Inflammatory risk factors and pathologies associated with Alzheimer's disease.

The importance of inflammatory processes in Alzheimer's disease (AD) progression has been confirmed during the past decade by the intensive investigation of inflammatory mediators in the brain of AD patients as well as by the genetic and drug manipulation of animal models of AD. Imaging studies have revealed that the activation of microglia occurs in early stages of the disease, even before plaque and tangle formation, and is correlated with early cognitive deficits. In this review, we analyze how different risk factors, such as trauma, stroke, infection, and metabolic diseases can lead to an acceleration of the inflammatory response in the AD brain and to an increased risk of developing this disorder. The use of imaging techniques for early detection of glial activation which offer the advantage of investigating how potential anti-inflammatory therapies may influence disease progression and levels of cognition is also discussed.