Biomedical subjects

Fabienne Picard

Publications and source records attributed to Fabienne Picard.

9 recordsLinked to original sources

PubMed2007

Cerebrospinal fluid anti-SSA autoantibodies in primary Sjogren's syndrome with central nervous system involvement.

BACKGROUND: Central nervous system involvement in primary Sjogren's syndrome is a matter of controversy, and its diagnosis remains difficult. METHODS: We report 3 patients with primary Sjogren's syndrome and central nervous system involvement in whom we assessed intrathecal immunoglobulin G synthesis and the presence of cerebrospinal fluid anti-SSA and anti-SSB autoantibodies. RESULTS: We found intrathecal immunoglobulin G synthesis and presence of cerebrospinal fluid anti-SSA autoantibodies in all patients, with demonstration for the first time of specific anti-SSA autoantibody intrathecal synthesis in 2 patients. CONCLUSION: We suggest that cerebrospinal fluid anti-SSA autoantibodies could serve as a biomarker for Sjogren's-syndrome-related central nervous system involvement.

Antibodies, Antinuclear↗

PubMed2006

Altered expression of alpha3-containing GABAA receptors in the neocortex of patients with focal epilepsy.

Impaired transmission in GABAergic circuits is thought to contribute to the pathogenesis of epilepsy. Although it is well established that major reorganization of GABA(A) receptor subtypes occurs in the hippocampus of patients with medically refractory temporal lobe epilepsy (TLE), it is unclear whether this disorder is also associated with alterations in GABA(A) receptor subtypes in the neocortex. Here we have investigated immunohistochemically the subunit composition and neocortical distribution of three major GABA(A) receptor subtypes using antibodies specifically recognizing the subunits alpha1, alpha2, alpha3, beta2/3 and gamma2. Cortical tissue was obtained at surgery from patients with TLE and hippocampal sclerosis (HS; n = 9), TLE associated with neocortical lesions (non-HS; n = 12) and frontal lobe epilepsy (FLE; n = 5), with post-mortem samples serving as controls (n = 4). A distinct laminar and neuronal expression pattern of the alpha-subunit variants was found across the neocortical regions examined in the temporal and frontal lobes in both control and patient tissue samples. In the five patients with FLE, GABA(A) receptor subunit staining was unchanged as compared to controls. In patients with TLE we observed a marked decrease in alpha3-subunit staining in the superficial neocortical layers (I-III), but no change in the deep layers (V and VI) or in the expression pattern of the alpha1 and alpha2-subunits. Reduced expression in alpha3-containing GABA(A) receptors was detected in six out of nine patients of the HS group and four out of twelve patients of the non-HS group. Histopathological changes were present in eight out of the ten patients with decreased alpha3-subunit staining. The selective reduction in alpha3-containing GABA(A) receptors was confirmed using semiquantitative measurements of optical density (OD). The specific changes unique to alpha3-subunit expression in the superficial neocortical layers of patients with TLE suggest that this subtype is of particular significance in the reorganization of cortical GABAergic systems in focal epilepsy.

Adolescent↗

PubMed2006

Tobacco habits modulate autosomal dominant nocturnal frontal lobe epilepsy.

Mutations in neuronal nicotinic acetylcholine receptors have been demonstrated in autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE). The beneficial effect of nicotine administration was previously reported in one single case. We investigated the influence of the tobacco habits of 22 subjects from two pedigrees with alpha4 mutations (776ins3 and S248F). Subjects were interviewed with respect to pattern of nicotine intake and seizures. Seizure freedom was significantly associated with tobacco use (P=0.024). All seven nonsmokers with manifest ADNFLE had persistent seizures. Seizure fluctuations, including long remissions, corresponded to changes in tobacco habits in several patients. One patient who recently had begun treatment with transdermal nicotine experienced improvement. We conclude that tobacco appears to be an environmental factor that influences seizure susceptibility in ADNFLE. Inactivation by desensitization of the mutant receptors by nicotine may explain the beneficial effect. The efficacy and safety of transdermal nicotine in ADNFLE should be further explored.

Administration, Cutaneous↗

PubMed2006

Nocturnal hypermotor seizures, suggesting frontal lobe epilepsy, can originate in the insula.

PURPOSE: To report three patients with drug-resistant nocturnal hypermotor seizures (NHSs), no detectable brain lesion, and clinically defined nocturnal frontal lobe epilepsy (NFLE) or autosomal dominant NLFE (ADNFLE), whose intracerebral EEG ictal onset primarily involved the insula, rather than the mesial or orbital frontal cortex. METHODS: Fourteen to 15 intracerebral electrodes were implanted in each patient, primarily sampling the frontal lobes with 80 to 91 recording leads covering the most likely side of seizure onset, and two to six leads placed within the ipsilateral insula. Electrical stimulation was used to test the epileptic threshold of frontal and insular brain regions at the various recording sites. RESULTS: In all three patients, a low-voltage fast activity was recorded within the anterosuperior aspect of the insula at ictal onset, either in isolation, or extending to the nearby frontal operculum in the ADNFLE patient. The role of the insula was further supported in all three patients either by the presence of high-amplitude spikes that clearly predominated over that region (n = 2) or by triggering the patient's typical aura or seizure when applying an electrical stimulation at that site, selectively (n = 2). CONCLUSIONS: The anterosuperior portion of the insula might play a pivotal role in generating nocturnal hypermotor seizures in some patients with nonlesional drug-resistant epilepsy suggesting NFLE or ADNFLE. Whether these patients are amenable to successful surgery remain an open issue.

Adolescent↗

PubMed2003

Exploration of a putative susceptibility locus for idiopathic generalized epilepsy on chromosome 8p12.

PURPOSE: A recent genome-wide scan revealed a major susceptibility locus for idiopathic generalized epilepsies (IGEs) in the chromosomal region 8p12 in 32 IGE families without members with juvenile myoclonic epilepsy (JME). This study explored the presence of an IGE locus in the chromosomal region 8p12. METHODS: Our study included 176 multiplex families of probands with common IGE syndromes. Parametric and nonparametric multipoint linkage analyses were carried out between the IGE trait and six microsatellite polymorphisms encompassing the putative susceptibility locus. To explore the associated phenotype-genotype relation, two distinct subgroups of families were selected by the presence (n = 64) or absence (n = 112) of a family member with JME. To adjust the phenotypic spectrum toward adolescent-onset IGEs, a third subgroup of 28 families without JME was chosen through an IGE proband with seizure onset at age 10-20 years. RESULTS: Parametric and nonparametric multipoint linkage analyses provided no evidence for linkage between IGE and markers encompassing the putative IGE locus in the chromosomal region 8p12. Furthermore, we found no hint of linkage along the candidate region in any of the three family subgroups. CONCLUSIONS: We failed to provide evidence for a major IGE locus in the chromosomal region 8p12. On the contrary, these parametric linkage results provide strong evidence against linkage across the candidate region under a broad range of genetic models. If there is a susceptibility locus for IGE in the chromosomal region 8p12, then the size of the effect or the proportion of linked families is too small to detect linkage in the investigated family sample.

Adult↗

PubMed2003

[Epilepsy and genetics].

Our knowledge in the field of epilepsy has evolved since the discovery of new specific inherited epilepsy syndromes. Causal mutations have been identified for some of these syndromes. They involve various ionic channels: Na+ channels in the generalized epilepsy with febrile seizures plus (GEFS+) among the idiopathic generalized epilepsies, nicotinic receptors in autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE), K+ channels in benign familial neonatal convulsions, and GABAA receptors in some forms of generalized epilepsy. The major challenge that lies ahead is to solve the genetics of the common forms of epilepsy following complex inheritance. It is likely that a number of genes coding for one or more ion channels may interact to produce specific epilepsy syndromes. A number of classical idiopathic generalized epilepsies have been mapped but no genes identified to date. It remains to be seen whether the molecular insights gained from the monogenic epilepsies will be directly relevant to the common epilepsies.

Epilepsies, Partial↗

PubMed2002

Early onset and rapidly progressive subacute sclerosing panencephalitis after congenital measles infection.

UNLABELLED: We report an 18-month-old girl with rapidly progressive subacute sclerosing panencephalitis, whose non immunised mother had measles at the time of delivery. The patient presented with repetitive episodes of myoclonic jerks of the head and arms, followed by a drop of head and trunk with frequent falls. EEG, CSF studies and MRI confirmed the diagnosis. Despite therapy with isoprinosine and valproate, seizure activity continued and she became vegetative within 2 months, with severe spasticity and swallowing difficulties, and died at the age of 28 months. Early age of onset and rapid progression were most likely related to haematogenous in utero acquisition of the measles virus prior to delivery, as well as immaturity of neuronal and immune systems. CONCLUSION: this case emphasises the importance of a high measles vaccine coverage in the population in order to prevent the risk of disease in general and, in particular, gestational measles.

Age of Onset↗

PubMed2002

Epileptic falls and gait disturbance in two young children with a sharp wave focus at the vertex: a variant of benign partial epilepsy of childhood?

We describe two young children who presented with frequent falls and myoclonic jerks affecting the trunk and legs associated with a sharp and slow wave epileptic focus at the vertex. The initial neurological examination and brain magnetic resonance imaging were normal. Both patients had a persistent gait dysfunction, sometimes asymmetrical, fluctuating with the intensity of the epilepsy and the electroencephalogram abnormalities. The localization of the epileptic focus at the vertex, corresponding to the motor control of the legs and trunk, can explain this peculiar semiology. The seizures were difficult to treat, but one patient is currently in remission. Although epileptic falls are most often a feature of severe epilepsies of childhood, we think that these two patients present a variant of benign partial epilepsy of childhood.

Child↗

PubMedDate not supplied

T-cell receptor Vbeta gene usage in CSF lymphocytes in X-linked adrenoleukodystrophy.

X-linked adrenoleukodystrophy (ALD) is a peroxisomal disorder with impaired very-long-chain fatty acid (VLCFA) metabolism that produces a neurological disease with significant variability of clinical phenotypes even within kindred. The two most common forms are the cerebral form (CALD) with an important inflammatory reaction at the active edge of demyelinating lesions, resembling some aspects of multiple sclerosis pathology, and adrenomyeloneuropathy (AMN), which involves the spinal cord and in which the inflammatory reaction is mild or absent. One hypothesis is that the phenotypic variability is related to T cell-mediated immune mechanisms playing a primary role in the demyelinating pathogenic process of CALD. The present study aims to test the hypothesis that CSF of patients with the CALD form contains highly restricted T cell populations. The variable regions of the T cell receptor beta chains (TCR Vbeta) were studied in CSF from 29 ALD patients with different phenotypes. RNA was extracted and cDNA synthesized from CSF lymphocytes; TCR Vbeta gene segments were amplified from the cDNA by polymerase chain reaction (PCR) using 20 family-specific primers. PCR products were analyzed by Southern blot. Some amplified Vbeta products were sequenced. The majority of ALD patients (21/29), whatever their phenotype, exhibited oligoclonal T cell expansion. However the overexpression of some TCR Vbeta families was heterogeneous among the different patients without any preponderance of specific Vbeta families or any clustering according to clinical phenotype. In particular a dominant TCR Vbeta utilization was not found in patients with CALD.

Adrenoleukodystrophy↗