by: Michael Sang
Introduction to Alzheimer's
Alzheimer's disease is a progressive degenerative disease of the brain. It is first described by the German neuropathologist Alois Alzheimer (1864-1915) in 1905. This disease worsens with advancing age, although there is no evidence that it is cause by the aging process.
The average life expectancy of a person with the disease is between five and ten years, but some patients today can live up to 15 years due to improvements in care and medical treatments. The cause of Alzheimer's has not been discovered yet and it cannot be possible to confirm a person has Alzheimer's until their autopsy following death.
How does Alzheimer's develop
What causes Alzheimer's? Well no one know exactly the development of this debilitating disease. But recent advances has produced several clues as to how it is born. Initially when we study the brain of a Alzheimer's victim, we focus on two specific areas. One is the cortex of the frontal and cerebral lobes1. The second is the hippocampus (meaning seahorses in Greek which it resembles2) which is located below the cerebral cortex and responsible for short-term memory. If we study samples of these two section, we would find three irregularities which are not found in normal brain matter. These three are called neurofibrillary tangles, neuritic plagues and granulovacuolar degeneration3.
A nerve cell has numerous axons and dendrites coming out of it. A neurofibrillary tangle is when the neuron changes. A number of dendrites are missing and the nucleus is filled with protein filaments resembling steel wool. Although all elderly people has a few of these helix shaped bundles in their brain for they are normal indicators of aging, Alzheimer's patients has more than usual. Their presence usually in the frontal and temporal lobes is a indication of AD.
Senile neuritic plagues are small round objects. They are masses of amyloid protein material composed of residue left over from healthy nerve endings that were broken off and decayed. Their presence near the cell further indicates something gone wrong. Neuritic plaques is the best evidence for diagnostics to make the determination of AD.
A third sign of neuron deterioration is granulovacuolar degeneration. This is when fluid-filled vacuoles are seen crowding inside the nerve cell, specifically in the triangular shaped cells of the hippocampus. This condition can only be observed in carefully sliced, stain and analyzed brain tissue.
The cell having lost all it's dendrites and nucleus soon disintegrates entirely, vanishing into the body's waste disposal system. With the depletion of enough nerve material the brain actually shrinks, sometimes by as much as ten percent5. The more cells the AD sufferer loses, the more mental functions he loses. Soon the person will have limited motor skills. People who were once witty and quick on their feet were reduced to the mental status of small children.
Diagnosis of Alzheimer's
How would you now if a person you knew has Alzheimer's? There are certain telltale signs that point to it. There was one patient6 that was convinced she was suffering from AD. As proof of her condition, she bought the a meeting several recent newspaper clippings, which she began to quote from memory. Obviously this person did not have the disease, she wouldn't have memorized complex and lengthy information. But forgetting on a regular basis doesn't indicate Alzheimer's either.
Stages of AD
In the initial stage, there is no clear evidence of memory trouble and deterioration in brain functions. The individual performs well on exams that test mental abilities (psychometric tests7) similar to those given to measure IQ.
In the second stage, the patient shows very mild memory problems with difficulty in remembering names of friends. The changes at this point is still very small. Occasionally, the patient might make a...