Search Results (441)

Cyclin-Dependent Kinase-Like 5 (CDKL5) Deficient Disorder (CDD) is a rare X-linked developmental and epileptic encephalopathy characterized by early-onset refractory epilepsy, severe neurodevelopmental impairment, and lifelong disability. Although more than thirty anti-seizure medications are available, most CDD patients remain pharmaco-resistant. Gene-based therapies are emerging, but therapeutic development is hindered by marked clinical heterogeneity, small patient populations, and the lack of robust, translatable brain-based biomarkers for clinical trials. Genetically engineered Cdkl5 mouse models recapitulate many cognitive, behavioral, and molecular features of CDD, yet their utility is limited by the absence of overt seizures, precluding seizure-based outcome measures. Here, we establish high-definition brain network (HDBN) biomarkers using advanced diffusion MRI tractography combined with graph-theoretical analysis to quantify whole-brain network organization in Cdkl5 knockout mice. Diffusion MRI enables non-invasive mapping of axonal connectivity by leveraging anisotropic water diffusion, while high-angular-resolution acquisition overcomes key limitations of conventional diffusion tensor imaging in regions with complex fiber architecture. We demonstrate that Cdkl5 knockout mice exhibit reproducible and region-specific disruptions in brain network organization, prominently affecting the somatosensory and somatomotor cortex, hippocampus, hypothalamus, amygdala, and superior colliculus—regions implicated in cognition, learning and memory, homeostasis, anxiety, and visual–motor function. In contrast, networks within the entorhinal cortex remain largely preserved. These findings identify HDBN metrics as sensitive, non-invasive biomarkers that capture clinically relevant circuit-level abnormalities in CDD. Because diffusion MRI–based network analyses are directly translatable across species, HDBN biomarkers provide a unified framework for therapeutic evaluation in mouse models, large animals, and human clinical trials, enabling longitudinal monitoring of disease progression and treatment response. Full article

The WW domain-containing oxidoreductase (WWOX) gene, well-known as a tumor suppressor, also has a crucial role as a transcription factor in the developing brain. The bi-allelic loss of the WWOX gene causes a condition characterized by drug-resistant epilepsy, developmental delay, and neurological impairments, often resulting in mortality within the first year of life, known as WWOX-related epileptic encephalopathy (WOREE) syndrome (MIM: 616211). Whole Exome Sequencing (WES) analysis was performed on a female patient who died within three months of birth and was diagnosed with microcephaly, severe early-onset refractory seizures, and drug-resistant epileptic encephalopathy. WES revealed a 38 kb CNV deletion spanning WWOX exons 6–7, and a known frameshift variant in exon 8, impairing a highly clinically significant region of the encoded protein. Clinical and genetic features of reported WOREE patients with WWOX gene deletions similar to our patient were analyzed. Our case highlights the clinical heterogeneity of WWOX variants in WOREE syndrome and expands the spectrum of reported compound heterozygous deletions. Further research needs to elucidate WWOX pathophysiology and improve diagnostic and therapeutic strategies. Full article

Background/Objectives: Early-onset epilepsy is associated with a high risk of developing drug-resistant epilepsy (DRE), often manifesting as developmental and epileptic encephalopathies (DEEs). This study aimed to characterize the incidence, syndromes, comorbidities, and etiology of early-onset DRE in Estonia. Methods: This study is a continuation of our earlier nationwide, population-based investigation and included all children with early-onset epilepsy (seizure onset before two years) who developed drug resistance in Estonia between 2013 and 2017 (n = 37). Cases were identified at the country’s only two pediatric neurology departments, ensuring nationwide coverage. Clinical data, electroencephalography, neuroimaging, genetic investigations (chromosomal microarray, single-gene tests, gene panels, exome/genome sequencing), and etiology were analyzed overall and by epilepsy type or syndrome. Results: A total of 37 children with early-onset DRE were included. The incidence of early-onset DRE was 26.5 per 100,000 person-years, peaking in the first year of life (36.1). Drug resistance developed in 43% within six months and 65% within one year. DEEs accounted for 76% of cases, most commonly infantile epileptic spasms syndrome (IESS/West syndrome, 35%). Structural abnormalities were observed in 49% of cases (50% of DEEs), most commonly congenital brain malformations (22%). Pathogenic genetic findings were identified in 41% overall (43% of DEEs). The etiology was established in 78% of children with DRE. Among DEEs, it was found in all Dravet syndrome patients (100%) and 62% of those with IESS/West syndrome. Global developmental delay/intellectual disability occurred in 86%, and motor impairment in 46%. Conclusions: Early-onset DRE, often presenting as DEE, has high incidence, progresses rapidly to drug resistance, and causes substantial comorbidities. Full article

Background and Clinical Significance: Parry–Romberg syndrome (PRS), also known as progressive hemifacial atrophy, is a rare disorder characterized by progressive unilateral hemifacial atrophy, with potential involvement of the cranial bones and the brain. Although neurological manifestations are frequently described, central nervous system involvement may be subclinical and detectable only through neuroimaging. Owing to its rarity and the lack of standardized diagnostic criteria, most available data derive from case reports and small case series. Case Presentation: We report the case of a 38-year-old female patient diagnosed with PRS (stage 2 according to the Guerrerosantos classification), with onset in childhood characterized by left parietal alopecia, followed by progressive left-sided hemifacial atrophy and a linear “en coup de sabre” lesion. Neurological examination was normal, with no history of seizures or focal deficits. Brain MRI revealed ipsilateral cutaneous, subcutaneous, muscular, and osseous atrophy, as well as atrophy of the left parotid and submandibular glands. Additionally, subcortical white matter lesions were identified in the left frontal lobe in the absence of hemispheric cerebral atrophy. Conclusions: This case highlights a significant radioclinical dissociation, demonstrating that central nervous system involvement may occur even in clinically stable and paucisymptomatic forms of PRS. This disease may be associated with subclinical intracranial abnormalities, underscoring the need for systematic neuroimaging evaluation even in the absence of neurological manifestations. Based on the available literature and the specific features of the present case, we propose a practical clinical framework and imaging algorithm to facilitate early diagnosis and to contribute to the standardization of the diagnostic approach in this rare disorder. Full article

Background/Objectives: Severe neurodevelopmental disorders caused by homozygous ASTN1 variants have recently been reported. The aim of this study is to present the expanded phenotype and prognostic findings through a longitudinal follow-up of a patient with a homozygous ASTN1 variant. Methods: We conducted a 15-year clinical evaluation of a girl who initially presented at 10 years of age. The genetic etiology was investigated using exome sequencing. Results: The patient had a profound intellectual disability, severe expressive language delay, and infantile-onset epilepsy. She also had microcephaly, achieved independent walking at age 7 and had speech limited to only two words at admission. A novel homozygous frameshift variant, c.2096del (p.Cys699Serfs*22), in ASTN1 was identified. Over the follow-up period, her postnatal microcephaly became more pronounced, and she experienced a late relapse into generalized tonic–clonic seizures after a decade-long remission. She remains entirely dependent on caregivers for basic self-care at age 25. Conclusions: ASTN1-related phenotype is associated with a severe neurodevelopmental disease, and the late relapse of seizures after prolonged remission highlights the need for lifelong neurological monitoring and multidisciplinary care. Full article

Background: Glutaric acidemia type 1 (GA1) is an autosomal recessive neurometabolic disorder caused by pathogenic variants in glutaryl-CoA dehydrogenase (GCDH), with variable clinical severity despite early biochemical detectability. Population-specific mutational spectra and genotype–phenotype correlations remain insufficiently defined in infantile-onset disease. Therefore, this study aimed to define the GCDH variant spectrum in GA1 patients with mild hepatopathy and assess genotype–phenotype correlations. Methods: We performed integrated clinical, biochemical, and molecular characterization of 15 unrelated patients with infantile-onset GA1. Whole-exome sequencing (WES) was performed for all participants, and the resulting data were compared with the reference sequence of the GCDH gene. Results: All patients presented within the first 6 months of life with macrocephaly, seizures, dystonia, and feeding difficulties. Neurological impairment and mild hepatopathy were variably observed, and one patient developed an acute encephalopathic crisis. Six homozygous GCDH variants were identified, predominantly missense. A common variant, c.541G>C (p.Glu181Gln), accounted for 73.3% of cases and defined a consistent phenotype of early macrocephaly and movement disorder with frequent mild hepatic involvement, suggesting regional enrichment and raising the possibility of a founder effect that warrants confirmation in future haplotype studies. A truncating variant, c.382C>T (p.Arg128Ter), was associated with severe early encephalopathy. Exon 6 represented a mutational hotspot. Biochemically, all patients showed elevated urinary glutaric and 3-hydroxyglutaric acids, increased glutarylcarnitine, and low-to-normal free carnitine, with higher metabolite levels in clinically more severe cases. All variants were pathogenic or likely pathogenic and extremely rare in population databases. Conclusions: This cohort reveals a striking predominance of the GCDH c.541G>C variant and establishes a clear biochemical signature with genotype-associated clinical patterns in infantile-onset GA1. These findings support a population-specific mutational spectrum, refine genotype–phenotype correlations, and underscore the importance of early molecular diagnosis to guide targeted neurological and hepatic monitoring as well as regional screening strategies. Full article

Background/Objectives: Idiopathic epilepsy is a lifelong neurologic disorder in dogs, but its genetic basis remains incompletely understood in many breeds. This study aimed to identify risk-associated markers in Siberian Huskies, quantify their effects, assess potential risk modifiers, and characterize the shared haplotype background of the associated signal. Methods: A genome-wide association study was conducted in 113 Siberian Huskies genotyped on the Illumina CanineHD array, integrating association, regression, and haplotype/IBD analyses. An independent follow-up cohort of 57 additional dogs was genotyped at the lead marker by Sanger sequencing. Sex and gonadectomy status/timing were also evaluated as potential modifiers of risk, using multivariable regression and time-to-event analyses. Results: A strong, localized association was identified on canine chromosome 3 (CFA3) within KCNIP4. The lead intronic marker was significantly enriched in cases, with all risk-allele homozygotes affected, most heterozygotes affected, and no control homozygotes observed. Risk-associated chromosomes shared extended haplotypes across the region, consistent with carriers inheriting a common risk haplotype from a relatively recent shared ancestor. Among carriers, male sex was associated with higher odds of epilepsy and earlier seizure onset, with more tentative evidence for a similar association with gonadectomy before 5 years of age. Conclusions: These findings prioritize a CFA3 region encompassing KCNIP4 as a major risk locus for idiopathic epilepsy in Siberian Huskies. Fine-mapping with high-coverage sequencing and functional follow-up will be required to pinpoint the causal variant(s) and support development of risk assessment tools. Until those studies are completed, this marker should be regarded as a research finding rather than a predictive test. Full article

Background: Pathogenic variants in the NEXMIF gene have been linked to a broad neurodevelopmental phenotype, encompassing autism spectrum disorder, intellectual disability, and epilepsy. Among epileptic manifestations, Jeavons Syndrome was observed in 24% of affected females in the largest cohort of NEXMIF-related disorders reported to date, but long-term adult outcomes remain poorly documented. Methods and Results: We report a 25-year-old Italian woman with drug-resistant Jeavons syndrome in which the combined approach of next-generation sequencing and chromosomal microarray analysis allowed us to identify, after a 13-year diagnostic odyssey, a de novo ~350 Kb microdeletion at Xq13.2q13.3 encompassing the entire NEXMIF coding region, with no other OMIM genes involved. To our knowledge, this is the first reported case of a patient harboring a deletion restricted to the entire coding sequence of the NEXMIF gene. The patient presented with moderate intellectual disability and seizure onset at age 10 years. Her epilepsy proved refractory to multiple antiseizure medications. Video-EEG/polygraphic monitoring at age 23 years confirmed epilepsy with eyelid myoclonia, demonstrating characteristic eyelid myoclonia with absences triggered by eye closure. Conclutions: This case provides a detailed clinical description of an adult patient useful for genetic counseling regarding adult outcomes and prognostic expectations. Furthermore, this study underscores the diagnostic value of chromosomal microarray analysis alongside next-generation sequencing in individuals with intellectual disability and drug-resistant epilepsy, in order to expedite the diagnostic pathway and enable timelier and more appropriate patient management. Full article

Background: Paraneoplastic limbic encephalitis (PLE) with anti-Ma2 antibodies is a rare immune-mediated disorder associated with testicular cancer, particularly in young males. While neurological manifestations are well documented, hypothalamic–pituitary dysfunctions remain underreported. We present a case of anti-Ma2 PLE associated with testicular cancer together with a systematic review of PLE associated with testicular cancer, selectively restricted to anti-Ma2 positive cases and focusing on hypothalamic–endocrine involvement. Case presentation: We describe a 21-year-old male diagnosed with anti-Ma2 PLE and intratubular germ cell neoplasia of the right testis. He underwent orchifunicolectomy and immunosuppressive therapy with neurological improvement. Four years later, he developed new-onset temporal seizures, decreased libido, and a polyuria–polydipsia syndrome. Dynamic endocrine testing, including a water deprivation test and copeptin measurement, supported a diagnosis of partial central diabetes insipidus (CDI). Methods: A systematic literature review was performed in accordance with PRISMA guidelines. PubMed was searched using predefined keywords without time restriction. Studies reporting PLE associated with testicular tumors in humans with confirmed anti-Ma2 antibody positivity were included. Results: Eleven studies were included, reporting a total of 38 patients with anti-Ma2-associated PLE and testicular cancer. Hypothalamic or diencephalic involvement was described in 16 patients (42.0%), while endocrine manifestations were explicitly reported in four cases. Only two previous reports mentioned CDI, without detailed diagnostic evaluation. Conclusions: This study highlights the importance of recognizing hypothalamic-endocrine manifestations in PLE. In patients presenting with polydipsia and polyuria, CDI should be carefully differentiated from primary polydipsia using dynamic testing. Hypothalamic involvement may emerge years after tumor treatment, warranting long-term endocrine surveillance. Full article

Introduction: Spondyloenchondrodysplasia with immune dysregulation (SPENCDI) is a rare autosomal recessive disorder caused by biallelic variants in the tartrate-resistant acid phosphatase 5 (ACP5) and characterized by variable skeletal, immunological, and neurological manifestations. Because early skeletal abnormalities may be subtle, diagnosis can be challenging in infancy. Materials and methods: We conducted a detailed clinical, immunological, radiological, and molecular evaluation of an infant with early-onset cytopenia, recurrent infections, seizures, and developmental delay. Genomic analysis was performed using whole exome sequencing (WES) and copy number variation sequencing (CNV-seq). In addition, we performed a structured narrative review of published ACP5-related SPENCDI cases to summarize the clinical spectrum and the currently reported use of Janus kinase (JAK) inhibitors. Results: Genomic analysis identified an ACP5 stop-gain variant (c.311G>A; p.Trp104*) with an apparently homozygous signal on WES. Re-evaluation of the copy-number data demonstrated an overlapping heterozygous 19p13.2–p13.13 deletion encompassing ACP5, indicating biallelic ACP5 defects consisting of a sequence variant on one allele and deletion of the other allele. Clinically, the patient showed prominent extra-osseous manifestations, including impaired T- and NK-cell cytotoxicity, before the emergence of definite radiographic skeletal abnormalities. Our literature review showed that skeletal abnormalities were repeatedly documented across published ACP5-related SPENCDI reports, although radiographic changes were often subtle and could be preceded by immune manifestations. Reported use of JAK inhibitors suggests potential benefit for immune dysregulation in selected patients, whereas the neurological response remains uncertain. Conclusions: This study reports a novel ACP5 variant and expands the known phenotypic spectrum of SPENCDI. SPENCDI should be considered in children with unexplained immune dysfunction and developmental delay, and suggestive neuroimaging findings, even when overt skeletal deformities are absent. Early genetic testing and targeted skeletal imaging may facilitate diagnosis. Full article

The relationship between epilepsy, obesity, and metabolic syndrome (MetS) has emerged as a rapidly evolving area of neurobiology inquiry. Emerging evidence suggests that epilepsy extends beyond neuronal hyperexcitability, reframing it as a systemic condition characterized by significant metabolic dysregulation. Converging supports a bidirectional relationship while seizures, antiseizure medications (ASM), and neuroinflammation induce exacerbate potentiate epileptogenesis through shared molecular pathways. At the cellular level, chronic epileptic activity induces oxidative stress, mitochondrial dysfunction, and the activation of microglia and astrocytes. This, in turn, leads to the release of pro-inflammatory cytokines including TNF-α, IL-1β, and IL-6. These mediators traverse the blood-brain barrier (BBB), subsequently modifying insulin signaling, and disrupting glucose homeostasis, which collectively fosters a pro-inflammatory and insulin-resistant environment. Furthermore, antiseizure medications such as valproate can exacerbate these effects by directly impairing insulin receptor signaling and altering adipokine production, ultimately contributing to weight gain and systemic metabolic dysregulation. Obesity and MetS induce neuroinflammatory and excitotoxic states that promote seizure onset via leptin resistance, reduced adiponectin levels, and compromised AMP-activated protein kinase (AMPK) signaling. Emerging evidence emphasizes the gut-brain axis as a crucial regulator in this reciprocal interaction. Dysbiosis, altered microbial metabolites (e.g., short-chain fatty acids), and heightened intestinal permeability facilitate systemic inflammation and BBB disruption, enhancing neuronal excitability. Insulin resistance in the brain disrupts synaptic transmission, impairs mitochondrial biogenesis, and compromises redox equilibrium, perpetuating a pathological cycle linking metabolic stress to epileptic activity. This review synthesizes the cellular, molecular, and systemic pathways connecting epilepsy, obesity, and MetS, and proposes that epilepsy be reconceptualized as a neuro-metabolic disorder. Insights into these convergent pathways provide a rationale for novel therapeutic strategies that simultaneously target seizure control and metabolic regulation, encompassing microbiota modulation, antioxidant therapy, and insulin-sensitizing interventions with the overarching aim of restoring neuro-metabolic homeostasis. Full article

Epilepsy is a progressive network disorder in which recurrent seizures drive maladaptive neurodevelopmental remodeling, cognitive decline, and pharmacoresistance, particularly in developmental epileptic encephalopathies. Cannabidiol (CBD) has emerged as an evidence-based adjunctive therapy for selected childhood-onset epilepsies; however, its broader clinical utility remains limited by heterogeneous responsiveness, restricted indications, and an incomplete understanding of developmental stage–specific efficacy and safety. Here, we synthesize molecular, preclinical and clinical evidence supporting the pleiotropic antiseizure and neuroprotective actions of CBD, including modulation of endocannabinoid-related G protein–coupled receptors, adenosine signaling, transient receptor potential channels, GABAergic maturation, and neuroinflammatory cascades. We highlight critical neurodevelopmental windows during which timely CBD intervention may exert disease-modifying effects by preventing pathological consolidation of hyperexcitable networks. Furthermore, we position human brain organoids as transformative translational platforms that recapitulate early human cortical development and epileptic network dynamics, enabling functional stratification of CBD-responsive phenotypes, developmental safety profiling, and precision therapeutic discovery within human-relevant neural circuits. Collectively, organoid-guided frameworks provide a mechanistic foundation for personalized, developmentally informed CBD therapy and advance precision medicine strategies aimed at modifying epileptogenic trajectories rather than solely suppressing seizures. Full article

Introduction: SLC6A1-related neurodevelopmental disorder (SLC6A1-NDD) is an epileptic encephalopathy linked to mutations in the SLC6A1 gene and is characterized by early-onset seizures and developmental delays. Despite the growing recognition of SLC6A1 as a major cause of early-onset epilepsy, the electrophysiological changes associated with the disorder remain inadequately characterized. This study aims to identify electrophysiological biomarkers of SLC6A1-NDD by characterizing EEG delta power using automated tools, EEGLAB (v2023.1) and Persyst 13, exploring age- and state-related effects. Methods: We analyzed EEG recordings from 20 patients with SLC6A1-NDD and 20 neurotypical age- and sex-matched controls using EEGLAB and Persyst, quantifying delta power and related metrics. The Wilcoxon signed-rank method tested for differences between patients and controls, area under the curve (AUC) values evaluated patient classifier models, and Pearson’s correlation assessed concordance between EEGLAB and Persyst. Results: Patients with SLC6A1-NDD exhibited significantly elevated delta power (19.4 ± 4.1) compared to controls (14.2 ± 3.0; p < 0.001). The mean delta power showed an age-dependent increasing trend in patients (b = 0.5), contrasting with a decline in controls (b = −1.0; p < 0.001). In Persyst, the frequency of delta activity above an optimized threshold best differentiated patients from controls in wake epochs (AUC = 0.93). Concordance between EEGLAB and Persyst was one-to-one but with moderate variability (R² = 0.644; p < 0.001). Conclusions: Elevated delta power is a notable feature of SLC6A1-NDD. Cross-platform comparison demonstrates the feasibility of quantitative EEG analysis, while imperfect concordance highlights the need for pipeline standardization. Future work should validate these findings in larger cohorts and, as suitable reference data emerge, benchmark delta power metrics against age-matched children with other developmental and epileptic encephalopathies. Full article

Mesial temporal lobe epilepsy (TLE) is the most common and severe form of focal epilepsy. This review examines the diverse mechanisms by which the GABAergic system contributes both to seizure generation and to protective processes that limit epileptogenesis and seizure progression in TLE. We focus on findings from established animal models of TLE as well as studies of surgically resected tissue from patients who had undergone therapeutic intervention. Experimental models include sustained electrical stimulation of the perforant path, as well as the kainic acid (KA) and Li-pilocarpine models. Although these paradigms induce status epilepticus (SE) through distinct mechanisms, they ultimately converge on prolonged excitation of hippocampal CA3 pyramidal neurons and interconnected regions of the hippocampus and broader limbic network. In response to epileptic seizures, GABA synthesis is enhanced, as evidenced by the marked upregulation of the GABA-synthesizing enzymes GAD65 and GAD67, along with their ectopic expression in glutamatergic mossy fibers of the hippocampus. Shortly after acute seizures, a transient expression of the embryonic GAD67 splice variant, GAD25, is observed, although its functional significance remains unclear. At the receptor level, animal models of TLE show upregulation of GABA_A receptor subunits α2, α4, β3, and γ2, accompanied by downregulation of α5 and δ subunits, suggesting reduced tonic inhibition. In contrast, hippocampal tissue from patients with TLE exhibits pronounced upregulation of α5 and δ subunits, indicative of enhanced extrasynaptic tonic inhibition. Similarly, whereas GABA_A receptor subunits are mildly downregulated in animal models, they are consistently upregulated across hippocampal subfields in human TLE, pointing toward strengthened GABAergic inhibition. Conversely, genetic variants of GABA_A receptor subunits and autoantibodies targeting these receptors can contribute to the etiology of epilepsy, often with onset in childhood. Moreover, degeneration or functional silencing of specific GABAergic interneuron populations—such as parvalbumin-positive neurons in the subiculum—can induce epilepsy in rodent models and is likewise associated with TLE in humans. Full article

Background/Objectives: Posterior reversible encephalopathy syndrome (PRES) is a neurological condition characterized by acute neurological symptoms and vasogenic edema, usually affecting the posterior circulation. It is described in end-stage renal disease (ESRD), but its presentation in peritoneal dialysis (PD) is not well defined. We aimed to describe the clinical, radiological, and dialysis-related features of PRES in PD patients and highlight factors relevant for diagnosis and management. Materials and Methods: We conducted a retrospective descriptive case series of four ESRD patients on PD or recently transitioned from PD to hemodialysis (HD) who developed PRES at a single center. Clinical data, laboratory results, dialysis characteristics, and neuroimaging findings were obtained from medical records. PRES was diagnosed based on acute neurological symptoms in the setting of severe hypertension and uremia, with CT and/or MRI findings supportive of PRES when present and exclusion of alternative diagnoses. Results: All patients presented with acute neurological manifestations, including headache, visual disturbances, seizures, and/or altered consciousness, in the context of marked hypertension and uremia. Neuroimaging findings ranged from normal CT/MRI to subtle bilateral occipital hypodensities and, in one case, extensive supra- and infratentorial vasogenic edema with internal hydrocephalus and subependymal edema. In three patients, inadequate volume or solute control on PD prompted temporary or permanent transition to HD to improve blood pressure and fluid management. With antihypertensive therapy, seizure control when required, correction of metabolic disturbances, and optimization of dialysis, all patients recovered clinically, with time to PRES resolution ranging from 7 to 43 days. Conclusions: PRES should be considered in PD patients with new-onset seizures, visual symptoms, or unexplained changes in mental status, particularly during hypertensive crises and uremia. Early CT/MRI, prompt blood pressure control, and careful adjustment of dialysis modality appear important for achieving favorable neurological outcomes. Full article