[The role of cholesterol in Alzheimer's neuro-pathogenesis].

Alzheimer's Disease (AD) is the most common neurodegenerative disorder in western societies affecting up to 15 million individuals worldwide.It leads to death after a progressive memory deficit and cognitive impairment accompanied by the appearance of two pathological hallmarks in specific brain areas: neurofibrillary tangles and amyloid plaques. Cholesterol homeostasis may play a key role in AD pathogenesis and this is supported by the demonstration that cholesterol-rich membrane domain, so-called Rafts,are disorganized in affected brains. Retrospective clinical studies indicate that individuals chronically treated with cholesterol synthesis inhibitors,statins, are at lower risk of developing AD but current literature is conflicting with regard to the neuroprotective effects of statins on cognitive impairment. Before recommending statins for prevention and/or treatment of AD it is important to investigate more the role of cholesterol levels in neurodegenerative disorders.