SCN1A Channels a Wide Range of Epileptic Phenotypes: Report of Novel and Known Variants with Variable Presentations.

SCN1A, the gene encoding for the Nav1.1 channel, exhibits dominant interneuron-specific expression, whereby variants disrupting the channel's function affect the initiation and propagation of action potentials and neuronal excitability causing various types of epilepsy. Dravet syndrome (DS), the first described clinical presentation of SCN1A channelopathy, is characterized by severe myoclonic epilepsy in infancy (SMEI). Variants' characteristics and other genetic or epigenetic factors lead to extreme clinical heterogeneity, ranging from non-epileptic conditions to developmental and epileptic encephalopathy (DEE). This current study reports on findings from 343 patients referred by physicians in hospitals and tertiary care centers in Greece between 2017 and 2023. Positive family history for specific neurologic disorders was disclosed in 89 cases and the one common clinical feature was the onset of seizures, at a mean age of 17 months (range from birth to 15 years old). Most patients were specifically referred for SCN1A investigation (Sanger Sequencing and MLPA) and only five for next generation sequencing. Twenty-six SCN1A variants were detected, including nine novel causative variants (c.4567A>Τ, c.5564C>A, c.2176+2T>C, c.3646G>C, c.4331C>A, c.1130_1131delGAinsAC, c.1574_1580delCTGAGGA, c.4620A>G and c.5462A>C), and are herein presented, along with subsequent genotype-phenotype associations. The identification of novel variants complements SCN1A databases extending our expertise on genetic counseling and patient and family management including gene-based personalized interventions.

Pediatric tumefactive multiple sclerosis case (with baló-like lesions), diagnostic and treatment challenges.

BACKGROUND: Multiple sclerosis (MS) is a demyelinating disease of the central nervous system, rare during childhood. MS variations, like tumefactive MS and Balo concentric sclerosis, constitute puzzling to treat diagnostic dilemmas for pediatric patients. Differential diagnosis, mainly from brain tumors, is an absolute necessity. In addition, apart from treating acute attacks, immunomodulatory alternatives are limited. CASE: We present a 12.5-year-old boy diagnosed, 5 years ago, with tumefactive relapsing-remitting MS, with severe recurrent clinical attacks. Definite diagnosis of demyelination was achieved via combined brain imaging including magnetic resonance (MR) imaging, MR spectroscopy and computed tomography, avoiding brain biopsy. Acute attacks showed satisfactory response to aggressive treatment choices, like plasmapheresis and cyclophosphamide, but age-appropriate immunomodulating treatment was available, only 2 years later. Finally, after a last radiological relapse, when he was 10 years old, fingolimod was initiated. He has been clinically and radiologically stable since, presenting an excellent treatment tolerance.

A dynamic trinucleotide repeat (TNR) expansion in the DMD gene.

Dystrophinopathies are allelic X-linked myopathies caused by large deletions/duplications or small lesions along the DMD gene. An unexpected dynamic trinucleotide (GAA) expansion, ranging from ∼59 to 82 pure GAA repeats, within the DMD intron 62, was revealed to segregate through three family generations. From the pedigree, two female patients were referred for DMD investigation due to chronic myopathy and a muscle biopsy compatible with dystrophinopathy. As the size of the GAA repeat is limited to 11-33 within the general population our findings may provide a novel insight towards a Trinucleotide Repeat Expansion. Whether this TNR has an impact on the reported phenotype remains to be resolved.

Frontal lobe epilepsy and mild malformation with oligodendroglial hyperplasia: Further observations on electroclinical and imaging phenotypes, and surgical perspectives.

OBJECTIVE: Mild malformation with oligodendroglial hyperplasia (MOGHE) is a recently described clinicopathologic entity, associated with drug-resistant epilepsy and extensive epileptogenic networks. Knowledge is accumulating about particular electroclinical phenotypes, correlations with imaging, and potential prognostic significance for surgical outcomes. The study adds relevant information by documenting the presence of a hyperkinetic frontal lobe seizure phenotype in adolescents and an epileptic encephalopathy phenotype in young children. METHODS: Five cases were subjected to a structured presurgical evaluation protocol, including EEG-FMRI, chronic and acute invasive EEG, subjected to frontal lobe surgery with postoperative follow-up between 15 months and 7 years. RESULTS: In the two adult cases, surface EEG demonstrated lateralized widespread frontal lobe epileptogenicity and hyperkinetic semiological features. MRI demonstrated cortical white matter blurring and deeper white matter abnormalities. EEG-FMRI suggested concordant frontal lobe involvement. iEEG demonstrated a widespread frontal lobe epilepsy network. The three young children demonstrated a diffuse epileptic encephalopathy phenotype, with nonlocalizing, nonlateralizing surface EEG, and "spasms" as the main seizure type. MRI demonstrated extensive frontal lobe subcortical gray and white matter abnormalities, consistent with MOGHE literature for this age, while EEG-FMRI, in 2/3, demonstrated concordant frontal lobe involvement. They did not undergo chronic iEEG, and the resection was assisted by acute intraoperative ECoG. All cases were subjected to extensive frontal lobectomies with Engel class IA (2/5), IB (1/5), and IIB (2/5) outcomes. SIGNIFICANCE: The study confirms the presence of frontal lobe epilepsy and epileptic encephalopathy phenotypes, in accordance with epilepsy phenotypes already described in MOGHE literature. Presurgical evaluation studies, including EEG-FMRI, can provide strong lateralizing and localizing evidence of the epileptogenic networks involved. All responded favorably to extensive frontal lobe resections, despite widespread epileptic activity recorded by surface and intracranial EEG pre- and postoperatively; an epileptic encephalopathy phenotype, in the first years of life, should not discourage such a resection.

Combined exome analysis and exome depth assessment achieve a high diagnostic yield in an epilepsy case series, revealing significant genomic heterogeneity and novel mechanisms.

OBJECTIVES: Genetics of epilepsy are highly heterogeneous and complex. Lesions detected involve genes encoding various types of channels, transcription factors, and other proteins implicated in numerous cellular processes, such as synaptogenesis. Consequently, a wide spectrum of clinical presentations and overlapping phenotypes hinders differential diagnosis and highlights the need for molecular investigations toward delineation of underlying mechanisms and final diagnosis. Characterization of defects may also contribute valuable data on genetic landscapes and networks implicated in epileptogenesis. METHODS: This study reports on genetic findings from exome sequencing (ES) data of 107 patients with variable types of seizures, with or without additional symptoms, in the context of neurodevelopmental disorders. RESULTS: Multidisciplinary evaluation of ES, including ancillary detection of copy number variants (CNVs) with the ExomeDepth tool, supported a definite diagnosis in 59.8% of the patients, reflecting one of the highest diagnostic yields in epilepsy. CONCLUSION: Emerging advances of next-generation technologies and 'in silico' analysis tools offer the possibility to simultaneously detect several types of variations. Wide assessment of variable findings, specifically those found to be novel and least expected, reflects the ever-evolving genetic landscape of seizure development, potentially beneficial for increased opportunities for trial recruitment and enrollment, and optimized, even personalized, medical management.

Genetic cause of epilepsy in a Greek cohort of children and young adults with heterogeneous epilepsy syndromes.

We describe a cohort of 10 unrelated Greek patients (4 females, 6 males; median age 6.5 years, range 2-18 years) with heterogeneous epilepsy syndromes with a genetic basis. In these patients, causative genetic variants, including two novel ones, were identified in 9 known epilepsy-related genes through whole exome sequencing. A patient with glycine encephalopathy was a compound heterozygote for the p.Arg222Cys and the p.Ser77Leu AMT variant. A patient affected with Lafora disease carried the homozygous p.Arg171His EPM2A variant. A de novo heterozygous variant in the GABRG2 gene (p.Pro282Thr) was found in one patient and a pathogenic variant in the GRIN2B gene (p.Gly820Val) in another patient. Infantile-onset lactic acidosis with seizures was associated with the p.Arg446Ter PDHX gene variant in one patient. In two additional epilepsy patients, the p.Ala1662Val and the novel non-sense p.Phe1330Ter SCN1A gene variants were found. Finally, in 3 patients we observed a novel heterozygous missense variant in SCN2A (p.Ala1874Thr), a heterozygous splice site variant in SLC2A1 (c.517-2A>G), as a cause of Glut1 deficiency syndrome, and a pathogenic variant in STXBP1 (p.Arg292Leu), respectively. In half of our cases (patients with variants in the GRIN2B, SCN1A, SCN2A and SLC2A1 genes), a genetic cause with potential management implications was identified.

Case Report: Intracranial Hypertension Secondary to Guillain-Barre Syndrome.

Guillain-Barre Syndrome (GBS), a common cause of acute flaccid paralysis, is characterized by a rapidly progressive, usually symmetric weakness of the extremities. Headache and intracranial hypertension (ICHT) are very rare complications of GBS. Herein we report our current case of an obese girl with typical signs of GBS associated with autonomic dysfunction, cranial nerve deficits and increased intracranial pressure (ICP). We also perform a systematic study presenting and discussing previous case reports of GBS associated with ICHT, papilledema or hydrocephalus, highlighting the differences of the current case compared to previous studies. Although intracranial hypertension is a rare complication of pediatric GBS, clinicians should promptly detect it. Obesity may be a predisposing factor, given the strong association between idiopathic intracranial hypertension (IIH) and weight gain. Neurological evaluation, fundus examination and low threshold for intracranial imaging should be an integral part of medical practice in case of obesity, headache or visual changes in GBS patients.

Evaluation of Genotypes and Epidemiology of Spinal Muscular Atrophy in Greece: A Nationwide Study Spanning 24 Years.

BACKGROUND: Promising genetic treatments targeting the molecular defect of severe early-onset genetic conditions are expected to dramatically improve patients' quality of life and disease epidemiology. Spinal Muscular Atrophy (SMA), is one of these conditions and approved therapeutic approaches have recently become available to patients. OBJECTIVE: Analysis of genetic and clinical data from SMA patients referred to the single public-sector provider of genetic services for the disease throughout Greece followed by a retrospective assessment in the context of epidemiology and genotype-phenotype associations. METHODS: Molecular genetic analysis and retrospective evaluation of findings for 361 patients tested positive for SMA- and 862 apparently healthy subjects from the general population. Spearman rank test and generalized linear models were applied to evaluate secondary modifying factors with respect to their impact on clinical severity and age of onset. RESULTS: Causative variations- including 5 novel variants- were detected indicating a minimal incidence of about 1/12,000, and a prevalence of at least 1.5/100,000. For prognosis a minimal model pertaining disease onset before 18 months was proposed to include copy numbers of NAIP (OR = 9.9;95% CI, 4.7 to 21) and SMN2 (OR = 6.2;95% CI, 2.5-15.2) genes as well as gender (OR = 2.2;95% CI, 1.04 to 4.6). CONCLUSIONS: This long-term survey shares valuable information on the current status and practices for SMA diagnosis on a population basis and provides an important reference point for the future assessment of strategic advances towards disease prevention and health care planning.

Focal epileptic seizures anticipation based on patterns of heart rate variability parameters.

BACKGROUND AND OBJECTIVE: Heart rate variability parameters are studied by the research community as potential valuable indices for seizure detection and anticipation. This paper investigates heart activity abnormalities during focal epileptic seizures in childhood. METHODS: Seizures affect both the sympathetic and parasympathetic system which is expressed as abnormal patterns of heart rate variability (HRV) parameters. In the present study, a clinical dataset containing 42 focal seizures in long-term electrocardiographic (ECG) recordings from drug-resistant pediatric epileptic patients (with age 8.2 ±â€¯4.3 years) was analyzed. RESULTS: Results indicate that the time domain HRV parameters (heart rate, SDNN, standard deviation of heart rate, upper envelope) and spectral HRV parameters (LF/HF, normalized HF, normalized LF, total power) are significantly affected during ictal periods. The HRV features were ranked in terms of their relevance and efficacy to discriminate non-ictal/ictal periods and the top-ranked features were selected using the minimum Redundancy Maximum Relevance algorithm for further analysis. Then, a personalized anticipation algorithm based on multiple regression was introduced providing an "epileptic index" of imminent seizures. The performance of the system resulted in anticipation accuracy of 77.1% and an anticipation time of 21.8 s. CONCLUSIONS: The results of this analysis could permit the anticipation of focal seizures only using electrocardiographic signals and the implementation of seizure anticipation strategies for a range of real-life clinical applications.

Tolosa-Hunt Syndrome: Clinical Manifestations in Children.

BACKGROUND: Tolosa-Hunt syndrome (THS) is a rare condition in children characterized by painful ophthalmoplegia caused by inflammation of unknown etiology in the cavernous sinus, superior orbital fissure, or orbital apex. Our main purpose was to report two pediatric cases of THS, a typical one and another extremely rare one preceded by facial palsy. METHODS: Both cases were diagnosed with THS based on the 2013 International Classification of Headache Disorders (ICHD-3 beta) criteria. A literature review was also performed concerning epidemiology, clinical and imaging features, diagnostic criteria, treatment, and outcome of THS with a focus on children. RESULTS: The first patient was a 14-year-old boy who presented with third nerve palsy, four weeks after the diagnosis and treatment of peripheral seventh nerve palsy and the second patient was a 10-year-old girl who presented with a five-day history left-sided ptosis, periorbital pain, and diplopia. CONCLUSIONS: THS is a rare condition in pediatric population that requires an extensive evaluation before the final diagnosis is made. Seventh nerve palsy preceding the diagnosis of THS is particularly rare in children. This patient represents only the second reported example of seventh nerve involvement in a child with THS.

Screening for TSC1 and TSC2 mutations using NGS in Greek children with tuberous sclerosis syndrome.

Tuberous Sclerosis Complex (TSC) is a rare neurocutaneous syndrome inherited by an autosomal dominant manner. The disorder is commonly manifested by the presence of multiple benign tumors located in numerous tissues, including the brain, heart, skin and kidneys. Seizures, autism, developmental and behavioral delay, as well as non-neurological phenotypic findings, are suggestive of TSC. The identification of one pathogenic mutation in either the TSC1 or TSC2 genes is considered to be an independent diagnostic criterion. In our study, seventeen Greek patients, 2yo on average, were analyzed for the presence of pathogenic germline mutations in the aforementioned loci by Next-Generation Sequencing. A TSC1/2 gene panel was designed for the molecular diagnosis of the disease. Patients underwent initial diagnosis based on their clinical symptoms, most frequently involving the presence of skin lesions and/or epilepsy. Only one case was familial. Sixteen different genetic alterations were identified in TSC1 and TSC2 genes in fifteen patients, giving a 88% detection rate by employing NGS technology. Overall, most pathogenic mutations (11/15) identified were located in the TSC2 gene with exon 41 being the most frequent. With respect to genotype-phenotype association, no patient TSC1 (+) developed SEGA or renal cysts. No significant differences were observed between different types of TSC2 mutations and any clinical feature. Sequencing also revealed 18 different SNPs across the TSC1 and 20 across the TSC2 genes. This is the first registry of the genetic profile of TSC patients in Greece using a custom-made gene panel as molecular diagnostic tool.

A computational platform for continuous seizure anticipation, monitoring and clinical evaluation.

The development of platforms that are able to continuously monitor and handle epileptic seizures in a non invasive manner is of great importance as they would improve the quality of life of drug resistant epileptic patients. In this work, a device and a computational platform is presented for acquiring low noise electroencephalographic signals, for the detection/prediction of epileptic seizures and the storage of ictal activity in an electronic personal health record. In order to develop this platform, a systematic clinical protocol was established including a number of drug resistant children from the University Hospital of Heraklion. Dry electrodes with innovative micro-spike design were proposed in order to increase the signal to noise ratio of the recorded EEG signals. A wearable low cost platform and its corresponding wireless communication protocol was developed focus on minimizing the interference with the patient's body. A computational subsystem with advanced algorithms provides detection/anticipation of upcoming seizure activity and aims to protect the patient from an accident due to a seizure or to improve his/her social life. Finally, the seizure activity information is stored in an electronic health record for further clinical evaluation.

In vitro proliferative and differentiating characteristics of CD133(+) and CD34(+) cord blood cells in the presence of thrombopoietin (TPO) or erythropoietin (EPO). Potential implications for hematopoietic cell transplantation.

We investigated the characteristics of cord blood (CD) CD133(+) and CD34(+) cells, by flow cytometry, clonogenic assays and assessment of the replating ability (area under the curve (AUC)) following 7-day liquid culture in the presence of early acting growth factors and either thrombopoietin (TPO) or erythropoietin (EPO). The CD34(+) population showed a more effective proliferation in all parameters tested and TPO proved to be more effective than EPO. On the contrary, the CD133(+) cell fraction retained and expanded more immature elements in a modest but consistent manner with either TPO or EPO. We conclude that CD133(+) and CD34(+) expanded cord blood cells could potentially be used in combination to overcome the shortcomings of cord blood transplantation in older children and adults.

An approach to absence epileptic seizures detection using Approximate Entropy.

Epilepsy is one of the most common chronic neurological diseases and the most common neurological chronic disease of childhood. The electroencephalogram (EEG) signal provides significant information neurologists take into consideration in the investigation and analysis of epileptic seizures. The Approximate Entropy (ApEn) is a formulated statistical parameter commonly used to quantify the regularity of a time series data of physiological signals. In this paper ApEn is used in order to detect the onset of epileptic seizures. The results show that the method provides promising results towards efficient detection of onset and ending of seizures, based on analyzing the corresponding EEG signals. ApEn parameters affect the method's behavior, suggesting that a more detailed study and a consistent methodology of their determination should be established. A preliminary analysis for the proper determination of these parameters is performed towards improving the results.

Absence seizure epilepsy detection using linear and nonlinear EEG analysis methods.

In this study, we investigated three measures capable of detecting absence seizures with increased sensitivity based on different underlying assumptions. Namely, an information-based method known as Approximate Entropy, a nonlinear alternative (Order Index), and a linear variance analysis approach. The results on the long-term EEG data suggest increased accuracy in absence seizure detection achieving sensitivity as high as 97.33% with no further application of any sophisticated classification scheme.

The impact of mode of delivery and gestational age on cord blood hematopoietic stem/progenitor cells.

Human cord blood has been successfully used as an alternative source of hematopoietic stem cells suitable for transplantation. The aim of this study was to assess the impact of gestational age and the mode of delivery on cord blood hematopoietic stem/progenitor cell characteristics. The mode of delivery does not seem to affect either the replating capacity of hematopoietic progenitors colony-forming unit-granulocyte-macrophage or the cord blood content in CD34(+) cells. The higher percentage of CD34(+) cells in cord blood from preterm deliveries compared to full-term ones indicates that hematopoietic progenitors from preterm cord blood may be suitable for transplantation. These findings should be taken into consideration when selection of cord blood units is required for potential use in transplantation.