Biomedical subjects

C Chiron

Publications and source records attributed to C Chiron.

At least 19 recordsLinked to original sources

PubMed2006

Devastating epileptic encephalopathy in school-aged children (DESC): a pseudo encephalitis.

PURPOSE: To describe the characteristics of a previously overlooked devastating epileptic encephalopathy that presents as intractable bilateral perisylvian epilepsy starting with prolonged status epilepticus (SE) in normally developing school-aged children. METHODS: Retrospective study over 7 years of all normally developing children admitted in our institution for a prolonged SE following non-specific febrile illness with at least one seizure recorded on EEG. RESULTS: Fourteen children were included at a median age of 7.5 years (4-11) (median follow-up of 4 years (1-7)). Intractable SE lasted 4-60 days (median 30). CSF cell count was normal in five cases and moderately increased in the others. During SE, seizures were recorded in 11 patients and involved temporal lobes in 7; the other 4 patients exhibited perisylvian clinical features with secondary generalization. Intractable epilepsy followed SE in all cases without any latent period. Persisting seizures were recorded in 10 patients and involved temporo-perisylvian regions in 8, frontal regions in 2; 3 others had perisylvian ictal semiology. Spiking was bilateral in 10 cases. MRI showed bilateral hippocampal hypersignal and/or atrophy in 10 cases (extended to the neocortex in 3). All children had major cognitive sequelae. When feasible (six patients), detailed neuropsychology suggested fronto-temporal impairment. CONCLUSIONS: Among so called grey matter encephalitis patients, we identified a recognizable pattern we propose to call Devastating Epileptic encephalopathy in School-age Children (DESC) that begins with prolonged SE triggered by fever of unknown cause, and persists as intractable perisylvian epilepsy with severe cognitive deterioration.

Anticonvulsants↗

PubMed2005

[Acceptability and tolerance of sodium valproate, a new sustained-action granule formulation, in monotherapy for epileptic children from 3 years old].

UNLABELLED: Sodium valproate (VPA) is an anti-epileptic drug which was until now administered to children as drinkable or injectable form. A new galenic form of this compound has been developed as microgranules with prolonged release (Micropakine)LP; MPK). This new galenic form of VPA allows a greater stability of the plasmatic rates, thus limiting the risk of amount-dependent adverse effects at the time of the peaks, and of less effectiveness at the time of the fall of the circulating rates. The main objective of this study was to evaluate the acceptability of the new galenic form of VPA, in monotherapy, for epileptic children with >or=3 years old. The evaluation was performed at day (D)90 by the patients using a hedonic visual scale. The secondary objectives were to evaluate the acceptability by the parents, the treatment compliance, the percentage of patients free of seizure at D 90, and the tolerance. Finally, the authors compared all these data to those recovered at the baseline in patients already treated by the previous drinkable VPA. A total of 307 patients were involved by 76 hospital neuropediatric physicians. The population was constituted by 110 children <5 years old and 197 children from 5 to 14 years old. MPK was well accepted for total population at D 90 (<5 years old: 83.3%; >or=5 years old: 80%). For patients previously treated by drinkable form of VPA (N=199), MPK was significantly better accepted than the drinkable form at D1 (<5 years, P=0.0189; >or=5 years, P<0.0001). Less difficulties were experienced by the parents to administrate MPK when compared to the drinkable form (P<0.001), mainly due to his neutral taste. Patients free of seizure at D 90 were 77% [70,3; 82,5]. Specially, fewer epileptic seizures were evidenced for all children previously treated at D1 by drinkable form of VPA. The treatment was well respected by the patients, which were compliant in 80% of the cases. The adherence to treatment was good since the treatment compliance was 87%. MPK was well tolerated. CONCLUSION: MPK in the microgranule form significantly improves the treatment acceptability with a good tolerance. Two daily intakes and neutral taste are two major advantages to favour the compliance in children, thus contributing to the efficacy of the antiepileptic treatment.

Administration, Oral↗

PubMed2005

[Epilepsy in chromosome aberrations].

Epilepsy is among the most frequent finding in many chromosome aberrations. While most chromosome aberrations can be associated with different seizure types, there are few aberrations which feature specific seizures and EEG patterns. Among the 400 different chromosomal imbalances described with seizures and EEG abnormalities, eight have a high association with epilepsy. These comprise: the monosomy 1p36, Wolf-Hirschhorn syndrome (4p-), Angelman syndrome, Miller-Dieker del 17p13.3, the inversion duplication 15 syndrome, ring 20 and ring 14 syndromes, Down's syndrome. These chromosomal regions where aberrations have an evident association with epilepsy may be useful targets for gene hunters. On the other hand, a better characterisation of epileptic syndrome in these disorders may lead to a better and specific treatment.

Child↗

PubMed2005

[Recent advances in pathogenic concepts and therapeutic strategies in Rasmussen's encephalitis].

Rasmussen's encephalitis (RE) is a rare inflammatory brain disease mainly affecting children and characterised by intractable epilepsy involving a single hemisphere that undergoes progressive atrophy. RE is characterized by refractory focal seizures, often associated with epilepsia partialis continua, progressive unilateral motor defect, slow EEG activity over the entire contralateral hemisphere, with focal white matter hyperintensity and insular cortical atrophy on neuroimaging. Surgical exclusion of the affected hemisphere is the only treatment that interrupts progression of the disease. Pathogenic concepts have considered viruses, autoimmune antibodies and autoimmune cytotoxic T lymphocytes that might contribute to the initiating or perpetuating events in the central nervous system. Based on these concepts, different therapeutic strategies have been pursued, such as antiviral agents, plasmapheresis, immuno-adsorption, immunosuppression or immunomodulation with intravenous immunoglobulins. However, due to the lack of large studies, to date there is no established therapeutic strategy for this devastating condition. In this review, we give an overview of the current state of immunopathogenic concepts for Rasmussen's encephalitis and discuss the different therapeutic options for future perspectives.

Early Diagnosis↗

PubMed2004

Regional cerebral glucose metabolism in epilepsies with continuous spikes and waves during sleep.

BACKGROUND: Epileptic syndromes with continuous spikes and waves during sleep (CSWS) represent a wide spectrum of epileptic conditions associated with cognitive dysfunctions that have the EEG pattern of CSWS as a common feature. Reported are the results of voxel-based analyses of brain glucose metabolism performed in a group of 18 children with CSWS. METHODS: Voxel-based analyses of cerebral glucose metabolism were performed using statistical parametric mapping (SPM). First, each patient was compared with a control group and the influence of age, epileptic activity, and corticosteroid treatment on metabolic abnormalities was studied. Also, disease-related changes in the contribution of a brain area to the level of metabolic activity in another brain area were investigated using pathophysiologic interactions in groups of patients compared with the control group. RESULTS: Individual SPM analyses identified three metabolic patterns: association of hypermetabolic and hypometabolic areas, hypometabolic areas only, and normal pattern. Age and intensity of awake interictal spiking did not significantly differ in patients showing focal hypermetabolism compared with the other ones. Treatment with corticosteroids was associated with absence of focal hypermetabolism. In the group of patients with hypermetabolic areas, analyses of pathophysiologic interactions showed disease-related altered functional connectivity between the parietal and frontal cortices. CONCLUSIONS: Cerebral metabolic patterns are heterogeneous among patients with CSWS. This metabolic heterogeneity could be related to the use of corticosteroid treatment before PET. The parietofrontal altered connectivity observed in patients with hypermetabolism is interpreted as a phenomenon of remote inhibition of the frontal lobes induced by highly epileptogenic and hypermetabolic posterior cortex.

Brain↗

PubMed2004

[Treatment of status epilepticus in children with epilepsy].

The treatment of status epilepticus (SE) in children with epilepsy depends on the epilepsy syndrome, in order to avoid worsening drugs such as IV barbiturates in severe myoclonic epilepsy in infancy (SMEI) (Dravet's syndrome) or IV benzodiazepam in tonic SE of Lennox-Gastaut syndrome. Intensive care procedures should not be systematical in convulsive SE (CSE) and are not indicated in non-convulsive SE (NCSE). Generalized CSE mostly involve SMEI before 3 years of age, symptomatic generalized epilepsy and partial lesional epilepsy. Treatment is an emergency and relies on IV benzodiazepines and, if necessary, IV phenytoine using plasmatic concentrations for an optimal management. The partial CSE of partial lesional epilepsy can result in focal deficit and need the same treatment as generalized CSE. NCSE consist in absence and/or myoclonic SE and are often unrecognised during a long time until EEG is performed. They mostly involve myoclonic epilepsies and can be controlled by IV benzodiazepines. The frequency of partial NCSE is underestimated, particularly in infants. Diagnosis relies on video EEG and treatment is the same as that used in partial CSE.

Anticonvulsants↗

PubMed2004

[Functional neuroimaging in children].

In pharmacoresistant partial epilepsy (PRPE) in children, functional cerebral imaging helps localizing the epileptogenic zone using SPECT (Single Photon Emission Computed Tomography) and PET (Positron Emission Tomography) and the functional motor and language cortex using functional MRI. Regarding SPECT, only ictal SPECT exhibits an acceptable sensitivity (80 p. 100), together with interictal SPECT and subtraction image processing. Regarding PET, sensitivity has not been validated yet compared with intracranial EEG, neither using 18FDG, nor using more recent tracers such as 11C-flumazénil or 11C-alpha-méthyl-tryptophane. However, both techniques are useful to decide the placement of the intracranial electrodes, particularly in cryptogenic cases or when preoperative data are discordant. Functional MRI for language is going to be validated compared with WADA test and to provide a very useful and non invasive alternative method to lateralize the language networks in children able to cooperate. FMRI also provides a unique opportunity to follow the post-lesional or post-surgery plasticity of these networks using repeated examinations in a same patient. Functional imaging techniques therefore provide a useful additional contribution in the presurgery work-up of PRPE in children.

Adolescent↗

PubMed2004

[Treatment protocol for long-term anti-epilepsy drugs in children with refractory epilepsy].

Long-term treatment of children with drug-resistant epilepsy has not been addressed in detail in the literature. Contraindications for surgery must be reassessed periodically. The epileptic nature and the focal characteristic of seizures must be verified, the absence of tumor, malformation or another indication for surgery (i.e. obstructed valve.), the choice of anti-epileptic drugs depending on the epilepsy syndrome, even following callosotomy, and the dose, that is often over-estimated, must also be re-evaluated.

Adolescent↗

PubMed2003

Spectrum of SCN1A mutations in severe myoclonic epilepsy of infancy.

OBJECTIVES: SCN1A mutations were recently reported in several patients with severe myoclonic epilepsy in infancy (SMEI). The authors analyzed SCN1A mutations in 93 patients with SMEI and made genotype-phenotype correlation to clarify the role of this gene in the etiology of SMEI. METHODS: All patients fulfilled the criteria for SMEI. The authors analyzed all patients for SCN1A mutations using denaturing high performance liquid chromatography. If a patient's chromatogram was abnormal, the authors sequenced the gene in the patient and both parents. RESULTS: SCN1A mutations were identified in 33 patients (35%). Most mutations were de novo, but were inherited in three patients. Parents carrying the inherited mutations had either no symptoms or a milder form of epilepsy. A greater frequency of unilateral motor seizures was the only clinical difference between patients with SCN1A mutations and those without. Truncating mutations were more frequently associated with such seizures than were missense mutations. The percentage of cases with family history of epilepsy was significantly higher in patients with SCN1A mutations. CONCLUSIONS: Unilateral motor seizures may be a specific clinical characteristic of SMEI caused by SCN1A mutations. Ten percent of SCN1A mutations are inherited from an asymptomatic or mildly affected parent, suggesting that SMEI is genetically heterogeneous. The increased frequency of familial epilepsy indicates that other genetic factors may contribute to this disorder.

Adult↗

PubMed2003

Absence of mutations in major GEFS+ genes in myoclonic astatic epilepsy.

Myoclonic astatic epilepsy (MAE) is a genetically determined condition of childhood onset characterized by multiple generalized types of seizures including myoclonic astatic seizures, generalized spike waves and cognitive deterioration. This condition has been reported in a few patients in generalized epilepsy with febrile seizures plus (GEFS+) families and MAE has been considered, like severe myoclonic epilepsy of infancy (SMEI), to be a severe phenotype within the GEFS+ spectrum. Four genes have been identified in GEFS+ families, but only three (SCN1A, SCNlB, GABRG2) were found in MAE patients within GEFS+ families. We analysed these three genes in a series of 22 sporadic patients with MAE and found no causal mutations. These findings suggest that MAE, unlike SMEI, is not genetically related to GEFS+. Although MAE and SMEI share the same types of seizures, only SMEI patients are sensitive to fever. This is probably its main link to GEFS+. A different family of genes is likely to account for MAE.

Child, Preschool↗

PubMed2003

Ictal SPECT in children with epilepsy: comparison with intracranial EEG and relation to postsurgical outcome.

In order to validate the ability of ictal single photon emission computed tomography (SPECT) to localize the epileptogenic zone (EZ) in children, we compared in 20 patients aged from 10 months to 17 years (mean 6.5 years) the topography of the area of increased ictal perfusion (IPA), determined on the basis of ictal minus interictal scan values, with that of the EZ determined by intracranial EEG recordings and assessed its relationship with the postsurgical outcome. Eighteen patients had symptomatic epilepsy and 10 had extratemporal epilepsy. All patients except one had an ictal injection (mean time lag from clinical seizure onset was 18 s). Ictal and interictal SPECT images were successively co-registered, normalized, subtracted, smoothed and superimposed on MRI. All patients with ictal injection exhibited one or several IPAs. The topography of the 'highest' IPA, i.e. the maximal cerebral blood flow (CBF) change between ictal and interictal SPECT, significantly colocalized with the site of onset of the discharge, and that of the lower IPAs with that of the area of propagation (P < 0.0001). At a threshold of 30% of the maximal CBF change, the IPAs detected the onset of the discharge with a sensitivity of 0.80 and a specificity of 0.70. The highest IPA localized the EZ in 12 out of 15 patients. In the three others it missed the EZ and showed the area of propagation because of rapid seizure propagation or of infraclinical seizure onset. Among the patients with favourable surgery outcome, the highest IPA colocalized with the resected area in 70% of cases. Ictal SPECT could therefore plays an important role as a non-invasive presurgical method of investigation by optimizing the placement of intracranial electrodes, thus improving the postsurgery outcome of paediatric partial epilepsy.

Adolescent↗

PubMed2002

[Long-term efficacy and tolerance of stiripentaol in severe myoclonic epilepsy of infancy (Dravet's syndrome)].

OBJECTIVE: To describe the long term efficacy and tolerance of stiripentol associated with valproate and clobazam in an exhaustive cohort of patients with severe myoclonic epilepsy of infancy (Dravet's syndrome), in which short term efficacy of such a treatment has recently been demonstrated in a placebo-controlled trial. RESULTS: In 46 patients the frequency and the duration of seizures was significantly reduced (p < 0.001) as well as the number of convulsive status at a median of three-year follow-up. Ten patients were dramatically improved (seizures significantly decreased in number [p = 0.002] and duration [p = 0.002] and status epilepticus disappeared), 20 were moderately improved (seizures significantly decreased in duration [p = 0.001] and status were less numerous), four had no response and efficacy was non evaluable in 12 mainly because of adverse events. Efficacy was better in the youngest patients. The most frequent adverse events were loss of appetite and loss of weight. They could be so severe in patients over 12 years of age that the stiripentol dosage could not be increased to 50 mg kg-1 j-1. CONCLUSION: This follow-up study shows that stiripentol added to valproate and clobazam maintains its efficacy at long term in children with severe myoclonic epilepsy of infancy and suggests that the tritherapy should be introduced as early as possible in these patients in order to suppress the convulsive status epilepticus.

Anti-Anxiety Agents↗

PubMed2002

Persistent epileptiform activity induced by low Mg2+ in intact immature brain structures.

We have determined the properties of seizures induced in vitro during the first postnatal days using intact rat cortico-hippocampal formations (CHFs) and extracellular recordings. Two main patterns of activity were generated by nominally Mg2+-free ACSF in hippocampal and cortical regions: ictal-like events (ILEs) and late recurrent interictal discharges (LRDs). They were elicited at distinct developmental periods and displayed different pharmacological properties. ILEs were first observed in P1 CHFs 52 +/- 7 min after application of low-Mg2+ ACSF (frequency 1.5 +/- 0.3 h-1, duration 86 +/- 3 s). There is a progressive age-dependent maturation of ILEs characterized by a decrease in their onset and an increase in their frequency and duration. ILEs were abolished by d-APV and Mg2+ ions. From P7, ILEs were followed by LRDs that appeared 89 +/- 8 min after application of low-Mg2+ ACSF (frequency approximately 1 Hz, duration 0.66 s, amplitude 0.31 +/- 0.03 mV). LRDs were no longer sensitive to d-APV or Mg2+ ions and persisted for at least 24 h in low-Mg2+ or in normal ACSF. ILEs and LRDs were synchronized in limbic and cortical regions with 10-40 ms latency between the onsets of seizures. Using a double chamber that enables independent superfusion of two interconnected CHFs, we report that ILEs and LRDs generated in one CHF propagated readily to the other one that was being kept in ACSF. Therefore, at a critical period of brain development, recurrent seizures induce a permanent form of hyperactivity in intact brain structures and this preparation provides a unique opportunity to study the consequences of seizures at early developmental stages.

Age Factors↗

PubMed2002

Prophylactic antiepileptic treatment in Sturge-Weber disease.

PURPOSE: In Sturge-Weber disease, motor and cognitive defects are supposed to result mostly from severe epilepsy. They might, therefore be partly prevented by prophylactic antiepileptic drug treatment. This condition constitutes a possible model for the study of prophylactic drug treatment in severe epilepsy. In the present study, we compared the outcome of patients treated prospectively with phenobarbitone before the first seizure, with those referred following the first seizure, in order to identify the issues related to the evaluation of prophylactic treatment of severe epilepsy. METHODS: Motor and cognitive outcome were compared in patients treated prophylactically with phenobarbitone (16 cases) and in those treated following the first seizures (21 cases). RESULTS: Whereas the incidence of motor deficit was similar in both groups (44 vs. 52%), that of mental retardation was lower in the group treated prophylactically (76.2 vs. 43.7%, P< 0.05). The major methodological issues encountered included the small number of patients identified at birth that could be included in the study, the need for randomization taking into account the size of the angioma, and the choice of the prophylactic medication, including the occurrence of epilepsy together with the course of motor and cognitive functions among the endpoints. CONCLUSION: Prophylactic anti-epileptic drug treatment is worth considering for Sturge-Weber disease, but a randomized prospective study is necessary to determine this. It should be multicentric, take in account the size of the angioma, and decide what the most appropriate medication should be.

Adolescent↗

PubMed2001

Functional imaging in the work-up of childhood epilepsy.

In children with medically intractable lesional epilepsy, surgery is deemed successful if the epileptogenic focus can be removed while major neurological functions are spared. Current techniques rely on invasive intracranial recordings. The new developments in functional imaging offer the possibility of localizing the epileptogenic focus noninvasively (PET/SPECT) and mapping cognitive functions (fMRI). Ictal SPECT shows hyperperfusion in the focus and has proved to have better localizing value than interictal PET or SPECT, which show focal hypometabolism or hypoperfusion. Ictal SPECT is useful for deciding on the placement of intracranial electrodes in extratemporal epilepsies, particularly in young children. Functional MRI has proved highly accurate for localizing motor and language networks, thus offering the possibilities of replacing the Wada test (language hemispheric lateralization) and studying postlesional brain plasticity. Despite the difficulties of functional imaging in children owing to the limited cooperation that can be expected, ethical constraints, and poor normative data, SPECT/PET and fMRI provide clinically useful information for presurgical work-up of childhood epilepsies.

Adolescent↗

PubMed2001

Ictal perfusion changes during occipital lobe seizures in infancy: report of two serial ictal observations.

Serial-ictal single-photon-emission computed tomography (SPECT) examinations are presented in two infants (ages 1 and 2 years), with early ictal and ictal in one, and ictal and late ictal images in the other. Both had pharmacoresistant occipital epilepsy, due to focal cortical dysplasia. In the first case, size of ictal hyperperfusion increased in the course of the seizure from early ictal to ictal state. A concomitant ictal hypoperfusion was observed around the hyperperfused area. In the second patient, there was a dramatic difference between ictal and late ictal images. In the late ictal state, the previous occipital ictal hyperperfusion and extraoccipital ictal hypoperfusion disappeared, together with homolateral posterotemporal and contralateral occipital hyperperfusion, corresponding to seizure propagation. Ictal extratemporal blood-flow changes are therefore highly dynamic, particularly in very young children.

Age Factors↗

PubMed2001

Successful surgical relief of seizures associated with hamartoma of the floor of the fourth ventricle in children: report of two cases.

OBJECTIVE AND IMPORTANCE: To discuss the physiopathology and surgical handling of seizures due to hamartoma of the floor of the fourth ventricle in two children. CLINICAL PRESENTATION: Two girls aged 3 years at the time of their operations presented with seizures due to a lesion of the floor of the fourth ventricle. The seizures began within the first days of life and consisted of hemifacial contraction, then head deviation, blinking of the eyelids, and intermittent dysautonomic manifestations. The interictal neurological condition seemed normal in one patient and showed a slight development delay in the other. An ictal electroencephalogram showed slow waves in the posterior areas. A magnetic resonance imaging scan revealed a mass that remained unchanged on serial examinations bordering the fourth ventricle, with an isointense signal on T1-weighted sequences and high-intensity signals on T2-weighted sequences without gadolinium enhancement. An ictal single-photon emission computed tomographic scan showed hyperperfusion in the lesion in both girls. INTERVENTION: The operation consisted of resection and disconnection of the lesion. An electrical recording was obtained in one patient during the operation while she was anesthetized; the recording, made by means of a depth electrode with five contacts inside the lesion, indicated that repetitive theta rhythmic discharges were present. Neuropathology was consistent with a hamartoma. In both girls, the seizures disappeared after their operations, and antiepileptic drugs were withdrawn (follow-up periods, 8 and 3 yr, respectively). CONCLUSION: Considering the results of single-photon emission computed tomography, the intralesional electrical record, and the relief of seizures after the operation, we postulate that the seizures arose from inside the lesion. This particular kind of noncortical seizure is similar to gelastic seizure due to hypothalamic hamartoma.

Brain Diseases↗

PubMed2001

[Cerebral imaging in childhood epilepsy: what's new?].

The important development of non invasive techniques of cerebral imaging dramatically improved the presurgical work-up and the study of mental sequelae in childhood epilepsy. MRI's spatial resolution improved, so it is possible to detect subtle epileptogenic lesions, even in very young patients. By visualizing more and more accurately the sulcogyral macroanatomy, MRI permits a genetic and syndromic approach of cerebral lesions associated with epilepsy. Ictal SPECT helps localizing the epileptogenic zone and placing intracranial EEG electrodes, using strict methodology with simultaneous video-EEG and multidisciplinary interpretation of the images. Functional MRI can localize motor cortex and language networks, as well as it can lateralize language with a good correlation with WADA test, using selected activation tasks in cooperative children. Interictal SPECT and PET show the dysfunctioning areas involved in the neuropsychological and behavioural disorders associated with epilepsy. Finally, fMRI may study post-lesional and post-surgical plasticity by comparing longitudinal studies in a given patient.

Brain↗