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Objective: In this study, we present the electroclinical features and outcomes of 92 patients with epileptic spasms (ES) in clusters without modified or classical hypsarrhythmia that started in either in infancy or in childhood; we compared both groups in terms of electroclinical features, etiology, treatment, evolution, and outcome., Methods: Between June 2000 and July 2022, 92 patients met the electroclinical diagnostic criteria of ES in clusters without hypsarrhythmia. Patients with ES associated with other epileptic encephalopathies including West Syndrome, as well as those with the specific etiology of ES and developmental and epileptic encephalopathy associated with CDKL5 were excluded., Results: The patients were divided into two groups based on the age at ES onset: those with ES onset before (Group 1) and those with ES onset after 2 years of age (Group 2). The features of ES and the type of associated seizures before and after ES onset, as well as the interictal and ictal EEG and electromyography findings were similar in both groups. The etiologies were mainly structural (40.2%), genetic (11.9%), and unknown (44.6%) in majority of the patients in both groups. Thirty-one patients were seizure-free, while in the remaining patients the seizures continued. Nine patients (9.8%) with unilateral structural lesions underwent surgery with good results. The neurological abnormalities and developmental findings prior to ES onset depended on the underlying etiology., Conclusion: Our series of patients may represent a well-defined epileptic syndrome or type of epilepsy with onset in infancy or childhood characterized by ES in clusters without hypsarrhythmia associated with focal and generalized seizures and EEG paroxysms without neurological deterioration., (Copyright © 2024. Published by Elsevier B.V.)

Purpose: We retrospectively analyzed the electroclinical features, treatment, and outcome of patients with Panayiotopoulos syndrome (PS) who presented with unusual clinical manifestations., Method: A retrospective, descriptive, multicenter study was conducted evaluating 44 patients with PS who had seizures with an unusual semiology. Data from patients with PS seen at eight Argentine centers between April 2000 and April 2019 were collected., Results: Twelve patients (29.2%) had ictal syncope or syncope-like epileptic seizures. Three children (7.3%) had recurrent episodes of vomiting. Four patients (9.7%) presented with urinary incontinence associated with autonomic signs and consciousness impairment. One child had hiccups with autonomic manifestations followed by eye deviation. One boy had episodes of laughter with autonomic symptoms followed by loss of consciousness. Six patients (14.6%) had hyperthermia without acute febrile illness with autonomic symptoms as the first manifestation. Six others (14.6%) had focal motor seizures characterized by eye and head deviation in four and eyelid blinking in two. Four patients (9.7%) had ictal headache as the initial manifestation followed by nausea and vomiting. Two children (4.8%) had their first seizure while asleep associated with cardiorespiratory arrest. Two children (4.8%) had oral automatisms, such as sucking and chewing. In two children (4.8%) coughing was the initial manifestation followed by emetic symptoms. One patient (2.3%) had vertigo with a sensation of fear, with eye deviation and unresponsiveness. One child started with continuous spikes and waves during slow sleep, behavior disturbances, and emetic symptoms., Conclusion: In this study, evidence of the existence of unusual clinical cases of PS with typical EEG patterns was found. Outcome was excellent., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Purpose: The objective of the study was to describe the initial clinical and electroencephalographic findings in children with late-infantile neuronal ceroid lipofuscinosis (LINCL)., Method: The clinical charts of 35 patients seen between 1990 and 2016 were reviewed. The patients were divided into two groups: Group 1 (G1) consisting of 12 patients with NCL type 2 (CLN2) disease confirmed by enzymatic activity in dried blood spots on filter paper and/or genetic studies, and Group 2 (G2) consisting of 23 patients with a diagnosis of LINCL based on pathology studies by muscle biopsy., Results: Mean age at symptom onset was 3 years in G1 and 3.4 years in G2. Symptoms at onset were epilepsy in 58%, language delay in 34%, and gait disturbances in 8% of patients in G1 and epilepsy in 52.1%, language delay in 26%, gait disturbances in 17.4%, and loss of visual acuity in 4.5% in G2. The most common seizure types in G1 patients were myoclonic in 3/7, generalized tonic-clonic in 2/7, focal motor in 1/7, and febrile seizures in 1/7; in G2 patients they were myoclonic in 5/12, generalized tonic-clonic in 3/12, myoclonic-atonic in 2/12, and febrile seizures in 2/12. A photoparoxysmal response to intermittent photic stimulation (IPS) was found in the initial EEG in 9/12 patients in G1 (mean age 3.8 years) and in 10/13 patients in G2 (mean age 3.9 years)., Conclusions: There were no significant differences between both groups. Seizures, especially myoclonic, are the most common symptom at onset followed by language delay and gait disturbances. Low-frequency IPS is a useful study that may help facilitate the diagnosis of the disease., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: To present a retrospective study of 13 children with benign epilepsy with centrotemporal spikes (BECTS), also known as benign rolandic epilepsy (BRE), associated with generalized spikes and waves as the only EEG manifestation at onset., Method: Charts of children with typical clinical criteria of BRE electroclinically followed-up between February 2000 and February 2015 were reviewed., Results: Among 309 patients who met the electroclinical criteria of BRE, we identified 13 children who presented with the typical clinical manifestations but who, on the EEG, only had generalized paroxysms at onset that continued along the course of the syndrome. Generalized spike-and-wave discharges were observed in all patients when awake and during sleep (100%). During the evolution no particular electroclinical pattern was observed. The patients responded well to antiepileptic drugs, such as valproic acid and levetiracetam. Outcome was good in all patients., Conclusions: We found evidence that patients with BRE may have generalized EEG discharges at onset as the sole manifestation lasting throughout the course of the syndrome. In some, focal paroxysms developed later. The course was benign. In our group of patients, clinical features and evolution were similar to those of typical cases of BRE. Response to valproic acid and levetiracetam was found to be particularly good., (Copyright © 2018 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

The concept of epilepsy syndromes, introduced in 1989, was defined as "clusters of signs and symptoms customarily occurring together". Definition of epilepsy syndromes based on electro-clinical features facilitated clinical practice and, whenever possible, clinical research in homogeneous groups of patients with epilepsies. Progress in the fields of neuroimaging and genetics made it rapidly clear that, although crucial, the electro-clinical description of epilepsy syndromes was not sufficient to allow much needed development of targeted therapies and a better understanding of the underlying pathophysiological mechanisms of seizures. The 2017 ILAE position paper on Classification of the Epilepsies recognized that "as a critical tool for the practicing clinician, epilepsy classification must be relevant and dynamic to changes in thinking". The concept of "epilepsy syndromes" evolved, incorporating issues related to aetiologies and comorbidities. A comprehensive update (and revision where necessary) of the EEG diagnostic criteria in the light of the 2017 revised terminology and concepts was deemed necessary. Part 2 covers the neonatal and paediatric syndromes in accordance with the age of onset. [Published with educational EEG plates at www.epilepticdisorders.com].

We report on an 18-month-old boy with unilateral left eye blinking as a single ictal manifestation without facial twitching. The clinical onset of this phenomenon was first recorded (as an occasional event) at age 3 months, and it was overlooked. By age 6 months, the child's blinking increased to almost daily occurrence in clusters: during blinking the infant showed intact awareness and occasional jerks in the upper limbs and right leg. A video-electroencephalography (video-EEG) documented clinical correlation with a focal pattern arising from the left occipital region, and brain magnetic resonance imaging (MRI) revealed severe brain damage, consisting in poroencephalic hollows and increased spaces in the convexities involving a large area of the left cerebral hemisphere. The boy was prescribed sodium valproate (30 mg/kg/d), resulting in drastic reduction of his clinical seizures. Follow-up to his current age documented good general status, with persistent partial right hemilateral seizures. The blinking progressively disappeared, and is no longer recorded. The pathogenic hypotheses of the unilateral ictal blinking include involvement of the ipsilateral cerebral hemisphere and/or the cerebellar pathways. Review of previous reports of unilateral eye blinking, arising from the ictal ipsilateral brain, revealed that different damaged regions may give rise to blinking ictal phenomena, likely via the trigeminal fibres innervating the subdural intracranial structures and the pial vessels in the ipsilateral affected brain. The eye blinking in the present child represents a further example of an ictal phenomenon, which is predictive of the damaged brain region., (© EEG and Clinical Neuroscience Society (ECNS) 2014.)

Objective: We analyzed the electroclinical features, etiology, treatment, and outcome of 12 patients with West syndrome (WS) associated with focal hypsarrhythmia (FH)., Methods: Between February 2005 and July 2013, 12 patients met the electroclinical diagnostic criteria of WS associated with FH. Hypsarrhythmia was considered to be focal when two or three brain lobes were involved. Patients with hemihypsarrhythmia were excluded., Results: All patients had epileptic spasms (ES) in clusters of a structural etiology. Four had a porencephalic cyst, two had focal cortical dysplasia, two had open-lip schizencephaly, and one each had unilateral polymicrogyria, shunted hydrocephalus, glioma, and cerebral hemiatrophy. Age at ES onset was between 2 and 8 months, with a mean age of 5 and a median age of 6 months. Seven patients had asymmetric ES, three had symmetric ES, and two patients had unilateral ES. FH was seen over the posterior regions in nine and over the anterior regions in three. Ictal EEG recordings showed diffuse high-amplitude slow waves in six patients, diffuse slow waves followed by voltage attenuation in three, and diffuse fast rhythms in three others. In three patients the ictal paroxysms were unilateral. Six patients responded well to surgery., Conclusion: ES associated with FH are secondary to structural lesions. Surgery should be considered earlier in the management of this group of patients., (Copyright © 2016 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: To retrospectively analyze the electroclinical features, etiology, treatment, and prognosis of 21 patients with encephalopathy with hemi-status epilepticus during sleep (ESES) or hemi-continuous spikes and waves during slow sleep (CSWSS) syndrome., Methods: Charts of 21 patients with hemi-ESES/CSWSS syndrome followed between 1997 and 2012 were analyzed. Inclusion criteria were: (1) Focal seizures or apparently generalized seizures and focal EEG epileptiform discharges; (2) Further occurrence of atypical absences, and myoclonic, atonic, and/or generalized seizures; (3) Cognitive impairment and/or behavioral disturbances; (4) Hemi-continuous spike-and-wave discharges during slow sleep in more than 85% of non-REM sleep at onset and throughout the ESES/CSWSS period., Results: Mean follow-up from onset of hemi-ESES/CSWSS was 8 years (range, 2-15 years). Idiopathic cases were not identified. Unilateral polymicrogyria was found in 11, shunted hydrocephalus in four, a porencephalic cyst associated with polymicrogyria in three, and a thalamic lesion in three children. All started with focal seizures with or without secondary generalization. During the hemi-ESES/CSWSS period, all children developed new types of seizure, such as negative and positive myoclonus, absences, motor deterioration, cognitive impairment, and behavioral disturbances. All AED responders returned to baseline cognitive development. Seven patients were refractory to AEDs., Conclusion: Our study suggests that the hemi-ESES/CSWSS syndrome has electroclinical features compatible with an epileptic encephalopathy. The most commonly used treatments were clobazam, ethosuximide, and sulthiame, alone or in combination. In refractory cases, high-dose corticosteroids were administered. Although the number of patients in this study is too low to draw definite conclusions, we consider that in children with hemi-ESES/CSWSS secondary to a unilateral lesion, surgery should be considered., (Copyright © 2013 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

Purpose: Myoclonic epilepsy in infancy (MEI) is characterized by brief generalized myoclonic seizures associated with generalized spike-wave paroxysms without other seizure types occurring in the first 3 years of life in developmentally normal children. In this study we analyze the electroclinical features, treatment, and outcome of 38 patients with MEI., Methods: A retrospective chart review was conducted in 38 patients followed at the Neurology Department of the Pediatric Hospital Juan P. Garrahan in Buenos Aires, Argentina, between 1990 and 2012., Key Findings: A total of 24 boys and 14 girls were identified. The mean and median ages at seizure onset were 16 and 18 months, respectively (range 3-40 months). Ten patients (28.9%) had a family history of epilepsy, and six (15.8%) had a family history of febrile seizures. All patients had several daily brief and isolated myoclonic seizures during wakefulness and predominantly in the first two stages of sleep. Twelve children (31.5%) had reflex myoclonus, triggered by a tactile stimulus in 10 and additionally by noise and light in 2. The remaining two had photosensitive myoclonic jerks. The interictal electroencephalography (EEG) recordings evidenced generalized spike waves, polyspikes, and polyspike-wave paroxysms. The interictal EEG was normal in 12 patients. The abnormalities on the ictal EEG were similar to those on the interictal EEG. Most of the patients responded well to valproic acid. After a mean follow-up of 13.5 years, 24 patients (63%) were without treatment. At the last examination, 32 patients had normal neurologic and neuropsychological evaluations. Two patients (5.2%) had significant cognitive impairment (an IQ of 60 and 63, respectively) despite good seizure control. Four patients (10.4%) had significant learning impairment, two of whom also had attention deficit hyperactivity disorder., Significance: MEI is a well-defined epileptic syndrome of unknown etiology, but likely of a genetic cause. It is self-limited and pharmacosensitive mainly to valproic acid., (Wiley Periodicals, Inc. © 2013 International League Against Epilepsy.)

Epilepsy with myoclonic-atonic seizures is characterized by myoclonic-atonic, absence, tonic-clonic, and eventually tonic seizures, appearing in previously normal children at ages 18-60 months. We analyzed the electroclinical features, treatment, and outcome of 69 patients with myoclonic-atonic seizures; these patients were followed between 1990 and 2012 at the Juan P. Garrahan Pediatric Hospital, Buenos Aires, Argentina. No structural or metabolic etiology was identified. Based on the electroclinical features and evolution, two groups could be distinguished. The first group of 39 patients with myoclonic and myoclonic-atonic seizures with or without generalized tonic-clonic seizures and absences associated with generalized spike- and polyspike-and-wave paroxysms had excellent prognoses. The second group of 30 patients had myoclonic jerks and myoclonic-atonic seizures associated with other seizure types including tonic seizures; some had myoclonic status epilepticus and cognitive deterioration. The interictal EEG showed frequent generalized spike- and polyspike-and-wave paroxysms. In 16 patients, the seizures remitted within 3.6 years. The two groups were distinguished in retrospect, when enough time had elapsed to evaluate cognitive deterioration and different seizure types. In conclusion, epilepsy with myoclonic atonic seizures is an epileptic syndrome with a broad clinical spectrum and variable prognosis., (Copyright © 2013 Elsevier Inc. All rights reserved.)

In this study, we describe three patients who each had an electroclinical overlap of two different epileptic encephalopathies (EE), with onset in a certain age period. Patient 1 had electroclinical features compatible with continuous spikes and waves during slow sleep (CSWSS) syndrome that changed into Lennox-Gastaut syndrome (LGS) (symptomatic, cause porencephalic cyst) at the age of 8.5 years. Patient 2 had LGS which evolved into CSWSS at the age of 6 years (symptomatic, cause polymicrogyria). The third patient had cryptogenic CSWSS syndrome at age the age of 7 years which evolved into LGS at the age of 7.5 years. All three patients could be considered to have two EE: CSWSS syndrome and LGS or to have had overlapping features of these epileptic syndromes., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Purpose: Early onset absence seizures have been considered a rare heterogeneous group with a poor prognosis. Only few patients may be categorized into well-known syndromes. We have evaluated electroclinical features, evolution, and the nosologic boundaries of early onset absence seizures., Methods: Forty-six neurologically normal patients with absence seizures associated with bilateral, synchronic, or asynchronic, and symmetric or asymmetric spike-and-wave paroxysms with onset in the first 3 years of life were included. Patients with abnormal neurologic examination and brain imaging were excluded from the study., Key Findings: In our study, 39 patients met the clinical and electroencephalography (EEG) criteria of well-defined epileptic syndromes. Childhood absence epilepsy was found in 11 patients, benign myoclonic epilepsy in infancy in 18 patients, eyelid myoclonic epilepsy in 4, and epilepsy with myoclonic absences in 6. We did not find clinical and EEG criteria of well-recognized epileptic syndromes in seven children. Nine of 11 patients with simple absence seizures became seizure free. All these patients had normal neurologic and neuropsychological evaluations. Of the 35 patients who had absence seizures associated with myoclonic seizures, 20 became seizure free. Fifteen of 35 children continue having seizures. At the last visit, 20 of these 35 patients had normal neurologic and neuropsychological evaluations, 11 presented with mild mental retardation, and 4 with severe mental retardation., Significance: Epilepsies with absence seizures of early onset are relatively uncommon. Most of the patients had well-defined epileptic syndromes with a variable evolution. The evolution depended on the epileptic syndromes., (Wiley Periodicals, Inc. © 2011 International League Against Epilepsy.)

We present a patient with cryptogenic focal epilepsy and another with Dravet syndrome, who experienced seizure aggravation and negative myoclonus, associated with continuous spikes and waves during slow sleep, induced by levetiracetam. For both patients levetiracetam was discontinued, and there was significant improvement of this particular electroclinical picture.

Purpose: We studied the electroclinical features and evolution in patients with childhood absence epilepsy (CAE) associated with electroencephalographic findings similar to those of benign focal epilepsies (BFE) with or without clinical manifestations compatible with these focal idiopathic syndromes., Methods: Between June 1994 and June 2002, we found 203 (3.6%) patients with typical electroclinical features of CAE among 8285 children with epilepsy. From this population of 203, we found 30 cases (14.7%) that also showed focal abnormalities of BFE on the EEG. Seven of these 30 cases also had clinical manifestations of BFE that preceded the onset of the absences., Results: There were 20 (66.5%) boys and 10 (33.5%) girls. Age at onset of absences ranged from 2 to 10.5 years, with a mean age of 5.5 years. Of 30, 7 had focal clinical seizures as well. Three of seven had seizures characteristic of Panayiotopoulos syndrome (PS), and the other four had seizures compatible with childhood occipital epilepsy (COE) of Gastaut. The focal seizures started between 3 and 7 years of age. In all patients seizures were under control within 2-24 months (mean: 11 months) after onset. The focal discharges disappeared in 26 patients at a mean age of 8 years (range 4-13 years), 1 year after the typical absences had disappeared. In four patients the focal paroxysms are still present., Conclusion: The association of two different idiopathic focal and generalized epilepsies in the same patient may be merely coincidental, but a close genetic relationship between both epileptic syndromes might be another hypothesis. Another explanation could be that our series of patients represent a subgroup of CAE.

We describe the electroclinical features, therapy, and long-term evolution of 17 patients with migrating focal seizures in infancy, and analyzed the charts of these patients seen between February 1985 and July 2005. Three different electroclinical patterns were recognized: (1) 8 cases with alternating simple focal motor seizures at onset. The ictal electroencephalography (EEG) pattern was characterized by recurrence of rhythmic focal spikes or rhythmic sharp activity in the Rolandic region; (2) 5 cases with complex focal seizures and progressive appearance of polymorphic delta- activity in 1 temporo-occipital region recurring independently; (3) 4 cases with focal complex seizures with motor manifestations. Ictal EEG showed flattening or fast activity in 1 frontotemporal region followed by unilateral fast poly-spikes in alternating clusters in both hemispheres. The focal seizures were refractory to antiepileptic drugs, and all patients except 3 had severe developmental delay. Migrating focal seizures in infancy is a newly defined and rare, but underrecognized, epileptic encephalopathy.

Purpose: To characterize the electroclinical features and evolution of childhood occipital epilepsy of Gastaut (COE-G)., Methods: Children with electroclinical criteria of COE-G were retrospectively identified and followed-up clinically, and with sleep and awake EEGs between 1990 and 2007., Results: We identified 33 patients with COE-G. In the same length of time, 201 children with Panayiotopoulos syndrome and 410 children with benign childhood epilepsy with centrotemporal spikes were registered. COE-G had a peak age at onset of 8.5 years. Visual manifestations were the most common ictal event. Ictal deviation of the eyes was frequent. Approximately half of the patients had migraine-like symptoms. In all patients the seizures occurred while awake, and 11 also had seizures during sleep. The majority of the patients had occipital spike-wave discharges when the eyes were closed that disappeared or attenuated when the eyes were opened. Prognosis was excellent in 80% of the cases., Conclusion: This study confirms the existence of COE-G, a rare but well-defined syndrome within the group of idiopathic focal epilepsies in childhood.

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.

We report on two girls and one boy with clinical and electroencephalographic features of late-onset childhood epilepsy with occipital paroxysms of the "Gastaut type", showing an unusual evolution. Neurological examination and brain imaging were normal in all three. At the age of 7.5 years, eight years and ten years respectively, the three children presented with episodes of visual symptoms when awake, and in one of them, the seizures were occasionally followed by oculocephalic deviation. The interictal EEG showed bilateral occipital spike-wave activated by eye closing. In two patients, the occipital seizures had been immediately followed by typical absences, since onset; in the other patient, five months after onset. The ictal EEG showed irregular bilateral occipital spike-wave discharges during the visual symptoms, followed by generalized spike-wave activity during the typical absences. The typical absences were activated by hyperventilation; the EEG did not show continuous spikes and waves during slow sleep. These three patients, with typical electroclinical features of "Gastaut type", childhood occipital epilepsy, demonstrated an evolution which, to our knowledge, has not been previously described. We investigated whether this unusual, age-dependent evolution was due to secondary bilateral synchrony or if these electroclinical features represent two types of idiopathic epileptic syndromes in the same patients.

Spasms are defined as epileptic seizures characterized by brief axial contraction, in flexion, extension or mixed, symmetric or asymmetric, lasting from a fraction of a second to 1-2s, and are associated with a slow-wave transient or sharp and slow-wave complex, followed or not by voltage attenuation. Epileptic spasms usually appear in clusters and are age-dependent. This type of epileptic spasms associated with the particular EEG pattern, hypsar rhythmia, constitutes the basis for the diagnosis of West syndrome. The question is, how to nosologically define those patients who clearly present epileptic spasms in clusters without modified or typical hypsarrhythmia and with or without focal paroxysmal discharges on the interictal EEG. In the present series, the four patients show that epileptic spasms in clusters may occur in infancy, without hypsarrhythmia. They all presented the following features: normal neuropsychological development before onset of epileptic spasms, clusters of epileptic spasms, focal clinical and/or EEG abnormalities, normal neuroradiological imaging, neurometabolic investigations and karyotypes. In three of the patients, seizures were refractory to AEDs. Epileptic spasms in clusters without hypsarrhythmia that start in the first year of life represent a subtype of infantile spasms that generally are refractory to AEDs. It is not yet clear whether it should be considered as a variant of West syndrome or not [Published with Video sequence].

Ictal blinking (IB) is a very rare disease manifesting as an epileptic motor event in children and adults. Until now it has not been included in any classification of focal seizures of the International League Against Epilepsy Commission. It could be unilateral or bilateral, isolated or in association with other motor manifestations such as limbs' clonus and spasms. Its pathogenesis has not been clearly established: paroxysmal discharges from different areas of the brain could cause IB by activation of trigeminal fibers. Herein authors report three infants and a child with IB, observed in three pediatric centers in two different countries. We also performed a review of literature data, suggesting IB as a seizure type to be included in international classifications, and describing the specific electroencephalographic pattern of this condition. [ABSTRACT FROM AUTHOR]

The term idiopathic focal epilepsies of childhood (IFE) is not formally recognised by the ILAE in its 2010 revision (Berg et al., ), nor are its members and boundaries precisely delineated. The IFEs are amongst the most commonly encountered epilepsy syndromes affecting children. They are fascinating disorders that hold many 'treats' for both clinicians and researchers. For example, the IFEs pose many of the most interesting questions central to epileptology: how are functional brain networks involved in the manifestation of epilepsy? What are the shared mechanisms of comorbidity between epilepsy and neurodevelopmental disorders? How do focal EEG discharges impact cognitive functioning? What explains the age-related expression of these syndromes? Why are EEG discharges and seizures so tightly locked to slow-wave sleep? In the last few decades, the clinical symptomatology and the respective courses of many IFEs have been described, although they are still not widely appreciated beyond the specialist community. Most neurologists would recognise the core syndromes of IFE to comprise: benign epilepsy of childhood with centro-temporal spikes or Rolandic epilepsy (BECTS/RE); Panayiotopoulos syndrome; and the idiopathic occipital epilepsies (Gastaut and photosensitive types). The Landau-Kleffner syndrome and the related (idiopathic) epilepsy with continuous spikes and waves in sleep (CSWS or ESES) are also often included, both as a consequence of the shared morphology of the interictal discharges and their potential evolution from core syndromes, for example, CSWS from BECTS. Atypical benign focal epilepsy of childhood also has shared electro-clinical features warranting inclusion. In addition, a number of less well-defined syndromes of IFE have been proposed, including benign childhood seizures with affective symptoms, benign childhood epilepsy with parietal spikes, benign childhood seizures with frontal or midline spikes, and benign focal seizures of adolescence. The term 'benign' is often used in connection with the IFEs and is increasingly being challenged. Certainly most of these disorders are not associated with the devastating cognitive and behavioural problems seen with early childhood epileptic encephalopathies, such as West or Dravet syndromes. However, it is clear that specific, and sometimes persistent, neuropsychological deficits in attention, language and literacy accompany many of the IFEs that, when multiplied by the large numbers affected, make up a significant public health problem. Understanding the nature, distribution, evolution, risk and management of these is an important area of current research. A corollary to such questions regarding comorbidities is the role of focal interictal spikes and their enduring impact on cognitive functioning. What explains the paradox that epilepsies characterised by abundant interictal epileptiform abnormalities are often associated with very few clinical seizures? This is an exciting area in both clinical and experimental arenas and will eventually have important implications for clinical management of the whole child, taking into account not just seizures, but also adaptive functioning and quality of life. For several decades, we have accepted an evidence-free approach to using or not using antiepileptic drugs in IFEs. There is huge international variation and only a handful of studies examining neurocognitive outcomes. Clearly, this is a situation ready for an overhaul in practice. Fundamental to understanding treatment is knowledge of aetiology. In recent years, there have been several significant discoveries in IFEs from studies of copy number variation, exome sequencing, and linkage that prompt reconsideration of the 'unknown cause' classification and strongly suggest a genetic aetiology. The IFE are strongly age-related, both with regards to age of seizure onset and remission. Does this time window solely relate to a similar age-related gene expression, or are there epigenetic factors involved that might also explain low observed twin concordance? The genetic (and epigenetic) models for different IFEs, their comorbidities, and their similarities to other neurodevelopmental disorders deserve investigation in the coming years. In so doing, we will probably learn much about normal brain functioning. This is because these disorders, perhaps more than any other human brain disease, are disorders of functional brain systems (even though these functional networks may not yet be fully defined). In June 2012, an international group of clinical and basic science researchers met in London under the auspices of the Waterloo Foundation to discuss and debate these issues in relation to IFEs. This Waterloo Foundation Symposium on the Idiopathic Focal Epilepsies: Phenotype to Genotype witnessed presentations that explored the clinical phenomenology, phenotypes and endophenotypes, and genetic approaches to investigation of these disorders. In parallel, the impact of these epilepsies on children and their families was reviewed. The papers in this supplement are based upon these presentations. They represent an updated state-of-the-art thinking on the topics explored. The symposium led to the formation of international working groups under the umbrella of 'Luke's Idiopathic Focal Epilepsy Project' to investigate various aspects of the idiopathic focal epilepsies including: semiology and classification, genetics, cognition, sleep, high-frequency oscillations, and parental resources (see ). The next sponsored international workshop, in June 2014, was on randomised controlled trials in IFEs and overnight learning outcome measures. [ABSTRACT FROM AUTHOR]

Objective To study the different epilepsy syndromes that included epileptic spasms (ES) in clusters without hypsarrhythmia (WoH). Methods Between 2/1990 and 7/2013, we registered 48 patients with the electroclinical diagnostic criteria of ES in clusters WoH. Results We recognized two subgroups. In the first subgroup of 30 patients, ES started at a mean age of 10.6 months (range, 2–40 months). Ictal EEG recordings showed diffuse high-amplitude slow waves in 15 patients, diffuse slow waves followed by voltage attenuation in six patients, diffuse fast rhythms in five, diffuse slow waves with superimposed fast rhythms in three, and diffuse sharp waves in one. In the second subgroup of 18 patients, nine had electroclinical features of Lennox–Gastaut syndrome, four had epilepsy with myoclonic and atonic seizures, two had Dravet syndrome, one 6-year-old boy had a non-convulsive status epilepticus characterized by atypical absences associated with ES, one had epilepsy with migrating seizures of infancy, and one patient had clinical features of subacute sclerosing panencephalitis with ES. ES started at a mean age of 6.3 years (range, 0.5–13 years). The ictal EEG recording during the ES showed diffuse fast rhythms in 10 cases, diffuse slow waves with superimposed fast rhythms in four, and diffuse slow waves in four. Conclusion Our study shows two subgroups of children with ESWoH. The first subgroup had a well-defined electroclinical syndrome predominantly in infancy, and in the second subgroup ES was one more seizure type associated with an epileptic encephalopathy other than West syndrome predominantly occurring in childhood. [ABSTRACT FROM AUTHOR]

Objective: Rolandic epilepsy is a common genetic focal epilepsy of childhood characterized by centrotemporal sharp waves on electroencephalogram. In previous genome-wide analysis, we had reported linkage of centrotemporal sharp waves to chromosome 11p13, and fine mapping with 44 SNPs identified the ELP4-PAX6 locus in two independent US and Canadian case-control samples. Here, we aimed to find a causative variant for centrotemporal sharp waves using a larger sample and higher resolution genotyping array. Methods: We fine-mapped the ELP4-PAX6 locus in 186 individuals from rolandic epilepsy families and 1000 population controls of European origin using the Illumina HumanCoreExome-12 v1.0 BeadChip. Controls were matched to cases on ethnicity using principal component analysis. We used generalized estimating equations to assess association, followed up with a bioinformatics survey and literature search to evaluate functional significance. Results: Homozygosity at the T allele of SNP rs662702 in the 30 untranslated region of PAX6 conferred increased risk of CTS: Odds ratio = 12.29 (95% CI: 3.20-47.22), P = 2.6 x 10-4 and is seen in 3.9% of cases but only 0.3% of controls. Interpretation: The minor T allele of SNP rs662702 disrupts regulation by microRNA-328, which is known to result in increased PAX6 expression in vitro. This study provides, for the first time, evidence of a noncoding genomic variant contributing to the etiology of a common human epilepsy via a posttranscriptional regulatory mechanism. [ABSTRACT FROM AUTHOR]

Objective Epileptic encephalopathy with electrical status epilepticus in sleep ( ESES) is a pediatric epilepsy syndrome with sleep-induced epileptic discharges and acquired impairment of cognition or behavior. Treatment of ESES is assumed to improve cognitive outcome. The aim of this study is to create an overview of the current evidence for different treatment regimens in children with ESES syndrome. Methods A literature search using PubMed and Embase was performed. Articles were selected that contain original treatment data of patients with ESES syndrome. Authors were contacted for additional information. Individual patient data were collected, coded, and analyzed using logistic regression analysis. The three predefined main outcome measures were improvement in cognitive function, electroencephalography ( EEG) pattern, and any improvement (cognition or EEG). Results The literature search yielded 1,766 articles. After applying inclusion and exclusion criteria, 112 articles and 950 treatments in 575 patients could be analyzed. Antiepileptic drugs ( AEDs, n = 495) were associated with improvement (i.e., cognition or EEG) in 49% of patients, benzodiazepines (n = 171) in 68%, and steroids (n = 166) in 81%. Surgery (n = 62) resulted in improvement in 90% of patients. In a subgroup analysis of patients who were consecutively reported (585 treatments in 282 patients), we found improvement in a smaller proportion treated with AEDs (34%), benzodiazepines (59%), and steroids (75%), whereas the improvement percentage after surgery was preserved (93%). Possible predictors of improved outcome were treatment category, normal development before ESES onset, and the absence of structural abnormalities. Significance Although most included studies were small and retrospective and their heterogeneity allowed analysis of only qualitative outcome data, this pooled analysis suggests superior efficacy of steroids and surgery in encephalopathy with ESES. [ABSTRACT FROM AUTHOR]

Summary: Purpose: To retrospectively analyze the electroclinical features, etiology, treatment and prognosis of 117 patients with encephalopathy with status epilepticus during sleep (ESES) or continuous spike and waves slow sleep (CSWSS) syndrome with a long-term follow-up. Methods: Charts of 117 patients with ESES/CSWSS syndrome followed between 1990 and 2012 were analyzed. Inclusion criteria were: (1) focal seizures or apparently generalized seizures and focal EEG epileptiform discharges; (2) further occurrence of atypical absences, and myoclonic, atonic, and/or generalized seizures; (3) cognitive impairment and/or behavior disturbances; (4) continuous spike-and-wave discharges during slow sleep in more than 85% of non-REM sleep. Patients with spike-and-wave discharges in less than 85% of slow sleep were also analyzed. Key findings: ‘Mean follow-up from onset of ESES/CSWSS was 13 years (range, 2–22 years) in the symptomatic/structural and non-idiopathic group consisting of 79 children and 10.5 years (range, 2–21 years) in the idiopathic group consisting of 38 children. The comparison of clinical findings and localization of paroxysmal EEG abnormalities (focal, multifocal, or generalized) at the different stages (before, during, and after ESES/CSWSS) and the percentage of spike-wave index during ESES/CSWSS between the symptomatic/structural and non-idiopathic and the idiopathic group was not statistically significant. Significance: ESES/CSWSS syndrome is an epileptic encephalopathy with similar electroclinical findings in children with a >85% spike-wave index and those with a <85% spike-wave index. In this series of patients, the most commonly used treatments were clobazam, ethosuximide, sulthiame, alone or in combination. In refractory cases, high-dose steroids were administered. Among the AED responders, the idiopathic cases returned to normality and the structural cases returned to baseline cognitive development. [Copyright &y& Elsevier]

Purpose: In children with symptomatic or idiopathic focal epilepsies, their disease may evolve into an epileptic encephalopathy related to continuous spike and wave during slow sleep (CSWS) or electrical status epilepticus during slow sleep (ESES). ESES syndrome implies serious risks of neuropsychologic impairment, and its treatment has frequently been disappointing. The aim of this study is to present our experience using sulthiame as add-on treatment in 53 patients with ESES syndrome that was refractory to other antiepileptic drugs (AEDs). Methods: Neurologic examinations, cerebral magnetic resonance imaging (MRI), and repeated prolonged sleep electroencephalography (EEG) studies were performed in all cases. Data about school achievements and or neuropsychological evaluations were obtained repeatedly during the follow-up of 1.5-16 years. Sulthiame was added in doses ranging between 5 and 30 mg/kg/day. Key Findings: Since add-on of sulthiame, 10 of 28 patients in the symptomatic group became seizure free: 4 patients with normal EEG studies and 6 with residual spikes. Nine of 28 patients showed a significant reduction in number of seizures and presented spikes but no ESES on EEG. The other nine cases showed neither clinical nor EEG improvement. A striking result was that 3 of 11 children with unilateral polymicrogyria and ESES syndrome became seizure free, and in another six a significant improvement in frequency of seizures and in EEG abnormalities seemed to be related to the add-on of sulthiame. Twenty-one of the 25 patients in the idiopathic group became seizure free and without ESES in <3 months after add on of sulthiame. In two of the patients the changes were seen in a few days. Significance: We understand that sulthiame may be effective as add-on treatment in children with ESES syndrome. [ABSTRACT FROM AUTHOR]

Early onset absence seizures have been considered a rare heterogeneous group with a poor prognosis. Only few patients may be categorized into well-known syndromes. We have evaluated electroclinical features, evolution, and the nosologic boundaries of early onset absence seizures. Forty-six neurologically normal patients with absence seizures associated with bilateral, synchronic, or asynchronic, and symmetric or asymmetric spike-and-wave paroxysms with onset in the first 3 years of life were included. Patients with abnormal neurologic examination and brain imaging were excluded from the study. In our study, 39 patients met the clinical and electroencephalography (EEG) criteria of well-defined epileptic syndromes. Childhood absence epilepsy was found in 11 patients, benign myoclonic epilepsy in infancy in 18 patients, eyelid myoclonic epilepsy in 4, and epilepsy with myoclonic absences in 6. We did not find clinical and EEG criteria of well-recognized epileptic syndromes in seven children. Nine of 11 patients with simple absence seizures became seizure free. All these patients had normal neurologic and neuropsychological evaluations. Of the 35 patients who had absence seizures associated with myoclonic seizures, 20 became seizure free. Fifteen of 35 children continue having seizures. At the last visit, 20 of these 35 patients had normal neurologic and neuropsychological evaluations, 11 presented with mild mental retardation, and 4 with severe mental retardation. Epilepsies with absence seizures of early onset are relatively uncommon. Most of the patients had well-defined epileptic syndromes with a variable evolution. The evolution depended on the epileptic syndromes. [ABSTRACT FROM AUTHOR]

To redefine benign myoclonus of early infancy (BMEI) through analysis of clinical and neurophysiologic features in 102 patients with the aim to widen the spectrum of the syndrome, including a number of different clinical expressions of transient nonepileptic paroxysmal movements occurring in normal infants. We recruited patients from one center in Argentina and two in Italy, including infants with normal neurologic and psychomotor development presenting with brief paroxysmal abnormal movements. Children with motor phenomena occurring only during sleep were excluded. Patients with abnormal interictal or ictal electroencephalography (EEG) findings were also excluded. The follow-up ranged from 2–40 years. One hundred and two infants (60 male) met the inclusion criteria. Age at onset ranged from 1–12 months, with a median age of 6.2 months. The following nonepileptic paroxysmal motor phenomena were recognized: (1) myoclonus, (2) spasms and brief tonic contractions, (3) shuddering, (4) atonia or negative myoclonus, (5) more than one type of motor phenomenon. In the majority of cases the episodes occurred only while awake and repeated several times a day. In 45 (44.1%) of the 102 cases contractions appeared in clusters. Based on the analysis of clinical and EMG features in this large series of infants, we postulate that the spectrum of the syndrome is wider than initially suspected, and that the different transient motor manifestations and their correlation with different EMG patterns will allow recognition of this definitely benign condition comprising a variety of episodic motor phenomena in normal babies. [ABSTRACT FROM AUTHOR]

Purpose: To discuss and propose a definition of autonomic status epilepticus (SE), describe its clinical and EEG features, and review what is known about its epidemiology, pathophysiology, differential diagnosis, and management. Methods: An international consortium of established researchers in the field was identified from their published work, agreed the purpose of the project, searched the literature, and, by use of e-mail communication, agreed the consensus document. Results: Autonomic SE is a condition lasting at least 30 min and characterized by epileptic activity causing altered autonomic function of any type at seizure onset or in which manifestations consistent with altered autonomic function are prominent (quantitatively dominant or clinically important) even if not present at seizure onset. It is best described, and probably most commonly encountered in children, with Panayiotopoulos syndrome. However, it also occurs in children with symptomatic epilepsies and, exceptionally, in adults. Its pathogenesis and most appropriate management are poorly understood Conclusions: It is hoped that this document will help clinical recognition of Autonomic SE, reduce misdiagnosis, and promote further interest and studies into what has been a relatively neglected area. [ABSTRACT FROM AUTHOR]

Objectives: To characterize the electroclinical features and evolution of Panayiotopoulos Syndrome (PS). Methods: Children with electroclinical criteria of PS were prospectively identified and followed-up clinically, and with sleep and awake EEGs between February 1990 and 2006. Results: We identified 192 patients with PS. In the same length of time 398 children with benign childhood epilepsy with centro-temporal spikes (BCECTS) were registered. PS had a peak age at onset of 5 years. Autonomic manifestations were one of the most common ictal event. Ictal deviation of the eyes and progression to generalized convulsions were also quite frequent. Approximately one third had partial status epilepticus. In all patients except five, the seizures occurred during sleep. One-third also had fits while awake. Sixteen children had concomitant symptoms of rolandic epilepsy and eight developed rolandic seizures after remission of PS seizures. Prognosis was excellent. Eighty-four (44.2%) had a single seizure, 79 (41.2%) had 2–5 fits, and 28 (14.6%) had frequent seizures. Conclusion: PS is less common than BCECTS, but is well defined and easily recognizable by clinical and EEG features, with autonomic manifestations as one of the most common ictal event. [ABSTRACT FROM AUTHOR]

Summary: Purpose: To characterize the clinical and EEG findings and evolution of the syndrome of benign focal seizures of adolescence (BFSA), as described by Loiseau et al. Methods: A prospective study was performed in adolescents with normal clinical and neurologic examinations and normal neuroradiologic studies who had focal seizures that occurred isolated or in a cluster, with or without secondary generalization in the first 24 to 48 h after onset. None of the patients was treated with antiepileptic drugs (AEDs). Results: Between January 1996 and January 2002, 15 patients with BFSA were enrolled in the study. Median age at onset of BFSA was 14 years. Thirteen patients had focal sensory or motor seizures. In two patients, the ictal manifestation was motion arrest associated with oral automatisms. Eight of them evolved to generalized tonic-clonic seizures. Thirteen patients had seizures only when awake, and the other two, both when awake and during sleep. Repeated interictal EEGs were normal, but in four of the patients who had seizures in a cluster, we were able to record an EEG within 8 h after seizure onset. Two of these four patients had focal seizures, and their waking EEG showed focal centroparietal theta activities. The other two patients had secondarily generalized seizures, and their waking EEG showed bilateral theta activities instead. Prognosis was excellent. Conclusions: BFSA is a well-defined seizure syndrome, recognizable by clinical and EEG features, as described by Loiseau et al. In teenagers with these electroclinical features with a normal neurologic examination and normal neuroradiologic findings, AEDs should be avoided. Key Words: Adolescence- Benign course-Epilepsy-Focal seizures. [ABSTRACT FROM AUTHOR]

Summary Epileptic encephalopathy with electrical status epilepticus during slow sleep (ESES) belongs to the group of epileptic encephalopathies that often prove refractory to AED treatment. The ketogenic diet (KD) has been used as an alternative to antiepileptic drugs (AEDs) for patients with refractory epileptic encephalopathies. Purpose In this retrospective study we assess the efficacy and tolerability of the KD in patients with ESES syndrome. Methods Between March 1, 1990 and April 1, 2013, 65 patients who met diagnostic criteria of ESES syndrome were seen at our department. Twelve of them were placed on the KD and followed for a minimum of 18 months. Results The children had previously received a mean of 5.5 different AEDs and were on a mean of 3 AEDs when the diet was started. Eighteen months after initiating the diet, seven of the initial patients (58%) remained on the diet; one patient (8.3%) had become seizure free, one (8.3%) had a 75–99% decrease in seizures, two (16.6%) had a 50–74% decrease in seizures, and the remaining three children (24.9%) had a <50% decrease in seizures. In the patient who had become seizure free and in the one who had a 75–99% seizure decrease AEDs were reduced. Conclusion The KD is a well-tolerated treatment option for patients with ESES syndrome, not only for structural cases but also for those with an unknown etiology. The diet should be considered in the management of this syndrome. [ABSTRACT FROM AUTHOR]