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Biomedical subjects

E A Cabanis

Publications and source records attributed to E A Cabanis.

At least 19 recordsLinked to original sources
PubMed1997

Localized proton magnetic resonance spectroscopy in patients with adult adrenoleukodystrophy. Increase of choline compounds in normal appearing white matter.

OBJECTIVES: To describe the changes in the results of magnetic resonance imaging and spectroscopy occurring in the normal-appearing white matter of patients with adult adrenoleukodystrophy and to present evidence of a particular change that may serve as a marker for the follow-up of the disease. DESIGN: Neurologic, magnetic resonance imaging, and localized proton spectroscopic examinations were performed in 11 patients with adult adrenoleukodystrophy and compared with 11 sex- and age-matched controls. PATIENTS: Eleven patients with adult adrenoleukodystrophy participated in a trial of dietary therapy with glyceryl trioleate and glyceryl trierucate (Lorenzo's oil) in the Fédération de Neurologie and the Institut National de la Santé et de la Recherche Médicale, Unité 134, at the Hôpital de la Salpêtrière in Paris, France. RESULTS: The results of magnetic resonance imaging of the white matter were normal in 2 patients and showed areas of mild symmetrical hypersignals on T2-weighted images and fluid attenuated inversion recovery sequences, localized in the posterior white matter in 9 patients. The results of spectroscopy indicated that the peak of the area of choline-containing compounds was increased at long echo times in patients with adult adrenoleukodystrophy, which may reflect very long-chain fatty acid accumulation in this disease. The peak of the area of myo-inositol-containing compounds was increased at short echo times in patients with adult adrenoleukodystrophy, which may indicate a rise in this metabolite concentration. The N-acetylaspartate-creatine amplitude ratio was significantly decreased in patients with motor deficit. The significance of this finding remains to be established. CONCLUSIONS: The results of localized proton magnetic resonance spectroscopy show abnormalities in the cerebral white matter of patients with adult adrenoleukodystrophy, which may contribute to the understanding of the pathophysiologic characteristics of the disease. Although changes in the results of spectroscopy found in this disease are not specific, the increase of choline-containing compounds may reflect the accumulation of very long-chain fatty acids in the central nervous system. Localized proton magnetic resonance spectroscopy may prove a valuable technique, in addition to magnetic resonance imaging, for noninvasive investigation of patients with adult adrenoleukodystrophy undergoing future clinical trials.

Adrenoleukodystrophy↗
PubMed1996

Notch3 mutations in CADASIL, a hereditary adult-onset condition causing stroke and dementia.

Stroke is the third leading cause of death, and vascular dementia the second cause of dementia after Alzheimer's disease. CADASIL (for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) causes a type of stroke and dementia whose key features include recurrent subcortical ischaemic events and vascular dementia and which is associated with diffuse white-matter abnormalities on neuroimaging. Pathological examination reveals multiple small, deep cerebral infarcts, a leukoencephalopathy, and a non-atherosclerotic, non-amyloid angiopathy involving mainly the small cerebral arteries. Severe alterations of vascular smooth-muscle cells are evident on ultrastructural analysis. We have previously mapped the mutant gene to chromosome 19. Here we report the characterization of the human Notch3 gene which we mapped to the CADASIL critical region. We have identified mutations in CADASIL patients that cause serious disruption of this gene, indicating that Notch3 could be the defective protein in CADASIL patients.

Adult↗
PubMed1996

Location of the human posterior eye field with functional magnetic resonance imaging.

The frontal eye field and parietal eye field are known to be involved during visually guided saccades. As the location of the human parietal eye field is not yet well known, functional MRI was used during such a saccade task to better localise this field. Besides activity in visual areas of the occipital cortex, bilateral activity was seen in the precentral sulcus, corresponding to the frontal eye field, and in the deep region of the intraparietal sulcus. It is suggested that this intraparietal area, bordering areas 39 and 40 of Brodmann, corresponds to the human parietal eye field.

Adult↗
PubMed1996

In vivo localized NMR proton spectroscopy of normal appearing white matter in patients with multiple sclerosis.

We used a rapid long TE proton magnetic resonance spectroscopic (MRS) sequence in the normal appearing white matter of 11 patients with definite multiple sclerosis (MS) localizing the volume of interest in the centrum semi-ovale. The metabolic changes were compared to the same area in 11 normal brains. We found a significant decrease in NAA/Cr ratios and a borderline significance of increase in Cho/Cr ratios in patients with MS. A discriminant analysis was performed on these data. This allowed to obtain a simple ratio, NAA/(Cho+Myo), which discriminated MS patients from controls. Our results indicate that normal appearing white matter on MRI is biochemically abnormal in patients with MS. In addition MRS could be routinely used after a standard MRI examination in patients with MS for clinical correlations, total load of the disease assessment and monitoring clinical trials.

Adult↗
PubMed1996

Magnetic resonance imaging using FLAIR pulse sequence in white matter diseases.

Fifty six patients among whom 39 had white matter diseases had MRI of the brain comparing FLAIR sequence to a conventional proton density sequence. Flair sequence allowed to detect 18 additional hypersignal (HS) that were not present on T2 sequence. These HS were located in the periventricular areas for 5 of them, near the cortical sulci in 10, and in the centrum semi-ovale for 3. FLAIR sequence permitted analyze 41 other lesions that were not obvious on proton density sequences. Thirty five of them were thus confirmed to be HS : 31 in the paracortical areas, 3 in the paraventricular regions and one in the internal capsule, whereas the remaining 6 were normal sulci of the brain. FLAIR sequence increases the sensitivity of MRI in white matter diseases.

Adolescent↗
PubMed1995

Is the length of the calcarine sulcus associated with the size of the human visual cortex? A morphometric study with magnetic resonance tomography.

PURPOSE: To determine whether the length and depth of the calcarine sulcus are associated and can be used for estimating the size of the primary visual area (area 17) and other regions in MR images of the human occipital lobe. METHODS: The length and depth of the calcarine sulcus and the projection areas of the mesial surface of the occipital lobe and of the total hemisphere were measured in MR images of 23 healthy subjects. RESULTS: A higher variability of the size of the projection area of the mesial surface of the occipital lobe compared with that of the remaining part of the hemisphere is found. The projection area of the mesial cortical surface of the occipital lobe is correlated with the length of the calcarine sulcus, but both parameters are not correlated with the depth of the calcarine sulcus and, therefore, also not with the size of the part of area 17 buried in the sulcus. CONCLUSION: The size of area 17 cannot be estimated by the length of the calcarine sulcus in MR images. Depth and length of the calcarine sulcus grow independently in the human brain. Different degrees of folding may cause the variability of architectonic areas.

Adolescent↗
PubMed1994

[Magnetic resonance imaging, ten years later].

The authors introduce the two following papers. A general review of MRI evolution during the ten past years is proposed. Some recent evolutions are emphasized: fast imaging, MR angiography, workstations devoted to 3D reformations and functional imaging are illustrated. The complementary position of CT and MR, and the worldwide machines diffusion are summarized. The authors of following papers are introduced and presented.

Brain↗
PubMed1993

Preliminary results of a magnetic resonance imaging (MRI) study of the pig brain placed in stereotaxic conditions.

Magnetic resonance imaging (MRI) of two pig brains was realized. The animals were placed in the stereotaxic conditions currently used in experiments. To allow the positioning of the animal in the MRI instrument, landmarks were previously traced on the snout of the pig. To avoid movements, animals were deeply anesthetized. MRI were taken in frontal, horizontal and sagittal directions. Afterwards, the brains of the pigs were frozen and cut into sections, frontal for one animal and sagittal for the other. Histologic and MR images were compared. The usefulness of this technique is discussed.

Animals↗
PubMed1993

A survey of different high resolution visualization modes of a volumetric object with applications.

In view of the variety of 3D representation techniques, a clinical study was carried out in order to evaluate their respective usefulness. It appears that a single technique cannot be claimed to be valid for all clinical situations and that a combination of representations brings more relevant information. Among the different techniques a clear delineation must be established between those which allow the accurate definition of landmarks (multiplanar reformation, surface representation), and those which do not (integral shading, reconstructed radiology). The main point is the possibility to recognize anatomical landmarks on these latter modes and to choose oblique cut planes in relation to them. Visualization quality is strongly dependent upon the acquisition protocol which must provide a spatial resolution as isotropic as possible.

Arachnoid Cysts↗
PubMed1993

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy maps to chromosome 19q12.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) has been recently reported as a cause of stroke. It is characterized, in the absence of hypertension, by recurrent subcortical ischaemic strokes, starting in early or midadulthood and leading in some patients to dementia. Magnetic resonance imaging and pathological examination show numerous small subcortical infarcts and a diffuse leukoencephalopathy underlaid by a non-arteriosclerotic, non-amyloid angiopathy. We performed genetic linkage analysis in two unrelated families and assigned the disease locus to chromosome 19q12. Multilocus analysis with the location scores method established the best estimate for the location of the affected gene within a 14 centimorgan interval bracketed by D19S221 and D19S222 loci.

Adult↗
PubMed1993

[Brain morphometry using MRI in Cri-du-Chat Syndrome. Report of seven cases with review of the literature].

The authors present the results of a morphometric study of the brain of 7 patients with cat cry syndrome, explored with Magnetic Resonance Imaging (MRI). A method is proposed in order to facilitate the identification of the anatomical slices. A characteristic anomaly is observed as a marked atrophy of the brainstem predominating at the pontine level and associated with a small cerebellum, atrophic middle cerebellar peduncles and cerebellar white matter. This apparently systematized atrophy obvious in children, seems similar to the one observed in patients presenting a olivopontocerebellar atrophy, possibly correlating with disturbance of coordination and developmental delay in motility as observed in these patients. This does not implicate the same subjacent functional neuroanatomical pathways.

Adolescent↗
PubMed1992

[Stilling Duane syndrome and MRI: 2 preliminary results].

Dynamic mode magnetic resonance imaging (DMMRI) allows good visualization of the oculomotor muscles and allows their dimensions to be measured both when they contract and when they relax. The accuracy of this method has been checked and the measurements of the cross section of medial and inferior recti and of superior obliques can be considered to be valid. Measurements of length are inaccurate and the other muscles are not perpendicular to the sectional planes generally used in MRI of the head. By means of a fixation scale situated in the tunnel of the machine, the maximum diameter of medial recti in their thickest part was evaluated in two girls affected by a Stilling Duane retraction syndrome of the left eye. Two direction of the gaze were explored: 25 degrees at the right, then 25 degrees at the left, these angles being obtained by the fixation of particular points of the tunnel scale. The measurements have been made on axial sections, then on coronal sections, both medio-orbital and apical. The first finding is that the diseased medial rectus is much bigger than the healthy one. When relaxed, its thickness is about the same as that of the contracted normal muscle. Coronal orbital cross sections clearly show recession of the belly of the diseased muscle towards the back of the orbit. When contracted it stays in the apical plane and when relaxed in the medio-orbital plane. Lastly the relaxation is much weaker for the pathological muscle than for the healthy one.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

The commissuro-mamillary plane in MRI of the brain (preliminary communication).

MRI sections of the brain in the coronal plane through the line joining the anterior commissure and the mamillary bodies display the constituent parts of the basal forebrain. The visualisation of the septal nuclei and the anterior columns of the fornix show the importance of this plane in the study of behaviour disorders and amnesic syndromes.

Corpus Striatum↗