Girdin deficiency causes developmental and epileptic encephalopathy with hippocampal sclerosis and interneuronopathy.

Dravet syndrome (Dravet) is a rare and severe form of developmental epileptic encephalopathy. Antiseizure medications (ASMs) for Dravet patients include valproic acid (VA) or clobazam (CLB), with or without stiripentol (STP), while sodium channel blockers like carbamazepine (CBZ) or lamotrigine (LTG) are contraindicated. In addition to their effect on epileptic phenotypes, ASMs were shown to modify the properties of background neuronal activity. Nevertheless, little is known about these background properties alterations in Dravet. Here, utilizing Dravet mice (DS, Scn1aA1783V/WT), we tested the acute effect of several ASMs on background electrocorticography (ECoG) activity and frequency of interictal spikes. Compared to wild-type mice, background ECoG activity in DS mice had lower power and reduced phase coherence, which was not corrected by any of the tested ASMs. However, acute administration of Dravet-recommended drugs, VA, CLB, or a combination of CLB + STP, caused, in most mice, a reduction in the frequency of interictal spikes, alongside an increase in the relative contribution of the beta frequency band. Conversely, CBZ and LTG increased the frequency of interictal spikes, with no effect on background spectral properties. Moreover, we uncovered a correlation between the reduction in interictal spike frequency, the drug-induced effect on the power of background activity, and a spectral shift toward higher frequency bands. Together, these data provide a comprehensive analysis of the effect of selected ASMs on the properties of background neuronal oscillations, and highlight a possible correlation between their effect on epilepsy and background activity.

Metabolic causes of pediatric developmental & epileptic encephalopathies (DEE)- genetic variant analysis in a south Indian cohort

Neuronal synchronization supports different physiological states such as cognitive functions and sleep, and it is mirrored by identifiable EEG patterns ranging from gamma to delta oscillations. However, excessive neuronal synchronization is often the hallmark of epileptic activity in both generalized and partial epileptic disorders. Here, I will review the synchronizing mechanisms involved in generating epileptiform activity in the limbic system, which is closely involved in the pathophysiogenesis of temporal lobe epilepsy (TLE). TLE is often associated to a typical pattern of brain damage known as mesial temporal sclerosis, and it is one of the most refractory adult form of partial epilepsy. This epileptic disorder can be reproduced in animals by topical or systemic injection of pilocarpine or kainic acid, or by repetitive electrical stimulation; these procedures induce an initial status epilepticus and cause 1-4 weeks later a chronic condition of recurrent limbic seizures. Remarkably, a similar, seizure-free, latent period can be identified in TLE patients who suffered an initial insult in childhood and develop partial seizures in adolescence or early adulthood. Specifically, I will focus here on the neuronal mechanisms underlying three abnormal types of neuronal synchronization seen in both TLE patients and animal models mimicking this disorder: (i) interictal spikes; (ii) high frequency oscillations (80-500 Hz); and (iii) ictal (i.e., seizure) discharges. In addition, I will discuss the relationship between interictal spikes and ictal activity as well as recent evidence suggesting that specific seizure onsets in the pilocarpine model of TLE are characterized by distinctive patterns of spiking (also termed preictal) and high frequency oscillations.

Electrical, molecular and behavioral effects of interictal spiking in the rat

Introduction. The problem of early diagnostics of orphan diseases is relevant for most countries of the world. The challenge for healthcare is to prevent new cases of orphan diseases by providing medical genetic testing and counseling at the stage of family planning. Department of psychoneurology of the State Intstitution "Institute of Pediatrics, Obstetrics and Gynecology named after Academician O.M. Lukyanova National Academy of Medical Sciences of Ukraine" has been dealing with the problem of orphan diseases since 2012 and has significant experience in their diagnosis and treatment in children.The aim of paper: to develop an algorithm for the genetic diagnosis of epileptic and developmental encephalopathies in children with developmental delay and dimorphic features based on modern data on the application and interpretation of genetic methods. A case which demonstrate the complexity of interpreting the results and algorithms for early diagnosis of patients and the importance of medical and genetic counseling is presentedMaterial and methods: clinical and neurological examination, sleep video-EEG monitoring during night sleep, brain magnetic resonance imaging (3.0T), whole-exome sequencing (WES).Results. The article presents the algorithm of genetic diagnosis of orphan diseases in children with developmental and epileptic encephalopathies, developmental delay, and dimorphic features. A clinical case of a boy with general developmental delay and atonic epileptic seizures is presented. Sleep EEG-monitoring showed epileptiform activity in the stage of slow-wave sleep localized in the central-parietal and left temporal areas in the form of benign childhood epileptiform patterns.Whole-exome sequencing detected a variant of uncertain significance (VUS) c.5887C>T(p.Arg1963Cys) of SON gene in a heterozygous state, which leads to the replacement of arginine to cysteine. Mutations in the SON gene in the heterozygous state have been described in patients with Zhu-Tokita-Takenouchi-Kim syndrome (OMIM: 617140).Conclusions: It is important for pediatricians and neurologists to be aware of orphan diseases in children with developmental and epileptic encephalopaties and developmental delay. Genetic tests are wide available but they require competent interpretation by clinicists. After obtaining the results, it is important to compare the obtained result with the phenotype of patient. In case the phenotype of patient match and the results of genetic test, (detected VUS) this mutation could be etiological factor of the disease. In our case, the clinical signs coincided with those described in 2015 by the authors of the first description of Zhu-Tokita-Takenuchi-Kim syndrome, and therefore genetic testing helped to verify the final diagnosis. Therefore genetic counseling is extremely important for detection of etiology and prognosis of early developmental and epileptic encephalopathies/

Granule cell dispersion is not accompanied by enhanced neurogenesis in temporal lobe epilepsy patients

Testing the efficacy of lamotrigine (LTG) in epileptic patients has been approached in several ways. The first pilot study examined the effect of a single dose of LTG in patients with frequent interictal spikes, and a reduction in spike frequency was observed. Subsequently, single doses reduced photosensitivity in appropriate patients. Single-blind administration of LTG for 1 week in addition to the patients' regular antiepileptic drugs (AEDs), in patients with refractory seizures, reduced seizures despite the short duration of therapy. This regimen was continued using a placebo-controlled crossover study with 1-week duration of treatment. Efficacy in partial and tonic-clonic seizures was subsequently confirmed in four double-blind crossover studies; a meta-analysis of these four studies showed a 30% reduction in partial seizures despite the intractable nature of the seizures in the patients included. Current studies aim at evaluating the drug as monotherapy and in different seizure types.

To explore the clinical phenotype and genetic characteristics of two children with developmental epileptic encephalopathy type 66. Genomic DNA was extracted from peripheral blood samples of the two children and their parents. Whole exome sequencing (WES) was carried out and suspected variant was verified by Sanger sequencing. The main manifestations of the two children were neonatal onset seizures, hypotonia, global developmental delay, and facial dysmorphisms. Cranial MRI showed delayed myelination in case 1 and cerebellar dysgenesis in case 2. WES has identified a de novo pathogenic variant in the PACS2 gene in both patients, namely c.625G>A (p.Glu209Lys)(NM_001100913.3), which was reported as a pathogenic variant before. This variant was predicted to be pathogenic according to the American College of Medical Genetics and Genomics guideline (PS2+PM2+PP3). The seizures were controlled after combination treatment of sodium valproate and levetiracetam in both cases. At last follow-up, the motor and intellectual development of the 2 cases were improved. Compared with the cases reported, the clinical symptoms and signs of our cases were relatively mild, and the treatment effects were fairly good. The variant of c.625G>A (p.Glu209Lys) in PACS2 gene is a hotspot variant of developmental epileptic encephalopathy 66. Gene testing can facilitate the clinical diagnosis and treatment.

Rectal administration of several different preparations of diazepam to a group of adult volunteer patients with epilepsy produced variable rates of absorption. Peak serum concentrations following 10 mg, 20 mg, and 30 mg of diazepam solution were achieved between 13-60 min, 10-120 min, and 30-90 min respectively. An experimental diazepam "solid solution" suppository was found to have significantly better absorption characteristics compared with the commercially available Valium suppository. Diazepam solution 20 mg was administered rectally in 10 adult epileptic patients with frequent spontaneous interictal spikes in their EEGs. A highly significant reduction in spike frequency was seen compared with placebo. The effect was most marked 10-20 min after administration of diazepam, when the mean spike count fell to 39 +/- 35 SD percent of the control value (p less than 0.01), and this corresponded with a mean serum diazepam level of 210 +2- 125 ng/ml.

Developmental epileptic encephalopathy (DEE) refers to conditions where cognitive functions are impacted both by seizures as well as interictal epileptiform activities and the neurobiological processes involved. They lead to early onset refractory epilepsy causing progressive decline in cerebral function, developmental delay, and significant EEG changes. Glutaminyl-tRNA synthetase (QARS) is encoded by the QARS gene and its mutation has been implicated as one of the causes of DEE. We report two cases of siblings with QARS mutation-associated DEE, severe global developmental delay, and microcephaly. The babies were born of a non-consanguineous marriage. All basic investigations and metabolic tests of both siblings were normal. Magnetic resonance imaging of the brain of both siblings showed loss of cerebral white matter. Electroencephalography showed multifocal epileptiform discharges in the left temporo-occipital and right frontal regions. Both siblings suffered from refractory epilepsy. Genetic tests and clinical exome sequencing revealed homozygous missense variation in exon 2 of the QARS 1 gene in both the siblings, and heterozygous states for their parents. There is a wide range of aetiologies for DEE with microcephaly, which have overlapping clinical presentations. With growing awareness and availability of genetic tests, it has become possible to do workups for complex neurological disorders. Establishing precise etiology helps in outlining the treatment (if available) and providing a prognosis to parents. It also plays a critical role in planning future pregnancies.

Allopregnanolone decreases interictal spiking and fast ripples in an animal model of mesial temporal lobe epilepsy

The X-linked human glutamate receptor subunit 3 (GRIA3) gene (MIM *305915, Xq25) encodes ionotropic α amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA)-type glutamate receptor subunit 3, which mediates postsynaptic neurotransmission. Variants in this gene can cause a variety of neurological disorders, primarily reported in male patients. Here, we report a female patient with developmental and epileptic encephalopathy who carries the novel de novo GRIA3 variant NM_007325.5: c.1982T > C: p.Met661Thr.

Interictal spike frequency varies with ovarian cycle stage in a rat model of epilepsy

Developmental epileptic encephalopathy (DEE) in children presents significant diagnostic and management challenges. Advances in whole-exome sequencing (WES) have enabled the identification of rare genetic variants, offering new insights into these complex conditions. Here, we report a 2.5-year-old girl with refractory epilepsy and DEE, in whom WES revealed a novel homozygous SULT4A1 splice-site variant. Although the SULT4A1 variant likely contributed to her condition, the later emergence of motor and speech delay in a sibling with the same mutation suggests variable expressivity or age-dependent onset, rather than incomplete penetrance. The patient partially responded to immunotherapy but continued to experience breakthrough seizures and developmental delays, highlighting the challenges in managing such disorders. This case underscores the importance of genetic testing, functional studies, and genetic counseling in the diagnosis and treatment of rare neurodevelopmental disorders.

Variations in the WWOX gene have been identified as the leading cause of several central nervous system disorders. However, most previous reports have focused on the description of clinical phenotype, neglecting functional verification. Herein, we presented a case of a patient with developmental epileptic encephalopathy (DEE) caused by WWOX gene variation. Our patient was a 13-month-old girl with abnormal facial features, including facial hypotonia, arched eyebrows, a broad nose, and a depressed nasal bridge. She also had sparse and yellow hair, a low anterior hairline, and a short neck. Before the age of 8 months, she was suffering from mild seizures. Her developmental delay gradually worsened, and she suffered infantile spasms. After treatment with vigabatrin, seizures subsided. WWOX gene homozygous variation c.172+1G>C was identified using whole exome sequencing. Further minigene assay confirmed that the variation site affected splicing, causing protein truncation and affecting its function. Clinical phenotype and minigene results suggest that WWOX gene homozygous variation c.172+1G>C can cause severe DEE. We also concluded that vigabatrin can effectively treat seizures.