**Diagnosis**

**Chapter 8**

**Pre-Analytical and Analytical Critical Factors Influencing**

**the High Variability of the Concentrations Levels of**

Armand Perret-Liaudet, Aline Dorey, Yannick Tholance, Benoit Dumont and

Additional information is available at the end of the chapter

Isabelle Quadrio

**1. Introduction**

http://dx.doi.org/10.5772/55512

**Alzheimer Disease Biomarkers in Cerebral Spinal Fluid**

Alzheimer's disease (AD) is a fatal neurodegenerative disorder characterized by a progressive neuronal death and loss of cognitive functions. AD is the most common type of dementia and its incidence rise to 10% in people aged over 90 [1]. Due to Increased longevity, it has been estimated that the number of people suffering from this neurodegenerative disorder will rise

Although clinical intervention to halt the disease is inefficient, the clinical and psychological cares are likely known to significantly improve the quality of life of the patient but also those of the family. At the prodromal stage of the disease (Mild cognitive Impairment linked to AD), there are no sufficient evidences that treating the patient improves the patient outcome. This lack of evidence poses in some cases an ethical problem that is to announce the diagnosis of AD at an autonomous patient who will shift irreversibly in the coming years to the dementia stages. However, as reported in new criteria established by the National Institute on Aging (NIA) and the Alzheimer's Association, core clinical criteria could be used by healthcare providers without access to advanced imaging techniques or cerebrospinal fluid analysis. Criteria including these last advanced tools still remain in the research field [3]. On the contrary, the diagnosis is highly aimed to be accurate at least at the clinical stage of mild dementia, to detect the AD pathology. Core clinical criteria seems to be enough to ensure the AD diagnosis and the use of biomarkers (imaging or CSF biomarkers) can only increase the certainty that the basis of the clinical dementia syndrome is the AD pathophysiological process

> © 2013 Perret-Liaudet et al.; licensee InTech. This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

> © 2013 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

and reproduction in any medium, provided the original work is properly cited.

from 26.6 million cases in 2006 to 106,8 million worldwide in 2050 [2].
