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O Combarros

Publications and source records attributed to O Combarros.

At least 37 records · Page 2Linked to original sources
PubMed2000

Clinico-electrophysiological correlation of extensor digitorum brevis muscle atrophy in children with charcot-marie-tooth disease 1A duplication.

The purpose of the study is to describe the electrophysiologic abnormalities accounting for the appearance and progression of extensor digitorum brevis (EDB) muscle atrophy in Charcot-Marie-Tooth-disease type 1A (CMT-1A) children. Twelve children with CMT-1A duplication were serially evaluated. Initial ages of clinico-electrophysiological exams ranged from 1 month to 4 years (mean: 2 years) and final ages from 6 to 23 years (mean: 13). All subjects had two or more electrophysiological studies of the peroneal nerve. EDB atrophy was observed in two out of 12 (17%) patients by the age of 5, in eight out of ten (80%) examined between 5 and 9 years, and in all eight (100%) patients who had reached the second decade at the end. Nerve conduction maturation was systematically abnormal, but by age of 5 the mean values of nerve conduction parameters of peroneal nerve did not significantly differ from those in older patients. Compound muscle action potential (CMAP) amplitudes of EDB were reduced in 42% of cases initially and 100% upon last exam. Furthermore, a constant finding throughout the study was progressive attenuation of CMAPs, these becoming unobtainable in four cases. EDB muscle atrophy in CMT-1A children is an age-dependent sign which is accounted for by gradual reduction of the distal peroneal nerve CMAP amplitudes.

Action Potentials↗
PubMed2000

The butyrylcholinesterase K variant is a protective factor for sporadic Alzheimer's disease in women.

INTRODUCTION: Recent reports indicate that the K variant of the butyrylcholinesterase (BCHE) gene may act in synergism with the epsilon4 allele of apolipoprotein E (APOE) to increase the risk of Alzheimer's disease (AD), but this is controversial. MATERIAL AND METHODS: We genotyped for the BCHE-K and APOE epsilon4 alleles in a sample of 249 AD patients and 250 controls derived from the same region in a Spanish population. RESULTS: A protective effect of the K variant of BCHE with an odds ratio of 0.41 (95% confidence interval 0.19-0.86, P=0.02) was observed among non-APOE epsilon4 carriers, but it was limited to women. CONCLUSION: Our study is the first to demonstrate that lower susceptibility to AD determined by the K variant of BCHE is dependent on gender.

Aged↗
PubMed1999

Polymorphisms in the presenilin 1 and presenilin 2 genes and risk for sporadic Alzheimer's disease.

We examined the possible involvement of polymorphisms of the presenilin 1 (PS1) and presenilin 2 (PS2) genes in the risk for sporadic Alzheimer's disease (AD), either through an independent effect or through interaction with the existing apolipoprotein E (ApoE) risk, in 211 AD cases and 188 age-matched control subjects. No significant differences were obtained in any of the comparisons relating the effect of the PS1 and PS2 polymorphisms; thus, these polymorphisms do not appear to be sufficient risk factors by themselves for sporadic AD. Although the ApoE varepsilon4 genotype is the only definite predictor of risk, homozygosity for either the 1 allele of the PS1 or the C allele of the PS2 genes may increase the risk conferred by the presence of an ApoE epsilon4 allele. Additionally, combination of PS1/11 and PS2/CC genotypes might have a small synergistic effect on the risk for AD.

Adult↗
PubMed1999

An early description of striatonigral degeneration.

Our aim was to revisit the papers published by Scherer 1933 describing four cases of sporadic olivopontocerebellar atrophy (OPCA) thought to represent the earliest description of striatonigral degeneration. One should note that extrapyramidal rigidity associated with OPCA was then considered a type of cerebellar parkinsonism. Two of Scherer's four patients had severe parkinsonism masking cerebellar signs. Pathologically both cases displayed marked degeneration of the striatum and nigra and partially developed pontocerebellar atrophy. Cerebellar ataxia was the outstanding feature in the other two, their pathological study showing severe pontocerebellar lesions and incipient striatonigral atrophy. Scherer stated that the severity of parkinsonism in OPCA is not correlated with the degree of cerebellar degeneration but with that of striatum and nigra. We conclude that Scherer gave the first accurate description of striatonigral degeneration. Moreover, his contribution was essential in ruling out the prevalent notion of cerebellar parkinsonism in OPCA.

Diagnosis, Differential↗
PubMed1999

Spinocerebellar ataxias in Spanish patients: genetic analysis of familial and sporadic cases. The Ataxia Study Group.

Autosomal dominant cerebellar ataxias (ADCA) are a clinically heterogeneous group of neurodegenerative disorders caused by unstable CAG repeat expansions encoding polyglutamine tracts. Five spinocerebellar ataxia genes (SCA1, SCA2, SCA3, SCA6 and SCA7) and another related dominant ataxia gene (DRPLA) have been cloned, allowing the genetic classification of these disorders. We present here the molecular analysis of 87 unrelated familial and 60 sporadic Spanish cases of spinocerebellar ataxia. For ADCA cases 15% were SCA2, 15% SCA3, 6% SCA1, 3% SCA7, 1% SCA6 and 1% DRPLA, an extremely rare mutation in Caucasoid populations. About 58% of ADCA cases remained genetically unclassified. All the SCA1 cases belong to the same geographical area and share a common haplotype for the SCA1 mutation. The expanded alleles ranged from 41 to 59 repeats for SCA1, 35 to 46 [corrected] for SCA2, 67 to 77 for SCA3, and 38 to 113 for SCA7. One SCA6 case had 25 repeats and one DRPLA case had 63 repeats. The highest CAG repeat variation in meiotic transmission of expanded alleles was detected in SCA7, this being of +67 units in one paternal transmission and giving rise to a 113 CAG repeat allele in a patient who died at 3 years of age. Meiotic transmissions have also shown a tendency to more frequent paternal transmission of expanded alleles in SCA1 and maternal in SCA7. All SCA1 and SCA2 expanded alleles analyzed consisted of pure CAG repeats, whereas normal alleles were interrupted by 1-2 CAT trinucleotides in SCA1, except for three alleles of 6, 14 and 21 CAG repeats, and by 1-3 CAA trinucleotides in SCA2. No SCA or DRPLA mutations were detected in the 60 sporadic cases of spinocerebellar ataxia, but one late onset patient was identified as a recessive form due to GAA-repeat expansions in the Friedreich's ataxia gene.

Adult↗
PubMed1998

Isolated unilateral hypoglossal nerve palsy: nine cases.

We report nine patients with hypoglossal nerve palsy as the sole neurological manifestation, without simultaneous involvement of other cranial nerves or long-tract signs. In four patients, no cause was found and the outcome was excellent. The next common cause proved to be metastatic disease at the base of the skull in three patients. Two exceptional causes were Chiari malformation in one case and dural arteriovenous fistula of the transverse sinus in another. Although the aetiological importance and ominous prognosis of neoplasia has been emphasized by others, our study suggests that an isolated hypoglossal nerve palsy may be benign and idiopathic.

Adolescent↗
PubMed1998

Gender effect on apolipoprotein E epsilon4 allele-associated risk for sporadic Alzheimer's disease.

INTRODUCTION: The role of gender in Alzheimer's disease (AD), and its possible interaction with apolipoprotein E (apoE), has been controversial. MATERIAL AND METHODS: ApoE allelic frequencies and the effect of apoE epsilon4 allele dosage on risk and age at onset of AD were evaluated, separately for men and women, in 100 patients with sporadic AD and 100 age-matched controls. RESULTS: The distribution of apoE alleles and the odds ratio for AD, when associated with 1 or 2 epsilon4 alleles, were not statistically different between men and women. No effect of the dosage of the epsilon4 allele was found on the age at onset of dementia in the 2 sex groups. CONCLUSION: Our data suggest that the relation of the apoE genotype to AD is not dependent on sex.

Alleles↗
PubMed1998

Association of the HLA-A2 allele with an earlier age of onset of Alzheimer's disease.

INTRODUCTION: The HLA-A2 allele has recently been considered as a risk factor in AD by advancing the age at onset of the disease, especially in subjects who were homozygous for the apoE epsilon4 allele. MATERIAL AND METHODS: We examined the distribution of apoE genotypes and A2 allele as a function of age at onset in 109 patients with sporadic and familial AD. RESULTS: In the early onset (< or =60 years) and late onset (>75 years) AD groups, there was, respectively, a 2.2 year and a 2.7 year earlier onset in the A2 positive cases. Age effect was not apparent in the middle onset (61-75 years) AD group. The effect of A2 allele on the age at onset was not different between familial and sporadic AD cases. The presence or absence of the A2 allele did not modify mean age at onset in the groups homozygous and heterozygous for epsilon4, and in cases with no epsilon4 alleles. CONCLUSION: Though the sample size was small, there is a trend in favor of an A2 effect on age at onset. Additionally, there is no evidence of interaction between A2 and apoE epsilon4 alleles on age at onset of AD.

Adult↗
PubMed1998

Charcot-Marie-Tooth disease type 1A with 17p duplication in infancy and early childhood: a longitudinal clinical and electrophysiologic study.

OBJECTIVE: We describe longitudinal clinical and electrophysiologic evaluation of Charcot-Marie-Tooth disease type 1A (CMT-1A) in infancy and early childhood. BACKGROUND: The clinical picture and electrophysiologic evaluation of CMT-1A during the age of nerve conduction maturation have not been documented. DESIGN/METHODS: Twenty at-risk children from six unrelated CMT-1A families were examined in the first 5 years of life. Initial ages were 1 month to 4 years (mean, 1.5 years) and final ages 4 to 19 years (mean, 9 years). All subjects had two or more motor and sensory conduction velocities (MCV and SCV), corrected distal motor latencies (DML), and F-waves. RESULTS: Twelve children were affected. Initially, two of these (17%) had symptoms, whereas five (42%) were symptomatic at the end. Numbers of abnormal examinations at the beginning was six (50%) and at conclusion was 10 (83%). None of the patients were disabled. From 2 years of age, all affected children had abnormal MCV, SVC, F-waves, and DML. Prolonged DML was already present in the first months of life and preceded slowing of MCV in three cases. CONCLUSION: The electrophysiologic studies were concordant with the presence or absence of the CMT-1A DNA duplication. In most CMT-1A patients, symptoms appear in early childhood, although the florid clinical picture does not occur until the second decade of life. Serial electrophysiologic studies can detect the CMT-1A gene carrier in infancy.

Adolescent↗