PET Neuroimaging in Dementia Conditions

Abstract

In neurodegenerative diseases, several studies have increasingly highlighted that the same neuropathology can trigger different clinical phenotypes or, vice versa, that similar clinical phenotypes can be triggered by different underlying neuropathologies. This evidence called for the adoption of a pathology spectrum-based approach. Conditions belonging to the same or different spectrum of diseases share brain deposition of abnormal protein aggregates, which lead to aberrant biochemical, metabolic, functional and structural changes. Positron emission tomography (PET) is a well-recognized and unique tool for the in vivo assessment of brain metabolism, molecular changes and protein load, and novel PET techniques are emerging for the study of specific protein alterations. The availability of PET neuroimaging tools for the assessment of brain function, molecular biology and neuropathology has opened new venues in research, in diagnostic design and in the conduction of new clinical trials. Appropriate use of PET tools is crucial in supporting a prompt diagnosis and in evaluating drug targets aiming to slow down or prevent dementia. This chapter critically reviews the role of distinct PET molecular tracers (i.e. neurodegeneration, amyloid, tau and neuroinflammation) in different neurodegenerative spectrum of diseases, highlighting their strengths and weaknesses, with special emphasis on methodological challenges and future applications.