L-serine treatment in patients with GRIN-related encephalopathy: a phase 2A, non-randomized study

GRIN-related disorders are rare developmental encephalopathies with variable manifestations and limited therapeutic options. Here, we present the first non-randomized, open-label, single-arm trial (NCT04646447) designed to evaluate the tolerability and efficacy of L-serine in children with GRIN genetic variants leading to loss-of-function. In this phase 2A trial, patients aged 2-18 years with GRIN loss-of-function pathogenic variants received L-serine for 52 weeks. Primary end points included safety and efficacy by measuring changes in the Vineland Adaptive Behavior Scales, Bayley Scales, age-appropriate Wechsler Scales, Gross Motor Function-88, Sleep Disturbance Scale for Children, Pediatric Quality of Life Inventory, Child Behavior Checklist and the Caregiver-Teacher Report Form following 12 months of treatment. Secondary outcomes included seizure frequency and intensity reduction and EEG improvement. Assessments were performed 3 months and 1 day before starting treatment and 1, 3, 6 and 12 months after beginning the supplement. Twenty-four participants were enrolled (13 males/11 females, mean age 9.8 years, SD 4.8), 23 of whom completed the study. Patients had GRIN2B, GRIN1 and GRIN2A variants (12, 6 and 5 cases, respectively). Their clinical phenotypes showed 91% had intellectual disability (61% severe), 83% had behavioural problems, 78% had movement disorders and 58% had epilepsy. Based on the Vineland Adaptive Behavior Composite standard scores, nine children were classified as mildly impaired (cut-off score > 55), whereas 14 were assigned to the clinically severe group. An improvement was detected in the Daily Living Skills domain (P = 0035) from the Vineland Scales within the mild group. Expressive (P = 0.005), Personal (P = 0.003), Community (P = 0.009), Interpersonal (P = 0.005) and Fine Motor (P = 0.031) subdomains improved for the whole cohort, although improvement was mostly found in the mild group. The Growth Scale Values in the Cognitive subdomain of the Bayley-III Scale showed a significant improvement in the severe group (P = 0.016), with a mean increase of 21.6 points. L-serine treatment was associated with significant improvement in the median Gross Motor Function-88 total score (P = 0.002) and the mean Pediatric Quality of Life total score (P = 0.00068), regardless of severity. L-serine normalized the EEG pattern in five children and the frequency of seizures in one clinically affected child. One patient discontinued treatment due to irritability and insomnia. The trial provides evidence that L-serine is a safe treatment for children with GRIN loss-of-function variants, having the potential to improve adaptive behaviour, motor function and quality of life, with a better response to the treatment in mild phenotypes.

X-Linked Epilepsies: A Narrative Review

X-linked epilepsies are a heterogeneous group of epileptic conditions, which often overlap with X-linked intellectual disability. To date, various X-linked genes responsible for epilepsy syndromes and/or developmental and epileptic encephalopathies have been recognized. The electro-clinical phenotype is well described for some genes in which epilepsy represents the core symptom, while less phenotypic details have been reported for other recently identified genes. In this review, we comprehensively describe the main features of both X-linked epileptic syndromes thoroughly characterized to date (PCDH19-related DEE, CDKL5-related DEE, MECP2-related disorders), forms of epilepsy related to X-linked neuronal migration disorders (e.g., ARX, DCX, FLNA) and DEEs associated with recently recognized genes (e.g., SLC9A6, SLC35A2, SYN1, ARHGEF9, ATP6AP2, IQSEC2, NEXMIF, PIGA, ALG13, FGF13, GRIA3, SMC1A). It is often difficult to suspect an X-linked mode of transmission in an epilepsy syndrome. Indeed, different models of X-linked inheritance and modifying factors, including epigenetic regulation and X-chromosome inactivation in females, may further complicate genotype-phenotype correlations. The purpose of this work is to provide an extensive and updated narrative review of X-linked epilepsies. This review could support clinicians in the genetic diagnosis and treatment of patients with epilepsy featuring X-linked inheritance.

The Evolving Landscape of Therapeutics for Epilepsy in Tuberous Sclerosis Complex

Tuberous sclerosis complex (TSC) is a rare multisystem genetic disorder characterized by benign tumor growth in multiple organs, including the brain, kidneys, heart, eyes, lungs, and skin. Pathogenesis stems from mutations in either the TSC1 or TSC2 gene, which encode the proteins hamartin and tuberin, respectively. These proteins form a complex that inhibits the mTOR pathway, a critical regulator of cell growth and proliferation. Disruption of the tuberin-hamartin complex leads to overactivation of mTOR signaling and uncontrolled cell growth, resulting in hamartoma formation. Neurological manifestations are common in TSC, with epilepsy developing in up to 90% of patients. Seizures tend to be refractory to medical treatment with anti-seizure medications. Infantile spasms and focal seizures are the predominant seizure types, often arising in early childhood. Drug-resistant epilepsy contributes significantly to morbidity and mortality. This review provides a comprehensive overview of the current state of knowledge regarding the pathogenesis, clinical manifestations, and treatment approaches for epilepsy and other neurological features of TSC. While narrative reviews on TSC exist, this review uniquely synthesizes key advancements across the areas of TSC neuropathology, conventional and emerging pharmacological therapies, and targeted treatments. The review is narrative in nature, without any date restrictions, and summarizes the most relevant literature on the neurological aspects and management of TSC. By consolidating the current understanding of TSC neurobiology and evidence-based treatment strategies, this review provides an invaluable reference that highlights progress made while also emphasizing areas requiring further research to optimize care and outcomes for TSC patients.

Effects of antiepileptic therapy on bone mineral status evaluated by phalangeal quantitative ultrasound in pediatric patients with epilepsy and motor impairment

BACKGROUND

In epileptic patients with motor disability, it's difficult to disentangle the effects of antiepileptic drugs (AEDs) on bone health from those provoked by impaired mobility. The aim of this study was to evaluate the effects of AEDs on bone mineral status by phalangeal quantitative ultrasound (QUS), a no-radiation and non-invasive method, in pediatric patients with motor impairment and epilepsy.

METHODS

We enrolled 56 patients (31 females, 25 males) with epilepsy and motor impairment and 24 children with only motor disability (13 females, 11 males). Patients were stratified by Gross Motor Function Classification System Scale (GMFCS) in 4 groups: group A1 with epilepsy and mild motor impairment (GMFCS levels I-II), group A2 with only mild motor impairment, group B1 with epilepsy and severe motor impairment (GMFCS levels III-V), group B2 with only severe motor impairment. The bone mineral status was evaluated by phalangeal QUS and amplitude-dependent speed of sound (AD-SoS) Z-score was calculated for each patient.

RESULTS

The four groups showed no significant differences in age, gender and 25-hydroxyvitamin D levels. The group B1 had a statistically lower amplitude-dependent speed of sound Z-score as compared to group A2 (P<0.05). The multivariate analysis of independent factors revealed a significant correlation between amplitude-dependent speed of sound Z-score and Gross Motor Function Classification System levels (P=0.004). The mean Z-score value decreased by 0.53, increasing the motor impairment.

CONCLUSIONS

The bone mineral status measured as AD-SoS strongly correlates with severity of motor disability evaluated by GMFCS as compared to antiepileptic therapy and 25-hydroxyvitamin D levels.

DNA methylation episignature and comparative epigenomic profiling of HNRNPU-related neurodevelopmental disorder

PURPOSE

HNRNPU haploinsufficiency is associated with Developmental and Epileptic Encephalopathy 54. This neurodevelopmental disorder is characterized by developmental delay, intellectual disability, speech impairment, and early onset epilepsy. We performed genome-wide DNA methylation (DNAm) analysis in a cohort of individuals to develop a diagnostic biomarker and gain functional insights into the molecular pathophysiology of HNRNPU-related disorder.

METHODS

DNAm profiles of individuals carrying pathogenic HNRNPU variants, identified through an international multi-center collaboration, were assessed using Infinium Methylation EPIC arrays. Statistical and functional correlation analyses were performed comparing the HNRNPU cohort to 56 previously reported DNAm episignatures.

RESULTS

A robust and reproducible DNAm episignature and global DNAm profile were identified. Correlation analysis identified partial overlap and similarity of the global HNRNPU DNAm profile to several other rare disorders.

CONCLUSION

This study demonstrates new evidence of a specific and sensitive DNAm episignature associated with pathogenic heterozygous HNRNPU-variants, establishing its utility as a clinical biomarker for the expansion of the EpiSign^TM diagnostic test.

Contribution of Genetic Test to Early Diagnosis of Methylenetetrahydrofolate Reductase (MTHFR) Deficiency: The Experience of a Reference Center in Southern Italy

BACKGROUND

the deficiency of 5,10-Methylenetetrahydrofolate reductase (MTHFR) constitutes a rare and severe metabolic disease and is included in most expanded newborn screening (NBS) programs worldwide. Patients with severe MTHFR deficiency develop neurological disorders and premature vascular disease. Timely diagnosis through NBS allows early treatment, resulting in improved outcomes.

METHODS

we report the diagnostic yield of genetic testing for MTHFR deficiency diagnosis, in a reference Centre of Southern Italy between 2017 and 2022. MTHFR deficiency was suspected in four newborns showing hypomethioninemia and hyperhomocysteinemia; otherwise, one patient born in pre-screening era showed clinical symptoms and laboratory signs that prompted to perform genetic testing for MTHFR deficiency.

RESULTS

molecular analysis of the MTHFR gene revealed a genotype compatible with MTHFR deficiency in two NBS-positive newborns and in the symptomatic patient. This allowed for promptly beginning the adequate metabolic therapy.

CONCLUSIONS

our results strongly support the need for genetic testing to quickly support the definitive diagnosis of MTHFR deficiency and start therapy. Furthermore, our study extends knowledge of the molecular epidemiology of MTHFR deficiency by identifying a novel mutation in the MTHFR gene.

The Perinatal Assessment of Paternal Affectivity (PAPA): Italian validation of a new tool for the screening of perinatal depression and affective disorders in fathers

BACKGROUND

Questionnaires for the screening of paternal perinatal psychological distress are based on clinical manifestations expressed by women, showing limitations in capturing the wide array of signs and symptoms exhibited by men. The current study aimed to validate the Perinatal Assessment of Paternal Affectivity, a new self-report tool for the screening of paternal depressive and affective disorder.

METHOD

This study used a cross-sectional design with a 3-month test-retest, involving respectively 385 (T1) and a sub-sample of 111(T2) fathers. Confirmatory factor analysis (CFA) was performed to test structural validity and concurrent validity was assessed by Spearman correlations. We assessed reliability using McDonald's ω and ordinal alpha. Group differences in PAPA scores based on sociodemographic were also tested.

RESULTS

The CFA reported a one factor structure as the optimal solution. The PAPA also showed adequate reliability and internal consistency as well as acceptable test-retest indices. Concurrent validity was confirmed by significant correlations between PAPA total score and standardized test scores. Non-Italian fathers and fathers who experienced recent stressful life events reported higher PAPA scores.

LIMITATIONS

Our sample was not homogeneous in terms of nationality and most of the participants, were from Northern Italy. Some risk factors associated with paternal parental psychological distress (e.g., unplanned pregnancy) have not been considered.

CONCLUSION

This study provides initial evidence of validity and reliability of the PAPA as a brief and sensitive screening tool to detect signs and symptoms of paternal affective disorder during both prenatal and postnatal period.

Cholesterol 24-hydroxylase is a novel pharmacological target for anti-ictogenic and disease modification effects in epilepsy

Therapies for epilepsy mainly provide symptomatic control of seizures since most of the available drugs do not target disease mechanisms. Moreover, about one-third of patients fail to achieve seizure control. To address the clinical need for disease-modifying therapies, research should focus on targets which permit interventions finely balanced between optimal efficacy and safety. One potential candidate is the brain-specific enzyme cholesterol 24-hydroxylase. This enzyme converts cholesterol to 24S-hydroxycholesterol, a metabolite which among its biological roles modulates neuronal functions relevant for hyperexcitability underlying seizures. To study the role of cholesterol 24-hydroxylase in epileptogenesis, we administered soticlestat (TAK-935/OV935), a potent and selective brain-penetrant inhibitor of the enzyme, during the early disease phase in a mouse model of acquired epilepsy using a clinically relevant dose. During soticlestat treatment, the onset of epilepsy was delayed and the number of ensuing seizures was decreased by about 3-fold compared to vehicle-treated mice, as assessed by EEG monitoring. Notably, the therapeutic effect was maintained 6.5 weeks after drug wash-out when seizure number was reduced by about 4-fold and their duration by 2-fold. Soticlestat-treated mice showed neuroprotection of hippocampal CA1 neurons and hilar mossy cells as assessed by post-mortem brain histology. High throughput RNA-sequencing of hippocampal neurons and glia in mice treated with soticlestat during epileptogenesis showed that inhibition of cholesterol 24-hydroxylase did not directly affect the epileptogenic transcriptional network, but rather modulated a non-overlapping set of genes that might oppose the pathogenic mechanisms of the disease. In human temporal lobe epileptic foci, we determined that cholesterol 24-hydroxylase expression trends higher in neurons, similarly to epileptic mice, while the enzyme is ectopically induced in astrocytes compared to control specimens. Soticlestat reduced significantly the number of spontaneous seizures in chronic epileptic mice when was administered during established epilepsy. Data show that cholesterol 24-hydroxylase contributes to spontaneous seizures and is involved in disease progression, thus it represents a novel target for chronic seizures inhibition and disease-modification therapy in epilepsy.

Deregulation of microtubule organization and RNA metabolism in Arx models for lissencephaly and developmental epileptic encephalopathy

X-linked lissencephaly with abnormal genitalia (XLAG) and developmental epileptic encephalopathy-1 (DEE1) are caused by mutations in the Aristaless-related homeobox (ARX) gene, which encodes a transcription factor responsible for brain development. It has been unknown whether the phenotypically diverse XLAG and DEE1 phenotypes may converge on shared pathways. To address this question, a label-free quantitative proteomic approach was applied to the neonatal brain of Arx knockout (ArxKO/Y) and knock-in polyalanine (Arx(GCG)7/Y) mice that are respectively models for XLAG and DEE1. Gene ontology and protein-protein interaction analysis revealed that cytoskeleton, protein synthesis and splicing control are deregulated in an allelic-dependent manner. Decreased α-tubulin content was observed both in Arx mice and Arx/alr-1(KO) Caenorhabditis elegans ,and a disorganized neurite network in murine primary neurons was consistent with an allelic-dependent secondary tubulinopathy. As distinct features of Arx(GCG)7/Y mice, we detected eIF4A2 overexpression and translational suppression in cortex and primary neurons. Allelic-dependent differences were also established in alternative splicing (AS) regulated by PUF60 and SAM68. Abnormal AS repertoires in Neurexin-1, a gene encoding multiple pre-synaptic organizers implicated in synaptic remodelling, were detected in Arx/alr-1(KO) animals and in Arx(GCG)7/Y epileptogenic brain areas and depolarized cortical neurons. Consistent with a conserved role of ARX in modulating AS, we propose that the allelic-dependent secondary synaptopathy results from an aberrant Neurexin-1 repertoire. Overall, our data reveal alterations mirroring the overlapping and variant effects caused by null and polyalanine expanded mutations in ARX. The identification of these effects can aid in the design of pathway-guided therapy for ARX endophenotypes and NDDs with overlapping comorbidities.

Expanding the neurological and behavioral phenotype of White-Sutton syndrome: a case report

Background

White-Sutton (WHSUS) is a recently recognized syndrome caused by mutations of the POGZ gene. Approximately 70 patients have been reported to date. Intellectual disability, hypotonia, behavioral abnormalities, autism, and typical facial dysmorphisms are recognized as WHSUS features; however, still few patients receive a comprehensive psychometric, behavioral and neurological examination. In this report, we describe the pediatric, dysmorphological, neurological, psychometric and behavioral phenotype in a new WHSUS patient due to a novel heterozygous POGZ mutation, highlighting the distinctive epileptic phenotype and the cognitive pattern.

Case presentation

The patient, an 8 years-old girl, presented history of hypotonia, motor and speech delay, and distinctive facial features. The diagnosis of WHSUS followed the identification of the de novo variant p.Asp828GlyfsTer36 (c.2482dupG) in the POGZ gene. The patient showed a distinctive neurological phenotype with the occurrence of both paroxysmal not-epileptic events in the first 6 months of age and EEG abnormalities without evidence of clinical seizures after the first year of age. Psychological and behavioral testing highlighted moderate intellectual and communication deficit, mild autism spectrum and visual-motor integration deficit.

Conclusions

This is the first described case of WHSUS with a co-existence of paroxysmal not-epileptic events and abnormal EEG without seizures in the same patient. Together with the available literature data, this observation suggests that paroxysmal not-epileptic events could be more frequent than expected and that this feature belongs to the WHSUS phenotypic spectrum. Autism is a known comorbidity of WHSUS but is still poorly investigated. Specific clinical testing could help detect also mild autistic phenotypes and better define autism prevalence in POGZ-related syndrome. Special attention should be given to symptoms such as stereotypies, social withdrawal, and hyperactivity that, when present, should be considered as possible signs of autism symptoms. The dissection of the neurological and behavioral phenotype is crucial for individualized therapies tailored to patient’s needs.

Intrafamilial variability in SPTAN1-related disorder: From benign convulsions with mild gastroenteritis to developmental encephalopathy

Mutations in SPTAN1 gene are responsible for a wide spectrum of neurodevelopmental disorders including early-onset epileptic encephalopathy with progressive brain atrophy, severe intellectual disability with cerebellar malformations, and relatively milder phenotypes with or without epilepsy. Herein, we report three affected individuals including two siblings of 13 and 8 years and their 39-year-old mother, carrying a novel pathogenic variant in SPTAN1 gene. The phenotype of the index cases and their mother was remarkable for the variable expressivity, including benign convulsions with mild gastroenteritis, intellectual disability and developmental encephalopathy with epilepsy. Our clinical observation suggests for the first time that variants in SPTAN1 gene might be involved in the aetiology of benign convulsions correlated with mild gastroenteritis.

Heterozygous KIF1A variants underlie a wide spectrum of neurodevelopmental and neurodegenerative disorders

BACKGROUND

Dominant and recessive variants in the KIF1A gene on chromosome 2q37.3 are associated with several phenotypes, although only three syndromes are currently listed in the OMIM classification: hereditary sensory and autonomic neuropathy type 2 and spastic paraplegia type 30, both recessively inherited, and mental retardation type 9 with dominant inheritance.

METHODS

In this retrospective multicentre study, we describe the clinical, neuroradiological and genetic features of 19 Caucasian patients (aged 3-65 years) harbouring heterozygous KIF1A variants, and extensively review the available literature to improve current classification of KIF1A-related disorders.

RESULTS

Patients were divided into two groups. Group 1 comprised patients with a complex phenotype with prominent pyramidal signs, variably associated in all but one case with additional features (ie, epilepsy, ataxia, peripheral neuropathy, optic nerve atrophy); conversely, patients in group 2 presented an early onset or congenital ataxic phenotype. Fourteen different heterozygous missense variants were detected by next-generation sequencing screening, including three novel variants, most falling within the kinesin motor domain.

CONCLUSION

The present study further enlarges the clinical and mutational spectrum of KIF1A-related disorders by describing a large series of patients with dominantly inherited KIF1A pathogenic variants ranging from pure to complex forms of hereditary spastic paraparesis/paraplegias (HSP) and ataxic phenotypes in a lower proportion of cases. A comprehensive review of the literature indicates that KIF1A screening should be implemented in HSP regardless of its mode of inheritance or presentations as well as in other complex neurodegenerative or neurodevelopmental disorders showing congenital or early onset ataxia.

Inflammation and reactive oxygen species in status epilepticus: Biomarkers and implications for therapy

Preclinical studies in immature and adult rodents and clinical observations show that neuroinflammation and oxidative stress are rapid onset phenomena occurring in the brain during status epilepticus and persisting thereafter. Notably, both neuroinflammation and oxidative stress contribute to the acute and long-term sequelae of status epilepticus thus representing potential druggable targets. Antiinflammatory drugs that interfere with the IL-1β pathway, such as anakinra, can control benzodiazepine-refractory status epilepticus in animals, and there is recent proof-of-concept evidence for therapeutic effects in children with Febrile infection related epilepsy syndrome (FIRES). Inhibitors of monoacylglycerol lipase and P2X7 receptor antagonists are also promising antiinflammatory drug candidates for rapidly aborting de novo status epilepticus and provide neuroprotection. Antiinflammatory and antioxidant drugs administered to rodents during status epilepticus and transiently thereafter, prevent long-term sequelae such as cognitive deficits and seizure progression in animals developing epilepsy. Some drugs are already in medical use and are well-tolerated, therefore, they may be considered for treating status epilepticus and its neurological consequences. Finally, markers of neuroinflammation and oxidative stress are measureable in peripheral blood and by neuroimaging, which offers an opportunity for developing prognostic and predictive mechanistic biomarkers in people exposed to status epilepticus. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

Use of nutritional supplements based on melatonin, tryptophan and vitamin B6 (Melamil Tripto®) in children with primary chronic headache, with or without sleep disorders: a pilot study

BACKGROUND

Headache is one of the main complaints in pediatric neurology. Exogenous melatonin has been shown to be useful and safe in improving sleep-wake cycles and sleep quality in children. Tryptophan as well plays a key role in sleep regulation. So far, no studies tried to analyze the effects of a combination of both melatonin and tryptophan in treating chronic headache in children affected also by night-time awakenings.

METHODS

Thirty-four children with a diagnosis of chronic headache (with or without sleep disorders) have been enrolled. The study was articulated in two steps: 1) each child was observed for one month without any intervention; 2) children have been then randomized into two groups: the "ME-group", which received the nutritional supplement melatonin for two months and the "MET-group", which received the nutritional supplements melatonin, tryptophan, and vitamin B6 for two months.

RESULTS

In terms of changes in number of headache events, responders in the ME-group were 91.7% and those in the MET-group were 66.7% (P=0.113). In terms of changes in number of night awakenings, in the ME group, mean number at baseline, after 30 days, and after 60 days were 3.6±3.2, 3.2±3.5, and 2.7±3.4 (P=0.495). In the MET group, mean number of night awakenings was 7.4±8.1, 4.0±4.4, and 3.3±2.9 (P=0.041).

CONCLUSIONS

Using either nutritional supplement for two months can help in decreasing the monthly number of headache episodes and night awakenings. The addition of tryptophan and vitamin B6 appears to have stronger influence on night awakenings reduction than melatonin only.

Inflammation and reactive oxygen species as disease modifiers in epilepsy

Neuroinflammation and reactive oxygen and nitrogen species are rapidly induced in the brain after acute cerebral injuries that are associated with an enhanced risk for epilepsy in humans and related animal models. These phenomena reinforce each others and persist during epileptogenesis as well as during chronic spontaneous seizures. Anti-inflammatory and anti-oxidant drugs transiently administered either before, or shortly after the clinical onset of symptomatic epilepsy, similarly block the progression of spontaneous seizures, and may delay their onset. Moreover, neuroprotection and rescue of cognitive deficits are also observed in the treated animals. Therefore, although these treatments do not prevent epilepsy development, they offer clinically relevant disease-modification effects. These therapeutic effects are mediated by targeting molecular signaling pathways such as the IL-1β-IL-1 receptor type 1 and TLR4, P2X7 receptors, the transcriptional anti-oxidant factor Nrf2, while the therapeutic impact of COX-2 inhibition for reducing spontaneous seizures remains controversial. Some anti-inflammatory and anti-oxidant drugs that are endowed of disease modification effects in preclinical models are already in medical use and have a safety profile, therefore, they provide potential re-purposed treatments for improving the disease course and for reducing seizure burden. Markers of neuroinflammation and oxidative stress can be measured in blood or by neuroimaging, therefore they represent testable prognostic and predictive biomarkers for selecting the patient's population at high risk for developing epilepsy therefore eligible for novel treatments. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.

Inflammation and Epilepsy: Preclinical Findings and Potential Clinical Translation

BACKGROUND

The lack of treatments which can prevent epilepsy development or improve disease prognosis represents an unmet and urgent clinical need. The development of such drugs requires a deep understanding of the mechanisms underlying disease pathogenesis. In the last decade, preclinical studies in models of acute seizures and of chronic epilepsy highlighted that neuroinflammation arising in brain areas of seizure onset and generalization is a key contributor to neuronal hyper-excitability underlying seizure generation. Microglia and astrocytes are pivotal cells involved in both the induction and perpetuation of the inflammatory response to epileptogenic injuries or seizures; other cell contributors are neurons, cell components of the blood brain barrier and leukocytes.

METHODS

From the clinical standpoint, neuroinflammation is now considered an hallmark of epileptogenic foci in various forms of focal onset pharmacoresistant epilepsies. Moreover, pharmacological studies in animal model with drugs targeting specific inflammatory molecules, and changes in intrinsic seizure susceptibility of transgenic mice with perturbed neuroinflammatory mechanisms, have demonstrated that neuroinflammation is not a bystander phenomenon but has a pathogenic role in seizures, cell loss and neurological co-morbidities. Understanding the role of neuroinflammation in seizure pathogenesis is instrumental for a mechanism-based discovery of selective therapies targeting the epilepsy causes rather than its symptoms, thereby allowing the development of novel disease-modifying treatments. Notably, clinical translation of laboratory findings may take advantage of anti-inflammatory drugs already in medical use for peripheral autoinflammatory or autoimmune disorders.

CONCLUSION

This review reports key preclinical and clinical findings supporting a role for brain inflammation in the pathogenesis of seizures. It also highlights the emerging proof-of-concept studies showing signs of clinical efficacy of target-specific anti-inflammatory interventions in epilepsies of differing etiologies. We will discuss the need for biomarkers and novel clinical trial designs for anti-inflammatory therapies that have a mechanism of action very different than standard antiepileptic drugs.

Targeting oxidative stress improves disease outcomes in a rat model of acquired epilepsy

Epilepsy therapy is based on antiseizure drugs that treat the symptom, seizures, rather than the disease and are ineffective in up to 30% of patients. There are no treatments for modifying the disease-preventing seizure onset, reducing severity or improving prognosis. Among the potential molecular targets for attaining these unmet therapeutic needs, we focused on oxidative stress since it is a pathophysiological process commonly occurring in experimental epileptogenesis and observed in human epilepsy. Using a rat model of acquired epilepsy induced by electrical status epilepticus, we show that oxidative stress occurs in both neurons and astrocytes during epileptogenesis, as assessed by measuring biochemical and histological markers. This evidence was validated in the hippocampus of humans who died following status epilepticus. Oxidative stress was reduced in animals undergoing epileptogenesis by a transient treatment with N-acetylcysteine and sulforaphane, which act to increase glutathione levels through complementary mechanisms. These antioxidant drugs are already used in humans for other therapeutic indications. This drug combination transiently administered for 2 weeks during epileptogenesis inhibited oxidative stress more efficiently than either drug alone. The drug combination significantly delayed the onset of epilepsy, blocked disease progression between 2 and 5 months post-status epilepticus and drastically reduced the frequency of spontaneous seizures measured at 5 months without modifying the average seizure duration or the incidence of epilepsy in animals. Treatment also decreased hippocampal neuron loss and rescued cognitive deficits. Oxidative stress during epileptogenesis was associated with de novo brain and blood generation of high mobility group box 1 (HMGB1), a neuroinflammatory molecule implicated in seizure mechanisms. Drug-induced reduction of oxidative stress prevented HMGB1 generation, thus highlighting a potential novel mechanism contributing to therapeutic effects. Our data show that targeting oxidative stress with clinically used drugs for a limited time window starting early after injury significantly improves long-term disease outcomes. This intervention may be considered for patients exposed to potential epileptogenic insults.

Heterozygous missense variants of SPTBN2 are a frequent cause of congenital cerebellar ataxia

Heterozygous missense variants in the SPTBN2 gene, encoding the non-erythrocytic beta spectrin 2 subunit (beta-III spectrin), have been identified in autosomal dominant spinocerebellar ataxia type 5 (SCA5), a rare adult-onset neurodegenerative disorder characterized by progressive cerebellar ataxia, whereas homozygous loss of function variants in SPTBN2 have been associated with early onset cerebellar ataxia and global developmental delay (SCAR14). Recently, heterozygous SPTBN2 missense variants have been identified in a few patients with an early-onset ataxic phenotype. We report five patients with non-progressive congenital ataxia and psychomotor delay, 4/5 harboring novel heterozygous missense variants in SPTBN2 and one patient with compound heterozygous SPTBN2 variants. With an overall prevalence of 5% in our cohort of unrelated patients screened by targeted next-generation sequencing (NGS) for congenital or early-onset cerebellar ataxia, this study indicates that both dominant and recessive mutations of SPTBN2 together with CACNA1A and ITPR1, are a frequent cause of early-onset/congenital non-progressive ataxia and that their screening should be implemented in this subgroup of disorders.

Effects of antiepileptic therapy on bone mineral status evaluated by phalangeal quantitative ultrasound in pediatric patients with epilepsy and motor impairment

BACKGROUND

In epileptic patients with motor disability, it's difficult to disentangle the effects of antiepileptic drugs (AEDs) on bone health from those provoked by impaired mobility. The aim of this study was to evaluate the effects of AEDs on bone mineral status by phalangeal quantitative ultrasound (QUS), a no-radiation and non-invasive method, in pediatric patients with motor impairment and epilepsy.

METHODS

We enrolled 56 patients (31 females, 25 males) with epilepsy and motor impairment and 24 children with only motor disability (13 females, 11 males). Patients were stratified by Gross Motor Function Classification System Scale (GMFCS) in 4 groups: group A1 with epilepsy and mild motor impairment (GMFCS levels I-II), group A2 with only mild motor impairment, group B1 with epilepsy and severe motor impairment (GMFCS levels III-V), group B2 with only severe motor impairment. The bone mineral status was evaluated by QUS and amplitude-dependent speed of sound (AD-SoS) Z-score was calculated for each patient.

RESULTS

The four groups showed no significant differences in age, gender and 25- hydroxyvitamin D levels. The group B1 had a statistically lower amplitude-dependent speed of sound Z-score as compared to group A2 (p<0.05). The multivariate analysis of independent factors revealed a significant correlation between amplitude-dependent speed of sound Z-score and Gross Motor Function Classification System levels (p=0.004). The mean Z-score value decreased by 0.53, increasing the motor impairment.

CONCLUSIONS

The bone mineral status measured as AD-SoS strongly correlates with severity of motor disability evaluated by GMFCS as compared to antiepileptic therapy and 25-hydroxyvitamin D levels.

Three de novo DDX3X variants associated with distinctive brain developmental abnormalities and brain tumor in intellectually disabled females

De novo DDX3X variants account for 1-3% of syndromic intellectual disability (ID) in females and have been occasionally reported in males. Furthermore, somatic DDX3X variants occur in several aggressive cancers, including medulloblastoma. We report three unrelated females with severe ID, dysmorphic features, and a common brain malformative pattern characterized by malformations of cortical development, callosal dysgenesis, basal ganglia anomalies, and midbrain-hindbrain malformations. A pilocytic astrocytoma was incidentally diagnosed in Patient 1 and trigonocephaly was found in Patient 2. With the use of family based whole exome sequencing (WES), we identified three distinct de novo variants in DDX3X. These findings expand the phenotypic spectrum of DDX3X-related disorders, demonstrating unique neuroradiological features resembling those of the tubulinopathies, and support a role for DDX3X in neuronal development. Our observations further suggest a possible link between germline DDX3X variants and cancer development.

Mutations in MAST1 Cause Mega-Corpus-Callosum Syndrome with Cerebellar Hypoplasia and Cortical Malformations

Corpus callosum malformations are associated with a broad range of neurodevelopmental diseases. We report that de novo mutations in MAST1 cause mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations (MCC-CH-CM) in the absence of megalencephaly. We show that MAST1 is a microtubule-associated protein that is predominantly expressed in post-mitotic neurons and is present in both dendritic and axonal compartments. We further show that Mast1 null animals are phenotypically normal, whereas the deletion of a single amino acid (L278del) recapitulates the distinct neurological phenotype observed in patients. In animals harboring Mast1 microdeletions, we find that the PI3K/AKT3/mTOR pathway is unperturbed, whereas Mast2 and Mast3 levels are diminished, indicative of a dominant-negative mode of action. Finally, we report that de novo MAST1 substitutions are present in patients with autism and microcephaly, raising the prospect that mutations in this gene give rise to a spectrum of neurodevelopmental diseases.

High Mobility Group Box 1 is a novel pathogenic factor and a mechanistic biomarker for epilepsy

Approximately 30% of epilepsy patients experience seizures that are not controlled by the available drugs. Moreover, these drugs provide mainly a symptomatic treatment since they do not interfere with the disease's mechanisms. A mechanistic approach to the discovery of key pathogenic brain modifications causing seizure onset, recurrence and progression is instrumental for designing novel and rationale therapeutic interventions that could modify the disease course or prevent its development. In this regard, increasing evidence shows that neuroinflammation is a pathogenic factor in drug-resistant epilepsies. The High Mobility Group Box 1 (HMGB1)/Toll-like receptor 4 axis is a key initiator of neuroinflammation following brain injuries leading to epilepsy, and its activation contributes to seizure mechanisms in animal models. Recent findings have shown dynamic changes in HMGB1 and its isoforms in the brain and blood of animals exposed to acute brain injuries and undergoing epileptogenesis, and in surgically resected epileptic foci in humans. HMGB1 isoforms reflect different pathophysiological processes, and the disulfide isoform, which is generated in the brain during oxidative stress, is implicated in seizures, cell loss and cognitive dysfunctions. Interfering with disulfide HMGB1-activated cell signaling mediates significant therapeutic effects in epilepsy models. Moreover, both clinical and experimental data suggest that HMGB1 isoforms may serve as mechanistic biomarkers for epileptogenesis and drug-resistant epilepsy. These novel findings suggest that the HMGB1 system could be targeted to prevent seizure generation and may provide clinically useful prognostic biomarkers which may also predict the patient's response to therapy.

A novel SHANK3 interstitial microdeletion in a family with intellectual disability and brain MRI abnormalities resembling Unidentified Bright Objects

BACKGROUND

SHANK3 mutations are responsible for Phelan-McDermid syndrome but they are also associated with autism and/or intellectual disability.

CASE REPORT

We report a family with four affected individuals including the 37 year-old mother, her 12 year-old male monozygotic twins and 8 year-old daughter harboring a novel SHANK3 interstitial microdeletion. All four members presented with intellectual disability of variable severity. The twins showed brain abnormalities similar to Unidentified Bright Objects (UBOs), typically detected in patients with Neurofibromatosis type 1 (NF1), but they did not display causative mutations in NF1 gene.

CONCLUSION

To date, this is the first report of an affected individual with SHANK3 interstitial deletion able to reproduce. Moreover, we found a previously unreported possible association between SHANK3 deletion and UBOs-like lesions in the brain.

Targeting oxidative stress improves disease outcomes in a rat model of acquired epilepsy

Epilepsy therapy is based on antiseizure drugs that treat the symptom, seizures, rather than the disease and are ineffective in up to 30% of patients. There are no treatments for modifying the disease-preventing seizure onset, reducing severity or improving prognosis. Among the potential molecular targets for attaining these unmet therapeutic needs, we focused on oxidative stress since it is a pathophysiological process commonly occurring in experimental epileptogenesis and observed in human epilepsy. Using a rat model of acquired epilepsy induced by electrical status epilepticus, we show that oxidative stress occurs in both neurons and astrocytes during epileptogenesis, as assessed by measuring biochemical and histological markers. This evidence was validated in the hippocampus of humans who died following status epilepticus. Oxidative stress was reduced in animals undergoing epileptogenesis by a transient treatment with N-acetylcysteine and sulforaphane, which act to increase glutathione levels through complementary mechanisms. These antioxidant drugs are already used in humans for other therapeutic indications. This drug combination transiently administered for 2 weeks during epileptogenesis inhibited oxidative stress more efficiently than either drug alone. The drug combination significantly delayed the onset of epilepsy, blocked disease progression between 2 and 5 months post-status epilepticus and drastically reduced the frequency of spontaneous seizures measured at 5 months without modifying the average seizure duration or the incidence of epilepsy in animals. Treatment also decreased hippocampal neuron loss and rescued cognitive deficits. Oxidative stress during epileptogenesis was associated with de novo brain and blood generation of disulfide high mobility group box 1 (HMGB1), a neuroinflammatory molecule implicated in seizure mechanisms. Drug-induced reduction of oxidative stress prevented disulfide HMGB1 generation, thus highlighting a potential novel mechanism contributing to therapeutic effects. Our data show that targeting oxidative stress with clinically used drugs for a limited time window starting early after injury significantly improves long-term disease outcomes. This intervention may be considered for patients exposed to potential epileptogenic insults.

Neuroinflammatory targets and treatments for epilepsy validated in experimental models

A large body of evidence that has accumulated over the past decade strongly supports the role of inflammation in the pathophysiology of human epilepsy. Specific inflammatory molecules and pathways have been identified that influence various pathologic outcomes in different experimental models of epilepsy. Most importantly, the same inflammatory pathways have also been found in surgically resected brain tissue from patients with treatment-resistant epilepsy. New antiseizure therapies may be derived from these novel potential targets. An essential and crucial question is whether targeting these molecules and pathways may result in anti-ictogenesis, antiepileptogenesis, and/or disease-modification effects. Therefore, preclinical testing in models mimicking relevant aspects of epileptogenesis is needed to guide integrated experimental and clinical trial designs. We discuss the most recent preclinical proof-of-concept studies validating a number of therapeutic approaches against inflammatory mechanisms in animal models that could represent novel avenues for drug development in epilepsy. Finally, we suggest future directions to accelerate preclinical to clinical translation of these recent discoveries.

Early onset Charcot-Marie-Tooth neuropathy type 2A and severe developmental delay: expanding the clinical phenotype of MFN2-related neuropathy

Charcot-Marie-Tooth (CMT) syndromes are a group of clinically heterogeneous disorders of the peripheral nervous system. Mutations of mitofusin 2 (MFN2) have been recognized to be associated with CMT type 2A (CMT2A). CMT2A is primarily an axonal disorder resulting in motor and sensory neuropathy. We report a male child with psychomotor delay, dysmorphic features, and weakness of lower limbs associated with electrophysiological features of severe, sensory-motor, axonal neuropathy. The patient was diagnosed with early onset CMT2A and severe psychomotor retardation associated with c.310C>T mutation (p.R104W) in MFN2 gene. CMT2A should be considered in patients with both axonal sensory-motor neuropathy and developmental delay.

De novo PIK3R2 variant causes polymicrogyria, corpus callosum hyperplasia and focal cortical dysplasia

We report an 8-year-old boy with a complex cerebral malformation, intellectual disability, and complex partial seizures. Whole-exome sequencing revealed a yet unreported de novo variant in the PIK3R2 gene that was recently associated with megalencephaly-polymicrogyria-polydactyly-hydrocephalus (MPPH) syndrome and bilateral perisylvian polymicrogyria (BPP). Our patient showed cerebral abnormalities (megalencephaly, perisylvian polymicrogyria, and mega corpus callosum) that were consistent with these conditions. Imaging also showed right temporal anomalies suggestive of cortical dysplasia. Until now, only three variants (c.1117G>A (p.(G373R)), c.1126A>G (p.(K376E)) and c.1202T>C (p.(L401P))) affecting the SH2 domain of the PIK3R2 protein have been reported in MPPH and BPP syndromes. In contrast to the variants reported so far, the patient described herein exhibits the c.1669G>C (p.(D557H)) variant that affects a highly conserved residue at the interface with the PI3K catalytic subunit α. The phenotypic spectrum associated with variants in this gene and its pathway are likely to continue to expand as more cases are identified.

A case of Lennox-Gastaut syndrome in a patient with FOXG1-related disorder

Lennox-Gastaut syndrome (LGS) is a drug-resistant epileptic encephalopathy of childhood with a heterogeneous etiology. Recently, genome-wide association studies have led to the identification of new de novo mutations associated with this epileptic syndrome. Herein, we report an 8-year-old child with intellectual disability, severe postnatal microcephaly, Rett-like features, and LGS, carrying a de novo missense mutation in the forkhead box G1 (FOXG1) gene. This gene is responsible for FOXG1 syndrome, characterized by severe postnatal microcephaly, moderate postnatal growth deficiency, mental retardation with poor social interaction, stereotyped behavior and dyskinesias, absent language, sleep disorders, and epilepsy. Nonspecific epilepsy syndromes have been associated with this genetic disorder. Thus, we hypothesize that FOXG1 might be a new candidate gene in the etiology of LGS and suggest screening for this gene in cases of LGS with concomitant microcephaly and clinical features overlapping with Rett syndrome.

A case of 14q11.2 microdeletion with autistic features, severe obesity and facial dysmorphisms suggestive of Wolf-Hirschhorn syndrome

We report on a 21-year old woman with intellectual disability, autistic features, severe obesity, and facial dysmorphisms suggestive of Wolf-Hirschhorn syndrome (WHS). Array-CGH analysis showed a 2.89 Mb deletion on chromosome 14q11.2 containing 47 known genes. The most interesting genes included in this deletion are CHD8, a chromodomain helicase DNA binding protein that is associated with autism spectrum disorders, and MMP14, a matrix metalloproteinase that has been linked to obesity and type 2 diabetes. This report shows that 14q11.2 microdeletions can mimic WHS and suggests that gene(s) in the deleted interval that may be responsible for a phenocopy of WHS.

Good cognitive performances in a child with Prader-Willi syndrome

We report the case of a child affected by Prader-Willi syndrome (PWS) with good cognitive performances and without relevant behavioral abnormalities.

The diagnosis of PWS, suspected on the basis of clinical features and past history, was confirmed by DNA methylation analysis. Additional genetic testing revealed a maternal uniparental disomy. Intellectual profile was analyzed by WISC-III and Raven’s Progressive Matrices CPM, while the behavior was evaluated by K-SADS-PL and Child Behavior Checklist/4-18 to the parents.

WISC-III test showed a Total Intelligence Quotient (T-IQ = 79) at the border level for age. The Verbal Intelligence Quotient (V-IQ) showed a lower score than the Performance Intelligence Quotient (P-IQ) (78 and 85, respectively). Raven’s Matrices CPM showed an intelligence level at 75-90° percentile for age. Concerning behavioral evaluation, a difficulty in impulse control was observed, with persistent but controllable search for food, without a clear psychopathological meaning. Also according to K-SADS-PL no areas of psychopathological dimensions were detected. In conclusion, in presence of consisting clinical features of PWS and high diagnostic suspicion, the diagnosis of PWS should be considered even in presence of a borderline IQ and in absence of psychopathological abnormalities.

The Pediatric Symptom Checklist as screening tool for neurological and psychosocial problems in a paediatric cohort of patients with coeliac disease

AIM

To screen for neurological and behavioural disorders in a paediatric cohort of patients with coeliac disease (CD) in order to detect possible differences related to compliance with gluten-free diet (GFD).

METHODS

We recruited a cohort of 139 patients divided into three groups: A (40 patients with newly diagnosed CD), B (54 patients with CD in remission after GFD) and C (45 patients with potential CD). Patients first underwent a screening neurological visit, detecting signs associated with CD, and then were evaluated with Pediatric Symptom Checklist (PSC), a psychosocial screen for cognitive, emotional and behavioural problems.

RESULTS

In the group B as compared to group A, there was a statistically significant decrease (p < 0.05) in the incidence of chronic fatigue, headache and inattention. The same applied to patients compliant to GFD vs. non-compliant. Potential coeliacs turning into overt CD had a higher incidence of headache and inattention compared with potential coeliacs showing normal mucosa. The PSC mean score in group A was statistically higher than in group B.

CONCLUSION

Gluten-free diet had a positive impact on neuropsychiatric symptoms. We suggest the use of PSC in the routine follow-up of coeliacs in order to allow an early detection of psychosocial problems.

Low-dose amitriptyline-induced acute dystonia in a patient with metachromatic leukodystrophy

Acute dystonia is an abrupt event mainly related to toxicity of drugs such as antiemetics, antipsychotics, anti-acids, and, more rarely, tricyclic antidepressants. Use of amitriptyline in metachromatic leukodystrophy (MLD), a lysosomal storage disorder (LSD) due to arylsulfatase A deficiency, is suggested to control neurological pain and irritability. We describe a patient with MLD who experienced acute dystonia as a side effect of low dosage of amitriptyline. The distribution of psychotropic drugs, including antidepressants, depends upon lysosomal trapping which is inefficient in LSD. The defective lysosomal depot might raise cerebral levels of amitriptyline, thus enhancing its adverse effects.Physicians caring for children with MLD treated with psychotropic drugs should be aware of such adverse events which are potentially related to lysosomal dysfunction. This experience raises a potential concern about the appropriate dose of amitriptyline in patients with MLD.

Short wheat challenge is a reproducible in-vivo assay to detect immune response to gluten

It has been reported that interferon (IFN)-γ-secreting T cells reactive to gluten can be detected in the peripheral blood of individuals with treated coeliac disease (CD) after a short consumption of wheat-containing food. By contrast, very little is known about the reproducibility of this in-vivo procedure in the same patient cohort which underwent two, or more, gluten consumptions. Fourteen coeliac patients in remission consumed wheat bread for 3 days; 13 underwent a second gluten challenge after a wash-out of 3-10 months on a strict gluten-free diet. Immune reactivity to gluten was analysed in peripheral blood by detecting IFN-γ before and 6 days after commencing a gluten diet. Gliadin-specific IFN-γ-secreting CD4(+) T cells increased significantly on day 6 of the first challenge. These cells resulted as prevalently human leucocyte antigen (HLA)-DQ restricted and with a phenotype of gut homing, as suggested by the expression of β7-integrin. Similarly, reactiveness to gliadin was observed after the second wheat consumption, although with an individual variability of responses at each challenge. Our findings confirmed that the short wheat challenge is a non-invasive approach to investigate the gluten-related immune response in peripheral blood of subjects intolerant to gluten. Furthermore, we demonstrated that the in-vivo procedure can be reproduced in the same subject cohort after a gluten wash-out of at least 3 months. Our study has important implications for the application of this procedure to clinical practice.

A further contribution to the delineation of the 17q21.31 microdeletion syndrome: central nervous involvement in two Italian patients

The 17q21.31 microdeletion syndrome is a genetic disorder characterized by intellectual disability, facial dysmorphisms and a typical behavioral phenotype. Patients are usually described as friendly and cooperative but they can also show behavioral problems such as hyperactivity, bad humor, temper tantrums and poor interaction. Central nervous system involvement includes callosal dysgenesis/absence, enlargement of lateral ventricles and abnormalities of cyngulate gyrus. We report on two Italian patients with the 17q21.31 microdeletion syndrome better emphasizing neuroimaging and neuropsychological characteristics. In particular, we carried out an assessment of intellectual efficiency and behavior that turned out to be within the mild-moderate range of mental retardation, as already reported in the literature. To the best of our knowledge this is the first report of a patient with the 17q21.31 microdeletion and a Chiari malformation type 1 coexisting with a mild anomaly of medulla oblongata. This malformation should be considered in patients with the 17q21.31 microdeletion syndrome, presenting suggestive symptoms (headache, neck pain, cerebellar signs or muscle weakness).

Safety for patients with celiac disease of baked goods made of wheat flour hydrolyzed during food processing

BACKGROUND & AIMS

Celiac disease (CD) is characterized by an inflammatory response to wheat gluten, rye, and barley proteins. Fermentation of wheat flour with sourdough lactobacilli and fungal proteases decreases the concentration of gluten. We evaluated the safety of daily administration of baked goods made from this hydrolyzed form of wheat flour to patients with CD.

METHODS

Patients were randomly assigned to consumption of 200 g per day of natural flour baked goods (NFBG) (80,127 ppm gluten; n = 6), extensively hydrolyzed flour baked goods (S1BG) (2480 ppm residual gluten; n = 2), or fully hydrolyzed baked goods (S2BG) (8 ppm residual gluten; n = 5) for 60 days.

RESULTS

Two of the 6 patients who consumed NFBG discontinued the challenge because of symptoms; all had increased levels of anti-tissue transglutaminase (tTG) antibodies and small bowel deterioration. The 2 patients who ate the S1BG goods had no clinical complaints but developed subtotal atrophy. The 5 patients who ate the S2BG had no clinical complaints; their levels of anti-tTG antibodies did not increase, and their Marsh grades of small intestinal mucosa did not change.

CONCLUSIONS

A 60-day diet of baked goods made from hydrolyzed wheat flour, manufactured with sourdough lactobacilli and fungal proteases, was not toxic to patients with CD. A combined analysis of serologic, morphometric, and immunohistochemical parameters is the most accurate method to assess new therapies for this disorder.