To study clinical, electroencephalographic and neuroimaging features in children with epileptic syndromes associated with focal clonic seizures (FCS). We examined 1258 patients with various forms of epilepsy with the onset of seizures from the first day of life to 18 years. FCS was identified in 263 patients (20.9%). FCS were included in the structure of 13 different epileptic syndromes: Rolandic epilepsy (28.1%), structural focal epilepsy (27.5%), structural focal epilepsy associated with benign epileptiform discharges of childhood (SFE-BEDC) (20.6%), focal epilepsy of unknown etiology (7.5%), epilepsia partialis continua (4.6%), pseudo-Lennox syndrome (3.4%), ESES syndrome (2.7%), Landau-Kleffner syndrome (1.5%), Dravet syndrome (1.1%), benign occipital epilepsy (1.1%), benign focal epilepsy in infancy (0.8%), MISF syndrome (0.8%), cognitive epileptiform disintegration (0.8%). In 50% of cases, epilepsy associated with FCS debuts before the age of 5 years (from 1 month to 18 years, average age 4.26±3.9). The groups of syndromes associated with FCS have different prognosis for remission of seizures. Prognostic predictors of seizure remission are: epileptic syndromes associated with BEDC, the presence of periventricular leukomalacia. A severe prognosis for the course of epilepsy is associated with local structural changes in the neocortex. Despite a favorable prognosis for seizures, continued diffuse interictal epileptiform activity with BEDC on the electroencephalogram is a predictor of the onset of cognitive impairment in children. Изучение клинических, электроэнцефалографических и нейровизуализационных характеристик эпилептических синдромов, ассоциированных с фокальными клоническими приступами (ФКП) у детей. Под наблюдением находились 1258 пациентов с дебютом приступов от 1-х суток жизни до 18 лет с различными формами эпилепсии. ФКП выявлены у 263 (20,9%) пациентов. ФКП вошли в структуру 13 различных эпилептических синдромов: роландической эпилепсии (28,1%), структурной фокальной эпилепсии (27,5%), фокальной эпилепсии детства у детей со структурными изменениями в мозге и доброкачественными эпилептиформными паттернами детства на ЭЭГ (20,6%), фокальной эпилепсии неизвестной этиологии (7,5%), Кожевниковской эпилепсии, включая энцефалит Расмуссена (4,6%), синдрома псевдо-Леннокса (3,4%), электрического эпилептического статуса медленного сна (2,7%), синдрома Ландау—Клеффнера (1,5%), тяжелой миоклонической эпилепсии младенчества (1,1%), доброкачественной затылочной эпилепсии (1,1%), доброкачественной фокальной эпилепсии младенчества (0,8%), MISF (0,8%), когнитивной эпилептиформной дезинтерграции (0,8%). В 50% случаев эпилепсия, ассоциированная с ФКП, дебютирует до 5 лет. Максимальное количество случаев дебюта приходится на возраст 4—7 лет. Группы синдромов, ассоциированных с ФКП, имеют разный прогноз в отношении ремиссии приступов. Найдены прогностические предикторы ремиссии приступов: эпилептические синдромы, ассоциированные с доброкачественными эпилептиформными паттернами ЭЭГ детства, наличие перивентрикулярной лейкомаляции. Тяжелый прогноз течения эпилепсии ассоциирован с локальными структурными изменениями неокортекса. Предиктор появления когнитивных нарушений у детей — продолженная диффузная межприступная эпилептиформная активность с доброкачественными эпилептиформными паттернами детства на ЭЭГ, несмотря на благоприятный прогноз относительно приступов.

Self-limited infantile epilepsy (SeLIE) has distinctive clinical features, and the PRRT2 gene is known to be a considerable genetic cause. There have been a few studies on PRRT2-positive SeLIE only, and anti-seizure medications are often required due to frequent seizures at initial seizure onset. This study aimed to provide clinical information for the early recognition of patients with PRRT2-positive SeLIE and to propose effective anti-seizure medications for seizure control. We retrospectively reviewed 36 patients diagnosed with SeLIE with genetically confirmed pathogenic variants of PRRT2. In addition, six atypical cases with neonatal-onset seizures and unremitting after 3 years of age were included to understand the expanded clinical spectrum of PRRT2-related epilepsy. We analyzed the initial presentation, clinical course, and seizure control response to anti-seizure medications. Patients with PRRT2-related epilepsy had characteristic seizure semiology at the initial presentation, including all afebrile, clustered (n = 23, 63.9%), short-duration (n = 33, 91.7%), and bilateral tonic-clonic seizures (n = 26, 72.2%). Genetic analysis revealed that c. 649dupC was the most common variant, and six patients had a 16p11.2 microdeletion containing the PRRT2 gene. One-third of the patients were sporadic cases without a family history of epilepsy or paroxysmal movement disorders. In the 33 patients treated with anti-seizure medications, sodium channel blockers, such as carbamazepine, were the most effective in seizure control. Our results delineated the clinical characteristics of PRRT2-positive SeLIE, differentiating it from other genetic infantile epilepsies and discovered the effective anti-seizure medications for initial clustered seizure control. If afebrile bilateral tonic-clonic seizures develop in a normally developed infant as a clustered pattern, PRRT2-positive SeLIE should be considered as a possible diagnosis, and sodium channel blockers should be administered as the first medication for seizure control.

A number of mutations to members of several CNS potassium (K) channel families have been identified which result in rare forms of neonatal onset epilepsy, or syndromes of which one prominent characteristic is a form of epilepsy. Benign Familial Neonatal Convulsions or Seizures (BFNC or BFNS), also referred to as Self-Limited Familial Neonatal Epilepsy (SeLNE), results from mutations in 2 members of the KV7 family (KCNQ) of K channels; while generally self-resolving by about 15 weeks of age, these mutations significantly increase the probability of generalized seizure disorders in the adult, in some cases they result in more severe developmental syndromes. Epilepsy of Infancy with Migrating Focal Seizures (EIMSF), or Migrating Partial Seizures of Infancy (MMPSI), is a rare severe form of epilepsy linked primarily to gain of function mutations in a member of the sodium-dependent K channel family, KCNT1 or SLACK. Finally, KCNMA1 channelopathies, including Liang-Wang syndrome (LIWAS), are rare combinations of neurological symptoms including seizure, movement abnormalities, delayed development and intellectual disabilities, with Liang-Wang syndrome an extremely serious polymalformative syndrome with a number of neurological sequelae including epilepsy. These are caused by mutations in the pore-forming subunit of the large-conductance calcium-activated K channel (BK channel) KCNMA1. The identification of these rare but significant channelopathies has resulted in a resurgence of interest in their treatment by direct pharmacological or genetic modulation. We will briefly review the genetics, biophysics and pharmacology of these K channels, their linkage with the 3 syndromes described above, and efforts to more effectively target these syndromes.

Sodium voltage-gated channel alpha subunit 2 (SCN2A) gene encodes the Nav1.2 subunit of voltage-gated sodium channel in pyramidal neurons. SCN2A gain-of-function mutations are identified more and more often with gene panels and whole exome sequencing. Phenotype ranges from benign neonatal or infantile seizures to severe epileptic encephalopathy. Although large series of patients targeting genetic background point out two main phenotypes with SCN2A encephalopathy, Ohtahara syndrome and malignant migrating partial seizures in infancy (EMPSI), we noticed that in fact, a peculiar clinical and electroencephalogram (EEG) sequence distinct from these syndromes should suggest the diagnosis early. We report three new cases with de novo SCN2A mutations - 166237617C>A p.(Asp1487Glu), c.407T>G p.(Met136Arg), and c.4633A>G p.(Met1545Val) - diagnosed by direct sequencing or genes panel, their follow-up ranging from 4 to 5 years. For all three patients, seizures started at two days of life and consisted of apnea and cyanosis with partial clonic or tonic, alternating on both sides with, up to 100/day, evolving to generalized tonic-clonic seizures (GTCS) and epileptic spasms by three months. First EEG showed a discontinuous pattern, evolving to multifocal spikes, by 3 (two patients) and 6 months (one). Seizure frequency decreased progressively by the middle or end of the first year of life. Only less frequent GTCS persisted during the second year of life for two patients. Improvement was observed in two patients with sodium channel blocker (phenytoin) used at age of 1 month for one patient and at 2 years for another one. All patients remained with severe psychomotor delay. All three infants share a condition different from Ohtahara syndrome in which tonic spasms predominate and suppression-burst pattern is obvious, and from EMPSI, in which partial migrating discharges involve successively the various parts of the brain including occipital regions with oculoclonic seizures, but there is neither discontinuous pattern nor therapeutic response to sodium channel blockers. Neonatal SCN2A encephalopathy has a recognizable phenotype starting soon after birth with alternating partial motor seizures evolving to infantile spasms and a discontinuous EEG pattern. Seizures improve spontaneously in the first year of life. This electroclinical sequence should indicate the search of SCN2A mutation and suggest the administration of sodium channel blockers.

Benign infantile epilepsy is an epileptic syndrome of infancy. Until now, only a small number of case-series have been published. To study the frequency, semiology and prognosis of benign infantile epilepsy. The 827 patients with one or more epileptic seizures seen at our hospital between 1 June 1994 and 1 March 2011 were included and prospectively followed. A diagnosis of benign infantile epilepsy was made in patients that fulfilled the following criteria at six month of evolution: one or more focal and/or generalised seizures, onset before 24 months, no neurological deficit and normal neuroimaging and interictal EEG. 77 cases (9%) met the diagnostic criteria. Semiology of the seizures was similar to that of other focal seizures in children under 24 months. 25% of the patients remained as isolated seizures. Among those with two or more seizures, the probability of achieving a 3 year initial remission without antiepileptic treatment was 86%. In the subgroup of patients with focal seizures without family history the probability was 74% and in five cases a global developmental delay/intellectual disability was detected thereafter. Benign infantile epilepsy is a frequent epileptic syndrome. Semiology of seizures is not useful to characterize the syndrome. A diagnosis of benign infantile epilepsy at six month of evolution implies a reasonably good prognosis, but possibly not as good as for other self-limited epilepsies of infancy. Frecuencia, semiologia y pronostico de la epilepsia infantil benigna. Introduccion. La epilepsia infantil benigna es un sindrome epileptico sobre el que hasta ahora se ha publicado tan solo un pequeño numero de series de casos. Objetivo. Estudiar la frecuencia, semiologia y pronostico de la epilepsia infantil benigna. Pacientes y metodos. Los 827 pacientes con una o mas crisis epilepticas no provocadas que consultaron en nuestro hospital entre el 1 de junio de 1994 y el 1 de marzo de 2011 fueron incluidos y seguidos prospectivamente. Se diagnosticaron de epilepsia infantil benigna los pacientes que cumplieron los siguientes criterios a los seis meses de evolucion: una o mas crisis focales o generalizadas, inicio antes de los 24 meses, ausencia de deficits neurologicos y electroencefalograma y neuroimagen normales. Resultados. Cumplieron los criterios diagnosticos 77 casos (9%). La semiologia de las crisis fue similar a la de otras crisis focales en niños menores de 24 meses. Un 25% de los pacientes permanecio como con crisis aisladas. Entre los de dos o mas crisis epilepticas, la probabilidad de alcanzar una remision inicial de tres años sin tratamiento antiepileptico fue del 86%. En el subgrupo de pacientes con crisis focales sin antecedentes familiares, la probabilidad fue del 74%, y en cinco casos se detecto posteriormente un retraso psicomotor o discapacidad intelectual. Conclusiones. La epilepsia infantil benigna es un sindrome epileptico frecuente. La semiologia de las crisis no es util para caracterizar el sindrome. El diagnostico de epilepsia infantil benigna a los seis meses de evolucion implica un pronostico razonablemente bueno, pero posiblemente no tanto como el de otras epilepsias autolimitadas de la infancia.