Search PubMed⌕ Search

Biomedical subjects

C Billard

Publications and source records attributed to C Billard.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Identification of language disorders in children. A contribution to the prevention of illiteracy].

Early identification of disorders of oral and written language development is essential for effective action before the vicious circle of educational failure and established psychosocial consequences. There has been growing awareness among health and education professionals that the means of recognizing, treating and teaching children with specific oral and written language disorders are inadequate. There is still a limited number of diagnostic tools that have not been fully evaluated. Nevertheless, considerable effort has been made in recent years to develop instruments for early detection and precise diagnostic evaluation. Developments in cognitive neuropsychology provide new approaches for the management of these disorders.

Child, Preschool↗
PubMed2001

[BREV: a new clinical scale for the evaluation of cognitive function in school-age and preschool-age children].

BREV (Batterie Rapide d'Evaluation des fonctions cognitives) is a new evaluation test for the screening of cognitive disorders in 4-9-year-old children, based on a neuropsychological process. It is made up of 17 subtests which have been carefully standardized. It is not an intelligence test but a tool for children' health professionals to use as a rapid neuropsychological screening test. It is particularly recommended for any child with a school learning disorder or neurological history with a high risk of cognitive disturbances such as epilepsy. It may also be used as a systematic screening test.

Child↗
PubMed2001

[Neuropsychology and academic achievement of epileptic children: executive-functions tests].

Children with epilepsy are exposed to learning disabilities. In young children, still not taught reading, spelling or mathematics, the standardized psychometric evaluation provides a usefull assessment tool enabling identification of the structural disturbances that will affect the learning process. For school-age children, assessment can be made in regard to the DSM IV criteria of specific learning disabilities, and within a neuropsychological framework that pays a particular attention to the executive functions.

Attention↗
PubMed2001

Cognitive function in adolescents and young adults in complete remission from benign childhood epilepsy with centro-temporal spikes.

Benign childhood epilepsy with centrotemporal spikes (BECTS) is a frequent, benign childhood epilepsy with a good prognosis. However, neuropsychological deficits have been reported during its active phase. In this study, we evaluate the long-term neuropsychological consequences of this reputedly benign epilepsy, particularly the relation between paroxysmal abnormalities and cerebral language lateralization. The neuropsychological outcomes concerning both overall cognitive and lateral hemispheric functions were studied in twenty-three adolescents and young adults in total recovery from BECTS, in thirty-three controls without any significant past neurological history and in ten adolescents and young adults with complete resolution of generalized idiopathic epilepsy (childhood absence epilepsy or CAE). Language lateralization was evaluated using classical neuropsychological procedures (dichotic listening tasks, dual-task procedure). No difference was seen in the three populations with respect to overall cognitive function: memory, language and the executive functions. Although the Performance IQ was lower in patients in remission from CAE, the results were within normal limits. However, qualitative analysis of the dual-task procedure suggested a different organizational pattern for cerebral language in adolescents and young adults in remission from BECTS as compared to controls and patients in remission from CAE. The different organization in cerebral pattern in BECTS patients appeared to be related to the initial epileptic focus as determined by the EEG and/or the sleep-recording. We discuss the relationship between the presence of paroxysmal anomalies in childhood and subtle functional lateralized hemispheric abnormalities in adulthood.

Adolescent↗
PubMed2000

Switch in the protein tyrosine phosphatase associated with human CD100 semaphorin at terminal B-cell differentiation stage.

Human CD100, the first semaphorin identified in the immune system, is a transmembrane protein involved in T-cell activation. In the present study, we showed that activation of peripheral blood or tonsillar B lymphocytes induced the expression of CD100 in CD38(+)CD138(-) cell populations, including in CD148(+) subpopulations, thus expressing a memory B-cell-like phenotype. Using an in vitro enzymatic assay, we found that protein tyrosine phosphatase (PTP) activities were immunoprecipitated with CD100 in these cell populations, which were isolated by cell sorting, as well as in most B-cell lines representing various stages of B-cell differentiation. Immunodepletion and Western blotting experiments demonstrated that CD45 was the PTP associated with CD100 in cell lines displaying pre-B, activated B, and pre-plasma cell phenotypes. CD45 also accounted for PTP activity immunoprecipitated with CD100 in CD38(+)CD138(-) cells sorted after activation of peripheral blood or tonsillar B lymphocytes. In contrast, no CD100-CD45 association was observed in plasma cell lines corresponding to the terminal B-cell differentiation stage. CD148, the other transmembrane PTP known to be implicated in lymphocyte signaling pathways, was either only partly involved in the CD100-associated PTP activity or not expressed in plasma cell lines, indicating the association of CD100 with another main PTP. Our data show that CD100 is differentially expressed and can functionally associate with distinct PTPs in B cells depending on their activation and maturation state. They also provide evidence for a switch in the CD100-associated PTP at terminal stage of B-cell differentiation.

ADP-ribosyl Cyclase↗
PubMed2000

Severe cognitive impairment in DMD: obvious clinical indication for Dp71 isoform point mutation screening.

Duchenne muscular dystrophy is associated with variable degrees of selective cognitive defect with lower scores for verbal intelligence and reading abilities. A number of findings have shown that rearrangements located in the second part of the gene seem to be preferentially associated with cognitive impairment. Several dystrophin transcripts are expressed in the brain. The more distal of them, Dp71, is predominant. We have carried out a mutational analysis of Dp71 transcript in 12 DMD patients severely, mildly or not retarded, all without detectable deletion or duplication. We have detected five point mutations causing Dp71 premature translation termination. All were found among the more severely mentally retarded patients of this group (VIQ < 50 and/or no reading acquisition).

Adolescent↗
PubMed2000

Continuous spikes and waves during slow sleep (CSWS): outcome in adulthood.

We report a longitudinal, electroencephalographic and neuropsychological analysis of epilepsy with continuous spikes and waves during slow sleep (CSWS) in a 19 year-old boy. The clinical course fluctuated, with temporary worsening or improvement of the paroxysmal abnormalities, epilepsy and cognitive functions. At the end of the follow-up period, seizures persisted. Evaluation of the boy's behaviour, language and cognitive function suggested a dysexecutive syndrome. We discuss the relationship between paroxysmal abnormalities and neuropsychological disorders.

Adult↗
PubMed1999

A placebo-controlled trial of lamotrigine add-on therapy for partial seizures in children. Lamictal Pediatric Partial Seizure Study Group.

OBJECTIVE: To compare the safety and efficacy of add-on lamotrigine and placebo in the treatment of children and adolescents with partial seizures. BACKGROUND: Add-on and monotherapy lamotrigine is safe and effective in adults with partial seizures, and reports of preliminary uncontrolled trials suggest similar benefits in children. METHODS: We studied 201 children with diagnoses of partial seizures of any subtype currently receiving stable conventional regimens of antiepileptic therapy at 40 study sites in the United States and France. After a baseline observation period (to confirm that more than four seizures occurred in each of two consecutive 4-week periods), patients were randomized to add-on lamotrigine or placebo therapy. A 6-week dose-escalation period was followed by a 12-week maintenance period. RESULTS: Compared with placebo, lamotrigine significantly reduced the frequency of all partial seizures and the frequency of secondarily generalized partial seizures in these treatment-resistant patients. The most commonly reported adverse events in the lamotrigine-treated patients were vomiting, somnolence, and infection; the frequency of these and other adverse events was similar to that in the placebo-treated group, with the exception of ataxia, dizziness, tremor, and nausea, which were more frequent in the lamotrigine-treated group. The frequency of withdrawals for adverse events was similar between groups. Two patients were hospitalized for skin rash, which resolved after discontinuation of lamotrigine therapy. CONCLUSIONS: Lamotrigine was effective for the adjunctive treatment of partial seizures in children and demonstrated an acceptable safety profile.

Adolescent↗
PubMed1999

[Symptoms of epilepsy in the child].

Convulsions and epilepsy in the child include widely diverse disorders, ranging from simple and benign to complex and severe. Initially, the general practitioner must consider the various diagnoses in order to prescribe appropriate investigations and treatment (now complex and numerous), or to orient the diagnosis. In the case of paroxysm, the initial step is to affirm the diagnosis of epileptic seizure, especially on the basis of the descriptions made by the child and by witnesses, possibly with the aid of an EEG. The second step is to determine the etiology, differentiating isolated seizures occurring in a particular context (for example febrile convulsions) from epileptic seizures with no special context. The description of the seizure and the inter-critical EEG lead to classifying the seizure as partial or generalised and, if it is repeated, to consider it as composing one of the childhood epileptic syndromes.

Child↗
PubMed1999

[Benign infantile convulsions. French collaborative study].

BACKGROUND: Benign infantile non febrile seizures are not well known, leading us to study their clinical and EEG characteristics. METHODS: Between 1981 and 1994, we assembled 34 patients with the following inclusion criteria: non febrile seizures between 1 month and 2 years of age, normal personal history, no abnormality on clinical, biological and radiological investigations, normal developmental outcome with at least 1 year follow-up. RESULTS: These 34 patients were recognized as 14 familial cases (identical seizures affecting parents) and 11 non familial cases. The other nine cases had different or undefined epilepsy in the family. The clinical and EEG characteristics were the same: at the mean age of 6 months, brief partial seizures (often secondarily or apparently generalized) occurring in a cluster of two to 12 episodes a day for a mean duration of 2.5 days, with ictal EEG showing focal discharge, often slow waves or focal spikes on post-ictal tracing and normal interictal EEG. CONCLUSION: The clinical and EEG characteristics are important in order to recognize this type of infantile convulsions (familial or not familial), which have a good prognosis and need no aggressive treatment.

Age of Onset↗
PubMed1999

[Epilepsy due to mesiotemporal sclerosis in children: 10 cases].

BACKGROUND: Mesio-temporal sclerosis is a frequent and probably underestimated cause of resistant temporal epilepsy in childhood. PATIENTS AND METHODS: Ten patients originating from West and North-East France are reported in this retrospective study. They were referred for partial temporal epilepsy which had begun between the ages of 3.5 and 15 years. Mesio-temporal sclerosis was diagnosed on MRI (ten cases) and on neuropathological examination (three cases). RESULTS: Complex partial seizures were noted in all patients, with most frequently fear, abnormal epigastric perception and oro-alimentary automatisms. Social and educational issues were altered due to frequent seizures and amnesic disturbances. An initial event, always a complex febrile seizure, was found in six patients. MRI study showed in all patients unilateral hippocampal atrophy and/or an increase in hippocampal T2 signal intensity on coronal sections. Ictal EEG showed homolateral temporal seizures six times. Hippocampo-amygdalectomy was performed in three patients with a good outcome. CONCLUSION: Epilepsy associated with mesio-temporal sclerosis belongs to intractable epilepsy in childhood. Early recognition of its symptoms would allow early pre-operative assessment in order to minimize developmental defects due to continuing epilepsy, and adverse cognitive effects of anti-epileptics.

Adolescent↗
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

Recurrence of the T666M calcium channel CACNA1A gene mutation in familial hemiplegic migraine with progressive cerebellar ataxia.

Familial hemiplegic migraine (HM) is an autosomal dominant migraine with aura. In 20% of HM families, HM is associated with a mild permanent cerebellar ataxia (PCA). The CACNA1A gene encoding the alpha1A subunit of P/Q-type voltage-gated calcium channels is involved in 50% of unselected HM families and in all families with HM/PCA. Four CACNA1A missense mutations have been identified in HM: two in pure HM and two in HM/PCA. Different CACNA1A mutations have been identified in other autosomal dominant conditions: mutations leading to a truncated protein in episodic ataxia type 2 (EA2), small expansions of a CAG trinucleotide in spinocerebellar ataxia type 6 and also in three families with EA2 features, and, finally, a missense mutation in a single family suffering from episodic ataxia and severe progressive PCA. We screened 16 families and 3 nonfamilial case patients affected by HM/PCA for specific CACNA1A mutations and found nine families and one nonfamilial case with the same T666M mutation, one new mutation (D715E) in one family, and no CAG repeat expansion. Both T666M and D715E substitutions were absent in 12 probands belonging to pure HM families whose disease appears to be linked to CACNA1A. Finally, haplotyping with neighboring markers suggested that T666M arose through recurrent mutational events. These data could indicate that the PCA observed in 20% of HM families results from specific pathophysiologic mechanisms.

Calcium Channels↗
PubMed1999

Neuropsychologic and adaptive functioning in adolescents and young adults shunted for congenital hydrocephalus.

The major aim of this study was to assess whether the syndrome of nonverbal learning disabilities described in hydrocephalic children is observed in adulthood. Eleven adults shunted for congenital hydrocephalus related to spina bifida and eight adults shunted for hydrocephalus related to aqueductal stenosis were administered an extensive neuropsychologic battery to investigate discrepancies between verbal and visuospatial cognition, verbal and visuospatial long-term memory, and psycho-social adaptive abilities. The results showed no discrepancies between Wechsler Performance IQ or Verbal IQ in either hydrocephalic group. Nevertheless, the subjects with spina bifida appeared more cognitively impaired than the subjects with aqueductal stenosis, who performed normally on the Wechsler Adult Intelligence Scale-Revised. Memory assessment using Signoret's Memory Battery revealed no discrepancy between verbal and visuospatial memory in the hydrocephalic group. Nevertheless, the subjects with spina bifida had poorer verbal and visuospatial memory performance than the subjects with aqueductal stenosis. There were no differences on the Vineland Adaptive Behavioral Scale between subjects with spina bifida and those with aqueductal stenosis in autonomy, socialization, and daily living skills. These results suggest that shunted congenital hydrocephalus is not characterized by nonverbal learning disabilities syndrome in adolescence or in adulthood.

Adaptation, Psychological↗
PubMed1998

Are Dp71 and Dp140 brain dystrophin isoforms related to cognitive impairment in Duchenne muscular dystrophy?

Molecular study and neuropsychological analysis were performed concurrently on 49 patients with Duchenne muscular dystrophy (DMD) in order to find a molecular explanation for the cognitive impairment observed in most DMD patients. Complete analysis of the dystrophin gene was performed to define the localization of deletions and duplications in relation to the different DMD promoters. Qualitative analysis of the Dp71 transcript and testing for the specific first exon of Dp140 were also carried out. Neuropsychological analysis assessed verbal and visuospatial intelligence, verbal memory, and reading skills. Comparison of molecular and psychometric findings demonstrated that deletions and duplications that were localized in the distal part of the gene seemed to be preferentially associated with cognitive impairment. Two altered Dp71 transcripts and two deleted Dp140 DNA sequences were found in four patients with severe cerebral dysfunction. These findings suggest that some sequences located in the distal part of the gene and, in particular, some DMD isoforms expressed in the brain may be related to the cognitive impairment associated with DMD.

Adolescent↗