Biobanks for biomarkers in neurological disorders: the Da Vinci bridge for optimal clinico-pathological connection

The diagnosis of dementing disorders is severely hampered by the absence of reliable biomarkers that can be measured in body fluids such as blood, urine and cerebro-spinal fluid (CSF). Searching for biomarkers is hampered by the huge variability between individuals; the use of autopsy specimens induces significant data fluctuation due to rapid post-mortem changes in the specimens. The search for biomarkers obtained from living donors has contributed already a vast amount of data. The role of amyloid and tau as early diagnostic markers in the pathology of dementia has been reported in differential involvement in Alzheimer's disease (AD), late onset Alzheimer disease (LOAD), Lewy Body dementia (DLBD), Vascular dementia, fronto-temporal lobar degeneration (FTLD), Mild cognitive impairment (MCI) and non neurological controls. In the coming decennia, brain/tissue/biobanks (BTB-banks) will have a major role in identifying the relevant biomarkers and will collect, preserve and type RNA and DNA extracted from brain/tissue/body fluids in order to update the pathological hallmarks of dementing disorders. The present paper reviews and compares the currently known/clinically applied biomarkers in dementia which can be identified and incorporated into clinical drug trials and elucidate proposed mechanisms of disease and drug action. Furthermore, the review screens a panel of biomarkers used for early and differential diagnosis and comments on the validity of these biomarkers in reflecting the typical hallmarks of neurological disorders.