Voyage au bout de la nuit: Aβ and tau imaging in dementias.

The last decade has witnessed the development and characterization of tracers for the evaluation of neuropathology in vivo. The introduction of these tracers, namely β-amyloid (Aβ) and later tau, are providing the tools to change the landscape and refine our understanding of Aβ and tau deposition in the brain, allowing to investigate the causes, refine diagnosis and improve treatment of major neurodegenerative conditions such as Alzheimer's disease (AD), chronic traumatic encephalopathy (CTE) and frontotemporal lobar degeneration (FTLD). Aβ and tau imaging allow examination of the regional and global changes of these disease markers over time as well as their relationship with other relevant parameters such as cognitive performance and neurodegenerative changes. Aβ and tau imaging will enable to establish the role Aβ and tau play -and interplay- in aging and disease. Aβ and tau imaging value resides in being not only diagnostic, prognostic or progression markers, but also surrogate markers of disease, crucial for patient recruitment and efficacy evaluation of disease-specific therapies.