Alzheimer's Disease

What Is Alzheimer's Disease?

Alzheimer's disease is a progressive, neurodegenerative disease that occurs when nerve cells in the brain die. There are different variants of Alzheimer's disease and each has slightly different presenting symptoms. The more common Alzheimer's disease symptoms that are seen include:

Early symptoms

• Impaired memory
• Problems with navigation
• Word-finding problems
• Depression

Later symptoms

• Impaired thinking, and behavior
• Confusion
• Restlessness
• Personality and behavior changes
• Impaired judgment
• Impaired communication
• Inability to follow directions
• Language deterioration
• Impaired thought processes that involve visual and spatial awareness
• Emotional apathy

With Alzheimer's disease, motor function is often preserved.

How is Alzheimer's different from other forms of dementia?

Alzheimer's disease is distinguished from other forms of dementia by characteristic changes in the brain that are visible only upon microscopic examination during autopsy. Brains affected by Alzheimer's disease must show the presence of the following:

• Fiber tangles within nerve cells (neurofibrillary tangles)
• Clusters of degenerating nerve endings (neuritic plaques)
  

Another characteristic of Alzheimer's disease is the reduced production of certain brain chemicals necessary for communication between nerve cells, especially acetylcholine, as well as norepinephrine, serotonin, and somatostatin.