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O Lyon-Caen

Publications and source records attributed to O Lyon-Caen.

At least 19 recordsLinked to original sources
PubMed2005

Hepatitis B vaccination and central nervous system demyelination: an immunological approach.

Demyelination events or multiple sclerosis following hepatitis B virus (HBV) vaccination have been reported. We therefore compared the T-cell response to HBsAg in patients with CNS demyelination following HBV vaccination and in HBV-vaccinated healthy individuals. Our data showed no differences in terms of T-cell proliferation or cytokine production between these groups and may help to allay concerns that HBV vaccination might trigger a deleterious immune response.

Adult↗
PubMed2005

[Isolated ptosis in a 58-year-old woman].

A 60-year-old woman who had experienced isolated ptosis for two years was seen when it had been fixed for one year. She had a personal and familial history of stromal corneal dystrophy. The diagnosis of mitochondrial cytopathy was made on the basis of clinical, electrophysiological, biological and histological findings. Surgical repair of the ptosis allowed visual recovery. The relationship between ptosis, corneal dystrophy and mitochondrial cytopathy is discussed.

Blepharoptosis↗
PubMed2005

[Adult onset hereditary leukoencephalopathies].

In clinical practice, the term "genetic leukoencephalopathy" refers to a group of genetic diseases whose common point is to give an aspect of diffuse leukoencephalopathy on MRI. With progress in diagnostic techniques including radiology, biochemistry or genetics, a large number of hereditary diseases causing leukoencephalopathy have been identified. Although generally beginning in childhood, these diseases often have more insidious clinical forms which can begin in adulthood. These forms remain poorly known. Some are accessible to treatment so their diagnosis appears essential. The diagnostic steps must be guided by clinical examination (neurological, ophthalmological and systemic), electromyography and MRI. The purpose of this review is to propose a classification of the genetic leukoencephalopathies and to give a progress report applicable in neurological practice.

Age of Onset↗
PubMed2005

Acute demyelination: an insight into the effect of mitoxantrone on CNS lesions.

We report the cases of 2 severely disabled patients with large inflammatory lesions suggestive of demyelination treated with mitoxantrone. Clinical condition was improved and brain lesions volume was reduced. On serial MR spectroscopy, there were variations in peaks between 0.9 and 1.4 ppm, suggestive of free lipids and amino acids. These variations may represent neurochemical markers of clinical recovery of large inflammatory lesions in multiple sclerosis.

Acute Disease↗
PubMed2004

A second-generation genomic screen for multiple sclerosis.

Multiple sclerosis (MS) is a debilitating neuroimmunological and neurodegenerative disorder. Despite substantial evidence for polygenic inheritance of the disease, the major histocompatibility complex is the only region that clearly and consistently demonstrates linkage and association in MS studies. The goal of this study was to identify additional chromosomal regions that harbor susceptibility genes for MS. With a panel of 390 microsatellite markers genotyped in 245 U.S. and French multiplex families (456 affected relative pairs), this is the largest genomic screen for MS conducted to date. Four regions met both of our primary criteria for further interest (heterogeneity LOD [HLOD] and Z scores >2.0): 1q (HLOD=2.17; Z=3.38), 6p (HLOD=4.21; Z=2.26), 9q (HLOD; Z=2.71), and 16p (HLOD=2.64; Z=2.05). Two additional regions met only the Z score criterion: 3q (Z=2.39) and 5q (Z=2.17). Further examination of the data by country (United States vs. France) identified one additional region demonstrating suggestive linkage in the U.S. subset (18p [HLOD=2.39]) and two additional regions generating suggestive linkage in the French subset (1p [HLOD=2.08] and 22q [HLOD=2.06]). Examination of the data by human leukocyte antigen (HLA)-DR2 stratification identified four additional regions demonstrating suggestive linkage: 2q (HLOD=3.09 in the U.S. DR2- families), 6q (HLOD=3.10 in the French DR2- families), 13q (HLOD=2.32 in all DR2+ families and HLOD=2.17 in the U.S. DR2+ families), and 16q (HLOD=2.32 in all DR2+ families and HLOD=2.13 in the U.S. DR2+ families). These data suggest several regions that warrant further investigation in the search for MS susceptibility genes.

Chromosome Mapping↗
PubMed2002

[Acute optic neuritis: clinical and MRI prognostic factors. Study of fifty patients].

The objective of this study was to evaluate the risk of visual outcome after acute optic neuritis (ON) in relation to clinical and MRI findings. Fifty cases of acute ON within one month were retrospectively studied. MRI with Short Tau Inversion Recovery (STIR) sequence of the optic nerve were obtained with a median time onset of 9 days after ON. Mean age of patients was 32.8 years, mean initial visual acuity was 3/10 and orbital pain was present in 86 percent100 of patients. The STIR sequence revealed lesion in 88 percent 100 of acutely symptomatic optic nerves. An initial low visual acuity (less than 2/10), the absence of orbital pain and involvement of the intracanalicular portion of the optic nerve on STIR sequence were statistically correlated with a poorer visual outcome (respectively p=0.0041, p=0.035 and p=0.011).

Acute Disease↗
PubMed2002

[Inflammatory optic neuropathy and multiple sclerosis].

The diagnosis of inflammatory optic neuritis remains essentially clinical, and may be improved by complementary investigations. The prognosis is related to the evolution of visual acuity and the risk of development of multiple sclerosis. The treatment of acute episodes is better precised but remains a matter of debate. Long term treatment has benefited from the results of recent MRI studies.

Humans↗
PubMed2001

[Genetic factors in multiple sclerosis].

GENERAL DATA: The clinical manifestations and neuropathological signs of multiple sclerosis have been recognized for more than one hundred years, but the cause remains unknown. EPIDEMIOLOGY: Multiple sclerosis is not evenly distributed throughout the world. There is an important north-south gradient in the northern hemisphere and inversely in the southern hemisphere; multiple sclerosis is more frequent in the higher altitudes. For a given latitude, there is a difference by ethnic origin. These observations indicate that multiple sclerosis is a multifactorial condition determined by both genetic and environmental factors. STRATEGIES OF GENETIC STUDIES: Progress in our knowledge of the human genome and statistical analysis techniques have made it possible to search for genetic factors in multiple sclerosis using two complementary approaches. The first is by anonymous screening and the second is to search for a candidate gene. The HLA locus is the only one with an identified predisposing effect for multiple sclerosis. It only accounts for 10 to 20% of the genetic predisposition for multiple sclerosis and many factors remain to be discovered.

Genetic Predisposition to Disease↗
PubMed2001

A longitudinal study of callosal atrophy and interhemispheric dysfunction in relapsing-remitting multiple sclerosis.

OBJECTIVES: To determine if callosal atrophy and interhemispheric dysfunction can be detected in the early stages of relapsing-remitting multiple sclerosis (MS) and to evaluate their progression in relation to the disability and evolution of lesions seen on magnetic resonance imaging during a 5-year period. METHODS: We compared 30 patients who had clinically definite early-onset replasing-remitting MS and mild disability with control subjects. Regional and segmental callosal size and extent of white matter abnormalities on magnetic resonance imaging, as well as performance on tasks exploring interhemispheric transfer of motor, auditory, and sensory information were assessed. Patients with MS were evaluated at baseline and after 5 years. Physical disability was determined at both times using the Expanded Disability Status Scale score. RESULTS: Patients with MS were seen with significant callosal atrophy and functional impairment of interhemispheric transfer at baseline that worsened during the 5-year study. A significant correlation was found between the magnitude of disability and the severity of morphological and functional callosal involvement at baseline. This association persisted at year 5. Baseline clinical characteristics such as age and prestudy relapse rate were unrelated to callosal size or interhemispheric performance. However, the number of baseline T2-weighted lesions was correlated with callosal involvement and this relation persisted at year 5. CONCLUSION: Patients who had relapsing-remitting MS in the early stages of the disease and mild disability had significant callosal involvement that progressed over time. The relationship between disability, T2-weighted lesions load, and degree of morphological and functional callosal impairment confirm the potential value of using callosal dysfunction as a surrogate marker of disease progression in MS.

Adult↗
PubMed2001

Correlating multiple MRI parameters with clinical features: an attempt to define a new strategy in multiple sclerosis.

MRI is the most powerful imaging technique in managing patients with suspected or confirmed multiple sclerosis (MS). However, conventional MRI variables show nonspecific abnormalities weakly correlated with clinical progression of the disease. New techniques, now routinely available, offer better characterisation of the pathophysiology. We combined conventional MRI, including lesion load, contrast enhancement and "black holes" with magnetisation transfer and diffusion-weighted imaging and localised proton MR spectroscopy (MRS) to study their relationship with disability, course and duration of MS. The variables that were the most significantly linked to the course of the disease (relapsing remitting versus secondary progressive) were lesion load, mean overall magnetisation transfer ratio and apparent diffusion coefficient (MGADC), the percentage of ADC in (PADCIMD), and out of (PAD-COMD) modal distribution, and the ratio N-acetylaspartate and creatine-containing compounds on MRS of the centrum semiovale. MGADC and PADCIMD were the independent factors most related to disability and duration of disease. Combining MRI techniques is clinically relevant and feasible for studies of MS and may be applied to other diseases of the central nervous system.

Adult↗
PubMed2001

[Study with localized proton magnetic resonance spectroscopy of 31 multiple sclerosis lesions: correlations with clinical and MRI features].

We have analyzed with localized proton magnetic resonance spectroscopy (MRS) 31 lesions in 28 patients with multiple sclerosis (MS). The course of the disease was either relapsing remitting, secondary progressive, or primary progressive. Four patients had an isolated neurological syndrome suggestive of MS. The decrease in the NAA/Cre ratio and the raise of the Cho/Cre ratio were more pronounced in patients with an acute isolated neurological syndrome, suggesting the predominance of an inflammatory process, and the presence of an axonal dysfunction in the initial course of the lesion. The NAA/Cre ratio was negatively correlated with clinical disability and thus could be used as an index of disease activity. Patients with a secondary progressive course exhibited a significant increase in the Myo/Cre ratio compared to those with a relapsing remitting course. Thus, there may be an association between the evolution towards a progressive disease and axonal loss or the development of gliosis. The isointense lesions to the cerebrospinal fluid on MRI T1 weighted sequences were characterized by a sharp raise in the Cho/Cre ratio suggesting demyelination and/or intense inflammation. Gadolinium enhanced lesions were not characterized by a specific neurochemical profile.

Adolescent↗
PubMed2001

[A case of mitochondrial cytopathy (MERFF) without ragged red fibers at the onset].

We report a case of a mitochondrial cytopathy (MERRF) with a late diagnosis because of the absence of Ragged-Red Fibers (RRF) in the first muscular biopsy performed in childhood. Eight years after the onset of the disease the familial history and the clinical manifestations were very suggestive of a mitochondrial cytopathy and a second biopsy was performed confirming the diagnosis of MERRF. The authors discuss several hypotheses to explain the negativity of the first muscular biopsy. The absence of ragged-red fibers does not exclude the diagnosis of a mitochondrial cytopathy and other investigations are justified such as the biochemical study of the respiratory chain and the molecular analysis of mitochondrial DNA.

Adult↗
PubMed2001

[The role of MRI in the diagnosis and the natural course of multiple sclerosis].

Magnetic resonance imaging (MRI) is very sensitive in depicting multiple sclerosis (MS) lesions, but its specificity is poor. New sequences such as fast spin echo and FLAIR (fluid attenuated inversion recovery) improve the detection of lesions. The exploration of the whole central nervous system, brain, optic nerves and spinal cord improves sensitivity and specificity. The existence of lesions at different ages responds to temporal dissemination. MRI has also allowed to better understand the natural history of MS, showing 5 to 10 times more radiological than clinical activity. In case of isolated demyelinating syndrome, MRI is the best predictor of the occurrence of definite MS and of the severity of disability in the subsequent 10 years. However, the diagnosis of MS remains clinical, and systematic control MRI are not useful in clinical practice.

Brain↗
PubMed2001

[Andermann syndrome in an Algerian family: suggestion of phenotype and genetic homogeneity].

Andermann syndrome or Agenesis of the Corpus Callosum with Polyneuropathy (MIM 218000) is an autosomal recessive disease almost exclusively found in Québec. Only few cases have been reported in other populations. The locus for Andermann syndrome was assigned to chromosome 15q13-q15 in French Canadian families. We performed a haplotype analysis with two markers of this chromosomal region in an Algerian consanguineous family with two affected sibs. The children were homozygous for both markers, suggesting genetic homogeneity in Andermann syndrome.

Adolescent↗
PubMed2000

Cytokines in genetic susceptibility to multiple sclerosis: a candidate gene approach. French Multiple Sclerosis Genetics Group.

The immune system is involved in the pathophysiology of multiple sclerosis (MS) but the initiating antigen(s) is not yet identified. Since cytokines control both the intensity and the quality of the immune response they may be relevant candidates for the genetic susceptibility to MS. To analyze the contribution of type 1 and type 2 cytokine and cytokine receptor genes in the genetic susceptibility to MS, we have examined, in 116 French MS sibpairs, whether there is significant linkage between MS and 15 cytokine or cytokine receptor genes using 31 highly polymorphic genetic markers. The data were analyzed using the maximum likelihood score and the transmission disequilibrium approaches. None of the candidate genes tested was significantly linked to MS on the whole population. However, after stratification of the analysis on the basis of sharing (or not) of the HLA-DRB1*1501 allele, indication of linkage was found for the IL2-RB gene. These findings suggest that the IL2-RB locus contributes to the genetic susceptibility in a subgroup of MS patients.

Cytokines↗