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Biomedical subjects

F Pasquier

Publications and source records attributed to F Pasquier.

At least 55 records · Page 3Linked to original sources
PubMed1999

The biochemical pathway of neurofibrillary degeneration in aging and Alzheimer's disease.

OBJECTIVE: To determine the spatiotemporal mapping of neurofibrillary degeneration (NFD) in normal aging and the different stages of AD. BACKGROUND: The pathophysiologic significance of AD lesions, namely amyloid plaques and neurofibrillary tangles, is still unclear, especially their interrelationship and their link with cognitive impairment. METHODS: The study included 130 patients of various ages and different cognitive statuses, from nondemented control subjects (n = 60, prospective study) to patients with severe definite AD. Paired helical filaments (PHF)-tau and Abeta were used as biochemical and histologic markers of NFD and amyloid plaques, respectively. RESULTS: NFD with PHF-tau was systematically present in variable amounts in the hippocampal region of nondemented patients age >75 years. When NFD was found in other brain areas, it was always along a stereotyped, sequential, hierarchical pathway. The progression was categorized into 10 stages according to the brain regions affected: transentorhinal cortex (S1), entorhinal (S2), hippocampus (S3), anterior temporal cortex (S4), inferior temporal cortex (S5), medium temporal cortex (S6), polymodal association areas (prefrontal, parietal inferior, temporal superior) (S7), unimodal areas (S8), primary motor (S9a) or sensory (S9b, S9c) areas, and all neocortical areas (S10). Up to stage 6, the disease could be asymptomatic. In all cases studied here, stage 7 individuals with two polymodal association areas affected by tau pathologic states were cognitively impaired. CONCLUSIONS: The relationship between NFD and Alzheimer-type dementia, and the criteria for a biochemical diagnosis of AD, are documented, and an association between AD and the extent of NFD in defined brain areas is shown.

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PubMed1999

Early diagnosis of dementia: neuropsychology.

Neuropsychology contributes greatly to the diagnosis of dementia. Cognitive deficits can be detected several years before the clinical diagnosis of dementia. The neuropsychological profile may indicate the underlying neuropathology. Neuropsychological assessment at an early stage of dementia has two goals: (a) to determine a memory disorder, not always associated with a memory complaint, and (b) to characterize the memory disorder in light of the cognitive neuropsychology and to assess other cognitive (and noncognitive) functions toward integrating the memory disorder in a syndrome. We review the global tools, the memory tests that describe the memory profile and indicate the underlying pathology, the assessment of other cognitive functions, and the neuropsychological patterns of typical Alzheimer's disease, frontotemporal dementia, primary progressive aphasia, semantic dementia, Lewy body dementia, subcortical dementia, and vascular dementia. These patterns must be interpreted in the light of the history, rate of progression, imaging results, and nature of existing behavioral disturbances. Moreover, there may be overlap between two or more pathologies, which complicates the diagnostic process. Follow-up of patients is necessary to improve diagnostic accuracy.

Alzheimer Disease↗
PubMed1999

Association between coding variability in the LRP gene and the risk of late-onset Alzheimer's disease.

We have sequenced the entire (89 exons) open reading frame of the LRP gene in 12 cases of Alzheimer's disease (AD) from Northern France. We have found no novel changes but confirm the occurrence of a polymorphism in exon 6 of the gene (A216V). This polymorphism is rare (2.8% of controls) and is in linkage equilibrium with previously reported polymorphisms. The V216 allele is negatively associated with the disease in a large case-controlled series. These data suggest that the LRP receptor may be involved in the pathobiology of AD, but the association that we report here cannot explain the previously reported genetic data implicating the LRP gene in AD. If the LRP gene is a major site of genetic variability leading to AD, there must be other biologically relevant variability in promoter or other regulatory elements of this large gene.

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PubMed1999

The clinical picture of frontotemporal dementia: diagnosis and follow-up.

Frontotemporal dementia (FTD) was diagnosed in 74 outpatients with a standardized assessment including neuropsychological tests, behavioural scale, structural and functional imaging. Clinical characteristics were consistent with the literature data. The cohort was followed for 2-6 years to determine the reliable variable for evaluating the progression of FTD. Every fourth patient died after a mean duration of 7 years. At first, FTD manifests itself in behavioural changes with relatively stable global cognition although language, verbal fluency and memory tests were reliable tools to follow the progression of the disease. Below 18 of Mini-Mental State Examination, mutism and apathy prevented from neuropsychological testing within the next 6 months. Behavioural disorders evolved with time but restlessness and hyperorality were long-lasting. Imaging showed the progression of a consistent pattern of anterior abnormalities with frequent leukoaraiosis.

Activities of Daily Living↗
PubMed1999

Confusional state in stroke: relation to preexisting dementia, patient characteristics, and outcome.

BACKGROUND AND PURPOSE: Acute confusional state (ACS) is frequent in hospitalized stroke patients. We previously showed that 16% of patients admitted for a stroke have preexisting dementia. The extent to which preexisting cognitive decline is associated with a risk of ACS at the acute stage of stroke remains to be systematically examined. The aim of this study was to evaluate the prevalence of ACS in acute stroke patients, to study the influence of preexisting cognitive decline and other patient characteristics, and to evaluate the influence of ACS on outcome. METHODS: We diagnosed ACS using DSM-IV criteria and the Delirium Rating Scale with a cutoff of 10 in 202 consecutive stroke patients aged 40 years or older (median age, 75 years; range, 42 to 101 years). Cognitive functioning before stroke was assessed with the Informant Questionnaire on Cognitive Decline in the Elderly. RESULTS: Forty-nine stroke patients (24.3%; 95% CI, 18.3% to 30.2%) had an ACS during hospitalization. Using logistic regression analysis, we found preexisting cognitive decline (P=0.006) and metabolic or infectious disorders (P=0.008) to be independent predictors of ACS. Functional, but not vital, prognosis was worse in patients with ACS at discharge and 6 months after stroke. CONCLUSIONS: ACS occurs in one fourth of stroke patients older than 40 years. Its occurrence requires inquiry for a preexisting cognitive decline, which usually remains unrecognized in the absence of a systematic evaluation.

Acute Disease↗
PubMed1999

Technetium HMPAO SPECT study in dementia with Lewy bodies, Alzheimer's disease and idiopathic Parkinson's disease.

UNLABELLED: The aim of this study was to compare the regional cerebral blood flow measurements studied by SPECT in dementia with Lewy bodies (DLB) and Alzheimer's disease (AD) to determine the contribution of SPECT to the differential diagnosis of these two diseases. METHODS: SPECT analysis with 99mTc-hexamethyl propyleneamine oxime (HMPAO) was performed in 20 patients with probable DLB, 20 patients with probable AD and 20 patients with idiopathic Parkinson's disease (IPD). Ten pairs of regions of interest were analyzed. Tracer uptake was expressed as a corticocerebellar activity ratio. RESULTS: Compared with IPD, in the DLB group there was a global decrease of HMPAO uptake in cortical regions of interest except in the posterior frontal and occipital regions; in the AD group there was limited left temporal and parietal hypoperfusion. In the DLB group, frontal HMPAO uptake was significantly lower than in the AD group. Two predictive scores were established by a factorial discriminant analysis from six left cortical indices (medial frontal, lateral frontal, posterior frontal, temporoparietal, parietal and parietooccipital) and the Mini-Mental State Examination, which correctly classified 53 of 60 patients (88%) (DLB, 18 of 20; AD, 16 of 20; IPD, 19 of 20). CONCLUSION: These findings indicate the presence of diffuse cortical abnormalities in DLB and suggest that SPECT may be useful in discriminating in vivo DLB from AD, revealing mainly frontal hypoperfusion in the former group. We estimate that SPECT study increases the possibility of separating DLB and AD because both disorders share different patterns of cerebral blood flow abnormality.

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PubMed1999

[Arterial hypertension and cognitive decline].

Arterial hypertension is the leading risk factor for all stroke subtypes. However, its relationship with cognitive decline and dementia is more complex than a simple causal relationship. Cognitive functions are worse in patients with arterial hypertension, especially when the level of education is lower, age higher and arterial hypertension more severe. Arterial hypertension is an independent factor of cognitive decline. It also leads to white matter changes which contribute to the cognitive decline. Longitudinal studies have shown that a higher blood pressure at the age of 70 years is associated with an increased risk of dementia (vascular or Alzheimer) 10 to 15 years later, but blood pressure spontaneously decreases as dementia occurs. Treatments of arterial hypertension decrease the incidence of stroke, but clinical trials are still necessary to determine if they also decrease the incidence of dementia. Preliminary results obtained in elderly subjects with systolic arterial hypertension, support this hypothesis.

Alzheimer Disease↗
PubMed1999

[Risk factors and mechanisms of post-stroke dementia].

Stroke significantly increases the risk of dementia in subjects aged 55 years or more. Twenty to 25 p. 100 of patients are demented 5 years after a stroke. Age and supratentorial location of the vascular lesion are risk factors for post-stroke dementia. Volume, left side of the lesion, large middle cerebral artery infarction, lesions of the frontal lobe, second stroke, diabetes, aphasia, clinical features expressing the severity of the stroke event in the acute phase, mitral valve prolapse, atrial fibrillation, depression, concomitant hypoxic/ischemic disorders, and white matter changes have also been found as predictors of dementia. There are many different mechanisms of vascular pathology that may lead to dementia: ischemic or hemorrhagic lesions, large vessel disease including multi-infarct and strategic single infarct, small-vessel disease including lacunes and white matter changes, hypoperfusion.... Post-stroke dementia may not be due only to vascular lesion. Some post-stroke dementias have a progressive onset and course. The cognitive decline may pre-exist to the stroke, even when a dementia is not diagnosed. This suggests a degenerative process. Alzheimer's disease is frequent in ages when the majority of strokes occur. Alzheimer's and vascular diseases share common risk factors such as age, APOE4, hypertension, and smoking. Patients with low MMS scores and AD patients are at risk for stroke. Moreover, white matter changes are associated with stroke and Alzheimer's disease and may contribute to the cognitive decline. Many post-stroke dementias could be multifactorial. Even when vascular lesions and degenerative changes (mainly Alzheimer changes) are not severe enough, no their own, to be the cause of dementia, their summation may reduce the preclinical stage of the degenerative process.

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PubMed1999

[Organization of memory centers and prospects].

The concept of memory centers is based on a multidisciplinary approach to memory disorders and dementia, especially Alzheimer's disease, a public health challenge. The first memory centers were established in the 80s in the US and the British Isles. The aims of these centers are to make a diagnosis (and to reassure the 'worried well'), to detect dementia, to provide a service for their management, to educate care takers, to evaluate new therapies, and to contribute to clinical and basic research. Follow-up is crucial. The first memory centers all experienced long delay to diagnosis of dementia and found that Alzheimer's disease was the first cause of consultation. These observations led to the creation of such centers in many countries. A survey of 20 French memory centers defined the "ideal memory center": an identified structure with a clinic and a day-care unit for diagnosis and follow-up, with neurological, psychological, psychiatric, and geriatric skills. It must be part of a medical and social network for the management of dementia and participate in a network of memory centers at the regional and national level. Relationships between dementia and somatic diseases, frequent in demented patients, are still poorly known. Dementia interferes with the clinical expression, the management, and the prognosis of somatic diseases, some of which, such as cardiovascular conditions, are possibly linked with dementia. Conversely, somatic diseases may rapidly worsen the cognitive state and induce delirium, leading to hospitalization. Medical wards are not all appropriate. Memory centers must also be involved in these care, educational and research issues.

Academic Medical Centers↗
PubMed1998

[Differential diagnosis of Alzheimer's disease].

The differential diagnosis of Alzheimer's disease has dramatically changed since the evolution of the diagnostic strategies (with definition of neuropsychological, behavioural, and imaging patterns) and disposal of cholinergic drugs indicated in Alzheimer's disease. The question is no more centred on exclusion of the traditional reversible dementias or depression. It is centred on the distinction between Alzheimer's disease and other degenerative diseases still often misdiagnosed with Alzheimer's disease such as frontotemporal dementias, dementia with Lewy bodies, and some focal atrophies that do not have the same physiopathology and should not be treated with anticholinesterase drugs. Besides, better knowledge on the links between cerebrovascular pathology and Alzheimer's disease, remind us that both pathologies may coexist and should be taken into account.

Alzheimer Disease↗
PubMed1998

[Prognosis of cerebral ischemic accidents].

One of the roles of neurologists is to determine the prognosis in patients with cerebral infarction. However, it remains difficult to determine the prognosis at the individual level. Patients with cerebral infarction are at risk of death, stroke recurrence, intercurrent complications and sequelae. A clinical improvement may occur years after stroke onset, especially for neuropsychological deficits. Predictors of outcome may lead to a more appropriate management of stroke patients and an optimization of the reinsertion.

Brain Ischemia↗
PubMed1998

Tacrine efficacy in Lewy body dementia.

BACKGROUND: Response to tacrine varies among patients with Alzheimer's disease (AD). Lewy body dementia (LBD) could be a high responder subtype of AD. The aim of the study was to compare the effects of tacrine in LBD and AD. METHODS: Seventy-five consecutive outpatients with mild or moderate AD were screened. Tacrine was given at a dose of 40 mg/day during 6 weeks. During the next 6 weeks, the patients were treated with 80 mg/day and afterwards with 120 mg/day. Patients were assessed at baseline and treated with a dose of 120 mg/day tacrine for 2 weeks. RESULTS: Analysis was performed on 39 patients (AD, N = 20; LBD, N = 19). Eight patients were lost to follow-up, eight patients manifested with side-effects, six suffered from an intercurrent somatic disease during the study and 14 patients had poor compliance or were treated with incompatible drugs. Twenty-two patients (11 AD/11 LBD) increased their cognitive performances with tacrine. Among the 22 patients, the improvement differed between the AD and the LBD groups. In AD, conceptualization improved; in LBD, the improvements occurred in verbal initiation and digit span. CONCLUSION: This study emphasizes the importance of using appropriate tests to determine the positive effects of pharmacological treatments.

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PubMed1998

The influence of coincidental vascular pathology on symptomatology and course of Alzheimer's disease.

The aim of this review is to determine the influence of coincidental cerebrovascular pathology on the symptomatology and course of Alzheimer's disease (AD). The link between stroke and AD is probably higher than expected by chance for the following reasons: (i) both pathologies share genetic risk factors such as the epsilon 4 allele of the apolipoprotein E gene; (ii) AD patients have changes in the brain vessels that may lead to either ischemic or hemorrhagic stroke or white matter changes or both; (iii) there is evidence of an increased risk of stroke in AD patients; (iv) there is evidence of a frequent association of AD and stroke at autopsy. Because of the summation of the various types of lesions, stroke lesions may lead to an increase progression of cognitive decline in AD patients. Recognition of a vascular component in a dementia syndrome is therefore useful for the management of AD patients. Whether an optimal management of risk factors for stroke may delay the clinical expression of dementia in patients with preclinical Alzheimer pathology should be evaluated.

Alzheimer Disease↗
PubMed1998

A new polymorphism in the APOE promoter associated with risk of developing Alzheimer's disease.

The epsilon4 allele of the Apolipoprotein E gene (APOE), one of the main allele of APOE polymorphism, is a major risk factor for the development of Alzheimer's disease. However, several data suggest that genetic factors, within the APOE locus, may also modulate the risk associated with this polymorphism. We look for new mutations in the APOE promoter, susceptible to modify the risk associated with the APOE epsilon4 allele. We characterised a G-->T mutation at -186 bp of the APOE gene TATA box, named Th1/E47cs. This new polymorphism is located in a consensus sequence of a potential transcriptional (Th1/E47) factor binding site. We studied the impact of this new polymorphism with those of other markers of the APOE locus in a large case-control study and observed that Th1/E47cs modulated the influence of the APOE epsilon4 allele on the risk of Alzheimer's disease.

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PubMed1998

Pronounced impact of Th1/E47cs mutation compared with -491 AT mutation on neural APOE gene expression and risk of developing Alzheimer's disease.

Possession of the apolipoprotein E (APOE) epsilon4 allele is the most frequently associated genetic susceptibility factor for Alzheimer's disease (AD). Recently, new polymorphisms in the regulatory region of the APOE gene have been described. We analysed the effects of three of these mutations (-491 AT, -427 CT and Th1/E47cs) on disease risk in a large case-control study, and tested their impacts on APOE allelic expression in brain tissues. The Th1/E47cs T allele was associated with an increased risk of occurrence of AD, while the -491 T allele was associated with a decreased risk, independently of the APOE epsilon2/epsilon3/epsilon4 polymorphism effect. However, the impact of the Th1/E47cs mutation was the strongest. The -427 CT polymorphism was not associated with the disease. In AD subjects heterozygous for the epsilon4 allele, analysis of allelic expression showed that the relative expression levels of the epsilon4 allele were higher than those of the corresponding controls. Consistent with epidemiological data, the relative level of expression of the epsilon4 allele was modified accordingly to the presence or absence of the two main promoter polymorphisms, indicating, in vivo, the deleterious effect of the Th1/E47cs T allele and the protective effect of the -491 T allele in population. These data indicate that in addition to the qualitative effect of the APOE epsilon2/epsilon3/epsilon4 polymorphisms on the AD occurrence, the quantitative variation of expression of these alleles due to functional APOE promoter mutations, is a key determinant of AD development.

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