Alzheimer's Disease

Alzheimer

Alzheimer’s disease is a brain disorder named for German physician Alois Alzheimer who first described it in 1906. Scientists have learned a great deal about Alzheimer’s disease in the century since Dr. Alzheimer first drew attention to it. Today we know that Alzheimer’s:

• Is a progressive and fatal brain disease. More than 5 million Americans now have Alzheimer’s disease. Alzheimer's destroys brain cells, causing problems with memory, thinking and behavior severe enough to affect work, lifelong hobbies or social life. Alzheimer’s gets worse over time, and it is fatal. Today it is the seventh-leading cause of death in the United States.

• Is the most common form of dementia, a general term for the loss of memory and other intellectual abilities serious enough to interfere with daily life. Vascular dementia, another common type of dementia, is caused by reduced blood flow to parts of the brain. In mixed dementia, Alzheimer’s and vascular dementia occur together.

• Has no current cure. But treatments with symptoms, combined with the right services and support, can make life better for the millions of Americans living with Alzheimer’s. We’ve learned most of what we know about Alzheimer’s in the last 15 years. There is an accelerating worldwide effort under way to find better ways to treat the disease, delay its onset, or prevent it from developing.

Just like the rest of our bodies, our brains change as we age. Most of us notice some slowed thinking and occasional problems remembering certain things. However, serious memory loss, confusion and other major changes in the way our minds work are not a normal part of aging. They may be a sign that brain cells are failing.

The brain has 100 billion nerve cells (neurons). Each nerve cell communicates with many others to form networks. Nerve cell networks have special jobs. Some are involved in thinking, learning and remembering. Others help us see, hear and smell. Still others tell our muscles when to move.

To do their work, brain cells operate like tiny factories. They take in supplies, generate energy, construct equipment and get rid of waste. Cells also process and store information. Keeping everything running requires coordination as well as large amounts of fuel and oxygen.

In Alzheimer’s disease, parts of the cell’s factory stop running well. Scientists are not sure exactly where the trouble starts. But just like a real factory, backups and breakdowns in one system cause problems in other areas. As damage spreads, cells lose their ability to do their jobs well. Eventually, they die.

Two abnormal structures called plaques and tangles are prime suspects in damaging and killing nerve cells. Plaques and tangles were among the abnormalities that Dr. Alois Alzheimer saw in the brain of Auguste D., although he called them different names.

• Plaques build up between nerve cells. They contain deposits of a protein fragment called beta-amyloid (BAY-tuh AM-uh-loyd). Tangles are twisted fibers of another protein called tau (rhymes with “wow”).

• Tangles form inside dying cells. Though most people develop some plaques and tangles as they age, those with Alzheimer’s tend to develop far more. The plaques and tangles tend to form in a predictable pattern, beginning in areas important in learning and memory and then spreading to other regions.

Scientists