Tangles destroy a vital cell transport system made of proteins. This electron microscope picture shows a cell with some healthy areas and other areas where tangles are forming. In healthy areas:
In areas where tangles are forming:
- The transport system is organized in orderly parallel strands somewhat like railroad tracks. Food molecules, cell parts and other key materials travel along the "tracks."
- Tau protein helps the tracks stay straight.
Progression through the brain:
- Tau collapses into twisted strands called tangles.
- The tracks can no longer stay straight. They fall apart and disintegrate.
- Nutrients and other essential supplies can no longer move through the cells, which eventually die.
- Plaques and tangles tend to spread through the cortex in a predictable pattern as Alzheimer's disease progresses.
The course of the disease depends in part on age at diagnosis and whether a person has other health conditions.
- Earliest Alzheimer's — changes may begin 20 years or more before diagnosis.
- Mild to moderate Alzheimer's stages — generally last from 2-10 years.
- Severe Alzheimer's — may last from 1-5 years.
The Alzheimer's Disease market
Alzheimer's Disease is the most common cause of dementia in older adults and affects approximately 46 million people worldwide. By mid-century, someone will develop the disease every 33 seconds. The worldwide cost of Alzheimer's Disease care is estimated to be US$818 billion and the global cost is expected to be US$2 trillion by 2030. Furthermore, the projected total number of people that will suffer from Alzheimer's Disease worldwide is anticipated to increase to 74.7 million by 2030 and 131.5 million by 2050. Remarkably, even though there is currently no approved treatment for it, there is already a global US$6 billion/year market for drugs which are used to attempt to moderate the disease. It is hard to overstate the market potential of an effective and safe Alzheimer's Disease drug.