The restoration of myelin sheaths on demyelinated axons remains a major obstacle in the treatment of multiple sclerosis (MS). Currently approved therapies work by modulating the immune system to ...reduce the number and rate of lesion formation but are only partially effective since they are not able to restore lost myelin. In the healthy CNS, myelin continues to be generated throughout life and spontaneous remyelination occurs readily in response to insults. In patients with MS, however, remyelination eventually fails, at least in part as a result of a failure of oligodendrocyte precursor cell (OPC) differentiation and the subsequent production of new myelin. A better understanding of the molecular mechanisms and signaling pathways that drive the process of myelin sheath formation is therefore important in order to speed the development of novel therapeutics designed to target remyelination. Here we review data supporting critical roles for three highly conserved intracellular signaling pathways: Wnt/β-catenin, PI3K/AKT/mTOR, and ERK/MAPK in the regulation of OPC differentiation and myelination both during development and in remyelination. Potential points of crosstalk between the three pathways and important areas for future research are also discussed.
To investigate monoallelic CLPB variants. Pathogenic variants in many genes cause congenital neutropenia. While most patients exhibit isolated hematological involvement, biallelic CLPB variants ...underlie a neurological phenotype ranging from nonprogressive intellectual disability to prenatal encephalopathy with progressive brain atrophy, movement disorder, cataracts, 3-methylglutaconic aciduria, and neutropenia. CLPB was recently shown to be a mitochondrial refoldase; however, the exact function remains elusive.
We investigated six unrelated probands from four countries in three continents, with neutropenia and a phenotype dominated by epilepsy, developmental issues, and 3-methylglutaconic aciduria with next-generation sequencing.
In each individual, we identified one of four different de novo monoallelic missense variants in CLPB. We show that these variants disturb refoldase and to a lesser extent ATPase activity of CLPB in a dominant-negative manner. Complexome profiling in fibroblasts showed CLPB at very high molecular mass comigrating with the prohibitins. In control fibroblasts, HAX1 migrated predominantly as monomer while in patient samples multiple HAX1 peaks were observed at higher molecular masses comigrating with CLPB thus suggesting a longer-lasting interaction between CLPB and HAX1.
Both biallelic as well as specific monoallelic CLPB variants result in a phenotypic spectrum centered around neurodevelopmental delay, seizures, and neutropenia presumably mediated via HAX1.
Term congenital heart disease (CHD) neonates display abnormalities of brain structure and maturation, which are possibly related to underlying patient factors, abnormal physiology and perioperative ...insults. Our primary goal was to delineate associations between clinical factors and postnatal brain microstructure in term CHD neonates using diffusion tensor imaging (DTI) magnetic resonance (MR) acquisition combined with complementary data-driven connectome and seed-based tractography quantitative analyses. Our secondary goal was to delineate associations between mild dysplastic structural brain abnormalities and connectome and seed-base tractography quantitative analyses. These mild dysplastic structural abnormalities have been derived from prior human infant CHD MR studies and neonatal mouse models of CHD that were collectively used to calculate to calculate a brain dysplasia score (BDS) that included assessment of subcortical structures including the olfactory bulb, the cerebellum and the hippocampus.
Neonates undergoing cardiac surgery for CHD were prospectively recruited from two large centers. Both pre- and postoperative MR brain scans were obtained. DTI in 42 directions was segmented into 90 regions using a neonatal brain template and three weighted methods. Clinical data collection included 18 patient-specific and 9 preoperative variables associated with preoperative scan and 6 intraoperative (e.g., cardiopulmonary bypass and deep hypothermic circulatory arrest times) and 12 postoperative variables associated with postoperative scan. We compared patient specific and preoperative clinical factors to network topology and tractography alterations on a preoperative neonatal brain MRI, and intra and postoperative clinical factors to network topology alterations on postoperative neonatal brain MRI. A composite BDS was created to score abnormal findings involving the cerebellar hemispheres and vermis, supratentorial extra-axial fluid, olfactory bulbs and sulci, hippocampus, choroid plexus, corpus callosum, and brainstem. The neuroimaging outcomes of this study included (1) connectome metrics: cost (number of connections) and global/nodal efficiency (network integration); (2) seed based tractography methods of fractional anisotropy (FA), radial diffusivity, and axial diffusivity. Statistics consisted of multiple regression with false discovery rate correction (FDR) comparing the clinical risk factors and BDS (including subcortical components) as predictors/exposures and the global connectome metrics, nodal efficiency, and seed based- tractography (FA, radial diffusivity, and axial diffusivity) as neuroimaging outcome measures.
A total of 133 term neonates with complex CHD were prospectively enrolled and 110 had analyzable DTI. Multiple patient-specific factors including d-transposition of the great arteries (d-TGA) physiology and severity of impairment of fetal cerebral substrate delivery (i.e., how much the CHD lesion alters typical fetal circulation such that the highest oxygen and nutrient rich blood from the placenta are not directed toward the fetal brain) were predictive of preoperative reduced cost (
< 0.0073) and reduced global/nodal efficiency (
< 0.03). Cardiopulmonary bypass time predicted postoperative reduced cost (
< 0.04) and multiple postoperative factors extracorporeal membrane oxygenation (ECMO), seizures and cardiopulmonary resuscitation (CPR) were predictive of postoperative reduced cost and reduced global/nodal efficiency (
< 0.05). Anthropometric measurements (weight, length, and head size) predicted tractography outcomes. Total BDS was not predictive of brain network topology. However, key subcortical components of the BDS score did predict key global and nodal network topology: abnormalities of the cerebellum predicted reduced cost (
< 0.0417) and of the hippocampus predicted reduced global efficiency (
< 0.0126). All three subcortical structures predicted unique alterations of nodal efficiency (
< 0.05), including hippocampal abnormalities predicting widespread reduced nodal efficiency in all lobes of the brain, cerebellar abnormalities predicting increased prefrontal nodal efficiency, and olfactory bulb abnormalities predicting posterior parietal-occipital nodal efficiency.
Patient-specific (d-TGA anatomy, preoperative impairment of fetal cerebral substrate delivery) and postoperative (e.g., seizures, need for ECMO, or CPR) clinical factors were most predictive of diffuse postnatal microstructural dysmaturation in term CHD neonates. Anthropometric measurements (weight, length, and head size) predicted tractography outcomes. In contrast, subcortical components (cerebellum, hippocampus, olfactory) of a structurally based BDS (derived from CHD mouse mutants), predicted more localized and regional postnatal microstructural differences. Collectively, these findings suggest that brain DTI connectome and seed-based tractography are complementary techniques which may facilitate deciphering the mechanistic relative contribution of clinical and genetic risk factors related to poor neurodevelopmental outcomes in CHD.
•Parents want counseling about sexual abuse recognition and prevention.•Counseling on menstruation was more relevant to their child's life.•Lack of counseling on pregnancy-related topics.•Lack of ...counseling on interactions between contraception and antiseizure medication.•Want neurologist initiated sexual and reproductive health care counseling.
To explore the experiences and preferences of parents/guardians of adolescents and young adults (AYA) of childbearing potential with co-occurring epilepsy and intellectual disability (ID) regarding counseling by neurologists on sexual and reproductive health (SRH) topics such as pregnancy, contraception, menstruation, and folic acid supplementation.
We conducted semi-structured interviews with parents/guardians of AYAs (12–28 years old) of childbearing potential with co-occurring epilepsy and ID, recruited from a tertiary-care children’s hospital. We confirmed the diagnoses of epilepsy and ID with the patient’s neurologist and parent/guardian. All degrees of ID (e.g. mild/moderate/severe) were eligible. We audio-recorded and transcribed interviews. Two coders performed qualitative thematic analysis.
Twenty-five parents/guardians completed interviews. Themes included: (1) Parents/guardians believe their child to be immune from sexual abuse due to their supervision, yet desire counseling about abuse recognition and prevention, which they also report not occurring (2) A common opinion was that counseling on menstruation was more relevant to their child's life than counseling about pregnancy-related topics (3) Parents/guardians reported a lack of counseling on pregnancy-related topics such as folic acid supplementation and teratogenesis and generally also reported some degree of interest in hearing about these topics from neurologists (4) Parents/guardians also reported a lack of counseling on drug interactions between contraception and ASMs, and were highly interested in learning more about this topic (5) Parents/guardians want neurologists to initiate annual comprehensive SRH counseling at puberty about most topics, but report that they often initiate SRH discussions themselves.
Parents/guardians of AYAs with epilepsy and ID prefer more frequent, neurologist-initiated, comprehensive conversations surrounding SRH particularly emphasizing menstruation and sexual abuse recognition/prevention. Findings may inform professional and patient education and health systems interventions including development of discussion guides and/or decision aides to improve SRH care for AYAs with epilepsy and ID.
Deep neural networks are increasingly being used in both supervised learning for classification tasks and unsupervised learning to derive complex patterns from the input data. However, the successful ...implementation of deep neural networks using neuroimaging datasets requires adequate sample size for training and well-defined signal intensity based structural differentiation. There is a lack of effective automated diagnostic tools for the reliable detection of brain dysmaturation in the neonatal period, related to small sample size and complex undifferentiated brain structures, despite both translational research and clinical importance. Volumetric information alone is insufficient for diagnosis. In this study, we developed a computational framework for the automated classification of brain dysmaturation from neonatal MRI, by combining a specific deep neural network implementation with neonatal structural brain segmentation as a method for both clinical pattern recognition and data-driven inference into the underlying structural morphology. We implemented three-dimensional convolution neural networks (3D-CNNs) to specifically classify dysplastic cerebelli, a subset of surface-based subcortical brain dysmaturation, in term infants born with congenital heart disease. We obtained a 0.985 ± 0. 0241-classification accuracy of subtle cerebellar dysplasia in CHD using 10-fold cross-validation. Furthermore, the hidden layer activations and class activation maps depicted regional vulnerability of the superior surface of the cerebellum, (composed of mostly the posterior lobe and the midline vermis), in regards to differentiating the dysplastic process from normal tissue. The posterior lobe and the midline vermis provide regional differentiation that is relevant to not only to the clinical diagnosis of cerebellar dysplasia, but also genetic mechanisms and neurodevelopmental outcome correlates. These findings not only contribute to the detection and classification of a subset of neonatal brain dysmaturation, but also provide insight to the pathogenesis of cerebellar dysplasia in CHD. In addition, this is one of the first examples of the application of deep learning to a neuroimaging dataset, in which the hidden layer activation revealed diagnostically and biologically relevant features about the clinical pathogenesis. The code developed for this project is open source, published under the BSD License, and designed to be generalizable to applications both within and beyond neonatal brain imaging.
•A framework for classification of brain dysmaturation from neonatal MRI is introduced.•Combine deep learning and structural brain segmentation.•Provides both clinical pattern recognition and data-driven inference.•Revealed diagnostic and biologic insight about clinical pathogenesis.•The code developed is open source, published under the BSD License.
Cerebrofaciothoracic dysplasia (CFTD) is a developmental disorder characterized by distinctive craniofacial dysmorphism, global developmental delay, and skeletal anomalies. CTFD is the result of ...biallelic autosomal recessive loss of function mutations in the transmembrane and coiled-coil domains one protein (TMCO1) gene. Based on a population of 27 molecularly confirmed cases, classic brain morphologies associated with CFTD have been described in the literature. Previous studies have demonstrated only mild ventriculomegaly, corpus callosum abnormalities, frontotemporal atrophy, and three cases of associated epilepsy. We present previously undescribed brain MRI findings in two children presenting with seizures due to TMCO1 mutation. MR Imaging demonstrated hippocampal malrotation, olfactory bulb agenesis and olfactory sulcus hypoplasia in both children, pontine hypoplasia, and cochlear nerve agenesis in one child. We demonstrate that TMCO1 may play a more extensive and previously undescribed role in neurodevelopment thereby expanding the phenotype associated with CFTD.
A carpet of ependymal motile cilia lines the brain ventricular system, forming a network of flow channels and barriers that pattern cerebrospinal fluid (CSF) flow at the surface. This CSF transport ...system is evolutionary conserved, but its physiological function remains unknown. Here we investigated its potential role in epilepsy with studies focused on CDKL5 deficiency disorder (CDD), a neurodevelopmental disorder with early-onset epilepsy refractory to seizure medications and the most common cause of infant epilepsy.
CDKL5
is a highly conserved X-linked gene suggesting its function in regulating cilia length and motion in the green alga
Chlamydomonas
might have implication in the etiology of CDD
.
Examination of the structure and function of airway motile cilia revealed both the CDD patients and the
Cdkl5
knockout mice exhibit cilia lengthening and abnormal cilia motion. Similar defects were observed for brain ventricular cilia in the
Cdkl5
knockout mice. Mapping ependymal cilia generated flow in the ventral third ventricle (v3V), a brain region with important physiological functions showed altered patterning of flow. Tracing of cilia-mediated inflow into v3V with fluorescent dye revealed the appearance of a flow barrier at the inlet of v3V in
Cdkl5
knockout mice. Analysis of mice with a mutation in another epilepsy-associated kinase, Yes1, showed the same disturbance of cilia motion and flow patterning. The flow barrier was also observed in the
Foxj1
±
and
FOXJ1Cre
ERT
:Cdkl5
y/fl
mice, confirming the contribution of ventricular cilia to the flow disturbances. Importantly, mice exhibiting altered cilia-driven flow also showed increased susceptibility to anesthesia-induced seizure-like activity. The cilia-driven flow disturbance arises from altered cilia beating orientation with the disrupted polarity of the cilia anchoring rootlet meshwork. Together these findings indicate motile cilia disturbances have an essential role in CDD-associated seizures and beyond, suggesting cilia regulating kinases may be a therapeutic target for medication-resistant epilepsy.
PDF
