Piotr Lewczuk
Neurochemical Dementia Diagnostics (NDD) is a routine diagnostic tool in the evaluation of patients with cognitive impairments, such as those with Alzheimer?s disease (AD). Currently, two groups of biomarkers analyzed in the cerebrospinal fluid (CSF) are taken into consideration: amyloid ? (A?) peptides and Tau proteins, along with the hyperphosphorylated forms of the latter (pTau). The analyses of these two groups of biomarkers can reveal pathologic alterations as early as twenty years before the onset of the clinical symptoms. In mild cognitive impairment (MCI), NDD can reliably predict which persons are at risk to convert to AD. The role of biomarkers of amyloid ? deposition in the brain tissue (including the CSF concentrations of A?42), as well as the biomarkers of neurodegeneration (including the CSF concentrations of Tau/pTau proteins), is reflected in the currently proposed diagnostic criteria for AD and MCI. Current further directions in the development of NDD include: (a) search for novel biomarkers with improved analytical or diagnostic performance, (b) optimization of the analysis of the biomarkers already available (for example, by improved quality control and inter-laboratory comparison of results), (c) applications of novel technologies enabling better management of patients samples, for example, application of multiplexing technologies, and (d) search for biomarkers in the blood. Neurochemical biomarkers for diagnosing dementias principally rely on the soluble correlates of well-known neuropathological features that characterize the underlying neurodegenerative diseases. This provides the unique chance to detect and track the disease even though clinical signs may not be observed. The probable diagnosis of neurodegenerative disorders is mainly based on clinical criteria, while definite diagnosis can only be made by neuropathological examination. Misdiagnosis is a frequent problem of clinical dementia diagnostics during the patient’s lifetime; consequently, neurochemical biomarkers for diagnosing dementias have gained enormous importance within the last decade.
