Relationship between clinical stages and distribution of neurofibrillary tangles in Alzheimer’s disease

Abstract

Introduction. Clinical signs can suggest the diagnosis of Alzheimer’s disease and can help in choosing the tactics of later diagnosis and treatment, usually it can be rendered with a degree of probability, because the definitive diagnosis is established by post-mortem cerebral biopsy. Aim of the study. In this paper, we aim to analyze the literature and to make a synthesis of the clinical signs and distribution of neurofibrillary tangles which can provide data about the severity of the Alzheimer’s disease. The main purpose is to identify the clinical signs in each microscopic stages of Alzheimer disease. Materials and methods. Literature sources were accessed via Sciencedirect by a search on the terms “Stageing of Alzheimer” and “Neurofibrillary tangles”. Results. The literature study has identified 3 clinical stages and 6 microscopic stages, which were combined for practical reasons, these stages are: (transentorhinal 1 and 2), (limbic 3 and 4) (isocortical 5 and 6). Transentorhinal stage represents the preclinical phase of disease, Limbic stage the incipient phase, and Isocortical stage, the presence of dementia. Conclusions. Each clinical stage of Alzheimer's disease has its microscopic equivalent, therefore, in establishing the presumptive diagnosis of Alzheimer's disease using the NINCDSADRDA criteria, the clinician may assume the degree of distribution of neurofibrillary tangles and affected areas, which will dictate the diagnostic, treatment and prognostic approach.