Bush T May16

Ask the Doctor
Dr Rosie Carey
Email: rosiek@absamail.co.za
de•men•tia
d ‘men(t)SH(ē)
noun: dementia
a chronic or persistent disorder of the
mental processes caused by brain disease
or injury and marked by memory disorders,
personality changes, and impaired reasoning.
It started imperceptibly. It was small things
at first: giving up on crosswords and doing
simple word-searches instead; forgetting
her favourite recipes; failing to read an easy
knitting pattern. She hid it well too, putting
her forgetfulness down to stress or anxiety.
By the time we realized that there was a
problem, my grandmother was well along the
path to full-blown dementia. Looking back
now, I realize that there was probably also
an element of denial that played a role in her
late diagnosis. None of us, her grandchildren
and children, wanted to believe that she had
dementia: not this woman who had been so
vivacious, strong-willed and independent
her whole life. But the harsh reality is that,
with the prevalence of dementia sitting at
around 14% of the population over 71 years
of age, none of us can afford to be in denial.
Dementia is going to affect most of us in
some way or another.
So, what is dementia? What causes it and
can it be treated or, even better, prevented?
The commonest form of Dementia is
Alzheimer’s Dementia (AD), accounting for 60-
80% of cases of dementia. It is characterized
by memory loss, behavioural and personality
changes and decreased cognitive function.
Less common forms of dementia include
vascular dementia, Lewy-body dementia,
HIV dementia and frontotemporal dementia.
The biggest risk factors for dementia are
age and genetics, however, there are other
modifiable risk factors such as smoking,
high blood pressure, poor diet, diabetes and
eating beef from suspect cows (having said
that, ‘mad cow disease’ is a very rare cause
of dementia!).
The pathophysiology of dementia depends
largely on the cause. With the normal aging
process, deposits of abnormal proteins
collect in the brain in very tiny amounts.
These are called plaques (made up of Betaamyloid
proteins) and tangles (made up of
Tau proteins) and are visible on scanning of
the brain. In AD, there is massively increased
deposition of plaques and tangles in the
brain. This protein deposition tends to take
place first in the area of the brain responsible
for memory, which is why memory loss is
one of the earliest signs of AD. Although we
don’t understand exactly how the plaques
and tangles cause AD, it appears that they
block communication between nerve cells
in the brain. Vascular dementia, the result
of uncontrolled hypertension, is caused by
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