Alzheimer's Disease Causes
- The exact underlying cause of Alzheimer's disease is still being debated. However, there are two known mechanisms by which the disease manifests and progresses. In addition to that, studies carried out by the Fisher Center for Alzheimer's Research Foundation as early as 2003 have found a positive correlation between people with Alzheimer's and various risk factors. This means that certain factors increase the chances of a person developing Alzheimer's disease in their lifetime. The first is age. One out of every eight people over the age of 65 has Alzheimer's as does one out of every two people over 85. The second is genetics. People with the ApoE 4 gene have a much higher likelihood of developing Alzheimer's than those without. A second gene, simply referred to as the "deterministic gene," was found in only a few thousand people amongst upwards of a million tested throughout the world. It guarantees that the carrier will develop Alzheimer's.
- Plaques are large masses of a protein called beta-amyloid which appear in the hippocampus and cerebral cortex of all persons with Alzheimer's disease. They are found in small amounts in the brains of most elderly, but Alzheimer's sufferers have more than ten times the amount. Though what causes the build-up of plaque is undetermined as yet, it's believed that these plaques are one of two primary reasons for the death of neurons within the brain of Alzheimer's patients and the subsequent cause of memory loss, confusion, and agitation for which the disease is known.
- The other possible cause of Alzheimer's disease is the mutation of tau proteins. Normal neurons communicate with one another via long tendrils or microtubules known as axons. Sheathing the length of these axons and holding their shape is a protective layer of tau protein. The tau proteins in the brains of Alzheimer's patients undergo a change by which they distort the shape of the neurons' axons. This results in structures called tangles or neurofibrillary tangles, and it is postulated that they impede the neurons' ability to communicate with one another.