The Scenario:

A German psychiatrist, Alois Alzheimer, had a patient in her fifties with accelerating memory, language, and behavior problems. (1a)

The Discovery:

After her death, Alzheimer discovered an 'unusual disease of the cerebral cortex', various abnormalities of the brain and the cerebral cortex was thinner than normal. Also, there were signs of the amyloid plaque and neurofibrillary tangles. (1b)

Amyloid Plaque

Neurofibrillary Tangle

These two images show what Alzheimer found within his patient's brain. They are formed due to some malfunction between neurons in the brain. Take a look at the diagram below.

Alois Alzheimer

Born in 1864 in Markbreit in Bavaria, Southern Germany, Alzheimer studied medicine in Berlin, Aschaffenburg Tubingen and Wurzburg where he graduated with a medical degree in 1887. (1a)

The Importance of Brain Neurons:

This picture shows the effects of an amyloid plaque as it penetrates and disrupts neurons. When this happens, it causes the victim to lose his or her ability to function correctly.
Remember that the brain is very delicate and any alternations to it will leave permanent damages! Also, every brain neuron is needed for the brain to function right. They are the 'highway' for information to travel.
As the neurons lose its connections with one another, it will shrivel up (tangle) and eventually die out.

Video Clip:Understanding Alzheimer's Disease

Dementia: a usually progressive condition (as Alzheimer's disease) marked by deteriorated cognitive functioning often with emotional apathy. (1c)

NOTE: "Stephen D. Silberstein, MD, is a board-certified neurologist. He is Professor of Neurology and Director of the Jefferson Headache Center at Thomas Jefferson University. He is a Fellow of the American College of Physicians (ACP) and the American Headache Society (AHS), and the American Academy of Neurology (AAN)." (1d)