Diagnóstico laboratorial da doença de Alzheimer e seu registro histórico

Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by dementia, clinically represented by loss of recent memory, interfering with the individual's cognition and daily activities. Since its discovery in 1906 by Alöis Alzheimer, its diagnosis has remained directed towards clinical manifestations, however, today, it is increased by assessments and interactions with other diseases, environmental, biochemical, genetic and epigenetic interferences. The identification of AD is performed by detecting accumulations of β amyloid plaques and intraneuronal deposits of neurofibrillary tangles, which are composed of hyperphosphorylated Tau protein aggregates, which cluster in the neuronal cytoplasm, destabilizing the microtubules and axonal transport. As a consequence, they can cause oxidative stress and fissures in the blood-brain barrier, developing cerebral inflammatory process, justifying neurodegeneration. In view of these facts, laboratory diagnostic criteria are important for early identification of the disease, enabling the minimization of its effects. Believing in this proposal, this study is developed with the analysis of the diverse sources of diagnosis of AD and the historical exposure of its events, through a narrative review involving exploratory research with a qualitative approach of sources of bibliographic and electronic information. Several areas of Health Sciences are found as sources of AD diagnosis, but first one of the most evident aspects is the clinical evaluation, as it is an analysis of exclusion of other dementia conditions. Structural and functional neuroimaging tests, such as computed tomography and magnetic resonance imaging, are also requested in the primary investigation, added later by the standard electroencephalogram and the quantitative exam. Tests linked to the gene part PSEN1 and PSEN2, and the ε4 allele of apolipoprotein E, are performed as alternative sources of diagnosis. The definitive evaluation of AD is obtained by anatomopathological examinations by necropsy or biopsy, being difficult to obtain or impracticable, except for a method that is little used due to ethical and cultural aspects. The diagnostic evolution of AD portrays a series of studies from different areas of study, revealing its importance in the family context in a marked and expressive way.