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One of the most painful aspects
of the disease is that the person sometimes will not recognize friends
or family members. Personality changes can occur, such as unusual agitation,
paranoia, depression, and social withdrawal. Later, people with AD may
wander, or be unable to find their way home. New research, however, has
shown that a part of the brain that processes visual and spatial information
may be damaged in people with AD. This may account for the problems AD
patients have with orienting themselves.) Patients may also become inattentive,
thus unable to care for their day-to-day bodily needs. Other parts of
the brain including the basal forebrain and hippocampus, areas important
for memory, are also affected by AD. Many AD sufferers die from other
causes such as pneumonia. From the time of diagnosis, AD patients generally
live 6-8 years, although many live for as long as 20 year after the diagnosis.
The symptoms of AD vary tremendously
from person to person, but in time, each person who has AD will experience
worsening symptoms. Many of the behavioral changes associated with AD
- depression, paranoia, and delusions - can be helped with medication.
However, there is no cure for AD, although some treatments hold promise.
Areas of the brain
affected by AD
A = Cerebral Cortex
B = Basal Forebrain
C = Hippocampus
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The microscopic
changes that occur in the brain of a person with AD were first noted
by German neurologist Alois Alzheimer in 1906. He performed an
autopsy on a woman who had become more and more confused in the years
preceding her death. He called the changes he observed in her brain
plaques
and tangles. These features can only be seen
upon autopsy. Tangles and plaques interfere with neuronal functions,
such as communicating with each other and sending messages to other
parts of the body.
It is unclear how
neurofibrillary tangles (NFT) form. NFTs are found inside of the neuron:
the neurons themselves become deformed and clump together. NFTs have
been described as looking like a rope tied in knots. A protein named
tau has
been shown to be involved in forming NFTs, but more research is needed
to solve the mystery of how and why NFTs form, and how exactly they
affect the brain.
Only
two drugs for treating AD have been approved by the US Food and Drug
Administration (FDA): Cognex and Aricept. These drugs are cholinesterase
inhibitors (generic names tacrine and donepezil, respectively).
These drugs inhibit the breakdown of acetylcholine by blocking the action
of cholinesterase, the key enzyme in the breakdown of acetylcholine.
Both drugs increase the level of the acetylcholine in the brain. Both
drugs also slow memory loss and help the person perform daily tasks.
It is important to note that these drugs are not a cure, they only lessen
the symptoms of AD.
First
and foremost, the chance of developing AD increases with age. With each
additional year of life, there is increased likelihood that one will
display symptoms of AD. Alzheimer's disease affects men and women about
equally, and strikes all ethnic groups.
As you age, some
connections in your brain may fail due to tangles or plaques, so it
makes sense that the more neural connections you have overall, the more
you will be able to compensate for the damaged connections. It's like
a sports team. If one player gets injured and there is a qualified player
on the bench who can substitute, the team will still function well.
The more players available to play for injured team members, the better
the team will fare.
Some brain disorders
which cause symptoms similar to AD are caused by slow viruses. However,
no one has identified a virus specific for AD.