disease (AD), , is a chronic neurodegenerative disorder that usually starts
slowly and worsens over time. This is why 60% to 70% of dementia cases. The
most common early symptoms are the difficulty of remembering recent events
(short term memory loss). As the disease progresses, symptoms may include
speech impairment, disorientation (including easy getting lost), mood swings,
loss of motivation, concerns and behavioral problems. As one person’s condition
declines, they often withdraw from the family and society. Gradual loss of
physical function, eventually leading to death. Although the rate of progress
may vary, the average life expectancy after diagnosis is three to nine years.
The cause of
Alzheimer’s disease is poorly understood. About 70% of the risk is thought to
be the inheritance of many normally involved genes. Other risk factors include
history of head injury, history of depression, or history of hypertension. The
disease process is associated with plaque and tangles in the brain. One
possible diagnosis is medical imaging and blood tests based on medical history
and cognitive tests to rule out other possible causes. Initial symptoms are
often mistaken for normal aging. Brain exams need a definitive diagnosis.
Mental and physical activity Avoiding obesity may reduce the risk of AD;
however, the evidence to support these recommendations is not strong. There are
no drugs to cure.
effect on brain:
that happen in the brain start at microscopic levels before begging signs of
wrong in the brain?
has billions of neurons or cells. Each of them connects to other networks. The
brain supply and nourish cells. Some cells used in memory, thinking, seeing,
hearing, and gives order to muscles. The cells receive power and get rid of its
symptoms composed of 4 steps.
symptoms are usually wrongly regarded to growing old or tension. Neuropsychological
testing can make mild cognitive difficulties up to 8 years before a human complete
the clinical criteria for diagnosis of AD. These early signs can affect the
most difficult activities of daily life. The most easily seen disorder is short
term memory loss, which shows up as difficulty in remembering recently learned
facts and inability to acquire new information. Subtle problems with the
executive functions of attentiveness, planning, flexibility, and abstract
thinking, or impairments in semantic memory (memory of meanings, and concept
relationships) can also be symptomatic of the early stages of AD.
with AD, increased learning and low memory eventually lead to definitive
diagnosis. In a small percentage, language difficulties, executive functions,
perception or execution of actions (apraxis) are more apparent than memory
problems, and AD does not affect all memory capacities equally. old memories of
the person’s life (episodic memory), acquired knowledge (semantic memory) and
implicit memory (such as cooking, using a fork or a cup of something the body’s
memory on the way to do) less affected than new facts or memories.
problems are often characterized by a decrease in vocabulary and a decrease in
vocabulary, so that oral and written language is usually poverty. At this
point, a person with Alzheimer’s disease can often communicate enough basic
ideas. While performing fine motor tasks such as writing, drawing or dressing,
some difficulties of coordination and movement planning (apraxia) may exist,
but they are often noticed. As the disease progresses, people with Alzheimer’s
disease can often continue to perform many tasks independently, but may need
help or denial with the most demanding activities on the site.
impairment eventually stops deliverance, with subjects that is unable to make
common activities of daily life.
difficulty because of difficulty in recalling vocabula , That leads to
recurrent wrong words . Complicated motor series becomes low hormonions as
passed and progression as AD , so the falling risk increase .Through this phase
,problems of memory gets worse, ant the patient sometimes fails to know his
last stage, The person is fully dependent on people who give him care .
language is decreased to less phrases or small words , lastly leads to full
loss of talking .But they can recognize
emotional signals ,excessive careless and fatigue are more common signs in this
period .Patient with AD disease fails to do simple jobs alone, muscle mass
,decrease and gets unable to nourish itself. The death happens usually due to
external causes as virus or infection.
of most AD cases is yet unknown .values for 2% to 6% of the cases due to genetic
differences .many hypothesis are trying to explain the reason of AD.
heritability of genetic of AD disease, based on surveys of family and twin
studies, varies from 50% to 80% about 0.1 % cases due to familial forms of
autosomal intevituane. That happens before age of 65. AD disease is known as
premature familial disease. Many of AD disease is due to mutations In one of
the genes, which encodes presehilins 1,2 and
amyloid precursor protein .Many of mutation that happens in amyloid
precursor protein and presenilin genes rises the production of little protein
which is called AB42, which is the master ingredient of semile plaques.
ancient, in which drug therapies are based on, is cholinergic hypothesis .That
suggests that AD is due to reduction of synthesis of acetylcholine neurotransmitter
on the wide scale medications wants to cure the deficiency in acetylcholine, so
cholinergic hypothesis doesn’t get a popular support.
In the 1991,
Amyloid hypothesis presumed that the deposition of amyloid beta extracellular
is the primary cause of AD .The location of the gene of APP on chromatin 21 is
the advocacy of this assumption, together with the patients having dawn
syndrome that have additional copy as the gene special isoform of ApoE4 is the
mark risk factor of AD.
diagnosed by the history of the patient, relative history and attitude
monitoring. Progressive computed tomography with medical imaging, single-photon
emission computed tomography and magnetic resonance imaging. Is used to
eliminate any other cerebral diseases or other types of dementia.
diagnosis is proved by very high accurate post mortem when the brain substance
is found can be tested histologically.
their is no proof that any measures can prevent AD. Some epidemiological
studies assumed that their is connection
between some factors as diet, heart risk, pharmaceutical products and some
mental activities of developing AD. Only clinical trials will proof that these factors can prevent AD or not.
of medication are recently used to cure the cognitive defitsal AD. Four of them
are acetyl cholinesterase inhibitors such as 1-rivastigrine, 2-galantine,
3-donepezil,4-tacrine,and the fifth on is NMDA receptor antagonist as
memmatine. But the advantage from their use is low. Their is no recent
medication has been obviously shown a decrease in the advancement of AD. The
decreasing in the activity of the cholinergic neurons is good known
characteristic of AD. Using acetylcholine esterase inhibitors to decrease the
role that acetylcholine is broken, so increasing the concentration of
acetylcholine in brain and battling the decrease of Ach happen by the death of
cholinergic neurons. Some evidence is found on the effectiveness of the
medication on mild to moderate AD. The only medication which is approved to be
used in advanced stage is donepezil. The most muted adverse effect is vomiting
and nausea, these adverse effects emerge in 10-20% of patients using this
altrated in mental activities as reading, writing, playing musical instruments,
finishing, puzzles or sociable interactive shows a decrease in risk of AD,
Education decrease the start of AD without changing the times of AD. Also
people who learn a second language decrease the risk of getting AD. Physical
activity can reduce the starting and delay AD.
healthy food like Japanese or Mediterranean diet could decrease the risk of AD.
The Mediterranean food could mend the results to people having AD. The people
eating food rich in fats and carbohydrates have high risk of developing AD.
Their is some studies assumed that small to high consuming of red wine may
lowers the risk of AD. Other studies assumes that caffeine is protective
against AD and some with flavonoids as coca may reduce the risk of AD.
It has a
high propagation to be as high as 24 million patient globally and
prognosticated to be doubled every 20 years. There are two measures are used in
AD, which is prevalence and incidence.
are working to progress or understanding about AD. But without clinical trials
and the help volunteers we can’t do anything. Every clinical trial done donates
very important and valuable knowledge for treatment or prevention of any