Integrating cerebrospinal fluid and [18F]-fluorodeoxyglucose positron emission tomography to diagnose Alzheimer's disease and research its pathophysiological substrates

Revealing the complex interactions and assessing potential integration between biomarkers is essential, especially in the early stages of AD, when biomarker alterations may serve to stage patients throughout the disease spectrum, improve phenotyping, and indicate the likelihood of progression to dementia. In this research, the integration of [18F]-FDG-PET and CSF biomarkers, two of the most used biomarkers in centers focused on neurocognitive disorders, enabled us to collect evidence on their analytical and diagnostic performance when used in a step-wise fashion. As part of the ongoing endeavor to create a common diagnostic chart for the precise and cost-effective use of biomarkers in neurocognitive diseases with neurodegenerative origin, these data gain further significance. Additionally, by combining semiquantitative [18F]-FDG-PET and CSF data, we were able to identify precise topographic correlations between metabolic values and CSF proteins that indicated distinct underlying disease processes. These findings add to the knowledge regarding the distribution of hypometabolism linked to neuronal loss, which is distinct from metabolic changes reflecting synaptic or axonal injury, and provide an indirect insight of the pathological processes taking place at various times in different parts of the brain. These results will be expanded into bigger cohorts in future research, which will also integrate additional newly discovered synaptopathy-expressing proteins for diagnostic and prognostic purposes.