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Alzheimer's attacks the
brain and destroys chemical messengers that brain cells
use to communicate with one another. A progressive,
degenerative disease, it frequently starts with trouble
remembering recent events or names of familiar people. The principle symptom is loss of recent
memory — old events are often retained in
crystal-clear detail, but today and yesterday are
obscure. While techniques have improved, no
single test yet provides a definitive diagnosis, except
for an examination of brain tissue after death.
Nevertheless, physicians trained in the latest techniques
can accurately diagnose the condition nine times out of
10 times.
Common
conditions which could also cause Memory
Impairment.
- Thyroid
Deficiency
- Anaemia
- Depression
- Tumors
- Stroke
- Nutritional
disorders
- Infectious
Diseases
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Warning
Signs for Alzheimer's
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Steps in the
diagnosis of Alzheimer's
- Detailed medical
history
- Physical exam
(including blood tests),
- Neurological exam
- Mental ability tests,
which involve performing simple mental exercises,
memorizing words and copying designs.
- Psychiatric evaluation
to check for depression.
- CT scans or MRIs are
used to rule out tumors, brain injuries and other
possible causes of symptoms. Some investigators
think they may be able to identify Alzheimer's by
using MRI scans to measure the size of structures
in the brain.
- Some use biomarkers,
measurements of biochemical substances such as
brain protein. The brain-protein test shows
promise, but it's still considered experimental
by the Alzheimer's Association.
- Testing for ApoE4, a gene linked to late-onset
Alzheimer's. This year, a major study cautioned
against using the test to predict Alzheimer's in
people who do not have symptoms. The test
identifies people who carry the high-risk gene,
but many people with the gene do not go on to
develop the disease. Thus, testing positive isn't
conclusive, but it is sure to generate worry as
well as cause potential problems.
- A new brain-imaging
techniques offer promise as a way to spot early
brain changes leading to the disease. A method
known as single photon emission computed
tomography, or SPECT, studied people
with memory problems and correctly identified 80
percent of those who went on to develop
Alzheimer's.
- CT
Scan spots Alzheimer's
Computed
Tomography scanning may provide the diagnostic
test for Alzheimer's disease. Researchers changed
the angle routinely used for head scan and
measured the width of the medial temporal
lobe directly on the CT images of 44
people subsequently shown by histoogy to have
Alzheimer's disease. The region was nearly half
the width in 75 control patients. Followup showed
that the test was positive in most patients
affected by Alzheimer's disease for at least a
year.
A step towards diagnosis
of Alzheimer's disease
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