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Biomedical subjects

M T Iba-Zizen

Publications and source records attributed to M T Iba-Zizen.

At least 37 records · Page 2Linked to original sources
PubMed1997

[CADASIS. Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalophathy].

CADASIL is an inherited arterial disease of the brain with an autosomal dominant pattern of transmission. The mapping of the affected gene in 1993 allowed us to describe the natural history of the disease. In some patients, the disease starts with attacks of migraine with aura at a mean age of 30 years. The most frequent clinical manifestations are subcortical transient ischemic attacks or completed strokes usually occurring between 40 and 50 years of age which are sometimes associated with severe mood disturbances. The disease leads about two decades later to death after a variable period of subcortical dementia associated with pseudobulbar palsy and urinary incontinence. In one given family, the severity of the clinical presentation varies among the affected subjects. MRI is always abnormal in symptomatic subjects. It shows more or less confluent hypersignals on T2-weighted images in white-matter and basal ganglia and hyposignals on T1-weighted images in the same regions corresponding to small infarcts. These signal abnormalities are even observed a long time before the onset of clinical manifestations as they are present in totally asymptomatic young family members. Histologic studies show a widespread palor of white-matter and multiple small infarcts in the white-matter and basal ganglia underlaid by a small artery disease of the brain. Electron microscopy studies show that the media of the white-matter and leptomeningeal small arteries is thickened by a granular, eosinophilic and non-amyloid material of undetermined origin close to the smooth muscle cells. These ultrastructural wall abnormalities have been observed in other arteries, particularly in muscular and skin arteries. Mutations of Notch3 gene located on chromosome 19 are responsible for the disease. The diagnosis should be discussed in subjects with a history of unexplained subcortical ischemic strokes, attacks of migraine with aura, mood disorders of subcortical dementia whenever associated with MRI signal abnormalities in white-matter and basal ganglia.

Brain↗
PubMed1997

[Clinical, biological and neuroradiological aspects of Sneddon's syndrome: 26 cases].

Sneddon syndrome is characterized by the association of livedo reticularis and cerebrovascular ischemic events. Clinical and MRI aspects are described in 26 patients with Sneddon syndrome. MRI features were classified in 6 groups according to the aspect and topography of the lesions. No correlation was found between the presence of vascular risk factors, valvulopathy or antiphospholipid antibodies and the presence of dementia or MRI lesions. There was a significant correlation between MRI extension of the lesions and clinical disability. Clinical course and MRI findings are presented according to the treatment.

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

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, genetic homogeneity, and mapping of the locus within a 2-cM interval.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a recently identified autosomal dominant cerebral arteriopathy characterized by the recurrence of subcortical infarcts leading to dementia. A genetic linkage analysis conducted in two large families recently allowed us to map the affected gene on chromosome 19 in a 12-cM interval bracketed by D19S221 and D19S215. In the present study, these first 2 families and 13 additional ones, including a total of 199 potentially informative meiosis, have been genotyped with eight polymorphic markers located between D19S221 and D19S215. All families were linked to chromosome 19. The highest combined lod score (Zmax = 37.24 at theta = .01) was obtained with marker D19S841, a new CAn microsatellite marker that we isolated from chromosome 19 cosmids. The recombinant events observed within these families were used to refine the genetic mapping of CADASIL within a 2-cM interval that is now bracketed by D19S226 and D19S199 on 19p13.1. These data strongly suggest the genetic homogeneity of this recently identified condition and establish the value of its clinical and neuroimaging diagnostic criteria. Besides their importance for the ongoing positional cloning of the CADASIL gene, these data help to refine the genetic mapping of CADASIL relative to familial hemiplegic migraine and hereditary paroxysmal cerebellar ataxia, conditions that we both mapped within the same chromosome 19 region.

Cerebral Arterial Diseases↗
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

[CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)].

Recently identified, CADASIL is a diffuse disease of small arteries, predominating in the brain. It starts during mid-adulthood and is characterized by recurrent ischemic events (transient or permanent), attacks of migraine with aura, severe mood disorders, subcortical dementia and, at MRI, a white spread leukoencephalopathy. There is so far no specific treatment and death occurs after a mean of twenty years. CADASIL is an autosomal dominant condition and the gene Notch 3 is located on chromosome 19, in the same region as another neurological disorder, familial hemiplegic migraine.

Brain Ischemia↗
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

Clinical spectrum of CADASIL: a study of 7 families. Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited arterial disease of the brain recently mapped to chromosome 19. We studied 148 subjects belonging to seven families by magnetic resonance imaging and genetic linkage analysis. 45 family members (23 males and 22 females) were clinically affected. Frequent signs were recurrent subcortical ischaemic events (84%), progressive or stepwise subcortical dementia with pseudobulbar palsy (31%), migraine with aura (22%), and mood disorders with severe depressive episodes (20%). All symptomatic subjects had prominent signal abnormalities on MRI with hyperintense lesions on T2-weighted images in the subcortical white-matter and basal ganglia which were also present in 19 asymptomatic subjects. The age at onset of symptoms was mean 45 (SD [10-6]) years, with attacks of migraine with aura occurring earlier in life (38.1 [8.03] years) than ischaemic events (49.3 [10.7] years). The mean age at death was 64.5 (10.6) years. On the basis of MRI data, the penetrance of the disease appears complete between 30 and 40 years of age. Genetic analysis showed strong linkage to the CADASIL locus for all seven families, suggesting genetic homogeneity. CADASIL is a hereditary cause of stroke, migraine with aura, mood disorders and dementia. The diagnosis should be considered not only in patients with recurrent small subcortical infarcts leading to dementia, but also in patients with transient ischaemic attacks, migraine with aura or severe mood disturbances, whenever MRI reveals prominent signal abnormalities in the subcortical white-matter and basal ganglia. Clinical and MRI investigations of family members are then crucial for the diagnosis which can be confirmed by genetic linkage analysis. The disease is probably largely undiagnosed.

Adult↗
PubMed1995

Autosomal dominant migraine with MRI white-matter abnormalities mapping to the CADASIL locus.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant cerebral arteriopathy mapped to chromosome 19 and characterized mainly by recurrent subcortical ischemic strokes and extensive white-matter signal abnormalities (WMAs) on magnetic resonance imaging. Other clinical features include migraine attacks and progressive subcortical dementia. Herein, we describe several members of the same family who suffered migraine attacks, mostly with aura, associated with WMAs, segregating with an autosomal dominant pattern of inheritance. One individual had a progressive subcortical dementia with similar WMAs. Although ischemic stroke, one of the hallmarks of CADASIL, was not present in this family, we hypothesized that the present disorder resulted from an alteration of the CADASIL gene. Genetic linkage analysis, using four chromosome 19 markers spanning the CADASIL locus, supports this hypothesis.

Adult↗
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

Pseudotumoral lymphocytic hypophysitis successfully treated by corticosteroid alone: first case report.

We report the first case of pseudotumoral lymphocytic hypophysitis successfully treated by corticosteroids without surgery. A 27-year-old woman had been monitored for chronic headache 13 months after giving birth, associated with amenorrhea and galactorrhea. Cranial magnetic resonance imaging revealed a markedly enlarged pituitary gland with a suprasellar extension; the only biochemical abnormality was a mild hyperprolactinemia. Because of a putative diagnosis of prolactinoma, bromocriptine was prescribed at a dose of 5 mg daily, soon followed by the transitory appearance of menstruation. Two years later, panhypopituitarism was present and was revealed by acute adrenal insufficiency. Magnetic resonance imaging revealed that the pituitary mass was the same as previously described, but hormonal investigation showed evidence of complete hypopituitarism and no hyperprolactinemia. Nuclear antibodies were negative as well as other autoantibodies. Human leukocyte antigen serological Class II typing was DR3/DR4. Lymphocytic hypophysitis was then suspected; in the absence of visual complication and because this patient refused surgery, corticosteroids were attempted at a daily dose of 60 mg of prednisone for 3 months, progressively decreased for the next 6 months. Under this treatment, a gradual recovery of all pituitary hormones was observed and magnetic resonance imaging showed a reduction of two-thirds in pituitary mass. Five months after the end of corticoid treatment, our patient relapsed with panhypopituitarism and an increase of pituitary volume. She underwent steroid treatment, and a biopsy was performed and confirmed the diagnosis of autoimmune hypophysitis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
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

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

[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↗