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J M Pinard

Publications and source records attributed to J M Pinard.

31 records · Page 2Linked to original sources
PubMed1996

X-linked malformations of neuronal migration.

Malformations of neuronal migration such as lissencephaly (agyria-pachygyria spectrum) are well-known causes of mental retardation and epilepsy that are often genetic. For example, isolated lissencephaly sequence and Miller-Dieker syndrome are caused by deletions involving a lissencephaly gene in chromosome 17p13.3, while many other malformation syndromes have autosomal recessive inheritance. In this paper, we review evidence supporting the existence of two distinct X-linked malformations of neuronal migration. X-linked lissencephaly and subcortical band heterotopia (XLIS) presents with sporadic or familial mental retardation and epilepsy. The brain malformation varies from classical lissencephaly, which is observed in males, to subcortical band heterotopia, which is observed primarily in females. The XLIS gene is located in chromosome Xq22.3 based on the breakpoint of an X-autosomal translocation. Bilateral periventricular nodular heterotopia (BPNH) usually presents with sporadic or familial epilepsy with normal intelligence, primarily in females, although we have evaluated two boys with BPNH and severe mental retardation. The gene for BPNH has been mapped to chromosome Xq28 based on linkage studies in multiplex families and observation of a subtle structural abnormality in one of the boys with BPNH and severe mental retardation.

Adult↗
PubMed1995

[Subcortical laminal heterotopia and lissencephaly: cerebral malformations of X-linked inheritance].

Subcortical laminar heterotopia (band heterotopia) is a brain malformation now recognized by MRI. We report 3 families (2 previously described) in which several members had subcortical laminar heterotopia or a more severe malformation (agyria/pachygyria). In these families, subcortical laminar heterotopia were observed in women and were associated with epilepsy or slight mental retardation depending on the extend of heterotopia. Males had lissencephaly with refractory epilepsy and severe mental retardation. The pedigrees of these families demonstrate that these 2 malformations originate from a single genetic origin. A single X-linked dominant gene is postulated. Diagnosis of subcortical laminar heterotopia in a female or lissencephaly in a male (except in the case of Miller-Dieker syndrome) requires appropriate genetic counselling in the family: brain imaging should be performed in relatives.

Adult↗
PubMed1994

Subcortical laminar heterotopia and lissencephaly in two families: a single X linked dominant gene.

Neuronal migration disorders can now be recognised by MRI. This paper reports two families in which the mothers had subcortical laminar heterotopia and four of their children had either similar heterotopia (two girls) or severe pachygyria or lissencephaly (two boys). Laminar heterotopia was more evident on MRI T2 weighted images. The patients had mild to severe epilepsy and mental retardation depending on the extent of cortical abnormalities. In these families, subcortical laminar heterotopia, pachygyria, and lissencephaly seem to share the same X linked or autosomal dominant gene. No chromosomal abnormalities, especially of chromosome 17, could be identified. For appropriate genetic counselling of the family of a child with lissencephaly or subcortical laminar heterotopia, MRI should be performed in parents or siblings with mental retardation or epilepsy.

Adolescent↗
PubMed1994

[GM2-Gangliosidosis variant B1 disclosed during adolescence by an isolated multi-systemic involvement of the central and peripheral nervous systems].

The authors report on a Portuguese family with 3 adult brothers affected with GM2-gangliosidosis (B1 variant) in a sibship of 4, and more specifically on one of these brothers with neurological onset at the age of 17. Psychosis, lower motoneuron involvement and dysarthria were predominant in two of the cases; the third had a cerebellar symptomatology. Hexosaminidase A activity, studied in leukocytes, was profoundly deficient when measured using the specific sulfated substrate, but nearly normal using a conventional assay (non-sulfated substrate). These results established the diagnosis of the unusual enzymological form of GM2-gangliosidosis known as the B1 variant, which had so far not been associated with an adult phenotype. Molecular studies are in progress to study genotype/phenotype correlations in this family in comparison with known mutations in the B1 variant and in adult GM2-gangliosidosis. This report also emphasizes that a metabolic etiology, leading to genetic counselling, should be considered in some familial degenerative neurological disorders.

Adolescent↗
PubMed1991

Diffuse cortical dysplasia, or the 'double cortex' syndrome: the clinical and epileptic spectrum in 10 patients.

Diffuse neuronal migration disorders associated with epilepsy can now be recognized by modern neuroimaging techniques, particularly high-resolution MRI. We report 10 patients with a recently described MRI picture of continuous or generalized band heterotopia underlying the cortical mantle, giving the appearance of a "double cortex." They have epilepsy, and almost all have mental retardation. The epileptic disorder varies in nature and degree of severity. Patients may present with infantile spasms, a Lennox-Gastaut syndrome, or other forms of secondary generalized or multifocal epilepsy. Response to medical treatment is variable. Callosotomy may lead to considerable reduction of drop attacks, present in 60%. Mental retardation is usually mild or moderate, and only rarely severe. It correlates with the type of epileptic syndrome, and is greater in patients with more disorganized cortex overlying the heterotopia. Recognition of this entity by MRI is important for appropriate diagnosis of the epileptic disorder, planning of therapeutic strategy, and prognosis.

Adolescent↗
PubMedDate not supplied

West syndrome due to perinatal insults.

Clinical, neuroradiological data and outcome of epilepsy of 32 patients with symptomatic infantile spasms caused by perinatal insults are reported. Neuroradiological investigations showed focal as well as diffuse cerebral lesions. Fifteen children had a porencephalic lesion, 12 had periventricular leukomalacia and five had diffuse bilateral cerebral atrophy, associated with status marmoratus in one child and bilateral ulegyria in another. Eight patients (25%) had epilepsy following West syndrome. In the group of 15 children with porencephalic cysts, the lesion was always unilateral, but topography and extension varied. Eight children had circumscribed cysts involving the rolandic or parieto-occipital regions, and the outcome of epilepsy was favorable. Seven patients had large lesions involving the frontal lobe, associated with unilateral hemispheric atrophy in four cases. These four children had an unfavorable epilepsy outcome. In the 12 patients with periventricular leukomalacia, all premature, eleven had no seizure relapse after the spasms; one of these children had epilepsy. In the five full-term patients with bilateral and diffuse cerebral lesions, three children had epilepsy at the last observation. In children with leukomalacia and in patients with localized porencephalic lesions the outcome of epilepsy appears to be better than in patients with diffuse cerebral lesions or in children with extensive porencephalic cysts, particularly those involving the frontal lobe.

Atrophy↗
PubMedDate not supplied

Callosotomy in West syndrome suggests a cortical origin of hypsarrhythmia.

Hypsarrhythmia and spasms of West syndrome have been postulated by some investigators to have a brainstem origin. Cortical involvement is also postulated because of the frequent association with cortical lesions. Cortical discharges have been proposed to stimulate subcortical structures (i.e., brainstem) and hypsarrhythmia is a secondarily generalized phenomenon produced by the brainstem. Two children with cryptogenic West syndrome refractory for several years to steroids and conventional antiepileptic drugs underwent total callosotomy. Hypsarrhythmia that was bilateral before operation became unilateral after the procedure and spasms became asymmetrical, suggesting that a corticocortical pathway through the corpus callosum is important in the generalization of hypsarrhythmia.

Brain Stem↗