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> > Dementia
Types of Dementia
Dementia is a general term used to describe the loss of the
ability to think, reason and remember. It is not a disease
itself, but rather a group of symptoms which accompanies certain
diseases. Most dementias are progressive, eventually becoming
severe enough to interfere with work performance, social activities
and daily functioning. They are caused by some underlying
neurodegenerative change affecting the brain (see below).
For some people, dementia can be inherited or familial.
Is there help
if I have this condition? There is a voluntary
organisation which provides information and helps individuals
and families affected by all types of dementia -
Alzheimer's
Australia
PO Box 108
Higgins ACT 2615
phone +61 (2) 6254
4233
www.alzheimers.org.au
Alzheimer’s
disease
Alzheimer’s disease is the most common form of dementia,
caused by specific brain changes for which there is no known
cure. The brain abnormally accumulates a protein called beta-amyloid
destroying the delicate connections between cells, and another
protein called tau which disrupts normal cellular activity.
These changes cause a curious inflammatory reaction in the
brain. We are studying the interactions between these processes
to determine the best targets for treatment.
The clinical symptoms of Alzheimer’s disease include
forgetfulness (recent events, activities or names) and difficulties
with simple maths and other activities. During life, diagnosis
can not be certain. Definite diagnosis occurs only at
brain
autopsy. We are working on determining better ways to diagnose
people for targeted treatments.
Frontotemporal
dementia
Frontotemporal dementia is a degenerative condition which
predominantly affects the front part of the brain (previously
known as Pick’s disease or frontal lobe dementia). Unlike
other neurodegenerative conditions, people with frontotemporal
dementia can have a variety of underlying cellular changes
in this part of the brain. We are working on understanding
why some people get one type of dementia rather than another,
and whether the type of cellular change matters for treatment.
The clinical symptoms of this pattern of cellular changes
include dramatic changes in personality, behaviour and some
thought processes. Diagnosis can be more certain during life
with brain imaging, although definite diagnosis of the cellular
abnormalities occurs only at
brain autopsy. We are working
on better ways to diagnose people with the different cellular
causes of this disease.
Dementia with
Lewy Bodies
Dementia with Lewy bodies is the second most frequent cause
of dementia, which, like Alzheimer’s disease, is caused
by specific brain changes for which there is no known treatment.
Some of the nerve cells of the brain abnormally accumulate
a protein called alpha-synuclein in structures called Lewy
bodies. We are working on determining the toxicity of this
problem and its role in the disease.
The clinical symptoms of these changes overlap with those
of Alzheimer’s disease making the condition difficult
to identify with certainty in life. Many patients may have
additional early features including visual hallucinations,
fluctuations in consciousness, and difficulties with moving.
Definite diagnosis occurs only at autopsy. We are working
on developing a way of scanning the brain to better diagnose
this type of dementia in life. This will help identify people
for targeted treatments.
Vascular dementia
The other major type of dementia is vascular dementia in
which the blood vessels in the brain change or become diseased.
This may have a significant impact on the cells of the brain
and cause similar clinical features to the neurodegenerative
diseases described above.
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