Epileptic seizures in a patient with mitochondrial myopathy, encephalopathy, lactic acidosis and strokelike episodes (MELAS)

This study reports a case of MELAS with epileptic seizure, and reviews the characteristics of seizures in patients with this syndrome. They are characterized by: (1) generalized and/or partial seizures, (2) frequent association with visual symptoms and hemiparesis, and (3) posteriorly predominant EEG abnormalities.     

Nocturnal epileptiform EEG discharges, nocturnal epileptic seizures, and language impairments in children: review of the literature

This review addresses the effect on language function of nocturnal epileptiform EEG discharges and nocturnal epileptic seizures in children. In clinical practice, language impairment is frequently reported in association with nocturnal epileptiform activity. Vice versa, nocturnal epileptiform EEG abnormalities are a common finding in children with specific language impairment. We suggest a spectrum that is characterized by nocturnal epileptiform activity and language impairment ranging from specific language impairment to rolandic epilepsy, nocturnal frontal lobe epilepsy, electrical status epilepticus of sleep, and Landau-Kleffner syndrome. In this spectrum, children with specific language impairment have the best outcome, and children with electrical status epilepticus of sleep or Landau-Kleffner syndrome, the worst. The exact nature of this relationship and the factors causing this spectrum are unknown. We suggest that nocturnal epileptiform EEG discharges and nocturnal epileptic seizures during development will cause or contribute to diseased neuronal networks involving language. The diseased neuronal networks are less efficient compared with normal neuronal networks. This disorganization may cause language impairments.     

Nocturnal epileptiform EEG discharges,nocturnal epileptic seizures,and language impairments in children: Review of the literature

This review addresses the effect on language function of nocturnal epileptiform EEG discharges and nocturnal epileptic seizures in children. In clinical practice, language impairment is frequently reported in association with nocturnal epileptiform activity. Vice versa, nocturnal epileptiform EEG abnormalities are a common finding in children with specific language impairment. We suggest a spectrum that is characterized by nocturnal epileptiform activity and language impairment ranging from specific language impairment to rolandic epilepsy, nocturnal frontal lobe epilepsy, electrical status epilepticus of sleep, and Landau–Kleffner syndrome. In this spectrum, children with specific language impairment have the best outcome, and children with electrical status epilepticus of sleep or Landau–Kleffner syndrome, the worst. The exact nature of this relationship and the factors causing this spectrum are unknown. We suggest that nocturnal epileptiform EEG discharges and nocturnal epileptic seizures during development will cause or contribute to diseased neuronal networks involving language. The diseased neuronal networks are less efficient compared with normal neuronal networks. This disorganization may cause language impairments.     

Epileptic syndromes: differential treatment in infants, children, and adolescents

This paper proposes therapeutic guidelines for the management of some epileptic syndromes in infants, children, and adolescents, based on available medical literature and clinical practice in the French Community of Belgium. The guidelines address both epileptic encephalopathies (West syndrome, Lennox-Gastaut syndrome, and Dravet syndrome) and idiopathic epilepsies (typical absence seizures, epilepsy with centro-temporal spikes and juvenile myoclonic epilepsy).     

Early epileptic encephalopathy with suppression bursts and olivary-dentate dysplasia.

A case of neonatal epileptic encephalopathy with suppression-bursts associated with olivary dentate nuclei dysplasia is reported. This unusual association shows that the so-called Ohtahara syndrome could correspond to several different brain malformations sometimes disclosable only by neuropathological examination.     

Familial mesial temporal lobe epilepsies: Clinical and genetic features

Familial mesial temporal lobe epilepsy (FMTLE) was first described as a benign syndrome with prominent psychic and autonomic seizures and no association with hippocampal sclerosis (HS) or febrile seizures (FS). Better definition of the syndrome allowed identification of more heterogeneous phenotypes with mild to severe epileptic disorders, and a variable association with HS and FS. The genetics of these conditions is largely unknown and the hope for the future is that the identification of FMTLE genes will lead to more appropriate approaches for the diagnosis and treatment of TLE.     

Acquired epileptiform aphasia in children (Landau-Kleffner syndrome)

The association of a language disorder with epilepsy is frequent in children, but there is usually no causal relationship. In acquired epileptiform aphasia (AEA), the so-called Landau-Kleffner syndrome, there is increasing evidence that the language disorder is directly caused by epileptic discharges in critical language areas and must be viewed as a special kind of epileptic aphasia. This is based on a review of the published cases of AEA over the last 30 years and on the analogies that can be made between AEA and other epileptic syndromes, mainly benign partial epilepsy with centrotemporal spikes. AEA can start early in development and present as developmental dysphasia. It is only one among other cognitive or behavioral disturbances that can be epileptic manifestations of some particular epileptic syndromes, for example, epilepsy with continuous spike waves during slow sleep, which probably has the same pathophysiology as AEA. AEA must be seen, at least in some cases, as a particular form of resistant epilepsy. AEA is an important model because it suggests that isolated cognitive and behavioral disturbances can be epileptic manifestations in children.     

Autism in Dravet syndrome: prevalence, features, and relationship to the clinical characteristics of epilepsy and mental retardation

Autism is a pervasive developmental disorder that frequently co-occurs with epilepsy. Dravet syndrome is a severe epileptic encephalopathy associated with psychomotor developmental delay. Autism in Dravet syndrome, however, has rarely been studied. In this study, the prevalence and features of autism in patients with Dravet syndrome, their potential association with mental retardation, and the clinical characteristics of epilepsy were investigated. Clinical data of 37 patients with Dravet syndrome were collected, and evaluations of autism and mental retardation were performed. Nine patients (24.3%) met the criteria for autism. All patients with autism showed speech delay, no emotional reciprocity, and narrow interests, whereas 89.3, 46.4, and 39.9% of patients without autism had speech delay, short temper, and narrow interests, respectively. Mental retardation was observed in 94.6% of patients with Dravet syndrome, with more frequent severe or profound mental retardation in those with autism. The clinical features of epilepsy did not statistically differ between the patients with autism and the patients without autism.     

Photosensitive Epilepsies and Photoconvulsive Responses in Arabs

The occurrence of photosensitivity (PS) was examined in 327 Arabs greater than or equal to 15 years of age with epilepsy by intermittent photic stimulation (IPS). A control group of 192 nonepileptic Arabs greater than or equal to 15 years of age were also examined by IPS. Of the epileptic patients, 24 (7.3%) were photosensitive, an incidence comparable to that in whites in contradistinction to the reported rarity among African blacks. This finding indicates that environmental factors, particularly excessive sunshine, does not appear to influence the occurrence of PS among epileptic patients. The occurrence of PS among epileptic patients may depend more strongly on the presence of an epileptic syndrome known to have association with PS.     

The prevalence of epilepsy in patients with celiac disease

PURPOSE: The relation between celiac disease and epilepsy is uncertain. Previous studies have suggested an association, whereas others have not. METHODS: We ascertained the prevalence of active epilepsy in a cohort of 801 celiac patients by patient interviews and retrospective case note review. All the celiac patients had diagnostic confirmation by small bowel biopsy. RESULTS: Twenty-one patients had a history of epileptic seizures, but only nine (1.1%) had active epilepsy. No specific epileptic syndrome was identified. CONCLUSIONS: This study suggests that a causal relation between gluten sensitivity and active epilepsy is unlikely.     

Long-term outcome of developmental and epileptic encephalopathies

Developmental and epileptic encephalopathies are conditions where there is developmental impairment related to both the underlying etiology independent of epileptiform activity and the epileptic encephalopathy. Usually they have multiple etiologies. Therefore, long-term outcome is related to both etiology-related factors and epilepsy-related factors–age at onset of epilepsy, type(s) of seizure(s), type of electroencephalographic abnormalities, duration of the epileptic disorder. This paper focuses on long-term outcome of six developmental and epileptic encephalopathies with onset from the neonatal period to childhood: early epileptic encephalopathy with suppression bursts, West syndrome, Dravet syndrome, Lennox-Gastaut syndrome, epilepsy with myoclonic atonic seizures and epileptic encephalopathy with continuous spike and waves during slow-wave sleep including Landau-Kleffner syndrome. For each syndrome, definition, main etiologies if multiple, and long-term outcome are discussed.     

Seizure frequency and characteristics in children with Down syndrome

Seizures have not historically been considered a major component of Down syndrome. We examined the prevalence of epileptic seizures in 350 children and adolescents with Down syndrome evaluated at a regional center between 1985 and 1997. Results showed that 28 patients (8%) had epileptic seizures: 13 (47%) partial seizures; 9 (32%) infantile spasms, and 6 (21%) generalized tonic-clonic seizures. In the infantile spasm group, there was no relationship between the initial electroencephalogram (EEG) pattern and response to treatment or long-term seizure control, or between type of pharmacologic treatment (valproic acid, adrenocorticotropic hormone or both) and clinical remission, EEG normalization or long-term seizure control. Neurodevelopmental outcome was poor despite good seizure control in the infantile spasm group. This regional study reinforces the relative association of seizures and Down syndrome. A prospective study including a national/international registry with emphasis on developmental assessment and long-term follow up is warranted.     

Epileptic syndromes, cognitive assessment and school placement: a study of 251 children

Two-hundred and fifty-one children (98 girls and 153 boys, aged from 3 to 17 years) with documented diagnosis of epileptic syndrome, IQ measurement, and information on school placement were included in this retrospective study. The relations between these three parameters as well as effects of age at onset and duration of epilepsy, seizure frequency, and number of antiepileptic drugs (AEDs) were analysed. Both IQ and schooling were univariately related to epileptic syndrome, age at onset and duration of epilepsy, and number of AEDs; seizure frequency was related to IQ but not to school placement. Multiple regression showed that IQ was independently related to epileptic syndrome and AED; multiple logistic regression showed that type of school (mainstream versus adapted or special) was independently related to IQ and AED. Children with idiopathic generalised or with localisation-related epilepsy had higher IQ scores and higher probability of mainstream schooling than those with symptomatic or cryptogenic generalised epilepsies or epileptic syndromes which were undetermined. Subtests profile of intelligence scale in localisation-related epilepsies showed different specific cognitive deficits, according to the location of the epileptic focus.     

A case of Lennox‐Gastaut syndrome in a patient with FOXG1‐related disorder

Lennox‐Gastaut syndrome (LGS) is a drug‐resistant epileptic encephalopathy of childhood with a heterogeneous etiology. Recently, genome‐wide association studies have led to the identification of new de novo mutations associated with this epileptic syndrome. Herein, we report an 8‐year‐old child with intellectual disability, severe postnatal microcephaly, Rett‐like features, and LGS, carrying a de novo missense mutation in the forkhead box G1 (FOXG1) gene. This gene is responsible for FOXG1 syndrome, characterized by severe postnatal microcephaly, moderate postnatal growth deficiency, mental retardation with poor social interaction, stereotyped behavior and dyskinesias, absent language, sleep disorders, and epilepsy. Nonspecific epilepsy syndromes have been associated with this genetic disorder. Thus, we hypothesize that FOXG1 might be a new candidate gene in the etiology of LGS and suggest screening for this gene in cases of LGS with concomitant microcephaly and clinical features overlapping with Rett syndrome.     

Quantitative MRI in Outpatient Childhood Epilepsy

Summary: Purpose: In adult studies, MRI volumetrics is a proven technique in presurgical assessment of epilepsy. Hippocampal volume loss is maximal in the syndrome of mesial temporal lobe epilepsy. We aimed (a) to validate this methodology in a pediatric outpatient epilepsy population (b) to determine the relationship of hippocampal asymmetry (HA) to epileptic syndromes and risk factors. Methods: Two neurologists classified the epileptic syndrome in 79 pediatric outpatients, according to the International Classification of Epilepsies and Epileptic Syndromes (ILAE). Hippocampal volumetrics were performed in all patients. HA was defined according to adult control values. Results: Inter-rater variability on measurement of HA was very small (Correlation of test retest of 0.97 on 17 children <3 years old). The rate of HA was 44/79 (57%). In 21 patients, (27%) potentially epileptogenic lesions (other than HA) were identified (cerebral dysgenesis n = 11). HA was present in 9/15 (60%) of temporal lobe epilepsy and in 15/28 (54%) extratemporal onset epilepsy and 5/11 (46%) of generalized symptomatic epilepsy. Analysis confined to <13 years also showed HA was not specific for epileptic syndrome. There was no significant association of febrile convulsions (13%) with HA or temporal lobe epilepsy. Conclusions: There is a high incidence of HA in childhood epilepsy. HA was not confined to clinically defined temporal lobe epilepsy. The poor correlation of epileptic syndrome to quantitative MRI findings may be due to the inadequacies of epilepsy classification in the younger child, with the clinical semiology providing misleading localizing information. Normative childhood data for hippocampal volumes and symmetry is needed.     

Double cortex syndrome: Electroclinical study of three cases

We describe three female patients (aged 10, 11 and 21 years) with a Magnetic Resonance appearance of band heterotopia, a diffuse neuronal migration disorder, also known as double cortex syndrome. The clinical picture was characterized by the association of epilepsy and mental retardation in all three cases, as has been previously described in patients with double cortex syndrome. The epileptic syndrome (Lennox-Gastaut syndrome in one case, and symptomatic partial epilepsy in the other two), the response to medical treatment, and the severity of mental retardation were markedly different in the three patients. No clear-cut relationship was found between the clinical picture and the severity of the neuronal migration disorder, as revealed by magnetic resonance imaging. In the three cases, EEG shares some common features: multifocal epileptic activity with frequent bilateral diffusion, and highamplitude anterior fast activity, intermingled in two patients with bursts of repetitive spikes. The study was partially supported by grants from the Paolo Zorzi Foundation for the Neurosciences, from the Mariani Foundation Paediatric Neurology and the Italian Ministry of Health.     

Malignant migrating partial seizures of infancy controlled by stiripentol and clonazepam

The syndrome of malignant migrating partial seizures of infancy (MMPSI) is characterized by early onset of multiple seizure types and overall poor prognosis. Seizures are markedly drug resistant and few reports have suggested the efficacy of some antiepileptic drugs. We report one case of MMPSI in which prolonged seizure control is obtained with an association of clonazepam, levetiracetam and stiripentol, confirming thus the possibility of complete sustained seizure control in this epileptic syndrome. Of more than 60 cases reported to date, ours is the forth in which sustained complete control of seizures was obtained.     

Cognitive problems related to epilepsy syndromes, especially malignant epilepsies.

Neurocognitive impairment is frequent in epilepsy patients. Causes are multiple, and may be influenced by several factors including the epilepsy syndrome. Most cognitive complaints in adult patients are mental slowness, memory difficulties and attention deficits. In children, cognitive problems are more diffuse, responsible for language troubles, learning difficulties, poor academic outcome, behavior problems and finally unfortunate socio-professional prognosis. The most devastating epilepsy syndromes such as epileptic encephalopathies are nearly exclusively described in infancy and childhood. This paper will review the major cognitive complaints in relation to the epilepsy syndrome, with a more detailed interest for the malignant epilepsies in infancy and childhood such as Ohtahara and West syndrome, Lennox-Gastaut syndrome and epileptic encephalopathis with continuous spike-and-wase during slow wave sleep. The impact of surgery on cognition will be briefly discussed in adults and youger patients.