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Purpose: To report on a new phenotype in a patient carrying a novel, undescribed de novo variant in POLR3B, affected by generalized myoclonic epilepsy and neurodevelopmental disorder, without neuropathy. It is known that biallelic pathogenic variants in POLR3B cause hypomyelinating leukodystrophy-8, and heterozygous de novo variants are described in association to a phenotype characterized by predominantly demyelinating sensory-motor peripheral neuropathy, ataxia, spasticity, intellectual disability and epilepsy, in which the peripheral neuropathy is often the main clinical presentation., Methods: We collected clinical, electrophysiological and neuroimaging data from the affected subject and performed a Trio-Clinical Exome Sequencing., Results: We detected a de novo novel heterozygous missense variant c.1132A>G in POLR3B (NM_018082.6) that was considered as likely pathogenic following ACMG criteria. We also consulted our custom genomic database of a total of 1485 patients that were genetically analysed from 2018 for epilepsy, and found no other de novo variants in the POLR3B gene., Conclusion: We hypothesize a possible genotype-phenotype correlation, particularly regarding epilepsy. We also provide a review of the literature about the previously described POLR3B heterozygous patients, with particular attention to the epileptic phenotype, underlining the association between POLR3B and early onset myoclonic epilepsy, which can represent the main manifestation of the disease at its onset., Competing Interests: Declaration of competing interest None., (Copyright © 2024 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Mutations in the MED13 gene are reported in the literature in association with clinically variable, neurodevelopmental disorders, which are characterized by mild-to-severe intellectual disability, autism spectrum disorder, attention deficit/hyperactivity disorder, epilepsy, ocular or skeletal abnormalities, congenital cardiac defects, and facial dysmorphisms. Here, we report a patient with an epileptic phenotype carrying a novel missense mutation characterized by developmental and epileptic encephalopathy with infantile spasms., Methods: Through trio-based WES, we identified a novel de novo heterozygous missense variant c.2501A>G in the MED13 gene. We reviewed all medical charts of the present patient and reviewed all previously reported cases with pathogenic variants of MED13., Results: This study involves a 24-month-old boy with epilepsy onset at the age of 3 months with drug-resistant focal seizures followed by infantile spasms at the age of 10 months. He had a severe, developmental delay along with microcephaly and dysmorphic features. From a literature review, it emerged that epilepsy is described in only one out of nineteen of previously reported patients with a phenotype of generalized, drug-resistant epilepsy with myoclonic-atonic seizures. Microcephaly, developmental delay, hypotonia, corpus callosum abnormalities, deafness, and retinal atrophy were common features in the previously described cases., Conclusion: This case expands the genetic landscape of infantile spasms as well as the phenotype of MED13-related disorders adding the electroclinical features of early-onset developmental and epileptic encephalopathy with infantile spasms to the previously described, generalized epilepsy with myoclonic-atonic seizures., Competing Interests: Declaration of Competing Interest None of the authors have any conflicts of interest to declare., (Copyright © 2022. Published by Elsevier Ltd.)

Purpose: Epilepsy is a main manifestation in the autosomal dominant mental retardation syndrome caused by heterozygous variants in MEF2C. We aimed to delineate the electro-clinical features and refine the genotype-phenotype correlations in patients with MEF2C haploinsufficiency., Methods: We thoroughly investigated 25 patients with genetically confirmed MEF2C-syndrome across 12 different European Genetics and Epilepsy Centers, focusing on the epileptic phenotype. Clinical features (seizure types, onset, evolution, and response to therapy), EEG recordings during waking/sleep, and neuroimaging findings were analyzed. We also performed a detailed literature review using the terms "MEF2C", "seizures", and "epilepsy"., Results: Epilepsy was diagnosed in 19 out of 25 (~80%) subjects, with age at onset <30 months. Ten individuals (40%) presented with febrile seizures and myoclonic seizures occurred in ~50% of patients. Epileptiform abnormalities were observed in 20/25 patients (80%) and hypoplasia/partial agenesis of the corpus callosum was detected in 12/25 patients (~50%). Nine patients harbored a 5q14.3 deletion encompassing MEF2C and at least one other gene. In 7 out of 10 patients with myoclonic seizures, MIR9-2 and LINC00461 were also deleted, whereas ADGRV1 was involved in 3/4 patients with spasms., Conclusion: The epileptic phenotype of MEF2C-syndrome is variable. Febrile and myoclonic seizures are the most frequent, usually associated with a slowing of the background activity and irregular diffuse discharges of frontally dominant, symmetric or asymmetric, slow theta waves with interposed spike-and-waves complexes. The haploinsufficiency of ADGRV1, MIR9-2, and LINC00461 likely contributes to myoclonic seizures and spasms in patients with MEF2C syndrome., (Copyright © 2021. Published by Elsevier Ltd.)

Purpose: GRIA3, encoding subunit 3 of glutamate ionotropic AMPA receptor, is associated with X-linked intellectual disability (ID), dysmorphic features, and non-syndromic epilepsy. We aimed to characterize electro-clinical features of patients with GRIA3 variants., Methods: We report a patient carrying a hemizygous missense variant c.2359 G > A (p.Glu787Lys) inGRIA3 gene. Following a literature search, we also reviewed clinical, electrophysiological, radiological, and genetic features of 19 patients with GRIA3 mutations., Results: This 26-month-old boy had developmental delay, early onset refractory myoclonic epilepsy, and non-convulsive refractory status epilepticus. In published reports, epilepsy was in 6 of 19 patients carrying different genotypes, though epilepsy and electroencephalogram features were not completely defined. Out of the 6 patients, one presented with generalized tonic-clonic seizures, two with myoclonic and clonic events (one also presented with epileptic spasms), and one with atypical absences and myoclonic jerks. Information on type of epilepsy was unavailable for 3 cases. Epilepsy onset was early in life and there was potential tendency for myoclonic/clonic events. The epilepsy was difficult to treat and prognosis is poor. Severity of ID ranged from mild to severe and was variably associated with bipolar affective disorder and autistic spectrum disorders. Other neurological features included hypotonia, asthenic body habitus with poor muscle bulk, and hyporeflexia., Conclusion: Our report expands knowledge on the electro-clinical and molecular spectrum of GRIA3 variants. Larger investigations will better define the prevalence of epilepsy, the epileptic phenotype, and syndromic features underlying GRIA3 variants., (Copyright © 2020. Published by Elsevier Ltd.)

CHD2 gene has been described in association with different types of childhood myoclonic epilepsy and is emerging as a gene involved in photosensitivity alone or combined with epilepsy. Recent studies suggest that CHD2 could be responsible for a proper phenotype characterized by infantile-onset generalized epilepsy, intellectual disability, and photosensitivity and in particular with self-induced seizures. We report the case of a child with CHD2 mutation and mild developmental impairment that since the age of 3 years started with myoclonic seizures apparently well responding to antiepileptic drugs and that subsequently developed intractable self-induced seizures. Through an accurate Video-EEG polygraphic analysis, we demonstrated that seizures are related to an abnormal increase of epileptiform activity after eye-closure or loss of fixation as observed in the Fixation-Off Sensitivity (FOS) phenomenon. In conclusion our study adds relevant features of the CHD2-epilepsy phenotype and confirms that CHD2 mutations produce a distinctive form of myoclonic epilepsy with visual-sensitive seizures., (Copyright © 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: to evaluate the efficacy and safety of intravenous (IV) lacosamide (LCM) in the treatment of seizure clusters (SC) and status epilepticus (SE) in hospitalized adult patients., Methods: we prospectively analyzed treatment response, seizure outcome, and adverse effects of IV LCM in 38 patients with seizure emergencies (15 with SC, 23 with SE) during a hospital stay. The loading dose of IV LCM was 200-400mg and the maintenance dose was 200-400mg daily. Response to IV LCM was evaluated within 20min, 4h and 24h of LCM infusion., Results: an acute anti-seizure effect after IV LCM was especially evident when it was first used - (SC) or second line (established SE) treatment. In particular, 87% of SC patients (13/15) and 80% of established SE (8/10) demonstrated response to LCM treatment, while no patients with super-refractory SE (0/8) responded to IV LCM according to our criteria. The loading of IV LCM was well tolerated, with mild adverse effects (2/38 temporary dizziness). In most patients, during and after administration of the loading dose of IV LCM a temporary (30min-1h) sedation was observed. No ECG and laboratory values-changes were documented in any of the patients., Conclusions: LCM is an effective and well-tolerated treatment when used to treat SC in hospitalized adult patients. As add-on therapy, it may be useful to stop seizure activity in patients with focal SE not responding to first/second-line intravenous AEDs., (Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Dravet syndrome (DS) is a rare disorder with seizure onset in the first year of life, typically beginning with prolonged febrile hemiclonic seizures or generalized tonic-clonic seizures. Photosensitivity is reported in more than 40% of patients. We present two cases of DS in which we had the chance to record occipital seizures induced by Intermittent Photic Stimulation (IPS)., Method: We retrospectively reviewed the medical records of 32 children affected by DS. All clinical notes were reviewed in order to evaluate the occurrence of seizures induced by IPS., Results: Among the 32 reviewed clinical records, two patients with IPS-induced seizures were found. In both patients seizures originated from the occipital-temporal region. Clinical history was characterized by generalized tonic-clonic seizures, and myoclonia. At the age respectively of 11 months and 20 months they presented a prolonged focal seizure induced by IPS at a frequency of 10 Hz. During the follow-up they additionally presented with hypomotor seizures, also induced by IPS during laboratory EEG examinations. The semiology of hypomotor seizures resembled what is described as "complex partial status", a type of non-convulsive status with ictal discharges arising unilaterally from the occipito-temporal region., Conclusion: Based on available literature, IPS induced occipital seizures have not been reported during the first year of life. Although pathophysiological features are not yet completely understood, both photosensitivity and occipital seizures should be considered in the diagnostic evaluation in DS. The documentation of IPS induced occipital seizures might contribute to widen the clinical and neurophysiological spectra of DS., (Copyright © 2014 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

West Syndrome (WS) is a severe epileptic encephalopathy occurring in the first year of life. According the ILAE classification of epileptic seizures and epilepsy the etiology could be symptomatic or cryptogenic. Some authors identified a small group of patients (5%) with a particular good outcome, a complete recovery from seizures and a normal cognitive development within the cryptogenic group that they suggested to be idiopathic. Between 1996 and 2007, at the Neurology Division of the Bambino Gesù Children's Hospital in Rome, we collected 241 patients with WS. Sixteen (6.6%) were considered with idiopathic aetiology. All clinical notes of these patients were reviewed in order to evaluate the prevalence of other epileptic syndrome after WS. Two of them had at the age of 8 and 3 months idiopathic WS, and at the age of 6 and 4 years respectively, they presented with childhood absence epilepsy (CAE) successfully treated with valproate. The favorable evolution of the WS and the later occurrence of an idiopathic form of epilepsy, such as CAE, confirm the possibility of an idiopathic aetiology for WS that, although rare, can represent one of the etiologies of otherwise severe syndrome. Even if a common physiophatogenetic role, probably related to a genetic predisposition, could be hypothesized and appears to be intriguing, no data are available and more studies are needed to confirm this hypothesis., (Copyright © 2010 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)