Prenatal exome sequencing: A useful tool for the fetal neurologist.

Prenatal exome sequencing (pES) is a promising tool for diagnosing genetic disorders when structural anomalies are detected on prenatal ultrasound. The aim of this study was to investigate the diagnostic yield and clinical impact of pES as an additional modality for fetal neurologists who counsel parents in case of congenital anomalies of the central nervous system (CNS). We assessed 20 pregnancies of 19 couples who were consecutively referred to the fetal neurologist for CNS anomalies. pES had a diagnostic yield of 53% (10/19) with most diagnosed pregnancies having agenesis or hypoplasia of the corpus callosum (7/10). Overall clinical impact was 63% (12/19), of which the pES result aided parental decision making in 55% of cases (6/11), guided perinatal management in 75% of cases (3/4), and was helpful in approving a late termination of pregnancy request in 75% of cases (3/4). Our data suggest that pES had a high diagnostic yield when CNS anomalies are present, although this study is limited by its small sample size. Moreover, pES had substantial clinical impact, which warrants implementation of pES in the routine care of the fetal neurologist in close collaboration with gynecologists and clinical geneticists.

Improving long-term outcomes in pediatric torcular dural sinus malformations with embolization and anticoagulation: a retrospective review of The Hospital for Sick Children experience.

OBJECTIVE: Torcular dural sinus malformations (tDSMs) are rare pediatric cerebrovascular malformations characterized by giant venous lakes localized to the midline confluence of sinuses. Historical clinical outcomes of patients with these lesions were poor, though better prognoses have been reported in the more recent literature. Long-term outcomes in children with tDSMs are uncertain and require further characterization. The goal of this study was to review a cohort of tDSM patients with an emphasis on long-term outcomes and to describe the treatment strategy. METHODS: This study is a single-center retrospective review of a prospectively maintained data bank including patients referred to and cared for at The Hospital for Sick Children for tDSM from January 1996 to March 2019. Each patient's clinical, radiological, and demographic information, as well as their mother's demographic information, was collected for review. RESULTS: Ten patients with tDSM, with a mean follow-up of 58 months, were included in the study. Diagnoses were made antenatally in 8 patients, and among those cases, 4 families opted for either elective termination (n = 1) or no further care following delivery (n = 3). Of the 6 patients treated, 5 had a favorable long-term neurological outcome, and follow-up imaging demonstrated a decrease or stability in the size of the tDSM over time. Staged embolization was performed in 3 patients, and anticoagulation was utilized in 5 treated patients. CONCLUSIONS: The authors add to a growing body of literature indicating that clinical outcomes in tDSM may not be as poor as initially perceived. Greater awareness of the lesion's natural history and pathophysiology, advancing endovascular techniques, and individualized anticoagulation regimens may lead to continued improvement in outcomes.

SCYL1 disease and liver transplantation diagnosed by reanalysis of exome sequencing and deletion/duplication analysis of SCYL1.

SCYL1 disease results from biallelic pathogenic variants in SCYL1. We report two new patients with severe hepatic phenotype requiring liver transplantation. Patient charts reviewed. DNA samples and skin fibroblasts were utilized. Literature was reviewed. 13-year-old boy and 9-year-old girl siblings had acute liver insufficiency and underwent living related donor liver transplantation in infancy with no genetic diagnosis. Both had tremor, global developmental delay, and cognitive dysfunction during their follow-up in the medical genetic clinic for diagnostic investigations after their liver transplantation. Exome sequencing identified a likely pathogenic variant (c.399delC; p.Asn133Lysfs*136) in SCYL1. Deletion/duplication analysis of SCYL1 identified deletions of exons 7-8 in Patient 1. Both variants were confirmed in Patient 2 and the diagnosis of SCYL1 disease was confirmed in both patients at the age of 13 and 9 years, respectively. SCYL1 protein was not expressed in both patients' fibroblast using western blot analysis. Sixteen patients with SCYL1 disease reported in the literature. Liver phenotype (n = 16), neurological phenotype (n = 13) and skeletal phenotype (n = 11) were present. Both siblings required liver transplantation in infancy and had variable phenotypes. Exome sequencing may miss the diagnosis and phenotyping of patients can help to diagnose patients.

Acute Deterioration in a Patient with Bilateral Chronic Subdural Hematomas Associated with Intracranial Hypotension Treated with an Epidural Blood Patch.

BACKGROUND: Intracranial hypotension due to cerebrospinal fluid (CSF) leak is often associated with secondary chronic subdural hematoma (CSDH). Although epidural blood patch (EBP) treatment for the CSF leak site has been reported to result in spontaneous regression of the CSDH in most cases, it is still debatable whether blocking CSF leak first in the patients with intracranial hematoma is always safe. CASE DESCRIPTION: A 72-year-old woman presented with orthostatic headache after a head injury and was diagnosed with intracranial hypotension. Computed tomography myelography and radioisotope cisternography failed to reveal the CSF leak point. The overflow leak test, a novel diagnostic method for intracranial hypotension, revealed a leakage at the cervical spine. Bilateral CSDHs were also observed by a computed tomography scan of the head. We performed EBP at the cervical spine and anticipated subsequent regression of the CSDH by normalizing intrathecal pressure. However, the patient became delirious the morning after EBP, and an emergency burr hole trepanation was performed. The patient's consciousness fully recovered, and her orthostatic headache improved as well. CONCLUSIONS: This case presentation demonstrated that in the case of intracranial hypotension with secondary CSDH, performing EBP and waiting for subsequent spontaneous regression of CSDH are not necessarily safe. Immediate burr hole trepanation should be prepared for the subsequent rapid symptomatic change of the CSDH after EBP.

Treatments in Aicardi-Goutières syndrome.

Comprehensive reviews of the clinical characteristics and pathogenesis of Aicardi-Goutières syndrome (AGS), particularly its contextualization within a putative type I interferonopathy framework, already exist. However, recent reports of attempts at treatment suggest that an assessment of the field from a therapeutic perspective is warranted at this time. Here, we briefly summarize the neurological phenotypes associated with mutations in the seven genes so far associated with AGS, rehearse current knowledge of the pathology as it relates to possible treatment approaches, critically appraise the potential utility of therapies, and discuss the challenges in assessing clinical efficacy. WHAT THIS PAPER ADDS: Progress in understanding AGS disease pathogenesis has led to the first attempts at targeted treatment. Further rational therapies are expected to become available in the short- to medium-term.

[Pre- and Postnatal Diagnosis of Congenital Central Nervous System Anomalies in Iceland in 1992-2016].

INTRODUCTION: The incidence of congenital anomalies of the central nervous system (CNS) in Iceland during 1992-2016 was examined along with timing of diagnosis, maternal residence, known risk factors and perinatal outcomes. MATERIAL AND METHODS: This was a retrospective study of all fe-tuses and newborns diagnosed with a CNS anomaly during the study period and their mothers. Information was obtained from the Icelandic Birth Registry and from maternal and neonatal medical records. Descriptive and inferential statistics were used in data analyzing. RESULTS: Annually, 3-12 cases of congenital CNS anomalies were diagnosed. Five year period incidence ranged from 1.4-2.4/1000 newborns, highest in 2012-2016. Over 89% were diagnosed -prenatally, of those 80% were terminated. The average gestational age at diagnosis of anencephaly was 19,3 weeks 1992-1996 vs. 11.6 weeks 2012-2016 (p=0,006). Urban area prenatal diagnosis was higher (94%) than rural (80%) (p=0.006). Known risk factors among mothers were uncommon, except for maternal obesity during the period 2012-2016 (23%). Of 57 live born children with CNS anomalies 37 (65%) were alive at the time of the study. CONCLUSION: The incidence of congenital anomalies of the CNS is stable and maternal risk factors are infrequent. Around 90% were diagnosed prenatally. Fetal anencephaly was diagnosed earlier at the end of the study period, after the introduction of a 11-14 week ultrasound scan in 2003, along with increased training among -healthcare professionals and improved ultrasound equipment. Higher prenatal detection rate in urban areas compared with rural may be explained by fewer ultrasound examinations being performed in less populated health districts, staff consequently receiving less training and experience and also with less advanced equipment.

Animal models of leukodystrophy: a new perspective for the development of therapies.

The leukodystrophies are a family of heritable disorders characterised by white matter degeneration, accompanied by variable clinical symptoms including loss of motor function and cognitive decline. Now thought to include over 50 distinct disorders, there are a vast array of mechanisms underlying the pathology of these monogenic conditions and, accordingly, a range of animal models relating to each disorder. While both murine and zebrafish models continue to aid in the development of potential therapies, many of these models fail to truly recapitulate the human condition - thus leaving substantial weaknesses in our understanding of leukodystrophy pathogenesis. Additionally, the heterogeneity in leukodystrophy presentation - both in patients and in vivo models - often results in a narrow focus on single disorders in isolation across much of the literature. Thus, this review aims to synthesise prominent research regarding the most common leukodystrophies in order to provide an overview of key animal models and their utility in developing novel treatments. We begin by discussing the ongoing revolution across the leukodystrophy field following the rise of next generation sequencing, before focusing more extensively on existing animal models from the mouse and zebrafish fields. Finally, we explore how these preclinical models have shaped the development of therapeutic strategies currently in development. We propose future directions for the field and suggest a more critical view of the dogma which has underpinned leukodystrophy research for decades.

Outcomes of Neonates With Complex Medical Needs.

BACKGROUND: Children with complex medical needs (CMN) are high healthcare resource utilizers, have varying underlying diagnoses, and experience repeated hospitalizations. Outcomes on neonatal intensive care (NICU) patients with CMN are unknown. PURPOSE: The primary aim is to describe the clinical profile, resource use, prevalence, and both in-hospital and postdischarge outcomes of neonates with CMN. The secondary aim is to assess the feasibility of sustaining the use of the neonatal complex care team (NCCT). METHODS: A retrospective cohort study was conducted after implementing a new model of care for neonates with CMN in the NICU. All neonates born between January 2013 and December 2016 and who met the criteria for CMN and were cared for by the NCCT were included. RESULTS: One hundred forty-seven neonates with a mean (standard deviation) gestational age of 34 (5) weeks were included. The major underlying diagnoses were genetic/chromosomal abnormalities (48%), extreme prematurity (26%), neurological abnormality (12%), and congenital anomalies (11%). Interventions received included mechanical ventilation (69%), parenteral nutrition (68%), and technology dependency at discharge (91%). Mortality was 3% before discharge and 17% after discharge. Postdischarge hospital attendances included emergency department visits (44%) and inpatient admissions (58%), which involved pediatric intensive care unit admissions (26%). IMPLICATIONS FOR PRACTICE: Neonates with CMN have multiple comorbidities, high resource needs, significant postdischarge mortality, and rehospitalization rates. These cohorts of NICU patients can be identified early during their NICU course and serve as targets for implementing innovative care models to meet their unique needs. IMPLICATIONS FOR RESEARCH: Future studies should explore the feasibility of implementing innovative care models and their potential impact on patient outcomes and cost-effectiveness.

What's New in Genetic Skin Diseases.

The discoveries of new genes underlying genetic skin diseases have occurred at a rapid pace, supported by advances in DNA sequencing technologies. These discoveries have translated to an improved understanding of disease mechanisms at a molecular level and identified new therapeutic options based on molecular targets. This article highlights just a few of these recent discoveries for a diverse group of skin diseases, including tuberous sclerosis complex, ichthyoses, overgrowth syndromes, interferonopathies, and basal cell nevus syndrome, and how this has translated into novel targeted therapies and improved patient care.

Neurometabolic disorders and congenital malformations of the central nervous system.

Both malformations of the central nervous system and neurometabolic disorders are common, mainly in highly consanguineous populations. Both metabolic pathways and developmental pathways are closely related and interact with each other. Neurometabolic disorders can lead to disturbances in brain development through multiple mechanisms that include deficits in energy metabolism, critical nutrient deficiency, accumulation of neurotoxic substrates, abnormality in cell membrane constituents, and interference in cell-to-cell signaling pathways. The anomalies observed include absent or hypoplastic corpus callosum, midline brain defects, and malformations of the cortex, the cerebellum and the brain stem. Early diagnosis of an underlying inherited neurometabolic disorders is critical for the institution of treatment, which may positively influence prognosis, and allow for proper genetic counseling. In this review, we discuss those disorders in which the structural brain malformation is a dominant feature, and propose a practical approach that will permit a physician to investigate, and treat these disorders.

Nervous System Malformations.

PURPOSE OF REVIEW: This article provides an overview of the most common nervous system malformations and serves as a reference for the latest advances in diagnosis and treatment. RECENT FINDINGS: Major advances have occurred in recognizing the genetic basis of nervous system malformations. Environmental causes of nervous system malformations, such as perinatal infections including Zika virus, are also reviewed. Treatment for nervous system malformations begins prior to birth with prevention. Folic acid supplementation reduces the risk of neural tube defects and is an important part of health maintenance for pregnant women. Fetal surgery is now available for prenatal repair of myelomeningocele and has been demonstrated to improve outcomes. SUMMARY: Each type of nervous system malformation is relatively uncommon, but, collectively, they constitute a large population of neurologic patients. The diagnosis of nervous system malformations begins with radiographic characterization. Genetic studies, including chromosomal microarray, targeted gene sequencing, and next-generation sequencing, are increasingly important aspects of the assessment. A genetic diagnosis may identify an associated medical condition and is necessary for family planning. Treatment consists primarily of supportive therapies for developmental delays and epilepsy, but prenatal surgery for myelomeningocele offers a glimpse of future possibilities. Prognosis depends on multiple clinical factors, including the examination findings, imaging characteristics, and genetic results. Treatment is best conducted in a multidisciplinary setting with neurology, neurosurgery, developmental pediatrics, and genetics working together as a comprehensive team.

Congenital malformations, palliative care and postnatal redirection to more intensive treatment - a review at a Swiss tertiary center.

PURPOSE: The so-called lethal malformations pose ethical challenges. Most affected fetuses die before or at birth. Live-born neonates commonly receive palliative care. If the postnatal course is better than expected, redirection towards more treatment may occur. We aimed to analyze this in a Swiss patient cohort. MATERIALS AND METHODS: Over 6 years, fetal malformation was suspected in 1113 cases. We identified patients prenatally assigned to palliative care, assessed pre- and postnatal diagnoses, and outcomes. RESULTS: Fourteen neonates received palliative care. Eleven patients received palliative care following late termination of pregnancy, for three, palliative care was planned and the fetus died during delivery, for two, the outcome was unknown (incomplete documentation). Genetic testing was performed in 50%. The predominant diagnostic group was central nervous system malformations (33%), followed by chromosomal aberrations (20%) and renal anomalies (17%). One child assigned to palliative care was resuscitated. Antenatal findings were anhydramnios and pulmonary hypoplasia. Postnatally, respiration was better than expected. The neonate was admitted to intensive care, died on day one. CONCLUSIONS: Nervous system malformations seem to be a major criterion for foregoing life-sustaining interventions. Redirection towards more treatment is rare. This may reflect precise prenatal prognostication; a degree of self-fulfilling prophecy cannot be excluded.

Attention training modulates resting-state neurophysiological abnormalities in posttraumatic stress disorder.

Recent research indicates the relative benefits of computerized attention control treatment (ACT) and attention bias modification treatment (ABMT) for posttraumatic stress disorder (PTSD); however, neural changes underlying these therapeutic effects remain unknown. This study examines how these two types of attention training modulate neurological dysfunction in veterans with PTSD. A community sample of 46 combat veterans with PTSD participated in a randomized double-blinded clinical trial of ACT versus ABMT and 32 of those veterans also agreed to undergo resting-state magnetoencephalography (MEG) recordings. Twenty-four veterans completed psychological and MEG assessments at pre- and post-training to evaluate treatment effects. MEG data were imaged using an advanced Bayesian reconstruction method and examined using statistical parametric mapping. In this report, we focus on the neural correlates and the differential treatment effects observed using MEG; the results of the full clinical trial have been described elsewhere. Our results indicated that ACT modulated occipital and ABMT modulated medial temporal activity more strongly than the comparative treatment. PTSD symptoms decreased significantly from pre- to post-test. These initial neurophysiological outcome data suggest that ACT modulates visual pathways, while ABMT modulates threat-processing regions, but that both are associated with normalizing aberrant neural activity in veterans with PTSD.

Outcome After Therapeutic Hypothermia in Term Neonates With Encephalopathy and a Syndromic Diagnosis.

The large randomized, controlled trials of therapeutic hypothermia for hypoxic-ischemic encephalopathy excluded neonates with congenital disorders. The objective of this study was to report our experience using hypothermia in neonates with signs of hypoxic-ischemic encephalopathy and a syndromic disorder or brain anomaly. Subjects were identified from a database of neonates admitted to the Neuro-Intensive Care Nursery at University of California, San Francisco. Of 169 patients fulfilling criteria for hypothermia, 8 (5%) had a syndromic disorder and were cooled per guidelines for nonsyndromic neonates. Perinatal characteristics of infants with and without syndromic disorder were not significantly different. Overall outcome was poor: 38% had evidence of acute hypoxic-ischemic injury, 3 subjects died, and 2 survivors had low developmental quotient (ie, 25). The risk versus benefit of therapeutic hypothermia for hypoxic-ischemic encephalopathy among neonates with congenital brain malformations or syndromic diagnoses is uncertain.

Therapies in Aicardi-Goutières syndrome.

Aicardi-Goutières syndrome (AGS) is a genetically determined disorder, affecting most particularly the brain and the skin, characterized by the inappropriate induction of a type I interferon-mediated immune response. In most, but not all, cases the condition is severe, with a high associated morbidity and mortality. A number of important recent advances have helped to elucidate the biology of the AGS-related proteins, thus providing considerable insight into disease pathology. In this study, we outline the clinical phenotype of AGS, paying particular attention to factors relevant to therapeutic intervention. We then discuss the pathogenesis of AGS from a molecular and cell biology perspective. Finally, we suggest possible treatment strategies in light of these emerging insights.

Aicardi-Goutières syndrome: a model disease for systemic autoimmunity.

Systemic autoimmunity is a complex disease process that results from a loss of immunological tolerance characterized by the inability of the immune system to discriminate self from non-self. In patients with the prototypic autoimmune disease systemic lupus erythematosus (SLE), formation of autoantibodies targeting ubiquitous nuclear antigens and subsequent deposition of immune complexes in the vascular bed induces inflammatory tissue injury that can affect virtually any organ system. Given the extraordinary genetic and phenotypic heterogeneity of SLE, one approach to the genetic dissection of complex SLE is to study monogenic diseases, for which a single gene defect is responsible. Considerable success has been achieved from the analysis of the rare monogenic disorder Aicardi-Goutières syndrome (AGS), an inflammatory encephalopathy that clinically resembles in-utero-acquired viral infection and that also shares features with SLE. Progress in understanding the cellular and molecular functions of the AGS causing genes has revealed novel pathways of the metabolism of intracellular nucleic acids, the major targets of the autoimmune attack in patients with SLE. Induction of autoimmunity initiated by immune recognition of endogenous nucleic acids originating from processes such as DNA replication/repair or endogenous retro-elements represents novel paradigms of SLE pathogenesis. These findings illustrate how investigating rare monogenic diseases can also fuel discoveries that advance our understanding of complex disease. This will not only aid the development of improved tools for SLE diagnosis and disease classification, but also the development of novel targeted therapeutic approaches.

Congenital portosystemic shunt: characterization of a multisystem disease.

OBJECTIVES: Congenital portosystemic shunts (CPSSs) are rare but increasingly recognized as a cause of important multisystem morbidity. We present new cases and a systematic literature review and propose an algorithm for the identification and care of affected patients. METHODS: We reviewed the charts of consecutive patients seen in our pediatric liver clinic between 2003 and 2010 and systematically reviewed the literature of cases with CPSS. RESULTS: We identified 316 published cases and 12 patients in our own clinic. Of the published cases (177 male), 185 had an extrahepatic and 131 an intrahepatic portosystemic shunt. Diagnosis was made at any age, from prenatal to late adulthood. Cardiac anomalies were found in 22% of patients. The main complications were hyperammonemia/neurological abnormalities (35%), liver tumors (26%), and pulmonary hypertension or hepatopulmonary syndrome (18%). The spectrum of neurological involvement ranged from changes in brain imaging, subtle abnormalities on neuropsychological testing, through learning disabilities to overt encephalopathy. Spontaneous shunt closure occurred mainly in infants with intrahepatic shunts. Therapeutic interventions included shunt closure by surgery or interventional radiology techniques (35%) and liver transplantation (10%) leading to an improvement of symptoms in the majority. These findings mirror the observations in our own patients. CONCLUSIONS: In this largest review of the reported clinical experience, we identify that children with CPSS may present with otherwise unexplained developmental delay, encephalopathy, pulmonary hypertension, hypoxemia, or liver tumors. When CPSS is diagnosed, children should be screened for all of these complications. Spontaneous closure of intrahepatic shunts may occur in infancy. Closure of the shunt is indicated in symptomatic patients and is associated with a favorable outcome.

Rhombencephalosynapsis: embryopathology and management strategies of associated neurosurgical conditions with a review of the literature.

OBJECT: Rhombencephalosynapsis (RS) is a rare congenital posterior fossa malformation characterized by dorsal fusion of the cerebellar hemispheres, hypogenesis or agenesis of the vermis, and fusion of the dentate nuclei and superior cerebellar peduncles. The objective of this institutional study is to review the clinical conditions associated with RS and analyze the varied biological profile of this unique condition. METHODS: The study data were collected retrospectively from the medical records of patients at Rainbow Babies and Children's Hospital. After required institutional review board approval, the authors obtained information regarding the cases of RS reviewed by the Departments of Radiology, Genetics, and/or Pediatric Neurology. Medical charts were systematically reviewed, and 9 patients were analyzed in detail. RESULTS: The authors describe 6 cases of RS and 3 cases of partial RS. This case series demonstrates an association between RS and symptomatic hydrocephalus (7 of 9 patients) and RS and Chiari malformation (5 of 9 patients). Patients with symptomatic hydrocephalus underwent endoscopic third ventriculostomy or ventriculoperitoneal shunt insertion. One of the patients with an associated Chiari malformation underwent foramen magnum decompression. CONCLUSIONS: The authors present a large case series of RS. Patients with RS often had hydrocephalus and/or a Chiari Type I or II hindbrain malformation. Neuroimaging findings of RS are presented along with hypotheses to explain the embryopathology of this unusual condition.

[The influence of MRI examination on prenatal guidance and therapeutic decisions in fetuses with central nervous system defects]. / Wplyw prenatalnego badania MR na poradnictwo prenatalne i zmiane decyzji terapeutycznych u dzieci z wadami wrodzonymi osrodkowego ukladu nerwowego.

PURPOSE: The aim of this study was the evaluation of diagnostic and prognostic value of prenatal US and MRI in fetuses with central nervous system abnormalities, and of the influence of incorporating MRI to diagnostic algorithm on the therapeutic decisions. MATERIALS AND METHODS: 123 pregnant women (16-40 weeks' gestation) underwent MRI due to abnormal appearance of fetal central nervous system in US (using Voluson-Kretz 730PRO). MRI has been performed on a 1.5-T Excite (GE), using a phased-array body coil, with T2-weighted sequences (SSFSET2) and orthogonal scans. The MRI findings have been compared to those from prenatal US. The influence of MRI examination in prenatal diagnostic on decisions concerning termination of pregnancy, method of delivery and neurosurgical intervention after birth was assessed. RESULTS: Among 123 fetuses with central nervous system abnormalities, 11 neonates died after birth (in 6 cases pathologic examination was performed), in 67 cases the MR findings were correlated with the results of the neonatal evaluation, all other cases have not been verified. Almost in 70% of the cases, MRI findings complemented the US diagnosis, in 22 cases changed it with respect to central nervous system defects, and in 18 cases--with respect to other system/organ abnormalities. In a few cases US failed to provide a correct diagnosis. In 3 cases, the MRI findings have not been confirmed with postnatal evaluation. CONCLUSIONS: Prenatal MRI in congenital central nervous system defects allows to obtain much more important therapeutic data and complement or correct the fetal sonographic diagnosis. Prenatal MRI allows to plan gynaecological, neonatal, neurosurgical treatment, and to predict neurological defects. It also improves prenatal guidance.