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Biomedical subjects

O Dulac

Publications and source records attributed to O Dulac.

At least 127 records · Page 7Linked to original sources
PubMed1991

A serial study of regional cerebral blood flow before and after hemispherectomy in a child.

Hemimegalencephaly (HME) is a severe unilateral brain malformation the prognosis of which may be improved by hemispherectomy. HME also provides a unique opportunity to compare normal and pathological hemispheric function in the same patient. We performed a serial functional cerebral imaging study in a child suffering from a neuropathologically confirmed left HME. He was hemispherectomized at 11 months because of intractable epilepsy; this led to cessation of seizures and dramatic psychomotor improvement. Regional cerebral blood flow (rCBF) was studied at 1, 7, 10, 12 and 25 months with single photon computed tomography (SPECT) using 133-Xenon and with simultaneous EEG recording. At one month of age SPECT was performed ictally. During left EEG discharges, rCBF was 40% higher on the left hemisphere than on the right, even in occipital and frontal regions, usually immature at this age. A crossed cerebellar hyperperfusion was also found. At 7 and 10 months, SPECT was performed interictally; rCBF was 45% lower in the left hemisphere than in the right. During follow-up, global and regional CBF values showed normal levels and normal maturation in the right hemisphere except for a mild and transient decrease observed one month after hemispherectomy. SPECT provides an additional procedure for studying hemispheric function in vivo. Serial SPECT imaging may be useful for the preoperative and postoperative evaluation in unilateral cerebral malformation.

Brain↗
PubMed1991

Treatment of infantile spasms with intravenous gamma-globulins.

In a prospective study, 23 children with infantile spasms received intravenous gammaglobulins in high doses. 19 patients present a West syndrome. 4 older patients were included in the study because infantile spasms had preceded their Lennox-Gastaut syndrome. None of the patients had recently undergone corticosteroid therapy. No effect was observed in 15 patients, while transitory clinical and/or electroencephalographic improvement was noted in 3. Complete normalization was obtained in the remaining 5 patients, of whom 4 had severe brain lesions. No correlation existed between the therapeutic results and immunological abnormalities, a deficiency in IgG subclasses in particular. On the whole, the therapeutic results were disappointing. But the existence of some cases in which spectacular electroencephalographic and/or clinical improvement was obtained leads us to suggest that IV gamma-globulins be used as auxiliary treatment in infantile spasms.

Electroencephalography↗
PubMed1991

Neuropsychological aspects of tuberous sclerosis in relation to epilepsy and MRI findings.

The neuropsychological performances, outcome of epilepsy and MRI topography of tubers of 23 children with tuberous sclerosis were reviewed. Seven children had normal intelligence, 10 had mental retardation, and six mental retardation and autism. An adverse association was found between the number of lesions and IQ, behaviour and severity of epilepsy. Posterior lesions, in addition to frontal-lobe dysfunction, were observed in children with autism. Tuberous sclerosis with well-defined cerebral lesions may represent a model for the relationship between different neuropsychiatric problems.

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↗
PubMed1991

Vigabatrin in childhood epilepsy.

Sixty-six children with various types of severe drug-resistant epilepsy were entered into a long-term, dose-rising study of vigabatrin after a 4-week run-in placebo period. All the children were receiving one to three other antiepileptic drugs, the doses of which were not changed during the 6-month dose titration phase. Following the introduction of vigabatrin, 11 patients became seizure free, and 28 responded with a greater than 50% reduction in seizure frequency. The following types of epilepsy responded favorably in order of decreasing efficacy: cryptogenic and symptomatic partial epilepsy, other symptomatic generalized epilepsy, and Lennox-Gastaut syndrome. However, three of nine patients with myoclonic epilepsy showed an increase in seizure frequency. Optimal responses were found with vigabatrin doses of 40 to 80 mg/kg/day, although no significant adverse effects were noted with doses of higher than 100 mg/kg/day. Thirty-eight responders continued on vigabatrin, 19 of whom have been treated for more than 1 year, with generally good efficacy. As a result of discontinuing concomitant antiepileptics, six patients are on monotherapy with vigabatrin, four of whom are seizure free. Vigabatrin tolerability was good, with 39 of 66 children reporting no adverse effects. Hyperkinesia was reported in 17 patients (26%), and two had to drop out of the study. All these patients had a history of hyperkinesia or mental retardation. In patients in whom vigabatrin dose was reduced because of hyperkinesia, a dose increase could later be instituted without recurrence of symptoms. There was no change in neurologic examination and no drug-related abnormalities in clinical laboratory data.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Therapeutic trial of vigabatrin in refractory infantile spasms.

Infantile spasms usually start during the first year of life and constitute one of the most difficult types of epilepsy to treat. They carry a very poor prognosis for both epilepsy and mental development. Seventy children, including 47 infants, with intractable infantile spasms were entered into an open study with vigabatrin as add-on therapy to the usual anticonvulsant treatment. All were resistant to previous treatments, including corticosteroids (43 patients), carbamazepine, benzodiazepines, and sodium valproate. Two children withdrew from the study because of intolerance to vigabatrin (hypotonia or hypertonia) before evaluation of efficacy could be made. Of the remaining 68 children, 29 (43%) showed complete suppression of spasms. Forty-six children had a greater than 50% reduction in spasms. The best response was observed in those with tuberous sclerosis (12/14 compared with 12/18 with symptomatic infantile spasms of other origin and 22/36 with cryptogenic infantile spasms). Following the initial response to treatment of these patients (n = 68), a long-term response was confirmed in 75% of children with symptomatic infantile spasms and 36% of children with cryptogenic infantile spasms. In eight children, all other anticonvulsant medication could be definitively withdrawn. Tolerability appeared excellent, with 52 of 70 patients reporting no side effects. Somnolence, hypotonia, weight gain, excitation, and insomnia were the most common problems at the beginning of the study and were usually transient. Given the poor prognosis of this type of childhood epilepsy, vigabatrin appears to be a very interesting advance in the management of drug-resistant infantile spasms.

Adolescent↗
PubMed1990

Prognosis for seizure control in infantile spasms preceded by other seizures.

Thirteen to 43% of patients with infantile spasms (IS) have other types of seizures, which are considered a feature of an unfavourable prognosis and, to some extent, as a contra-indication for steroid treatment. The present series comprised 43 patients treated with steroids, who suffered from other types of seizures prior to IS. The first seizures resulted from 2 different conditions, correlated to a different outcome of epilepsy. In 27 patients with prenatal encephalopathy, the first seizures were the first manifestation of the epilepsy and IS responded poorly to steroids. In the other 16 patients, the first seizures were occasional, due to acute brain damage, and the following IS responded favourably to steroid therapy. Rational therapeutic indications should take in account the etiology of seizures that precedes IS, and steroids should be administered when IS are due to acute peri- or postnatal acute brain damage.

Age Factors↗
PubMed1990

Quantification of diffuse and focal delta activity in hypsarrhythmia.

In order to determine whether or not there is any correlation between the various aspects of hypsarrhythmia and the etiology, we studied one of the major components of this pattern, delta activity, in patients with infantile spasms. In 3 different etiologic groups of patients (prenatal, perinatal and cryptogenic) we divided this activity into 2 types: diffuse (DSA) and focal slow activity (FSA). These two activities were quantified in 3 consecutive minute periods of wakefulness, drowsiness and slow sleep. The mean values of DSA and FSA remained unchanged during the 3 consecutive minute periods and in the different stages of vigilance. DSA and FSA differed significantly according to the etiology, with a predominance of DSA in the cryptogenic group and of FSA in the prenatal group. DSA was not correlated with either sex or age. The focal component seems to be related to brain lesions, whereas the diffuse component appears to be as a stereotyped neurophysiological phenomenon independent of brain lesions, sex or age.

Delta Rhythm↗
PubMed1990

["Benign" form of myoclonic epilepsy in children].

Among 62 children with myoclonic epilepsy who had first seizures between 1 and 10 years, without clinical or radiological evidence of brain lesion, we selected the 16 patients who had exhibited several types of fits and had stopped having seizures for over two years. First seizures occurred between 18 months and 4 years, and they were generalized clonic, tonic-clonic or tonic. After a mean 3 months' period, patients started also to have absence and myoclonic fits. During the period with various types of seizures, that lasted a mean 10 months, patients were ataxic and hyperkinetic, and 11 of them suffered myoclonic absence status for several hours or days. The EEG showed a high voltage rhythmic slow-wave activity with spikes, differing from the slow spike wave tracing of the Lennox-Gastaut syndrome, and there was no photosensitivity. The mean duration of the epilepsy was 1 year and 4 months and the last seizures were convulsive, occurring mainly during sleep. The clinical and EEG pattern, the high familial incidence are shared by the Doose syndrome, of which the present series seems to be a subgroup, as are other well-defined syndromes: benign and severe myoclonic epilepsies of infancy.

Child, Preschool↗
PubMed1990

Pharmacokinetics of the individual enantiomers of vigabatrin (gamma-vinyl GABA) in epileptic children.

1. The pharmacokinetics of the enantiomers of vigabatrin were investigated after oral administration of a single 50 mg kg-1 dose of the racemate to two groups of six epileptic children (I: 5 months-2 years, II: 4-14 years). 2. The mean (+/- s.d.) values of maximum plasma concentration and area under the plasma concentration-time curve of the R(-) enantiomer were significantly higher than those of S(+) vigabatrin in both groups: R(-) Cmax: 21 +/- 6.6 (I)-41.3 +/- 13.9 (II) vs S(+) Cmax: 13.9 +/- 4.5 (I)-23.8 +/- 12.2 (II) mg l-1; R(-) AUC: 106 +/- 28.5 (I)-147 +/- 34 (II) vs S(+) AUC: 90.9 +/- 27.9 (I)-117 +/- 26 (II) mg l-1 h. In group I, the half-life of the R(-) isomer was significantly shorter than that of the S(+) isomer; in group II, the half-lives were comparable. 3. For the R(-) enantiomer the area under the curve, and the elimination half-life increased linearly with age. 4. During chronic administration (50 mg kg-1 vigabatrin racemate twice a day for 4 days), the morning trough plasma drug concentrations did not increase.

Adolescent↗
PubMed1990

[Delayed acute measles encephalitis].

Delayed acute encephalitis is a rare complication of measles that may occur either in immunodepressed patients or in patients without overt immunodepression. In the present series of 8 cases, diagnosis was made on CSF/serum measles antibody titre and/or intranuclear paramyxovirus nucleocapsides identified by electron microscopy in the central nervous system cells. The disease is characterized by the association of focal defects (monoparesis, hemiparesis, aphasia, a.s.o.) with periodic myoclonic jerks without major impairment of consciousness. The encephalitis lasted 2 to 4 weeks and 3 patients died. With the exception of 1 case, all the patients had severe sequelae after a follow-up of 1 to 9 years. The EEG showed diffuse polymorphous delta waves, with a predominance on the side opposite to the myoclonias and pseudoperiodic complexes in all cases. CT scan was abnormal in 4 of 6 cases, showing hypodense areas. Antiviral or immunogenic therapeutic trials were administered to 5 patients without clear improvement. Sensitive methods of antibody dosage seem to be useful for the early diagnosis of the disease.

Acute Disease↗
PubMed1989

Electron microscopic and Golgi study in a case of hemimegalencephaly.

Pathological findings in a case of hemimegalencephaly are presented. Hemispherectomy, performed because of intractable seizures, allowed an electron microscopic and Golgi study. Glial abnormalities consisted of hyperplasia of glia cells with giant astrocytes often containing several nuclei and proliferation of numerous Rosenthal fibers. Golgi stain showed many giant neurons with a perikaryon covered by perisomatic processes, and a complex dendritic tree. Glial abnormalities could be correlated with the firmness of the hemisphere and intense hypersignal on magnetic resonance imaging. Giant neurons were associated with an increase in size of the perikaryon and dendritic tree; this pattern suggests a polyploidy.

Brain↗
PubMed1989

Encephalopathy with calcifications of the basal ganglia in children. A reappraisal of Fahr's syndrome with respect to 14 new cases.

Calcifications of the basal ganglia are described under the heading of "Fahr's syndrome". The clinical pattern is variable and the syndrome may be sporadic or familial. This study describes a personal series of 14 cases of encephalopathy with calcification of the basal ganglia and reviews the literature cases. A four-group classification is proposed. The first group includes encephalopathy, microcephaly, dwarfism, retinal degeneration or optic atrophy, symmetrical patchy demyelination with calcifications and probable autosomal recessive inheritance. Some cases have an early onset, a rapid evolution. Others have a later onset, longer course and retinal degeneration. In the second group, the children suffer from a congenital encephalopathy or a cerebral palsy without clear deterioration, without short stature, ocular impairment or persistent CSF abnormalities. This group has not been reported in the literature. The cases do not seem to be genetic. The precise cause in unknown but a sporadic non progressive anoxo-ischemic, or viral prenatal disease is suggested. In the third group, the association of encephalopathy, microcephaly, and persistent CSF lymphocytosis, has a high recurrence rate. The pathogenesis is still a matter of dispute. The fourth group is characterized by autosomal dominant calcifications of the basal ganglia with or without neurological abnormalities. Finally calcium metabolism disorders and mitochondrial encephalomyopathy may be associated with calcifications of the basal ganglia.

Basal Ganglia Diseases↗