Infantile epileptic spasms syndrome in a child with lissencephaly associated with de novo PAFAH1B1 variant and coincidental CMV infection.

Type 1 lissencephaly is a brain malformation characterized by agyria and pachygyria and is known to be caused by congenital infections and genetic variations. Here we present a case of a 4-month-old female with new onset infantile epileptic spasms syndrome (IESS) with initial etiology concerned for congenital cytomegalovirus (cCMV) due to a positive urine CMV PCR and maternal viral syndrome during pregnancy. Her brain MRI was significant for type 1 lissencephaly without other radiographical features of cCMV. The patient initially responded to high dose Prednisolone but had relapse of spasms at 9-month-old and required an ACTH course. She later developed generalized tonic seizures and focal impaired awareness seizures. Subsequent whole exome sequencing (WES) trio revealed a de novo PAFAH1B1 (c.405G > A, p.W135*) heterozygous nonsense variant which is pathogenic and thus solved the diagnostic puzzle. This case demonstrates that the absence of cCMV stigmata should raise concern for alternative etiology in cases of lissencephaly and the importance of genetic evaluation for subsequent management and family counseling.

Laser amygdalohippocampotomy reduces contralateral hippocampal sub-clinical activity in bitemporal epilepsy: A case illustration of responsive neurostimulator ambulatory recordings.

Responsive neurostimulation (RNS) is a valuable tool in the diagnosis and treatment of medication refractory epilepsy (MRE) and provides clinicians with better insights into patients' seizure patterns. In this case illustration, we present a patient with bilateral hippocampal RNS for presumed bilateral mesial temporal lobe epilepsy. The patient subsequently underwent a right sided LITT amygdalohippocampotomy based upon chronic RNS data revealing predominance of seizures from that side. Analyzing electrocorticography (ECOG) from the RNS system, we identified the frequency of high amplitude discharges recorded from the left hippocampal lead pre- and post- right LITT amygdalohippocampotomy. A reduction in contralateral interictal epileptiform activity was observed through RNS recordings over a two-year period, suggesting the potential dependency of the contralateral activity on the primary epileptogenic zone. These findings suggest that early targeted surgical resection or laser ablation by leveraging RNS data can potentially impede the progression of dependent epileptiform activity and may aid in preserving neurocognitive networks. RNS recordings are essential in shaping further management decisions for our patient with a presumed bitemporal epilepsy.

Developmental Regression Followed by Epilepsy and Aggression: A New Syndrome in Autism Spectrum Disorder?

Autism spectrum disorder (ASD) with regression (ASD-R) involves the loss of previously attained developmental milestones, typically during the first or second year of life. As children age, it is not uncommon for them to develop comorbid conditions such as aggressive behaviors or epilepsy, which can inhibit habilitation in language and social function. In this paper, we hypothesize that aggressive behaviors and epilepsy more commonly develop in patients with ASD-R than in those without a history of regression (ASD-NR). We conducted a retrospective review of non-syndromic patients with ASD over 12 years of age and compared the rates of epilepsy and aggression between ASD-R and ASD-NR patients. Patients with ASD-R, as compared to ASD-NR patients, demonstrated non-significantly higher rates of epilepsy (51.8% vs. 38.1%, p = 0.1335) and aggressive behaviors (73.2% vs. 57.1%, p = 0.0673) when evaluated separately. The rates for combined epilepsy and aggression, however, were statistically significant when comparing ASD-R versus ASD patients (44.5% vs. 23.8%, p = 0.0163). These results suggest that epilepsy with aggression is more common in ASD-R as compared to ASD-NR patients. When considering the impact of epilepsy and aggression on quality of life, these co-morbidities effectively cause a second regression in patients who experienced an earlier regression as toddlers. A larger, prospective trial is recommended to confirm these associations and further define the timeline in which these characteristics develop from early childhood to adolescence.

Clinical features and drug-resistance in pediatric epilepsy with co-occurring autism: A retrospective comparative cohort study.

OBJECTIVE: We conducted a retrospective comparative cohort study to determine the phenotypic and real-world management differences in children with epilepsy and co-occurring autism as compared to those without autism. METHODS: Clinical variables, EEG, brain MRI, genetic results, medical and non-medical treatment were compared between 156 children with both epilepsy and autism, 156 randomly selected and 156 demographically matched children with epilepsy only. Logistic regression analyses were conducted to determine predictors of drug-resistant epilepsy (DRE). RESULTS: As compared to the'matched' cohort, more patients with autism had generalized motor seizures although not statistically significant after Benjamini-Hochberg correction (54.5%, vs 42.3%, p = .0314); they had a lower rate of electroclinical syndromes (12.8%, vs 30.1%, p = .0002). There were more incidental MRI findings but less positive MRI findings to explain their epilepsy in children with autism (26.3%, vs 13.8% and 14.3%, vs 34.2%, respectively; p = .0003). In addition, LEV, LTG, and VPA were the most common ASMs prescribed to children with autism, as opposed to LEV, OXC, and LTG in children without autism. No difference in the major EEG abnormalities was observed. Although the rates of DRE were similar (24.8%, vs 26.6%, p = .7203), we identified two clinical and five electrographic correlates with DRE in children with both epilepsy and autism and a final prediction modeling of DRE that included EEG ictal findings, focal onset seizures, generalized motor seizures, abnormal EEG background, age of epilepsy onset, and history of SE, which were distinct from those in children without autism. SIGNIFICANCE: Our study indicates that detailed seizure history and EEG findings are the most important evaluation and prediction tools for the development of DRE in children with epilepsy and co-occurring autism. Further studies of epilepsy in specific autism subgroups based on their etiology and clinical severity are warranted.

Genetic Diagnosis Impacts Medical Management for Pediatric Epilepsies.

BACKGROUND: Evidence of the impact of genetic diagnosis on medical management in individuals with previously unexplained epilepsy is lacking in the literature. Our goal was to determine the impact of genetic diagnosis on medical management in a cohort of individuals with early-onset epilepsy. METHODS: We performed detailed phenotyping of individuals with epilepsy who underwent clinical genetic testing with an epilepsy panel and/or exome sequencing at Boston Children's Hospital between 2012 and 2019. We assessed the impact of genetic diagnosis on medical management. RESULTS: We identified a genetic etiology in 152 of 602 (25%) individuals with infantile- or childhood-onset epilepsy who underwent next-generation sequencing. Diagnosis impacted medical management in at least one category for 72% of patients (110 of 152) and in more than one category in 34%. Treatment was impacted in 45% of individuals, including 36% with impact on antiseizure medication choice, 7% on use of disease-specific vitamin or metabolic treatments, 3% on pathway-driven off-label use of medications, and 10% on discussion of gene-specific clinical trials. Care coordination was impacted in 48% of individuals. Counseling on a change in prognosis was reported in 28% of individuals, and 1% of individuals had a correction of diagnosis. Impact was documented in 13 of 13 individuals with neurotypical development and in 55% of those with epilepsy onset after age two years. CONCLUSION: We demonstrated meaningful impact of genetic diagnosis on medical care and prognosis in over 70% of individuals, including those with neurotypical development and age of epilepsy onset after age two years.

Vitamin B6 decreases the risk of levetiracetam discontinuation in children with epilepsy: A retrospective study.

OBJECTIVES: Levetiracetam (LEV) is an anti-seizure medication (ASM) known to have significant behavioral side effects in children with epilepsy. These side effects may be improved by supplemental vitamin B6 (pyridoxine) use. Our research aimed to study risk factors for LEV side effects and the role of vitamin B6 in altering this risk. METHODS: We retrospectively analyzed the demographic and clinical profile of all pediatric patients on LEV treatment between July 2019 and December 2020. T-tests, Chi-square and Fisher exact tests were used to assess predictors of LEV discontinuation. A p-value of <0.05 was considered statistically significant. RESULTS: 150/240 (62%) children were on additional medications besides LEV for epilepsy management. Thirty-five percent children reported side effects, especially behavioral and mood concerns. Of the patients who reported side effects on LEV, 71% were taking vitamin B6 (n = 59). The rate of LEV discontinuation was significantly lower for children on vitamin B6 than children not taking B6, regardless of monotherapy or polypharmacy (49% v 88% respectively, p = 0.001). Over half of the patients who were able to remain on LEV reported improved behavior with B6 supplementation as compared to those who were unable to continue LEV (17/30, 57% versus 0/26, 0%; p < 0.001). CONCLUSIONS: Levetiracetam side effects significantly impact the tolerability of this ASM in children with epilepsy. Our results suggest that vitamin B6 supplementation can significantly reduce the odds of discontinuing LEV due to its behavioral side effects.

Pediatric stiff limb syndrome with polyautoimmunity of anti-GAD-65, anti-islet cell, and thyroid peroxidase antibodies: A case report and review of literature.

We report an early childhood onset Stiff Limb Syndrome (SLS) in association with unusual polyautoimmunity of GAD-65, anti-islet cell, and Thyroid Peroxidase (TPO) autoantibodies, who has achieved a nearly complete neurological recovery following combined immunotherapy, symptomatic and physical therapy. The patient had normal MRIs of the brain and spinal cord and a negative paraneoplastic work-up. Subsequently, she developed hypothyroidism requiring levothyroxine supplementation. We then conducted an extensive review of literature and identified 52 previously reported pediatric Stiff Man Syndrome (SMS)/Stiff Person Syndrome (SPS) or SLS cases, which has demonstrated a common association with other systemic autoimmune conditions. In the available literature, screening for concurrent autoimmunity has only been reported infrequently. We found that a paraneoplastic process is extremely rare in pediatric cases. Timely diagnosis and initiation of immunotherapy are critical to a favorable outcome. Therefore, we recommend to include SMS/SPS or SLS as an important differential diagnosis for MRI-negative myelopathy. Further clinical and research efforts should be focused on understanding the role of both genetic predisposition and environmental insults in the autoimmunity of pediatric SMS/SPS or SLS.

Occipital intermittent rhythmic delta activity (OIRDA) in pediatric focal epilepsies: A case series.

In this case series, we have identified an atypical pattern of OIRDA (Occipital intermittent rhythmic delta activity) on the electroencephalograms (EEGs) of three pediatric patients with self-limited focal epilepsies, including Childhood Epilepsy with Centrotemporal Spikes (CECTS), and Panayiotopoulos syndrome (PS). Previously, OIRDA was described as a symmetric sinusoidal occipital-maximal activity, often associated with childhood idiopathic generalized epilepsies, although it was also reported among other physiologic or pathological entities including focal epilepsy. We have observed in our case series that OIRDA, without prominent field effect, is lateralized or maximal on the hemispheric side ipsilateral to the more defining epileptiform discharges in these focal epilepsies. They also exhibit a notched morphology due to the intermixed sharp wave activities, although the sharp waves are not occurring repetitively. This report provides additional evidence that OIRDA can be associated with a spectrum of idiopathic focal epilepsies and may suggest a cortical origin of OIRDA in these patients as opposed to a hypothesized subcortical generator in patients with primary generalized absence epilepsy, even though further investigation is warranted for either hypothesis.

The Stress-Induced Atf3-Gelsolin Cascade Underlies Dendritic Spine Deficits in Neuronal Models of Tuberous Sclerosis Complex.

Hyperactivation of the mechanistic target of rapamycin (mTOR) kinase, as a result of loss-of-function mutations in tuberous sclerosis complex 1 (TSC1) or TSC2 genes, causes protein synthesis dysregulation, increased cell size, and aberrant neuronal connectivity. Dysregulated synthesis of synaptic proteins has been implicated in the pathophysiology of autism spectrum disorder (ASD) associated with TSC and fragile X syndrome. However, cell type-specific translational profiles in these disease models remain to be investigated. Here, we used high-fidelity and unbiased Translating Ribosome Affinity Purification (TRAP) methodology to purify ribosome-associated mRNAs and identified translational alterations in a rat neuronal culture model of TSC. We find that expression of many stress and/or activity-dependent proteins is highly induced while some synaptic proteins are repressed. Importantly, transcripts for the activating transcription factor-3 (Atf3) and mitochondrial uncoupling protein-2 (Ucp2) are highly induced in Tsc2-deficient neurons, as well as in a neuron-specific Tsc1 conditional knock-out mouse model, and show differential responses to the mTOR inhibitor rapamycin. Gelsolin, a known target of Atf3 transcriptional activity, is also upregulated. shRNA-mediated block of Atf3 induction suppresses expression of gelsolin, an actin-severing protein, and rescues spine deficits found in Tsc2-deficient neurons. Together, our data demonstrate that a cell-autonomous program consisting of a stress-induced Atf3-gelsolin cascade affects the change in dendritic spine morphology following mTOR hyperactivation. This previously unidentified molecular cascade could be a therapeutic target for treating mTORopathies. SIGNIFICANCE STATEMENT: Tuberous sclerosis complex (TSC) is a genetic disease associated with epilepsy and autism. Dysregulated protein synthesis has been implicated as a cause of this disease. However, cell type-specific translational profiles that are aberrant in this disease are unknown. Here we show that expression of many stress and/or activity-dependent proteins is highly induced while some synaptic proteins are repressed in neurons missing the Tsc2 gene expression. Identification of genes whose translation is abnormal in TSC may provide insights to previously unidentified therapeutic targets.

A genetic model to dissect the role of Tsc-mTORC1 in neuronal cultures.

Tuberous sclerosis complex (TSC) is an autosomal dominant disease caused by mutations in either of two genes, TSC1 or TSC2, whose protein products form a complex that is essential in the regulation of mammalian target of rapamycin (mTOR) activity. TSC is characterized by the presence of benign tumors called hamartomas, which within the brain are known as cortical tubers. Neurological manifestations in TSC patients include epilepsy, mental retardation, and autistic features. In response to hormones, growth factors, or nutrients, the phosphatidylinositol 3-kinase or extracellular signal-regulated kinase-Tsc-mTOR pathways activate the translation machinery and regulate cell growth and/or size. Loss of TSC1 or TSC2 function results in constitutive activation of mTOR leading to tumor formation. Nevertheless, regulation of mTOR activity in nondividing neuronal cells and roles of mTOR hyperactivation in the neurological aspects of TSC remain elusive. Here, we have established a genetic model of mTOR complex 1 (mTORC1) activation in culture by using lentiviral vector-mediated TSC2 knockdown, which offers a reliable tool for analyzing the TSC-mTORC1 signaling in neurons.

Interaction of survival of motor neuron (SMN) and HuD proteins with mRNA cpg15 rescues motor neuron axonal deficits.

Spinal muscular atrophy (SMA), caused by the deletion of the SMN1 gene, is the leading genetic cause of infant mortality. SMN protein is present at high levels in both axons and growth cones, and loss of its function disrupts axonal extension and pathfinding. SMN is known to associate with the RNA-binding protein hnRNP-R, and together they are responsible for the transport and/or local translation of ß-actin mRNA in the growth cones of motor neurons. However, the full complement of SMN-interacting proteins in neurons remains unknown. Here we used mass spectrometry to identify HuD as a novel neuronal SMN-interacting partner. HuD is a neuron-specific RNA-binding protein that interacts with mRNAs, including candidate plasticity-related gene 15 (cpg15). We show that SMN and HuD form a complex in spinal motor axons, and that both interact with cpg15 mRNA in neurons. CPG15 is highly expressed in the developing ventral spinal cord and can promote motor axon branching and neuromuscular synapse formation, suggesting a crucial role in the development of motor axons and neuromuscular junctions. Cpg15 mRNA previously has been shown to localize into axonal processes. Here we show that SMN deficiency reduces cpg15 mRNA levels in neurons, and, more importantly, cpg15 overexpression partially rescues the SMN-deficiency phenotype in zebrafish. Our results provide insight into the function of SMN protein in axons and also identify potential targets for the study of mechanisms that lead to the SMA pathology and related neuromuscular diseases.

Tsc2-Rheb signaling regulates EphA-mediated axon guidance.

Tuberous sclerosis complex is a disease caused by mutations in the TSC1 or TSC2 genes, which encode a protein complex that inhibits mTOR kinase signaling by inactivating the Rheb GTPase. Activation of mTOR promotes the formation of benign tumors in various organs and the mechanisms underlying the neurological symptoms of the disease remain largely unknown. We found that Tsc2 haploinsufficiency in mice caused aberrant retinogeniculate projections that suggest defects in EphA receptor-dependent axon guidance. We also found that EphA receptor activation by ephrin-A ligands in neurons led to inhibition of extracellular signal-regulated kinase 1/2 (ERK1/2) activity and decreased inhibition of Tsc2 by ERK1/2. Thus, ephrin stimulation inactivates the mTOR pathway by enhancing Tsc2 activity. Furthermore, Tsc2 deficiency and hyperactive Rheb constitutively activated mTOR and inhibited ephrin-induced growth cone collapse. Our results indicate that TSC2-Rheb-mTOR signaling cooperates with the ephrin-Eph receptor system to control axon guidance in the visual system.

Endoplasmic reticulum stress plays a central role in development of leptin resistance.

Leptin has not evolved as a therapeutic modality for the treatment of obesity due to the prevalence of leptin resistance in a majority of the obese population. Nevertheless, the molecular mechanisms of leptin resistance remain poorly understood. Here, we show that increased endoplasmic reticulum (ER) stress and activation of the unfolded protein response (UPR) in the hypothalamus of obese mice inhibits leptin receptor signaling. The genetic imposition of reduced ER capacity in mice results in severe leptin resistance and leads to a significant augmentation of obesity on a high-fat diet. Moreover, we show that chemical chaperones, 4-phenyl butyric acid (PBA), and tauroursodeoxycholic acid (TUDCA), which have the ability to decrease ER stress, act as leptin-sensitizing agents. Taken together, our results may provide the basis for a novel treatment of obesity.

DNA vaccine and the CNS axonal regeneration.

Vaccines have been considered in treating many CNS degenerative disorders, including Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), epilepsy, multiple sclerosis (MS), spinal cord injury (SCI), and stroke. DNA vaccines have emerged as novel therapeutic agents because of the simplicity of their generation and application. Myelin components such as NOGO, MAG and OMGP are known to trigger demyelinating autoimmunity and to prevent axonal regeneration. For these reasons DNA vaccines encoding NOGO, MAG and OMGP, and fragments thereof, make them suitable vehicles for treatment of SCIs and MS. We need to obtain a deeper understanding of the immunologic mechanisms underlying the neuroprotective immunity to optimize the design of DNA vaccines for their use in clinical setting. In this review, we discuss recent findings suggesting that DNA vaccines hold a promising future for the treatment of axonal degeneration and demyelination.

Physiological roles of neurite outgrowth inhibitors in myelinated axons of the central nervous system--implications for the therapeutic neutralization of neurite outgrowth inhibitors.

It has long been recognized that the central nervous system (CNS) exhibits only limited capacity for axonal regeneration following injury. It has been proposed that myelin-associated inhibitory molecules are responsible for the nonpermissive nature of the CNS environment to axonal regeneration. Experimental strategies to enhance regeneration by neutralizing these inhibitory molecules are rapidly advancing toward clinical application. It is therefore important that the physiological distribution and functions of these supposed inhibitory molecules should be understood. In this review, we examine the distribution of these inhibitors of neurite outgrowth in relation to the longitudinal polarization of the myelinated axon into the node of Ranvier and associated domains and explore their potential domain specific physiological functions. Potential implications for the therapeutic strategy of neutralizing these inhibitory molecules to promote neural repair are discussed.

Oligodendrocytes regulate formation of nodes of Ranvier via the recognition molecule OMgp.

The molecular mechanisms underlying the involvement of oligodendrocytes in formation of the nodes of Ranvier (NORs) remain poorly understood. Here we show that oligodendrocyte-myelin glycoprotein (OMgp) aggregates specifically at NORs. Nodal location of OMgp does not occur along demyelinated axons of either Shiverer or proteolipid protein (PLP) transgenic mice. Over-expression of OMgp in OLN-93 cells facilitates process outgrowth. In transgenic mice in which expression of OMgp is down-regulated, myelin thickness declines, and lateral oligodendrocyte loops at the node-paranode junction are less compacted and even join together with the opposite loops, which leads to shortened nodal gaps. Notably, each of these structural abnormalities plus modest down-regulation of expression of Na(+) channel alpha subunit result in reduced conduction velocity in the spinal cords of the mutant mice. Thus, OMgp that is derived from glia has distinct roles in regulating nodal formation and function during CNS myelination.

Recombinant DNA vaccine encoding multiple domains related to inhibition of neurite outgrowth: a potential strategy for axonal regeneration.

Myelin-derived proteins, such as tenascin-R (TN-R), myelin associate glycoprotein (MAG), and Nogo-A, inhibit the CNS regeneration. By targeting specifically the inhibitory epitopes, we have investigated whether vaccination with a recombinant DNA molecule encoding multiple domains of myelin inhibitors may be useful in CNS repair. We show here that the recombinant DNA vaccine is able to activate the immune system but does not induce experimental autoimmune encephalomyelitis (EAE) in Lewis rats. Importantly, it promotes axonal regeneration in a spinal cord injury model. Thus, the application of DNA vaccine, encoding multiple specific domains of major inhibitory proteins and/or their receptors, provides another promising approach to overcome the inhibitory barriers during CNS regeneration.

Optic nerve regeneration in polyglycolic acid-chitosan conduits coated with recombinant L1-Fc.

Autografts have been extensively studied to facilitate optic nerve (ON) regeneration in animal experiments, but the clinical application of this approach to aid autoregeneration has not yet been attempted. This study aims to explore the guided regeneration by an artificial polyglycolic acid-chitosan conduit coated with recombinant L1-Fc. Consistent with previous studies; in vitro assay showed that both chitosan, a natural biomaterial, and the neural cell adhesion molecule L1-Fc enhanced neurite outgrowth. Rat optic nerve transection was used as an in vivo model. The implanted PGA-chitosan conduit was progressively degraded and absorbed, accompanied by significant axonal regeneration as revealed by immunohistochemistry, anterograde and retrograde tracing. The polyglycolic acid-chitosan conduit coated with L1-Fc showed more effective to promote axonal regeneration and remyelination. Taken together, our observations demonstrated that the L1-Fc coated PGA-chitosan conduits provided a compatible and supportive canal to guild the injured nerve regeneration and remyelination.

NB-3/Notch1 pathway via Deltex1 promotes neural progenitor cell differentiation into oligodendrocytes.

Neurons and glia in the vertebrate central nervous system arise in temporally distinct, albeit overlapping, phases. Neurons are generated first followed by astrocytes and oligodendrocytes from common progenitor cells. Increasing evidence indicates that axon-derived signals spatiotemporally modulate oligodendrocyte maturation and myelin formation. Our previous observations demonstrate that F3/contactin is a functional ligand of Notch during oligodendrocyte maturation, revealing the existence of another group of Notch ligands. Here, we establish that NB-3, a member of the F3/contactin family, acts as a novel Notch ligand to participate in oligodendrocyte generation. NB-3 triggers nuclear translocation of the Notch intracellular domain and promotes oligodendrogliogenesis from progenitor cells and differentiation of oligodendrocyte precursor cells via Deltex1. In primary oligodendrocytes, NB-3 increases myelin-associated glycoprotein transcripts. Thus, the NB-3/Notch signaling pathway may prove to be a molecular handle to treat demyelinating diseases.

Nogo-A at CNS paranodes is a ligand of Caspr: possible regulation of K(+) channel localization.

We report Nogo-A as an oligodendroglial component congregating and interacting with the Caspr-F3 complex at paranodes. However, its receptor Nogo-66 receptor (NgR) does not segregate to specific axonal domains. CHO cells cotransfected with Caspr and F3, but not with F3 alone, bound specifically to substrates coated with Nogo-66 peptide and GST-Nogo-66. Binding persisted even after phosphatidylinositol- specific phospholipase C (PI-PLC) removal of GPI-linked F3 from the cell surface, suggesting a direct interaction between Nogo-66 and Caspr. Both Nogo-A and Caspr co-immunoprecipitated with Kv1.1 and Kv1.2, and the developmental expression pattern of both paralleled compared with Kv1.1, implicating a transient interaction between Nogo-A-Caspr and K(+) channels at early stages of myelination. In pathological models that display paranodal junctional defects (EAE rats, and Shiverer and CGT(-/-) mice), distances between the paired labeling of K(+) channels were shortened significantly and their localization shifted toward paranodes, while paranodal Nogo-A congregation was markedly reduced. Our results demonstrate that Nogo-A interacts in trans with axonal Caspr at CNS paranodes, an interaction that may have a role in modulating axon-glial junction architecture and possibly K(+)-channel localization during development.