Definitive confirmation of Alzheimer's disease is typically obtained through which postmortem procedure?

• A. Spinal fluid analysis
• B. Genetic testing in living patients
• C. Brain imaging to detect plaques in life
• D. Postmortem examination for amyloid plaques

Answer: (D)

Definitive confirmation comes from postmortem neuropathology, where brain tissue is examined directly for the disease’s hallmark lesions. Pathologists look for extracellular beta-amyloid plaques and intracellular neurofibrillary tangles, which together confirm Alzheimer's disease. While tests done in living patients—such as spinal fluid biomarkers or brain imaging to infer plaques, and genetic testing for risk—can strongly suggest the diagnosis, they do not provide the conclusive histopathological proof that autopsy offers. Therefore, inspecting the brain after death for amyloid plaques is the definitive confirmation.