Biomarkers for Alzheimer's disease and other forms of dementia: clinical needs, limitations and future aspects.

An early diagnosis of Alzheimer's disease (AD) and other types of dementia-causing disorders is vital in order to achieve effective treatments. Fortunately, in the recent years the search for specific biomarkers has undergone a rapid evolution. New technologies in proteomics and genomics have permitted great advances in defining biochemical markers in cerebrospinal fluid (CSF) and in blood. Novel imaging techniques are also improving the diagnosis and early detection of brain changes in vivo. Furthermore, combined analysis of different biomolecules, or of biochemical and neuroimaging studies, increase diagnostic sensitivity and specificity. However, the discovery of sensitive and specific biomarkers for neurodegenerative diseases needs to overcome some important challenges. With the available technology, standardization of methods is essential to reducing inconsistency and increasing reliability. Global initiatives, multicenter studies and consensus protocols of analysis are of critical importance. The present review summarizes the results achieved in the search for an early diagnosis of neurodegenerative disorders, and reflects the limitations and the perspectives of the field. Copyright 2009 Elsevier Inc. All rights reserved.