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C Chiron

Publications and source records attributed to C Chiron.

At least 19 recordsLinked to original sources
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↗
PubMed2000

Stiripentol in severe myoclonic epilepsy in infancy: a randomised placebo-controlled syndrome-dedicated trial. STICLO study group.

BACKGROUND: Stiripentol is an inhibitor of cytochrome P450 that showed antiepileptic efficacy in severe myoclonic epilepsy in infancy (SMEI) in association with clobazam and valproate in an open study. To confirm these results, 41 children with SMEI were included in a randomised, placebo-controlled, add-on trial. METHODS: After a baseline period of 1 month, placebo (n=20) or stiripentol (n=21) was added to valproate and clobazam during a double-blind period of 2 months. Patients then received stiripentol in an open fashion. Responders were defined as having more than 50% reduction in the frequency of clonic (or tonic-clonic) seizures during the second month of the double-blind period compared with baseline. FINDINGS: 15 (71%) patients were responders on stiripentol (including nine free of clonic or tonic-clonic seizures), whereas there was only one (5%) on placebo (none were seizure free; stiripentol 95% CI 52.1-90.7 vs placebo 0-14.6). The 95% CI of the difference was 42.2-85.7. Percentage of change from baseline was higher on stiripentol (-69%) than on placebo (+7%), p<0.0001. 21 patients on stiripentol had moderate side-effects (drowsiness, loss of appetite) compared with eight on placebo, but side-effects disappeared when the dose of comedication was decreased in 12 of the 21 cases. INTERPRETATION: This controlled trial shows the antiepileptic efficacy, of add-on stiripentol in children with SMEI. The results also provide good reason to focus studies on a specific epilepsy syndrome-a small sample of patients is sufficient to show the efficacy that might have been missed in a heterogeneous population.

Anti-Anxiety Agents↗
PubMed2000

Mental and behavioural outcome of infantile epilepsy treated by vigabatrin in tuberous sclerosis patients.

Vigabatrin (VGB) has demonstrated high efficacy in infantile spasms (IS) due to tuberous sclerosis. Our first objective was to evaluate the cognitive long term effect outcome of children whose refractory spasms definitely disappeared when VGB was given as an add on drug. Our second objective was to determine the response of generalized epilepsy (infantile spasms) compared to partial epilepsy on cognitive impairment. A non selected series of 13 children underwent psychometric and behavioural evaluation before VGB initiation at a mean of 3 years on VGB treatment. Eight of them could perform detailed neuropsychological tests at follow-up. Seven had infantile spasms (Group I), they all were spasm free before 2 years of age and five remained with rare partial seizures (mean age, 5.5 years). Six others had partial epilepsy without spasms (Group II) and five remained with rare seizures (mean age, 7.5 years). Patients of Group I experienced dramatic changes. Developmental quotient (DQ) significantly rose in six out of seven by ten to more than 45 points (P = 0.03) and autistic behaviour disappeared in five out of the six who presented with. The four tested children had normal verbal level after 5 years and could integrate at school but they remained with marked visuospatial disabilities. By contrast, patients of Group II remained with an unchanged DQ of about 60 so that both groups had similar DQ levels on follow-up. The cessation of spasms with VGB is therefore associated with significant improvement of cognition and behaviour in children with tuberous sclerosis. Controlling secondary generalization induced by infantile spasms seems to be a key factor for mental development.

Anticonvulsants↗
PubMed1999

Hemispheric specialization using SPECT and stimulation tasks in children with dysphasia and dystrophia.

Developmental dysphasia, a severe childhood learning disorder, is thought to result from problems in hemispheric specialization involving both left and right cerebral hemispheres. Regional cerebral blood flow (rCBF) was measured at rest and during stimulation of both hemispheres independently: dichotic listening for the left, dichaptic palpation for the right. Eight right-handed boys with expressive dysphasia, aged 8 to 12 years, were investigated using SPECT and compared with eight right-handed age-matched boys with Duchenne muscular dystrophy with reading disorders but normal speech. rCBF values at rest were also compared with those of five right-handed age-matched normal boys. In the dichotic task, children with dysphasia differed from children with dystrophia by failure to increase rCBF in the left hemisphere, in Broca's area, but rCBF increased in the right hemisphere, in the region homologous to Broca's area. In the dichaptic task, rCBF increased bilaterally for children with dysphasia whereas in children with dystrophia rCBF increased only in the right hemisphere. At rest the physiological asymmetry was reversed in favor of the right hemisphere in all areas except Broca's area. Surprisingly, the same applied at rest and for all areas in children with dystrophia. These results confirm that functional specialization of both hemispheres is impaired in developmental dysphasia. Moreover, they suggest that learning disabilities associated with Duchenne muscular dystrophy could also be related to abnormal hemispheric specialization.

Adolescent↗
PubMed1999

Callosotomy for epilepsy after West syndrome.

PURPOSE: To analyze the results of callosotomy in 17 children with symptomatic generalized epilepsy after West syndrome, according to the different seizure types and surgical procedures, to define selection criteria for candidates to callosotomy. METHODS: Callosotomy was performed in two successive stages. Partial callosotomy, anterior in 13 and posterior in three, was followed by completion in 14 cases in all but four patients (complete callosotomy in one stage in one, no completion in three). All patients had clinical, video-EEG, and neuropsychological evaluation before and after each stage of callosotomy, with a mean final follow-up of 4 years. RESULTS: Seizure frequency improved in only two of 13 patients after anterior callosotomy, in none of three after posterior callosotomy, but in nine of 14 after complete callosotomy. After complete callosotomy, spasms disappeared in 80% of the cases, and drop attacks, the most severe ictal event, completely stopped or were dramatically reduced in 90% of the children. One patient no longer had episodes of status epilepticus, and another one acquired the ability to walk after complete callosotomy. From the cognitive viewpoint, nine patients with improved seizure frequency after complete callosotomy also had improved behavior and cognitive functions, but two others experienced speech deterioration after posterior callosotomy at age 11 years and completion of callosotomy at age 16 years. CONCLUSIONS: As in other severe generalized epilepsies in childhood, drop attacks provide the best indication for complete callosotomy in patients with previous West syndrome. Because drop attacks can be identifiable by falls only, the previous acquisition of walking should be considered as a key feature for any benefit to be obtained.

Child↗
PubMed1999

Stiripentol: efficacy and tolerability in children with epilepsy.

PURPOSE: Stiripentol (STP) is a new antiepileptic drug (AED) that inhibits cytochrome P450, resulting in increased plasma concentrations of concomitant AEDs. The efficacy and tolerability of STP as an add-on therapy in children were assessed. METHODS: Two hundred twelve patients with refractory epilepsy, aged from 1 month to 20.5 years, received STP either in a single-blind, placebo-controlled trial (108 patients) or in a further open trial (104 other patients selected by epilepsy syndrome for possible efficacy based on the results of the previous trial). RESULTS: Among the 97 patients who could be analyzed for efficacy in the placebo-controlled study, the median seizure frequency was lower at 3 months with STP than with the placebo (p<0.0001); 49% responded to the drug, including 10% who became seizure free. Patients with partial epilepsy had the highest response rate (57%). Results were confirmed in the open study where 68% of the 91 patients receiving STP responded at 3 months. These patients were mainly those with partial epilepsy (73%) who were receiving carbamazepine (CBZ) (75%) as comedication (p<0.001). Ten of the 20 children with severe myoclonic epilepsy in infancy also responded with clobazam (CLB) as comedication. Efficacy was sustained long term in 74% of the 94 patients still receiving STP at a mean 30-month follow-up. Adverse events were reported in 48% of the 212 patients, mainly anorexia and loss of weight, but these events required STP discontinuation in only nine cases. Side effects were minimized in the open trial by optimizing the dose of comedication. CONCLUSIONS: STP seems to be a promising add-on drug, particularly when combined with CBZ in patients with partial childhood epilepsy refractory to vigabatrin (VGB) and with CLB in patients with severe myoclonic epilepsy in infancy.

Adolescent↗
PubMed1999

Early diagnosis of subependymal giant cell astrocytoma in children with tuberous sclerosis.

OBJECTIVES: Intraventricular astrocytomas (subependymal giant cell astrocytomas) of tuberous sclerosis have a poor prognosis due to the obstruction of CSF flow. The aim of this study was to determine whether they could be differentiated during childhood and at an early preclinical stage, from subependymal nodules without any growing potential. METHODS: The first two MRIs of all children referred to this neuropaediatric centre between 1987 and 1996 were retrospectively blindly reviewed. RESULTS: Out of 60 patients, 24 disclosed subependymal nodules localised near the foramen of Monro, and eight of the 24 developed astrocytomas. Subependymal nodules were first detectable on MRI from 1 year of age in all cases and the first MRI evidence of growth occurred between 1 and 9 years (mean 4 years). At an early stage, subependymal nodules had different characteristics in patients who developed subependymal giant cell astrocytomas from those who did not. The nodules over 5 mm in diameter that were incompletely calcified and enhanced by gadolinium were at higher risk of growing, particularly in children with a familial history of tuberous sclerosis. To detect the subependymal giant cell astrocytomas earlier in tuberous sclerosis, it is advisible to systematically perform an MRI examination before 2 years of age and to repeat it every year if the patient has risk factors for developing astrocytomas.

Brain Neoplasms↗
PubMed1999

Use of subtraction ictal SPECT co-registered to MRI for optimizing the localization of seizure foci in children.

UNLABELLED: Ictal SPECT studies are increasingly used to localize seizure foci in children with refractory epilepsy, but few studies have reported on ictal-interictal subtraction images co-registered to MRI at this age. METHODS: Twenty-seven children with partial epilepsy (aged 3 mo-18 y) underwent ictal ethyl cysteinate dimer (ECD) SPECT (20 mCi/1.73 m2) combined with video-electroencephalography (EEG) and interictal ECD SPECT followed 2 d later by three-dimensional MRI. Ictal-interictal and interictal-ictal subtraction images were computed by registering and normalizing the ictal to the interictal SPECT scans for each child. The ictal, interictal SPECT and subtraction images were registered to each child's MRI. Difference images (ictal-interictal) were then superimposed on MRI for anatomic localization of the perfusion changes. Intra- and interobserver reproducibility and "facility of interpretation" of overlay images were compared with standard analysis of the non-coregistered ictal and interictal scans. RESULTS: Overlay images allowed the detection of at least one hyperperfused focus in 93% of the children, compared with 74% using ictal and interictal scans separately. Seizure onset was suspected clinically, on EEG or on MRI in 20 children. Overlay images were concordant (n = 11) or larger (n = 7) than the suspected focus in 18 of 20 (90%), whereas these images failed to show any abnormality in 1 child and were discordant with MRI in another patient. In the remaining 7, images showed cortical localization in 6 patients. Among the 5 patients who underwent electrocorticography, overlay images were concordant in 3, larger in 1 and absent in 1. The intra- and interobserver reproducibility and facility of interpretation were significantly higher using overlay images than standard analysis, even when ictal and interictal SPECT were co-registered. CONCLUSION: The co-registration of ictal-interictal subtraction SPECT images to MRI seems to be a helpful technique in localizing the onset of seizure and guiding the intracranial recording in childhood epilepsy. Moreover, this method improves sensitivity, enhances intra- and interobserver reproducibility and makes interpretation easier.

Adolescent↗
PubMed1999

[Ictal SPECT in the epileptic child. Contribution of subtraction interictal images and superposition of with MRI].

Ictal SPECT is a highly sensitive method to localize the epileptogenic focus in refractory temporal lobe epilepsy in adults. In extratemporal epilepsy, sensitivity can be improved by subtracting interictal from ictal images and superimposing subtraction images on MRI. In children, such a procedure is potentially interesting because most epilepsies are extratemporal and ictal SPECT not yet routinely developed. The aim of this study was to test the feasibility of ictal SPECT with subtraction image processing in a pediatric population. Twenty-six children with refractory partial epilepsy and aged from 3 months to 18 years underwent ictal ECD-SPECT (20 mCi/1.73 m2) combined with video-EEG and interictal ECD-SPECT plus 3D-MRI two days later. Ictal-interictal subtraction images were computed by registering and normalizing the ictal to the interictal SPECT scans for each child. The ictal, interictal SPECT and subtraction images were registered to the children's MRI. Difference images were then superimposed to MRI for anatomical localization of the perfusion changes (overlay images). Looking for perfusion changes, overlay images allowed to detect at least one hyperperfused focus in 92 p. 100 of the 26 children compared to 73 p. 100 visually comparing ictal and interictal scans separately. Seizure onset was suspected on clinical and/or EEG and/or MRI in 19 children. Positive overlay images were concordant (n = 11) or larger (n = 7) than the suspected focus in 17/19 (90 p. 100), whereas they failed to show any abnormality in 1 child and were discordant with MRI in another one. In the 7 remaining patients, images showed cortical localization in 6 cases. Ictal SPECT is therefore faisable in very young children. Ictal-interictal subtraction SPECT images co-registered to MRI improves sensitivity compared to classical visual analysis. It seems therefore to be a helpful technique to localize the onset of seizure and to guide the intracranial recording in childhood epilepsy.

Adolescent↗
PubMed1998

[Treatment of infantile spasms with vigabatrin as first-line therapy and in monotherapy: apropos of 70 infants].

BACKGROUND: Steroids (hydrocortisone or ACTH) still remain the usual treatment for infantile spasms (IS). However, since 1990, some authors have reported the efficacy of vigabatrin (VGB), especially in cases related to tuberous sclerosis. POPULATION AND METHODS: Seventy children with infantile spasms were treated by VGB first line monotherapy. Modalities of treatment and monitoring were the same for all children. VGB was given at the daily dose of 100 mg/kg during 1 week. If spasms persisted, the daily VGB dose was increased to 150 mg/kg during a 2nd week. In case of persistence of IS, on the 15th day, hydrocortisone was then added to VGB. Of the 70 infants, 39 were symptomatic and 31 cryptogenic. RESULTS: On VGB, 37 children (54%) stopped having IS within a mean 3.5 days. Response to VGB was different according to etiology. Among cryptogenic cases, 22 infants (71%) definitively stopped having spasms and only one relapsed. Among symptomatic cases, only 15 infants (38%) stopped having IS, and half (8/15) relapsed. VGB mean daily dose at cessation of spasms was 114 mg/kg. Side effects were transient drowsiness (27%) and agitation (12%). Mean follow-up was 10 months (1-24 months). Seventy-five percent of the infants presenting with a focus of spike after the 1st month of treatment relapsed. CONCLUSION: Infants with cryptogenic spasms have a good response to VGB monotherapy. When mental retardation is noticed before IS, and MRI is normal, there is no efficacy. In these cases, the best treatment seems to be prolonged corticotherapy associated with VGB.

Anti-Inflammatory Agents↗
PubMed1998

Autism and visual agnosia in a child with right occipital lobectomy.

OBJECTIVES: Autistic disorder is a developmental handicap with an unknown neurological basis. Current neuropsychological models for autism suggest an abnormal construction of visual perceptual representation or a deficit in executive functions. These models predict cerebral lesions in the temporo-occipital or frontal regions of autistic patients. The present study aimed at studying the presence of symptoms of autism and visual agnosia in a 13 year old girl who had a right temporo-occipital cortical dysplasia that was surgically removed at the age of 7. METHODS: Neuropsychological evaluation included Wechsler and Kaufman intelligence scales, a test of word fluency, digit span, Corsi block, California verbal learning, Trail making, Benton facial recognition, Snoodgrass object recognition tests, Rivermead face learning subtest, and developmental test of visual perception. The ADI-R was used to show current and retrospective diagnosis of autistic disorder. Neuroimagery included brain MRI, single photon emission computed tomography (SPECT), and PET. RESULTS: Brain MRI showed a right occipital defect and an abnormal hyperintensity of the right temporal cortex. PET and SPECT disclosed a left frontal hypometabolism together with the right occipital defect. Neuropsychological testing showed a visual apperceptive agnosia and executive function deficits. Psychiatric study confirmed the diagnosis of autistic disorder. CONCLUSIONS: Although the possibility that autism and visual agnosia were dissociable factors in this patient cannot be excluded, the finding of both deficits supports the possibility that occipito-temporal lesions can predispose to the development of autism.

Adolescent↗