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Biomedical subjects

C Raybaud

Publications and source records attributed to C Raybaud.

At least 37 records · Page 2Linked to original sources
PubMed1999

The pitfall of silent neurosarcoidosis.

Sarcoidosis in childhood is seldom reported. Most cases are observed in older children and preadolescents as bilateral pulmonary disease and eye lesions. Arthritic features are more likely to be observed in infants and children younger than 4 years of age who do not develop pulmonary disease. Neurosarcoidosis is exceptional in this age group and seldom suspected when the neurologic symptoms are present. The authors report a pediatric patient with systemic sarcoidosis who developed a severe but silent neurologic involvement. Numerous masslike lesions were discovered on systematic cranial magnetic resonance imaging. The authors recommend a complete screening of extrapulmonary manifestations in children with sarcoidosis. The proper management of patients with incidentally discovered neurosarcoidosis has yet to be established.

Brain Diseases↗
PubMed1999

Benign childhood epilepsy with centrotemporal spikes and hippocampal atrophy.

A boy without significant family or personal history had three consecutive nocturnal seizures at 1-month intervals at age 10 years, all simple focal seizures with motor and sensory symptoms, the last with secondary generalization. Waking and napping EEG showed focal sharp changes typical of benign epilepsy with centrotemporal spikes (BECTS). A magnetic resonance imaging documented a marked right hippocampal atrophy (HA). After valproic acid (VPA) therapy, there were no more seizures, and there were fewer EEG changes. An EEG performed in the younger, fully asymptomatic 8-year-old sister documented unilateral right focal sharp waves. This case shows that HA, as well as other central nervous system lesions, can be found fortuitously in patients with BECTS.

Atrophy↗
PubMed1999

Late-onset epilepsy associated with regional brain cortical dysplasia.

RATIONALE: Cortical dysplasia (CD) designates a diverse group of malformations resulting from one or more abnormalities in the development of the cerebral cortex. The clinical manifestations of CD are varied, probably depending on the type, location and extent of CD. Epilepsy is a potential late manifestation of any cortical malformation. To our knowledge, however, no study has focused specifically on late onset of epilepsy in patients with localized CD. MATERIAL AND METHODS: We studied patients with localized CD confirmed by MRI. Patients were divided into 2 groups according to age at onset of epilepsy. Group 1 included patients in whom the first seizure occurred up to the age of 12 (early-onset group) and group 2 included patients in whom the first seizure occurred after the age of 12 (late-onset group). The two groups were compared with regard to the type of CD, clinical findings and EEG findings. RESULTS: Thirty-three patients with various forms of CD were studied. Onset of epilepsy occurred in adolescence or adulthood in 9 cases (37%). In 6 of these (17% overall), the first seizure occurred in adulthood. CD were posterior bilateral pachygyria (1), unilateral polymicrogyria (3), focal dysplasia with subcortical gray matter heterotopia (1), perisylvian bilateral polymicrogyria (1), bioccipital polymicrogyria (1) and bilateral nodular periventricular gray matter heterotopia (2). The incidence of neurological signs was lower in the late-onset group. Mental retardation was moderate or absent, thus allowing a fairly normal lifestyle. All patients presented partial seizures with a lower incidence of drug resistance (p < 0.01). EEG demonstrated preservation of background activity and absence of diffuse or multifocal abnormalities. CONCLUSION: Onset of epilepsy with various forms of CD may be delayed until adolescence or adulthood. Prognosis of epilepsy is usually more favorable in these cases.

Adolescent↗
PubMed1999

De novo highly complex chromosome rearrangement (CCR) involving five breakpoints with congenital anomalies analyzed by FISH.

We report on a child with ptosis, epicanthal folds, depressed nasal bridge, carp-shaped mouth, low set ears, hirsutism, pectus excavatum, and developmental and language delay presenting with a balanced complex chromosomal rearrangement (CCR). R- and G-banding methods and fluorescence in situ hybridization were used to document that this is a complex translocation with five breakpoints involving chromosomes 1, 7, 10 and 21.

Abnormalities, Multiple↗
PubMed1998

Predictive significance of magnetic resonance imaging at 4 months of adjusted age in infants after a perinatal neurologic insult.

The aim of this prospective study was to evaluate the predictive significance of magnetic resonance imaging (MRI) performed at 4 months of corrected age in 60 neonates after a perinatal neurologic insult. Follow-up ranged from 2 to 5 years of chronological age. MRI examination was normal in 10; isolated external hydrocephalus was found in 15 infants. Twenty-three of these infants developed normally. Focal or multifocal lesions were shown in 6 infants, of whom 2 developed normally. Diffuse brain involvement was present in 29 cases as atrophy (n = 18), leukomalacia (n = 5), basal ganglia lesions (n = 3), and delayed myelination (n = 3). All but 4 infants showed neurologic impairment. MRI performed at 4 months of adjusted age is of prognostic significance in neonates who suffer a moderate or mild neurologic insult.

Basal Ganglia↗
PubMed1998

Prenatal diagnosis of fetal corpus callosum agenesis by ultrasonography and magnetic resonance imaging.

Corpus callosum agenesis (CCA) was evaluated by ultrasound examination and magnetic resonance imaging (MRI) in 14 cases. Ultrasonography was able to suspect CCA by indirect signs but a definitive diagnosis of CCA was achieved in only four cases. MRI was able to diagnose complete CCA in 13 cases and showed absence of the posterior portion of the corpus callosum in one case. Additional neurological abnormalities including heterotopia, gyration anomaly, asymmetry of the cerebral hemispheres, and Dandy-Walker variant were documented in five cases, as well as an ocular anomaly which was present in one case, by MRI examination. Prenatal counselling for fetal agenesis of the corpus callosum is difficult as the prognosis is uncertain. The association with other cerebral abnormalities increases the likelihood of a poor outcome and ultrasonographic assessment of the fetal brain is limited. We found MRI to be a safe and useful additional procedure to complement ultrasonographic diagnosis or suspicion of CCA.

Adult↗
PubMed1998

[Anatomic MRI study of commissural agenesis and dysplasia of the Telencephalon (Agenesis of the corpus callosum and related anomalies). Clinical correlations and morphogenetic interpretation].

A series of 78 patients presenting with agenesis of the cerebral commissures and properly investigated with MR imaging, was reviewed and analyzed morphologically. Results were compared with descriptive data from the literature, and with the developmental models proposed. From this, a model of a-commissural brain is described: the lamina terminalis would be homologous to a telencephalic anterior medullary velum of which the commissure would be the anterior commissure, and the lamina of white matter described as the Probst's and the fornical bundles, would be homologous to a posterior medullary velum having become a medial medullary velum due to the division of the prosecephalon into two cerebral hemispheres, and of which the commissure would be the (posterior) calloso-hippocampal commissure. Also, the comparison with the model establishes that in the actual malformations, defects of the cingulum and of at least some of the intralobaroccipital association bundles are observed beside the commissural defect. Such a model would reclassify these disorders, distinguishing the "simple" commissural defects, complete or segmental, global or dissociated, without or with a ventricular expansion, from more complex forms with multicystic defects, adding major dysplastic lesions of the dura mater, leptomeninges and parenchyma, to the commissural defects. Paradoxically, the latter group seems to be clinically less severe than the "simple agenesis" group, of which prognosis (including the neurologic and intellectual disorders as well as the associated pathologies) is generally very poor; this should be seriously considered since the antenatal diagnosis of these malformations is made routinely with ultrasonography and MRI.

Agenesis of Corpus Callosum↗
PubMed1997

Three-dimensional MRI of hemifacial spasm with surgical correlation.

MRI was used to investigate 100 patients with hemifacial spasm, using 3D-FT T2-weighted (CISS) and contrast-enhanced 3D-FT T1-weighted (turbo-FLASH) sequences in all cases. MR angiography was performed in 54 patients, using 3D-MT FISP images. Decompression of the facial nerve through a retromastoid craniotomy was performed in all patients. Hemifacial spasm caused by tumours in the cerebellopontine angle was not included. Vascular contact with the facial nerve root-exit zone or at the internal auditory canal was present in 96 of 100 patients with hemifacial spasm. The vessel responsible was the vertebral artery (VA) in 18 cases, the posterior inferior cerebellar artery (PICA) in 23, the anterior inferior cerebellar artery (AICA) in 22, the VA and PICA in 24, VA and AICA in 3, PICA and AICA in 1, VA, PICA and AICA in 4, and a vein in 1 case. CISS images showed compressive vascular loops better than contrast-enhanced turbo-FLASH images alone. The sensitivity of MRI was high, since only one false-negative case was found among the 100 patients who underwent surgery.

Adult↗
PubMed1997

Neurologic onset of Behçet's disease: a diagnostic enigma in childhood.

Neuro-Behçet's disease, which is uncommonly reported in childhood, encompasses a wide variety of clinical features since any part of the neuraxis may be involved. It carries a serious prognosis and represents a leading cause of death or severe disability. Neuro-Behçet's disease may occur in 5% to 50% of adults with Behçet's disease and is usually subsequent to other systemic manifestations. In this report, we express the possibility of a primary neurologic presentation of Behçet's disease in childhood with pseudotumor cerebri and meningoencephalitis as exclusive initial features. We focus on diagnostic problems when major features of Behçet's disease are missing at the outset. We emphasize the high sensitivity of magnetic resonance imaging to make the diagnosis of cerebral vasculitis or thrombosis with a good reliability to clinical features.

Adolescent↗
PubMed1995

Functional magnetic resonance imaging at 1.5 T during sensorimotor and cognitive task.

Functional activations of the human brain cortex were observed with a standard 1.5-tesla MR imaging system using a long time echo fast low-angle shot sequence. Neural activation increases regional cerebral blood flow resulting in increased capillaries and venous blood oxygenation. Processing requires adapted algorithms because the time course of intensity signal showed fluctuations of the baseline. The use of a 'follow-up' method to generate activation maps is proposed. Brain activation was detected in striate cortex during photic stimulation and in sensorimotor areas while subjects were moving their hands. In mental imagery tasks, we observed a primary and secondary visual cortex activation during memory recall of the flashing light. Motor ideation showed an activation of the rolandic areas.

Adult↗
PubMed1995

[Current imaging of vasculo-neural conflicts in the cerebellopontine angle].

UNLABELLED: To demonstrate the high sensitivity of high definition MRI and particularly "Constructive Interference in Steay State" (Ciss) imaging sequence, in depicting neurovascular conflicts in the CP angle cistern, cisternographic imaging and high definition T1 weighed (Turbo flash), contrast enhanced imaging were used to investigate hemifacial spasm (72 patients) and tinnitus with abnormal BER (5 patients). The study was complemented with Angio MR in 25 patients. The results were compared with findings in a control group of 200 patients, and with the surgical observations in 57 operated cases. In hemifacial spasm, the morphology of the neurovascular conflict was determined, as well as the site of compression (lateral medullary fossa 38 cases; nerve 9; both 15 cases), and the vessel involved (VA 25 cases; PICA 16 cases; AICA 10 cases; VA and PICA 8 cases; VA and AICA 3 cases; lateral medullary vein 1 case). In tinnitus (5 cases), the AICA was involved in every case in the IAM. Among 57 operated cases, only one false negative was observed. In the asymptomatic control group, a nerovascular conflict was observed in 3, 5% of the cases only. CONCLUSION: CISS imaging is the single most efficient technique, but the combined used of the 3 types of imaging brings the highest diagnostic efficiency, for identifying a neurovascular conflict in the CPA cistern.

Adult↗
PubMed1995

In vivo MR study of brain maturation in normal fetuses.

PURPOSE: To illustrate normal maturation of the fetal brain, including the migrational layer, gray matter, early myelination of internal capsules, optic radiations, and corona radiata. METHODS: Seventy-seven fetal brains, ranging from 21 to 38 weeks of gestational age, were examined with MR in vivo; 33 were considered normal. MR examinations were performed as T1-weighted sequences in the axial, sagittal, and coronal planes. The neuropathologic examination (four cases) and clinical and/or neuroradiologic examinations confirmed the antenatal data. RESULTS: From 21 to 25 weeks, the cerebral ventricles are large, corresponding to the relative fetal hydrocephalus. A slight high signal intensity can be observed in the basal ganglia as early as 21 weeks. In the cerebral hemispheres, a multilayered pattern that can be observed from 23 to 28 weeks includes the cortical ribbon, the germinal matrix, and an intermediate layer corresponding to the migrating glial cells. These findings are probably related to areas of increased cellularity. A high signal intensity can be seen within the dorsal part of the brain stem as early as 23 weeks, within the posterior limb of the internal capsules at 31 weeks, and within the central area of the cerebral hemispheres at 35 weeks. Those patterns are probably caused by the evolving process of myelination. CONCLUSIONS: MR allows depiction of signal changes corresponding either to an increase in cellularity or to the evolving processes of myelination, depending on the stage of the pregnancy.

Brain↗
PubMed1994

3D-FT MRI of the facial nerve.

Contrast-enhanced 3D-FT MRI of the intrapetrous facial nerve was obtained in 38 patients with facial nerve disease, using a 1.0 T magnet and fast gradient-echo acquisition sequences. Contiguous millimetric sections were obtained, which could be reformatted in any desired plane. Acutely ill patients, were examined within the first 2 months, included: 24 with Bell's palsy and 6 with other acute disorders (Herpes zoster, trauma, neuroma, meningeal metastasis, middle ear granuloma). Six patients investigated more than a year after the onset of symptoms included 3 with congenital cholesteatoma, 2 with neuromas and one with a chronic Bell's palsy. The lesion was found incidentally in two cases (a suspected neurofibroma and a presumed drop metastasis from an astrocytoma). Patients with tumours had nodular, focally-enhancing lesions, except for the leptomeningeal metastasis in which the enhancement was linear. Linear, diffuse contrast enhancement of the facial nerve was found in trauma, and in the patient with a middle ear granuloma. Of the 24 patients with an acute Bell's palsy 15 exhibited linear contrast enhancement of the facial nerve. Three of these were lost to follow-up, but correlation of clinical outcome and contrast enhancement showed that only 4 of the 11 patients who made a complete recovery and all 10 patients with incomplete recovery demonstrated enhancement. Possible explanations for these findings are suggested by pathological data from the literature. 3D-FT imaging of the facial nerve thus yields direct information about the of the nerve condition and defines the morphological abnormalities. It can also demonstrate contrast enhancement which seems to have some prognostic value in acute idiopathic Bell's palsy.

Adolescent↗
PubMed1994

3D-FT thin sections MRI of prolactin-secreting pituitary microadenomas.

We studied 76 patients with endocrinological features of prolactin-secreting microadenoma by MRI, using three dimensional (3D) gradient echo acquisition (FLASH) sequences. MRI revealed a focal signal abnormality in the pituitary in all 37 patients who had not previously taken bromocriptine. However, focal abnormality was shown in only half the patients had been on dopamine agonist therapy; the MRI findings in these 39 patients were not affected by the duration and dosage bromocriptine, nor by the time elapsed since its discontinuation. The microadenoma gave spontaneous high signal on the unenhanced T1-weighted images in 8 cases; it was not seen on unenhanced images in 25 cases. It appeared as low signal within the enhancing gland in 51 cases but enhanced in 7 cases. The 3D technique gives thin (1 mm) slices and therefore facilitates detection of small focal abnormalities in the pituitary gland (2 x 2 mm). In the 19 previously treated patients in whom MRI did not demonstrate a focal abnormality, it showed localised atrophy of the gland in 3, a large, round gland with homogeneous signal in 1, and a heterogeneous appearance in 11; it was normal in 4 cases.

Adolescent↗
PubMed1994

Detection of i(17q) chromosome by fluorescent in situ hybridization (FISH) with interphase nuclei in medulloblastoma.

Medulloblastomas are the most frequent primitive neurectodermal tumors in children. An isochromosome for the long arm of 17, i(17q), is found in 30% of medulloblastomas. For some authors, this abnormality is observed in cases with a shorter survival time. In our cytogenetic studies of 30 medulloblastomas, we observed i(17q) in only three cases, a monosomy 17 in two cases, a monosomy 22 in four cases, nonspecific numerical or structural abnormalities in five cases, and normal karyotypes in 12 cases. We compared the results of karyotypic analysis after culture and FISH with a chromosome 17 alpha satellite DNA probe on interphase nuclei in five cases of medulloblastoma. In one case, i(17q) was only observed in four cells in karyotypic analysis, in three cases a normal karyotype was found, and in one case karyotypic analysis was impossible. In all of these cases, i(17q) was observed in a great number of nuclei by FISH on interphase nuclei. Our study shows that the FISH on interphase nuclei permitted us to observe i(17q) in the cases where it was not or could not be completely detected by karyotypic analysis. The association of these two techniques is required to detect i(17q), an abnormality whose prognosis value in medulloblastomas is now recognized.

Adolescent↗
PubMed1994

[Percutaneous venoplasty for the implantation of a dual-chamber cardiac pacemaker].

During reoperation for pacemaker implantation, venous catheterisation of the homolateral subclavian vein encountered obstruction at the brachiocephalic vein. Balloon angioplasty of the severe brachiocephalic stenosis was performed via the femoral vein. After repeat subclavian venous catheterisation two new pacing wires could be introduced without difficulty followed by active fixation in the atrium and passive fixation in the ventricular apex. The initial ventricular pacing wire was isolated and respected. The femoral vein approach gave simple and direct access to the site of dilatation at a distance to the operative field which was shielded from an infectious risk. The technique and results of percutaneous venous recanalisation have not been extensively analysed during reoperation for cardiac pacing. In chronic cardiac pacing, the success of homolateral operation despite venous occlusion or stenosis, ensures preservation of the venous capital.

Aged↗
PubMed1994

[Functional cerebral neuro-imaging at 1.5 Tesla. The results of visual, sensorimotor and auditory stimulations].

Functional activation of the cerebral cortex can be observed with a standard 1.5 Tesla MRI magnet. We used a repeated FLASH 2D one-section sequence with a long echo (TE = 60 ms) and a small passing band. Modification of regional cerebral oxygenation due to neurone activation seems to be the main source of contrast. Sensorimotor stimulation was effected by an unusual mobilization of the fingers. Visual stimulation was performed by intermittent lightings at a frequency of 8 Hz. Auditory stimulation relied on listening to speech sounds. Signal increases were localized on the cerebral cortex with precise anatomico-functional correlation. Using a clinical 1.5 Tesla magnet requires an adequate treatment of data. Thus, stimulated cerebral activity can be portrayed by MRI therapy opening a new way for anatomico-functional cerebral studies.

Acoustic Stimulation↗