Aim. We retrospectively analysed the electroclinical features, treatment, and outcome in patients with unilateral polymicrogyria (PMG), focussing on epileptic syndrome with or without encephalopathy, with status epilepticus during sleep (ESES) or continuous spikes and waves during slow sleep (CSWS) syndrome. Methods. From June 1990 to December 2012, 39 males and 27 females, aged 5-26 years, were studied. We did not include patients with bilateral PMG or cases with unilateral PMG associated with other cerebral lesions. The mean follow-up period was 12 years (range: 3-22 years). Results. Mean age at epilepsy onset was 6.5 years. Focal motor seizures occurred in all cases and 25 had secondary generalised seizures. Six patients also had complex focal seizures. Interictal EEG recordings showed focal spikes in all cases. For 43 of 53 patients with epilepsy, aged 2-9.5 years, the electroclinical features changed. An increase in frequency of focal motor seizures was reported in 20 patients, negative myoclonus occurred in 32 patients, atypical absences in 25 patients, and positive myoclonus in 19 patients. All patients had a continuous symmetric or asymmetric pattern of spike-wave activity during slow-wave sleep. Conclusion. For patients presenting with congenital hemiparesis, negative or positive myoclonus, and absences and focal motor seizures with ESES/CSWS, unilateral PMG should be considered. Brain MRI is mandatory to confirm this cortical malformation. The most commonly used treatments were clobazam, ethosuximide, and sulthiame, alone or in combination. For refractory cases, high-dose steroids were administered and surgery was performed in two patients. Outcome was relatively benign.
This study describes the clinical and electroencephalographic characteristics of epileptic spasms, and more especially those that occur during the first two years of life (infantile spasms). West syndrome has been clearly defined as the association between infantile spasms with an electroencephalographic pattern of hypsarrhythmia. Although intellectual deficit appears in almost all cases in which infantile spasms are not controlled with medication, this is a developmental aspect of the condition and not a manifestation that must necessarily be present in order to define the syndrome. The analysis of the interictal and ictal electroencephalogram readings, together with the clinical characteristics of the spasms and the neurological examination of patients, provides some orientation as regards the causations. Despite the spectrum that the title of this work focuses on, the study does not cover the treatment of early infants with West syndrome. Emphasis is placed on the differential diagnoses of West syndrome with other epileptic syndromes that manifest in the first two years of life, and more especially with a series of abnormal non-epileptic motor phenomena that occur in early infants. All these last non-epileptic disorders are displayed in a table, but benign myoclonus of early infancy or Fejerman syndrome is given as a paradigmatic example for the differential diagnosis. The primordial aim is to prevent neurologically healthy early infants from receiving antiepileptic drugs and even adrenocorticotropic hormone or corticoids due to a mistaken diagnosis.
Idiopathic focal epilepsy (IFE) with rolandic spikes is the most common childhood epilepsy, comprising a phenotypic spectrum from rolandic epilepsy (also benign epilepsy with centrotemporal spikes, BECTS) to atypical benign partial epilepsy (ABPE), Landau-Kleffner syndrome (LKS) and epileptic encephalopathy with continuous spike and waves during slow-wave sleep (CSWS). The genetic basis is largely unknown. We detected new heterozygous mutations in GRIN2A in 27 of 359 affected individuals from 2 independent cohorts with IFE (7.5%; P = 4.83 × 10(-18), Fishers exact test). Mutations occurred significantly more frequently in the more severe phenotypes, with mutation detection rates ranging from 12/245 (4.9%) in individuals with BECTS to 9/51 (17.6%) in individuals with CSWS (P = 0.009, Cochran-Armitage test for trend). In addition, exon-disrupting microdeletions were found in 3 of 286 individuals (1.0%; P = 0.004, Fishers exact test). These results establish alterations of the gene encoding the NMDA receptor NR2A subunit as a major genetic risk factor for IFE.
In this chapter we include a series of epilepsies with onset in pediatric age characterized by focal seizures, idiopathic etiology, normal psychomotor development, and a benign course related to the spontaneous remission of seizures without sequelae. These entities are age-dependent and seizures tend to disappear spontaneously. For these reasons often the drug treatment is not necessary. On the basis of genetic assessment idiopathic focal epilepsies can be divided into two groups: nonautosomal dominant and autosomal dominant. In the group of nonautosomal entities we include benign epilepsy with centro-temporal spikes, Panayiotopoulos syndrome, idiopathic childhood occipital epilepsy described by Gastaut, and benign idiopathic midline spikes epilepsy. Seizures are rare, sometimes prolonged, as autonomic status in Panayiotopoulos syndrome. A common feature is the presence of peculiar EEG interictal paroxysmal abnormalities. In the group with an autosomal dominant mode of inheritance we include benign familial infantile seizures and benign familial neonatal-infantile seizures. These entities are characterized by partial seizures in cluster, self-limited in a brief period during the first months of life. There are no typical interictal EEG abnormalities. In some families a mutation in SCN2A, the gene coding for the 2? subunit of the voltage-gated sodium channel, has been described.
Paroxysmal kinesigenic dyskinesia with infantile convulsions (PKD/IC) is an episodic movement disorder with autosomal-dominant inheritance and high penetrance, but the causative genetic mutation is unknown. We have now identified four truncating mutations involving the gene PRRT2 in the vast majority (24/25) of well-characterized families with PKD/IC. PRRT2 truncating mutations were also detected in 28 of 78 additional families. PRRT2 encodes a proline-rich transmembrane protein of unknown function that has been reported to interact with the t-SNARE, SNAP25. PRRT2 localizes to axons but not to dendritic processes in primary neuronal culture, and mutants associated with PKD/IC lead to dramatically reduced PRRT2 levels, leading ultimately to neuronal hyperexcitability that manifests in vivo as PKD/IC.
The purpose of this review is to provide guidance for appropriate diagnosis and management of idiopathic childhood occipital epilepsy of Gastaut. The typical clinical features are visual seizures that typically consist of brief elementary visual hallucinations, which are mainly multicolored and circular. Ictal blindness and deviation of the eyes are also common symptoms. The seizures are usually frequent and diurnal. The electroencephalography is the only investigation with abnormal results, showing occipital spikes and often occipital paroxysms demonstrating fixation-off sensitivity. Brain magnetic resonance imaging is used to exclude symptomatic occipital epilepsy. Patients usually respond well to antiepileptic medication and about two-thirds remit by the age of 16 years. Idiopathic childhood occipital epilepsy of Gastaut is frequently misdiagnosed as migraine with visual aura, acephalgic, or basilar migraine. Differentiation from symptomatic occipital epilepsy, particularly when children are otherwise normal, can be difficult. Most children need prophylactic antiepileptic medication.
Typical benign rolandic epilepsy (BRE) is a frequent and well-delineated epileptic syndrome in childhood. Mild cognitive and behavioral difficulties are increasingly recognized in the course of BRE and should not be considered as atypical features. Atypical features are recognized on electroclinical grounds. These features, particularly early age at onset and frequent spikes or spike-wave discharges, seem to be risk factors for neuropsychological deficits but also for an atypical evolution of BRE. Atypical evolutions of BRE are defined by the appearance of severe neuropsychological impairments and continuous spike-and-waves during slow sleep (CSWSS). The clinical expressions of these situations correspond to the syndromes known as atypical benign focal epilepsy of childhood (ABFEC), status of BRE, Landau-Kleffner syndrome (LKS), and CSWSS syndrome, which may be part of a continuum related to BRE.
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.
Eyelid myoclonia and absences (EMA) induced by eye closure associated with brief, fast, and generalized paroxysms of polyspikes and waves was considered as an epileptic syndrome and a type of seizure as well. We analyzed the electroclinical features and evolution of EMA, and tried to determine if it represents a well-defined epileptic syndrome or a non-specific condition associated to other epilepsies.
Whole genome sequencing and the screening of 103 families recently led us to identify PRRT2 (proline-rich-transmembrane protein) as the gene causing infantile convulsions (IC) with paroxysmal kinesigenic dyskinesia (PKD) (PKD/IC syndrome, formerly ICCA). There is interfamilial and intrafamilial variability and the patients may have IC or PKD. Association of IC with hemiplegic migraine (HM) has also been reported. In order to explore the mutational and clinical spectra, we analyzed 34 additional families with either typical PKD/IC or PKD/IC with migraine.
This is an update on severe epilepsies in infancy that are associated with genetic etiologies, either chromosomal abnormalities or gene mutations. These severe epilepsies may present the clinical and electroencephalographic phenotype of the so called epileptic encephalopathies, although a significant number of cases do not comply with the criteria to be included among the already known categories, as classified by the International League Against Epilepsy. Several chromosomal abnormalities, with or without a characteristic physical phenotype, are associated with epileptic encephalopathies in infants. Many patients are affected by metabolic or structural cerebral diseases of genetic etiology, in which seizures are not the only manifestation. Inborn errors of metabolism, deficiencies in cerebral transporters, mitochondrial encephalopathies, several neuroectodermosis, and part of the brain malformations and disorders of cortical development are examples. Recognition of new gene mutations in infants with epileptic encephalopathies or other severe epilepsies whose brain imaging studies, neurometabolic screenings and conventional cariotypes are normal, is emphasized in this review. An algorhythm for diagnosis and treatment of neonatal seizures with no determined etiology is also included. Finally, the new molecular genetics techniques applied in the diagnostic approach of these conditions, such as Array Comparative Genomic Hybridization, the identification of copy number variations and the eventual sequencing of genes, are commented but not described. The concept for pediatricians and pediatric neurologists is that mutations in one gene may provoke different epileptic syndromes, whereas one epileptic syndrome may be provoked by mutations in different genes.
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).
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