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Metabolic diseases, brain malformations, and central nervous system infections
Published in Lena Hellström-Westas, Linda S. de Vries, Ingmar Rosén, Atlas of AMPLITUDE-INTEGRATED EEGs in the NEWBORN, 2008
Lena Hellström-Westas, Linda S de Vries, Ingmar Rosén
Burst-suppression EEG background is associated with some severe encephalopathies, such as non-ketotic hyperglycinemia, hemimegalencephaly, and Ohtahara syndrome.161–164 Other EEG findings, including asymmetries and epileptic seizure activity, may also be present. Some of the background EEG changes associated with these diseases can also be found in the aEEG, as seen in the examples below.
Central nervous system: Paediatric and neurodevelopmental disorders
Published in Angus Clarke, Alex Murray, Julian Sampson, Harper's Practical Genetic Counselling, 2019
A persisting and severe epileptic encephalopathy may have many different causes. Among those with an underlying genetic basis, there is a wide range of genes that can be involved. There are two X-chromosome genes to mention, ARX and CDKL5, and three autosomal dominant genes, SCN1A, STXBP1 and GRIN2A, to single out as especially important. The phenotypes associated with SCN1A constitute a wide range of clinical disorders, from ‘benign’ febrile seizures in young children, often familial, to Dravet syndrome, that often begins with severe febrile seizures at ∼6 months and then leads into a severe lifelong epilepsy disorder that changes in character, is difficult to treat and is not usually passed to children because patients are unlikely to reproduce. Also difficult to treat is the lifelong epileptic disorder that can result from mutations in CDKL5, most often affecting girls and often also causing microcephaly, autism and spasticity and sharing some behavioural features with Rett syndrome. ARX mutations will often cause infantile spasms, like CDKL5 mutations, and are also known as a cause of lissencephaly. Pathogenic variants in STXBP1 are an important cause of the Ohtahara syndrome. Different mutations in GRIN2A may have different effects on the function of the NMDA receptor and may respond best to different treatments. The potential for such a rational approach to therapeutics is one of the eagerly anticipated benefits of molecular precision diagnostics in the channelopathies. However, this will not be as straightforward as ‘one drug for (seizures caused by) one gene’.
Genetic and clinical variations of developmental epileptic encephalopathies
Published in Neurological Research, 2023
Gül Demet Kaya Özçora, Elif Söbü, Uğur Gümüş
Developmental and epileptic encephalopathy type 7 (DEE 7) was the most common type in our study group. DEE 7 is frequently characterised by neonatal-onset refractory seizures, delayed neurodevelopment and persistent neurologic deficits. Seizures resolve by 3–4 years of age with improvement in EEG abnormalities. The severity of the disease may vary within the family. In our study, all patients with DEE 7 had neonatal seizures. The initial EEGs of patients 6 and 9 revealed a burst-suppression pattern that could subsequently progress to multifocal epileptiform activity (MFED), and were consistent with a clinical diagnosis of Ohtahara syndrome. Patients 6 and 9 were exitus, patient 7 was followed because of refractory epilepsy and patient 8 was developing close to normal. Dysmorphology was also present in patients 6 and 9. The authors note that the phenotypic variability could be due to the interplay of pathogenic mutations, modifying genes and more subtle environmental factors. In children with self-limiting neonatal epilepsy due to a pathogenic KCNQ2 variant, the flow of brain potassium ions is disturbed but to a lesser extent than in children with KCNQ2 developmental and epileptic encephalopathy. This difference possibly explains why these children have less severe disease than children with KCNQ2 developmental and epileptic encephalopathy [19–22]. In our study, the form with the most severe phenotype and the most resistant seizures was seen in DEE 7 and half of these patients died. Patients 6, 7 and 9 had de-novo mutations and patient 8 had a familial mutation and mild phenotypic features.
High-Definition transcranial direct current stimulation in early onset epileptic encephalopathy: a case study
Published in Brain Injury, 2018
Oded Meiron, Rena Gale, Julia Namestnic, Odeya Bennet-Back, Jonathan David, Nigel Gebodh, Devin Adair, Zeinab Esmaeilpour, Marom Bikson
Epileptic encephalopathy syndromes such as Ohtahara syndrome (OS), present during infancy (first 3 months), can invoke frequent continuous tonic spasms, focal motor seizures, hemiconvulsions, generalized tonic-clonic seizures, focal myoclonus, and suppression-burst pattern (SB), which can be detected with electroencephalography (EEG) (1). This severe electroclinical condition is often classified as “infantile spasms with hypsarrhythmia” related to non-metabolic structural brain abnormalities and hypsarrhythmic EEG features consisting of multifocal spikes, sharp wave activity, and high-voltage slow wave activity (2–5). The prognosis is generally poor since newborns with Ohtahara syndrome frequently die during infancy and survivors invariably manifest severe psychomotor impairments and remain in a persistent vegetative state (6).
Neonate, Infant, Childhood, and Adolescent Epilepsy Syndromes
Published in The Neurodiagnostic Journal, 2023
Ohtahara Syndrome (also known as EIEE) is a syndrome characterized by frequent underlying intractable seizures and reduced life expectancy. According to the National Institute of Neurological Disease (NINDS n.d.a), it is distinguished by seizures that are hard to control and developmental delays. Tonic seizures are commonly seen. Ohtahara syndrome is considered an “epileptic encephalopathy.” This term indicates that the epileptic activity itself might directly contribute to additional cognitive and behavioral impairments. It is thought that suppressing epileptic activity might minimize this additional damage (NINDS n.d.a).