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Biomedical subjects

D Hannequin

Publications and source records attributed to D Hannequin.

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

Identification of three novel mutations (E196K, V203I, E211Q) in the prion protein gene (PRNP) in inherited prion diseases with Creutzfeldt-Jakob disease phenotype.

Inherited prion diseases are characterized by mutations in the PRNP gene encoding the prion protein (PrP). As the other sporadic or infectious prion disease forms, they are almost all characterized by the accumulation in the brain of an abnormal misfolded form of the patient's PrP. Brain extracts can often transmit the disease once inoculated in a recipient animal. Inherited prion diseases with Creutzfeldt-Jakob disease (CJD) phenotype are autosomal forms, although sporadic cases have been reported. We report three novel mutations of the PRNP gene in unrelated patients with clinical and histopathologic features of CJD. The three mutations were missense: c635G>A (E196K), c656G>A (V203I) and c680G>C (E211Q). Familial history of neurologic disorders was evidenced for patients carrying the E196K and E211Q mutations. E196K would be predicted to have more severe effects on protein stability than V203I and E211Q. These mutations expand the spectrum of mutations in PRNP and reduce the proportion of CJD patients in whom genetic alterations have not been found.

Aged↗
PubMed2000

Dysarthria and orofacial apraxia in corticobasal degeneration.

The authors evaluated dysarthria and orofacial apraxia (OFA) in 10 patients with a clinical diagnosis of corticobasal degeneration (CBD). Nine patients were slightly dysarthric according to the French version of the Frenchay Dysarthria Assessment, which evaluates the motricity of the components of the vocal tract. The severity of dysarthria assessed by an intelligibility score was correlated to the global severity of the disease, but not to the duration of the disease. Voluntary movements of the tongue and the lips were impaired in all patients. OFA, evaluated with simple and sequential gestures, was present in nine patients. Sequential gestures were more frequently impaired. The score of OFA was not correlated to the severity of dysarthria, suggesting independent underlying mechanisms. Thus, when specifically assessed, dysarthria and OFA are more frequent in CBD than usually reported. We propose that the underlying pathophysiology is the result of a deficit in programming and execution of repetitive movements.

Aged↗
PubMed2000

APOE promoter polymorphisms do not confer independent risk for Alzheimer's disease in a French population.

The apolipoprotein E (APOE, gene; apoE, protein) isoforms are associated with differential risk of Alzheimer's disease (AD). An additional involvement of APOE promoter polymorphisms in AD risk has recently been suggested by several studies. Indeed, three polymorphisms of the APOE regulatory region (-219 G/T, -427 C/T and -491 A/T) have been found associated with AD even after adjustment on the apoE status. We analysed these three promoter region polymorphisms in a large French case-control study (388 AD cases and 386 controls). We found that the -427 T and -491 A alleles were associated with an increased risk of developing AD, but not the -219 G/T alleles. However, a strong linkage disequilibrium was observed between the alleles of these promoter region polymorphisms and the APOE coding region alleles. We therefore retested association after adjustment on apoE status and found that the sole association which remained significant was the association with the -427 T allele. The alpha level was equal to 0.03 (0.09 after Bonferroni correction for multiple comparisons). Analysis of promoter haplotypes also yielded non-significant results. Thus our study does not reinforce the hypothesis of an independent involvement of the APOE promoter region polymorphisms in AD risk.

Adult↗
PubMed2000

[Evaluation of motor speech function in the diagnosis of various forms of dysarthria].

Perceptual analysis is not sufficient enough to identify specific dysarthria types. In order to improve the discrimination between dysarthria types, we developed a standardized evaluation of different functions controlling speech motor performances. This was applied to 90 patients suffering from hypokinetic, spastic or ataxic dysarthria and 15 control subjects. A discriminate analysis showed that 71.4 p. 100 of the cases were correctly classified. This model was validated within a new group of 21 patients and showed that the less severe dysarthric parkinsonian patients were difficult to distinguish from control subjects. The discriminate analysis was then used for 20 patients with atypical parkinsonism. Seven patients with progressive supranuclear palsy were considered to have hypokinetic dysarthria. The 6 patients with multisystem atrophy and 7 with corticobasal degeneration were classified among the 3 dysarthric types. We suggest that motor speech evaluation may contribute to differential diagnosis within groups of patients suffering from atypical parkinsonism.

Aged↗
PubMed2000

Giant cervical epidural veins after lumbar puncture in a case of intracranial hypotension.

A 29-year-old woman presented with dilated epidural veins and incapacitating headache after undergoing a lumbar puncture. Two months later, the results of follow-up MR imaging were normal. These findings suggest that temporary dilation of the epidural vein may occur in association with post-lumbar puncture intracranial hypotension syndrome. In these cases, it seems useful to confirm whether the patient has recently undergone a lumbar puncture.

Adult↗
PubMed2000

[Isolated truncular paralysis of the musculocutaneous nerve of the upper limb].

Isolated palsy of the musculocutaneous nerve, terminal branch of the lateral cord of the brachial plexus, is rare. It is responsible for sensory loss of the distal forearm and weakness of elbow flexion. It occurs after shoulder or clavicle surgery, trauma (fracture, dislocation, blows on the shoulder), violent exercice or extension of the forearm, prolonged positioning of the shoulder in extension-abduction-external rotation and phlebotomy. Different mechanisms such as stretching, compression or direct nerve injury are encountered. We report 5 cases with isolated musculocutaneous nerve palsy, including bilateral palsy caused by violent forearm extension. In other cases, mechanisms were an extensive stretching during surgery and compression caused by prolonged supine position. Different injury locations and causes described in literature are reviewed.

Accidents, Traffic↗
PubMed2000

[The assessment of long-term memory and semantic knowledge].

Following a previous review about the different components of memory (Eustache et al., Revue Neurologique, 1998), this paper is devoted to the evaluation of both autobiographical and semantic memory. An original method to analyse autobiographical memory is proposed. The different tasks used for the analysis of semantic memory are detailed with a particular emphasis given to the category -specific semantic impairments.

Humans↗
PubMed1999

Early-onset autosomal dominant Alzheimer disease: prevalence, genetic heterogeneity, and mutation spectrum.

To determine the prevalence of early-onset Alzheimer disease (EOAD) and of autosomal dominant forms of EOAD (ADEOAD), we performed a population-based study in the city of Rouen (426,710 residents). EOAD was defined as onset of disease at age <61 years, and ADEOAD was defined as the occurrence of at least three EOAD cases in three generations. Using these stringent criteria, we calculated that the EOAD and ADEOAD prevalences per 100,000 persons at risk were 41.2 and 5.3, respectively. We then performed a mutational analysis of the genes for amyloid precursor protein (APP), presenilin 1 (PSEN1), and presenilin 2 (PSEN2) in 34 families with ADEOAD ascertained in France. In 19 (56%) of these families, we identified 16 distinct PSEN1 missense mutations, including 4 (Thr147Ile, Trp165Cys, Leu173Trp, and Ser390Ile) not reported elsewhere. APP mutations, including a novel mutation located at codon 715, were identified in 5 (15%) of the families. In the 10 remaining ADEOAD families and in 9 additional autosomal dominant Alzheimer disease families that did not fulfill the strict criteria for ADEOAD, no PSEN1, PSEN2, or APP mutation was identified. These results show that (1) PSEN1 and APP mutations account for 71% of ADEOAD families and (2) nonpenetrance at age <61 years is probably infrequent for PSEN1 or APP mutations.

Adult↗
PubMed1999

Usefulness of transcranial color-coded sonography in the diagnosis of cerebral vasospasm.

BACKGROUND AND PURPOSE: The noninvasive diagnosis of cerebral vasospasm with the use of conventional transcranial Doppler ultrasonography (TCD) is based on a velocity study of the middle cerebral artery (MCA). The authors report a prospective comparative study between transcranial color-coded sonography (TCCS), conventional transcranial Doppler (TCD), and angiography in the diagnosis of cerebral vasospasm after surgical treatment for aneurysm. METHODS: Thirty consecutive patients underwent routine angiography after surgical treatment for intracranial aneurysm. The distribution of vasospasm was determined after a prospective calculation of the angiographic diameter of the MCA, internal carotid artery (ICA), and anterior cerebral artery (ACA). The blood flow velocities (systolic and maximum) of the MCA, ICA, and ACA were evaluated by TCCS and TCD. RESULTS: The correlation between mean maximum velocity and angiographic diameter was significant for the MCA (r=-0.637, P<0.0001), ICA (r=-0.676, P<0.0001), and ACA (r=-0.425, P<0.01). TCCS sensitivity and specificity were higher than those for TCD for MCA (100% and 93%, respectively) and ICA (100% and 96.6%, respectively). For ACA, the sensitivity and specificity were 71.4% and 84.8%, respectively. CONCLUSIONS: The authors suggest that TCCS is useful for accurate monitoring of cerebral vasospasm in the MCA and ICA. In the ACA, TCCS monitors the hemodynamic state of the anterior part of the circle of Willis, which could expose the patient to a delayed ischemic deficit.

Adult↗
PubMed1999

The neurobiological basis of time estimation and temporal order.

Time estimation may be evaluated with the use of four major paradigms: temporal discrimination, verbal estimation, temporal production, and temporal reproduction. On the basis of testing of normal subjects and patients with brain lesions, it has been shown that the cerebellum, the basal ganglia, and the prefrontal cortex are involved in time estimation. In particular, studies in humans and animals have indicated that facilitation of dopamine transmission speeds up the internal clock, while inhibition of dopamine transmission slows it down. It has been hypothesized that the central timer is located in the cerebellum, while the planning abilities subserving the estimation of longer intervals are mediated by the prefrontal cortex. It remains to be determined whether time estimation is related to memory of temporal order or context and whether time-related tasks are correlated with working memory.

Animals↗
PubMed1999

[Cortico-basal degeneration].

Cortico-basal degeneration (CBD) has recently emerged as a distinctive entity of the Parkinson-plus syndromes but presents with great clinical and anatomopathological heterogeneity. The purpose of this review is to increase awareness of the syndrome and facilitate its recognition in both typical and unusual cases. We will herein review the 398 cases found in the English and French literature with their clinical, laboratory and pathological features.

Aged↗
PubMed1998

No association of apolipoprotein epsilon 4 allele with schizophrenia even in cognitively impaired patients.

Given the strong association of the apolipoprotein E (apoE) allele epsilon 4 (epsilon 4) with Alzheimer's disease or cognitive decline in elderly, we tested whether cognitive performance in schizophrenic subjects is associated with an increase in the frequency of the ApoE epsilon 4 allele. Our data indicate that in our sample: (1) there is no association between schizophrenia and the ApoE epsilon 4 allele; and (2) the ApoE epsilon 4 allele is not of major importance with regard to the cognitive decline observed in schizophrenia.

Adult↗
PubMed1998

Apolipoprotein E epsilon4 allele and familial aggregation of Alzheimer disease.

OBJECTIVE: To investigate the relationship among risk for Alzheimer disease (AD), familial aggregation of AD, and the apolipoprotein E (apoE) epsilon4 allele in first-degree relatives of probands with AD and known apoE genotype. PATIENTS: Two hundred ninety subjects fulfilling the criteria of the National Institute of Neurological Communicative Disease and Stroke-Alzheimer's Disease and Related Disorders Association for probable AD were ascertained from March 1, 1992, to December 31, 1996, through consecutive admissions in several university hospitals. DESIGN AND METHODS: Family data were collected on 1176 first-degree relatives (parents and siblings), aged 40 to 90 years. Most living relatives underwent a clinical examination, whereas we relied on family history for clinical data for deceased or unavailable relatives. First, we conducted standard survival analyses to estimate cumulative lifetime risk (LTR) for AD among relatives and to investigate for sex and apoE genotype effects on LTR. Then, we assessed to what extent clustering of secondary AD could be explained by the apoE epsilon4 allele by deriving the expected proportions of relatives with 0, 1, or 2 apoE epsilon4 alleles conditionally on the proband's genotype. RESULTS: Cumulative LTR for AD among first-degree relatives increased significantly with the number of epsilon4 alleles present in the proband. By 90 years of age, LTRs in relatives of probands with epsilon3/epsilon3, epsilon3/epsilon4, and epsilon4/epsilon4 genotypes were 29.2%, 46.1%, and 61.4%, respectively. Significant sex-by-apoE genotype interaction effects on LTR were observed. Women had about a 2-fold higher risk for AD than men among relatives of epsilon4 carriers but not among relatives of non-epsilon4 carriers. The predicted proportion of epsilon4 carriers in relatives of probands with epsilon3/epsilon3 genotype remains about 50% lower than the corresponding LTR for AD, indicating that familial clustering of AD is largely due to other factors than the apoE epsilon4 allele. Although aggregation of AD in families of probands with the epsilon4 allele is more prominent, we estimated that AD would not develop in about 30% of female and up to 60% of male relatives carrying at least 1 epsilon4 allele, even by 90 years of age. CONCLUSION: Our results support the hypothesis that the apoE epsilon4 allele enhances AD susceptibility, but putative factors enhancing risk for AD remain to be found.

Adult↗
PubMed1998

Segregation of a missense mutation in the microtubule-associated protein tau gene with familial frontotemporal dementia and parkinsonism.

Frontotemporal dementia and parkinsonism (FTDP) is the second most common cause of neurodegenerative dementia after Alzheimer's disease. Recently, several kindreds with an autosomal dominant form of FTDP have been reported and in some families the pathological locus was mapped to a 2 cM interval on 17q21-22. The MAPT gene, located on 17q21 and coding for the human microtubule-associated protein tau, is a strong candidate gene, since tau-positive neuronal inclusions have been observed in brains from some FTDP patients. Direct sequencing of the MAPT exonic sequences in 21 French FTDP families revealed in six index cases the same missense mutation in exon 10 resulting in a Pro-->Leu change at amino acid 301. Co-segregation of this mutation with the disease was demonstrated by restriction fragment analysis in two families for which several affected relatives were available. The Pro301Leu mutation was not observed in either 50 unrelated French controls or in 11 patients with sporadic frontotemporal dementia. This mutation, which occurs in the second microtubule-binding domain of the MAPT protein, is likely to have a drastic functional consequence. The observation of this mutation in several FTDP families might suggest that disruption of binding of MAPT protein to the microtubule is a key event in the pathogenesis of FTDP.

Adult↗
PubMed1998

De novo presenilin 1 mutations are rare in clinically sporadic, early onset Alzheimer's disease cases. French Alzheimer's Disease Study Group.

The presenilin 1 (PS1) gene, located on chromosome 14, is the major gene involved in the autosomal dominant forms of early onset Alzheimer's disease (AD). In order to estimate the frequency of de novo PS1 mutations, we have sequenced the PS1 open reading frame in 13 clinically diagnosed patients with no affected relatives, who had developed AD before the age of 50. In one case with onset at 37 years, we identified a missense mutation resulting in a methionine to lysine substitution at codon 139 of the PS1 gene. This substitution is the fourth identified at the same codon. This study, in agreement with previous reports, suggests that de novo PS1 mutations can occur but at a low frequency.

Adult↗