Alzheimer's disease is a chronic neurodegenerative disease that is often related to old age.
Alzheimer's disease was first diagnosed by German psychiatrist and pathologist Alois Alzheimer in 1906. He extensively studied the loss of cognitive functions that one his patients, Auguste Deter, then age 54, was undergoing. Until then, her clinical phenotype was simply known as "presenile dementia". After Deter passed away, he prepared and observed histological samples of her brain, discovering what is until today considered as the cause of the condition. Without using the microscope however, the severe atrophy that her brain had undergone was easily noticeable.
- Senile plaques, extraneural deposits of beta-amyloid peptide.
- Intraneuronal accumulation of tau protein, as a result of hyperphosphorylation.