Causes and Development ALZHEIMER’S DISEASE Causes and Development Lesson Content 0% Complete 0/4 Steps Alzheimer’s disease is thought to be caused by the abnormal buildup of proteins in and around brain cells. Amyloid plaques are deposits outside the brain cells — they prevent the brain from passing signals properly. Neurofibrillary tangles are deposits inside the brain cells — they kill the cells by blocking off food and energy, causing dementia that worsens over time. Neuronal death causes shrinking in the outer layer of the brain (the cortex) which is vital to memory, language and judgment — Alzheimer’s disease is characterized by this shrinkage. Previous Lesson Back to Course Next Lesson