Alzheimer's Dementia and its Various Biomarker Details with Several Detection Methodologies - A Comprehensive Review

Dementia is the most critical neurodegenerative disease that gradually destroys memory and other cognitive functions. Hence early detection is utmost necessary and to build an effective detection model, its required to understand its type, symptoms, stages & causes. This review work deep dives into most critical dementia type which is still incurable i.e., “Alzheimer's” and surveyed different biomarkers (CFS, Aβ42, t-Tau, p-Tau, miRNAs, HNE, TNF, etc.) as well as diagnosis methodologies - APM, AI/ML, Deep learning & Fuzzy logic algorithms implementation based on medical images data generated using CTS, MRI, sMRI, fMRI, PET, Retinal photography (most cost effective) those were used in AD early detection. This review work summarizes various techniques mentioned in survey/articles/research papers and analyzed their accuracy, data sources, affordability, features used as well as issues. Based on this paper, new techniques may be designed. This study emphasis on the use of retinal images to build most affordable, accessible, and efficient future system on AD detection.