-transfer RNA synthetase 2 (RARS2, MIM *611524, NM_020320.5). RARS2 catalyzes the transfer of L-arginine to its cognate tRNA during the translation of mitochondrially-encoded proteins. The classical presentation of RARS2-related mitochondrial disorder includes pontocerebellar hypoplasia (PCH), progressive microcephaly, profound developmental delay, feeding difficulties, and hypotonia. Most patients also develop severe epilepsy by three months of age, which consists of focal or generalized seizures that frequently become pharmacoresistant and lead to developmental and epileptic encephalopathy (DEE). CASE PRESENTATION: Here, we describe a six-year-old boy with developmental delay, hypotonia, and failure to thrive who developed an early-onset DEE consistent with Lennox-Gastaut Syndrome (LGS), which has not previously been observed in this disorder. He had dysmorphic features including bilateral macrotia, overriding second toes, a depressed nasal bridge, retrognathia, and downslanting palpebral fissures, and he did not demonstrate progressive microcephaly. Whole genome sequencing identified two variants in RARS2, c.36 + 1G > T, a previously unpublished variant that is predicted to affect splicing and is, therefore, likely pathogenic and c.419 T > G (p.Phe140Cys), a known pathogenic variant. He exhibited significant, progressive generalized brain atrophy and ex vacuo dilation of the supratentorial ventricular system on brain MRI and did not demonstrate PCH. Treatment with a ketogenic diet (KD) reduced seizure frequency and enabled him to make developmental progress. Plasma untargeted metabolomics analysis showed increased levels of lysophospholipid and sphingomyelin-related metabolites. CONCLUSIONS: Our work expands the clinical spectrum of RARS2-related mitochondrial disorder, demonstrating that patients can present with dysmorphic features and an absence of progressive microcephaly, which can help guide the diagnosis of this condition. Our case highlights the importance of appropriate seizure phenotyping in this condition and indicates that patients can develop LGS, for which a KD may be a viable therapeutic option. Our work further suggests that analytes of phospholipid metabolism may serve as biomarkers of mitochondrial dysfunction.

Adaptive, behavioral, and emotional outcomes following postoperative pediatric cerebellar mutism syndrome in survivors treated for medulloblastoma.

OBJECTIVE: Patients who experience postoperative pediatric cerebellar mutism syndrome (CMS) during treatment for medulloblastoma have long-term deficits in neurocognitive functioning; however, the consequences on functional or adaptive outcomes are unknown. The purpose of the present study was to compare adaptive, behavioral, and emotional functioning between survivors with and those without a history of CMS. METHODS: The authors examined outcomes in 45 survivors (15 with CMS and 30 without CMS). Comprehensive neuropsychological evaluations, which included parent-report measures of adaptive, behavioral, and emotional functioning, were completed at a median of 2.90 years following craniospinal irradiation. RESULTS: Adaptive functioning was significantly worse in the CMS group for practical and general adaptive skills compared with the group without CMS. Rates of impairment in practical, conceptual, and general adaptive skills in the CMS group exceeded expected rates in the general population. Despite having lower overall intellectual functioning, working memory, and processing speed, IQ and related cognitive processes were uncorrelated with adaptive outcomes in the CMS group. No significant group differences or increased rates of impairment were observed for behavioral and emotional outcomes. CONCLUSIONS: Survivors with CMS, compared with those without CMS, are rated as having significant deficits in overall or general adaptive functioning, with specific weakness in practical skills several years posttreatment. Findings from this study demonstrate the high risk for ongoing functional deficits despite acute recovery from symptoms of CMS, highlighting the need for intervention to mitigate such risk.

Prognostic Significance of Central Skull Base Remodeling in Chiari II Malformation.

BACKGROUND AND PURPOSE: Outward convexity of the basiocciput and posterior atlanto-occipital membrane are common in patients with Chiari II malformation associated with an open neural tube defect. We aimed to determine if the severity of these findings correlated with the need for future hydrocephalus treatment. MATERIALS AND METHODS: A retrospective chart and imaging review identified patients who underwent open neural tube defect repair at a quaternary care pediatric hospital from July 2014 through September 2022. Patients were classified by the need for hydrocephalus treatment and whether they received prenatal or postnatal neural tube defect repair. Measurements of imaging parameters related to posterior fossa maldevelopment and skull base remodeling were performed. RESULTS: Compared with 65 patients who did not require hydrocephalus treatment, 74 patients who required treatment demonstrated statistically significantly greater mean basiocciput convexity (P < .001). While the mean basiocciput length in the hydrocephalus treatment group was smaller (P < .001), the ratio of basiocciput convexity to length was larger (P < .001). Notably, 100% of patients with a basiocciput convexity of ≥4 mm required hydrocephalus treatment. The mean posterior atlanto-occipital membrane convexity was significantly greater for patients who required hydrocephalus treatment in the postnatal group (P = .02), but not the prenatal group (P = .09). CONCLUSIONS: Pediatric patients with Chiari II malformation who ultimately required surgical hydrocephalus treatment had greater outward convexity of the basiocciput but had greater posterior atlanto-occipital membrane outward convexity only if the repair was performed postnatally. Together these measurements may be useful in predicting the need for hydrocephalus treatment.

Pediatric and adult meningeal, parenchymal, and spinal tuberculosis: A neuroimaging review.

Neurotuberculosis is defined as a tuberculous infection of the meninges, brain parenchyma, vessels, cranial and spinal nerves, spinal cord, skull, and spine that can occur either in a localized or in a diffuse form. It is a heterogeneous disease characterized by many imaging appearances and it has been defined as "the great mimicker" due to similarities with many other conditions. The diagnosis of central nervous system (CNS) tuberculosis (TB) is based on clinical presentation, neuroimaging findings, laboratory and microbiological findings, and comprehensive evaluation of the response to anti-TB drug treatment. However, the absence of specific symptoms, the wide spectrum of neurological manifestations, the myriad of imaging findings, possible inconclusive laboratory results, and the paradoxical reaction to treatment make the diagnosis often challenging and difficult, potentially delaying adequate treatment with possible devastating short-term and long-term neurologic sequelae. Familiarity with the imaging characteristics helps in accurate diagnosis and may prevent or limit significantly morbidity and mortality. The goal of this review is to provide a comprehensive up-to-date overview of the conventional and advanced imaging features of CNS TB for radiologists, neuroradiologists, and pediatric radiologists. We discuss the most typical neurotuberculosis imaging findings and their differential diagnosis in children and adults with the goal to provide a global overview of this entity.

Heteroplasmic pathogenic m.12315G>A variant in MT-TL2 presenting with MELAS syndrome and depletion of nitric oxide donors.

The MT-TL2 m.12315G>A pathogenic variant has previously been reported in five individuals with mild clinical phenotypes. Herein we report the case of a 5-year-old child with heteroplasmy for this variant who developed neurological regression and stroke-like episodes similar to those observed in mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). Biochemical evaluation revealed depletion of arginine on plasma amino acid analysis and low z-scores for citrulline on untargeted plasma metabolomics analysis. These findings suggested that decreased availability of nitric oxide may have contributed to the stroke-like episodes. The use of intravenous arginine during stroke-like episodes and daily enteral L-citrulline supplementation normalized her biochemical values of arginine and citrulline. Untargeted plasma metabolomics showed the absence of nicotinamide and 1-methylnicotinamide, and plasma total glutathione levels were low; thus, nicotinamide riboside and N-acetylcysteine therapies were initiated. This report expands the phenotype associated with the rare mitochondrial variant MT-TL2 m.12315G>A to include neurological regression and a MELAS-like phenotype. Individuals with this variant should undergo in-depth biochemical analysis to include untargeted plasma metabolomics, plasma amino acids, and glutathione levels to help guide a targeted approach to treatment.

Advances in Imaging Modalities for Pediatric Brain and Spinal Cord Tumors.

BACKGROUND: Neuroimaging has evolved from anatomical imaging toward a multi-modality comprehensive anatomical and functional imaging in the past decades, important functional data like perfusion-weighted imaging, permeability imaging, diffusion-weighted imaging (DWI), and diffusion tensor imaging (DTI), tractography, metabolic imaging, connectomics, event-related functional imaging, resting state functional imaging, and much more is now being offered. SUMMARY: Precision diagnostics has proven to be essential for precision treatment. Many minimal invasive techniques have been developed, taking advantage of digital subtraction angiography and interventional neuroradiology. Furthermore, intraoperative CT and/or MRI and more recently MR-guided focused ultrasound have complemented the diagnostic and therapeutic armamentarium. KEY MESSAGES: In the current manuscript, we discuss standard imaging sequences including advanced techniques like DWI, DTI, susceptibility-weighted imaging, and 1H magnetic resonance spectroscopy, various perfusion weighted imaging approaches including arterial spin labeling, dynamic contrast enhanced imaging, and dynamic susceptibility contrast imaging. Pre-, intra, and postoperative surgical imaging including visualize imaging will be discussed. The value of connectomics will be presented for its value in neuro-oncology. Minimal invasive therapeutic possibilities of interventional neuroradiology and image-guided laser ablation and MR-guided high-intensity-focused ultrasound will be presented for treatment of pediatric brain and spinal cord tumors. Finally, a comprehensive review of spinal cord tumors and matching neuropathology has been included.

Circulating tumor DNA sequencing of pediatric solid and brain tumor patients: An institutional feasibility study.

The potential of circulating tumor DNA (ctDNA) analysis to serve as a real-time "liquid biopsy" for children with central nervous system (CNS) and non-CNS solid tumors remains to be fully elucidated. We conducted a study to investigate the feasibility and potential clinical utility of ctDNA sequencing in pediatric patients enrolled on an institutional clinical genomics trial. A total of 240 patients had tumor DNA profiling performed during the study period. Plasma samples were collected at study enrollment from 217 patients and then longitudinally from a subset of patients. Successful cell-free DNA extraction and quantification occurred in 216 of 217 (99.5%) of these initial samples. Twenty-four patients were identified whose tumors harbored 30 unique variants that were potentially detectable on a commercially-available ctDNA panel. Twenty of these 30 mutations (67%) were successfully detected by next-generation sequencing in the ctDNA from at least one plasma sample. The rate of ctDNA mutation detection was higher in patients with non-CNS solid tumors (7/9, 78%) compared to those with CNS tumors (9/15, 60%). A higher ctDNA mutation detection rate was also observed in patients with metastatic disease (9/10, 90%) compared to non-metastatic disease (7/14, 50%), although tumor-specific variants were detected in a few patients in the absence of radiographic evidence of disease. This study illustrates the feasibility of incorporating longitudinal ctDNA analysis into the management of relapsed or refractory patients with childhood CNS or non-CNS solid tumors.

Quantitative assessment of cerebrospinal fluid flow and volume in enlargement of the subarachnoid spaces of infancy using MRI.

BACKGROUND: The etiology of enlarged subarachnoid spaces of infancy is unknown; however, there is radiologic similarity with normal pressure hydrocephalus. Adults with normal pressure hydrocephalus have been shown to have altered cerebrospinal (CSF) flow through the cerebral aqueduct. OBJECTIVE: To explore potential similarity between enlarged subarachnoid spaces of infancy and normal pressure hydrocephalus, we compared MRI-measured CSF flow through the cerebral aqueduct in infants with enlarged subarachnoid spaces of infancy to infants with normal brain MRIs. MATERIALS AND METHODS: This was an IRB approved retrospective study. Clinical brain MRI examinations including axial T2 imaging and phase contrast through the aqueduct were reviewed for infants with enlarged subarachnoid spaces of infancy and for infants with a qualitatively normal brain MRI. The brain and CSF volumes were segmented using a semi-automatic technique (Analyze 12.0) and CSF flow parameters were measured (cvi42, 5.14). All data was assessed for significant differences while controlling for age and sex using analysis of covariance (ANCOVA). RESULTS: Twenty-two patients with enlarged subarachnoid spaces (mean age 9.0 months, 19 males) and 15 patients with normal brain MRI (mean age 18.9 months, 8 females) were included. Volumes of the subarachnoid space (P < 0.001), lateral (P < 0.001), and third ventricles (P < 0.001) were significantly larger in infants with enlarged subarachnoid spaces of infancy. Aqueductal stroke volume significantly increased with age (P = 0.005), regardless of group. CONCLUSION: CSF volumes were significantly larger in infants with enlarged subarachnoid spaces of infancy versus infants with a normal MRI; however, there was no significant difference in CSF flow parameters between the two groups.

Arterial Spin Labeling Changes Parallel Asymmetric Perisylvian and Perirolandic Symptoms in 3 Pediatric Cases of Anti-NMDAR Encephalitis.

BACKGROUND AND OBJECTIVES: Anti-NMDA receptor autoimmune encephalitis (NMDAR AE) is an autoantibody-mediated disorder characterized by seizures, neuropsychiatric symptoms, movement disorder, and focal neurologic deficits. Conventionally defined broadly as an inflammatory brain disease, the heterotopic localization is rarely discussed in children. Imaging findings are often nonspecific, and there are no early biomarkers of disease other than the presence of anti-NMDAR antibodies. METHODS: We conducted a retrospective analysis of our pediatric NMDAR AE cases (as determined by either positive serum or CSF antibodies or both) at Texas Children's Hospital between 2020-2021 and extracted medical record data of those patients who had arterial spin labeling (ASL) as part of their imaging workup for encephalitis. The ASL findings were described in the context of their symptoms and disease courses. RESULTS: We identified 3 children on our inpatient floor, intensive care unit (ICU), and emergency department (ED) settings who were diagnosed with NMDAR AE and had ASL performed as part of their focal neurologic symptom workup. All 3 patients presented with focal neurologic deficits, expressive aphasia, and focal seizures before the onset of other well-characterized NMDAR AE symptoms. Their initial MRI revealed no diffusion abnormalities but uncovered asymmetric and predominantly unilateral multifocal hyperperfusion of perisylvian/perirolandic regions on ASL that correlated with focal EEG abnormalities and their focal examination findings. All 3 patients were treated with first-line and second-line therapies, and their symptoms improved. DISCUSSION: We found that ASL may be a suitable early imaging biomarker to highlight perfusion changes corresponding to the functional localization of NMDAR AE in pediatric patients. We briefly highlight the neuroanatomic parallels between working models of schizophrenia, chronic NMDAR antagonist administration (ketamine abuse), and NMDAR AE affecting primarily language centers. The regional specificity seen in NMDAR hypofunction may make ASL a reasonable early and specific biomarker of NMDAR AE disease activity. Future studies are necessary to evaluate regional changes in those patients who present with primarily psychiatric phenotypes rather than classical focal neurologic deficits.

Treatment of Langerhans cell histiocytosis with subcutaneous cytarabine.

Patients with Langerhans cell histiocytosis (LCH) have been effectively treated with intravenous cytarabine. Intravenous or subcutaneous cytarabine infusions have been effective for leukemia patients, and pharmacokinetic studies have shown very similar blood levels of the drug with either route. We present three LCH patients treated with subcutaneous cytarabine either because intravenous access could not be maintained or due to patient refusal. One patient with pulmonary and skin LCH had a complete response. Another patient had a partial response of pulmonary and cutaneous lesions, but progressive bone disease. The third patient was treated for LCH-related cerebellar changes eight years after the diagnosis of isolated diabetes insipidus, with stable brain MRI for 5 years post-treatment. Subcutaneous cytarabine administration provides an alternative for patients with LCH in whom vascular access is not possible or practical, such as in some resource-limited circumstances.

Imaging of pediatric calvarial and skull base tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee/ASPNR White Paper.

A standardized imaging protocol for pediatric oncology patients is essential for accurate and efficient imaging, while simultaneously promoting collaborative understanding of pathologies and radiologic assessment of treatment response. The objective of this article is to provide standardized pediatric imaging guidelines and parameters for evaluation of tumors of the pediatric orbit, calvarium, skull base, and temporal bone. This article was drafted based on current scientific literature as well as consensus opinions of imaging experts in collaboration with the Children's Oncology Group Diagnostic Imaging Committee, Society of Pediatric Radiology Oncology Committee, and American Society of Pediatric Neuroradiology.

Multidisciplinary management of a neonate with kaposiform hemangioendothelioma with extensive cranial fossa destruction.

Kaposiform hemangioendothelioma is a rare, benign, locally destructive vascular tumor. Kasabach-Merritt phenomenon, a consumptive coagulopathy, is a life-threatening complication associated with kaposiform hemangioendothelioma. We describe a case of kaposiform hemangioendothelioma complicated by Kasabach-Merritt phenomenon in a neonate born with a large facial mass with deep extension toward the cranium and airway. The mass was not identified prenatally. The patient was a 37-week gestation age female neonate born via spontaneous vaginal delivery and noted to have a large left-sided facial mass that was not noted on the most recent prenatal ultrasound at 22 weeks gestation age. At birth, the patient was in respiratory distress and required continuous positive airway pressure support. Imaging revealed a large highly vascularized soft tissue mass adjacent to the airway with intracranial extension and bony destruction. Fine needle aspiration confirmed kaposiform hemangioendothelioma. On day of life 6, the patient was noted to have thrombocytopenia, elevated d-dimer, anemia, and hypofibrinogenemia, consistent with Kasabach-Merritt phenomenon, which resolved at day of life 12. Given the location and extent of the mass, medical therapy with single agent oral sirolimus was chosen over surgery. At 13-month follow-up, the infant is well on sirolimus therapy, and the mass has decreased in size, both clinically and on imaging. This case highlights the importance of prompt diagnosis and management of kaposiform hemangioendothelioma with extensive craniofacial and bony involvement with Kasabach-Merritt phenomenon with single oral therapy of sirolimus. Fibrinogen concentrate may be considered in the Kasabach-Merritt phenomenon refractory to cryoprecipitate.