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Purpose: Myoclonic status in nonprogressive encephalopaties (MSNE) is characterized by recurrence of long-lasting myoclonic status appearing in infants and young children with nonprogressive encephalopathy. Here, we describe the electroclinical features and evolution of MSNE. Methods: Between February 1, 1990 and July 31, 2005, 29 patients who met diagnostic criteria of MSNE were enrolled in the study at our department and have been followed up to the present time. Results: Three main subgroups could be identified. The first subgroup of 18 patients presented myoclonic absences and rhythmic myoclonias. These were followed by a brief silent period related to a subcontinuous delta-theta activity involving the central areas, and rhythmic delta waves with superimposed spikes mainly involving the parietooccipital regions and often activated by eye closure. It was found in all children with a genetic etiology. The second subgroup included five patients showing a pattern characterized by inhibitory phenomena associated with a dystonic component and sudden irregular rapid lightning-like jerks. The EEG showed subcontinuous multifocal slow spike-waves, predominating in frontocentral regions. These patients are affected by a cortical malformation or the etiology is unknown. The third subgroup included six children who initially suffered from myoclonic absences. The status was initially characterized by subcontinuous generalized spike-wave-type paroxysms related to rhythmic myoclonia of face and limbs. After 1–3 weeks, the EEG showed sharp theta waves with very slow pseudorhythmic continuous spikes in the central regions and vertex. The etiology was found to be perinatal anoxic injury. Conclusion: MSNE should be considered as a new epileptic syndrome in the group of epileptic encephalopathy. [ABSTRACT FROM AUTHOR]

Background: Rolandic epilepsy (RE) is the most common genetic childhood epilepsy, consisting of focal, nocturnal seizures and frequent neurodevelopmental impairments in speech, language, literacy and attention. A complex genetic aetiology is presumed in most, with monogenic mutations in GRIN2A accounting for >5% of cases., Objective: To identify rare, causal CNV in patients with RE., Methods: We used high-density SNP arrays to analyse the presence of rare CNVs in 186 patients with RE from the UK, the USA, Sardinia, Argentina and Kerala, India., Results: We identified 84 patients with one or more rare CNVs, and, within this group, 14 (7.5%) with recurrent risk factor CNVs and 15 (8.0%) with likely pathogenic CNVs. Nine patients carried recurrent hotspot CNVs including at 16p13.11 and 1p36, with the most striking finding that four individuals (three from Sardinia) carried a duplication, and one a deletion, at Xp22.31. Five patients with RE carried a rare CNV that disrupted genes associated with other epilepsies ( KCTD7 , ARHGEF15 , CACNA2D1, GRIN2A and ARHGEF4 ), and 17 cases carried CNVs that disrupted genes associated with other neurological conditions or that are involved in neuronal signalling/development. Network analysis of disrupted genes with high brain expression identified significant enrichment in pathways of the cholinergic synapse, guanine-exchange factor activation and the mammalian target of rapamycin., Conclusion: Our results provide a CNV profile of an ethnically diverse cohort of patients with RE, uncovering new areas of research focus, and emphasise the importance of studying non-western European populations in oligogenic disorders to uncover a full picture of risk variation., Competing Interests: Competing interests: LA is a contractor for Eli Lilly and Company. SVT has received research grants from the Scientific bodies under the Government of India. DM consults for Cyberonics., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)