Inverse association between CSF Aβ 42 levels and years of education in mild form of Alzheimer's disease: the cognitive reserve theory.

In Alzheimer's disease (AD), the cognitive reserve theory predicts that at any level of assessed clinical severity, the underlying brain pathology is more advanced in patients with more cognitive reserve. Recent evidences suggest that cerebrospinal fluid (CSF) biomarkers may reflect the brain pathology in AD. We investigated the relationship between education level and CSF concentrations of β-amyloid, total tau and phosphorylated tau (ptau-181) in a cohort of 70 subjects newly diagnosed with AD.

[Dysthyroidism in elderly patients. Clinical characteristics].

FROM A CLINICAL POINT OF VIEW: Diagnosis of dysthyroidism in the elderly is particularly difficult because of the lack of sensitivity and specificity of classical symptoms and examinations. Neuro-mental and cardiovascular signs are frequent: dysthyroidism should always be searched for in the presence of dementia, depressive syndrome, heart failure or tachyarrhythmia. BIOLOGICAL DATA: Simple screening must therefore be widely proposed and relies on complete thyroid stimulating hormone (TSH) assay, further completed by free thyroid hormone assay.

Dehydroepiandrosterone (DHEA) and aging.

Dehydroepiandrosterone sulfate (DHEAS) is the most abundant circulating steroid hormone in humans and can readily be converted to its parent steroid DHEA by tissue sulfatases. Yet, a biologic function for these steroids has not been defined. The link between DHEA and aging has been raised by: (1) its well documented age-related decline, and (2) a preventive effect of DHEA on numerous age-related illnesses: ischemic heart-disease, cognitive impairment, immunodeficiency, malignancies, osteoporosis.

[Actions of dehydroepiandrosterone: possible links with aging].

Dehydroepiandrosterone (DHEA) and its sulfo-conjugated derivative (SDHEA), secreted by the adrenal glands, are the most abundant circulating steroids in the human organism. The well-established fact that levels decrease progressively with age suggests a role in the aging process. They could also play a preventive role via an antitumoral action, stimulation of the immune system, an antiosteoporotic effect, a neuropsychologic action and cardiovascular protection.