|What is the
Cause of Parkinson's disease?
"I need to know
where the disease is coming from and what causes it - why me?"
- Parkinson's disease primarily affects the part
of the brain that is responsible for the control of movement. The small part
that is damaged (degenerates) is called the substantia nigra, located deep
at the base of the brain. As PD progresses, other areas of the brain also
- The pigmented nerve cells in the substatia
nigra manufacture dopamine, that functions as a chemical messenger, or
'neurotransmitter'. Dopamine is responsible for helping to send messages
between cells within the brain that normally ensures smooth, controlled body
- The low dopamine levels in PD result in the
typical symptoms of slowness of movement, muscular stiffness, tremor and
poor balance. Everyday movements like walking, getting up from a chair,
writing and doing up buttons becomes more difficult.
- Normal ageing reduces dopamine production, but
the reduction in dopamine levels is much more marked in PD. Over 80 per cent
of dopamine production has to be lost before symptoms and signs of PD begin
to show. Old age alone is not sufficient to cause PD.
- Despite much research, no one knows what
causes the brain damage that results in PD. Genetic factors play a role and
unidentified environmental toxins may be important. It is most likely that
PD is caused by a combination of several interacting factors that exacerbate
the slow age-related degeneration in dopamine production.
- PD is not caused by infection, poor
diet, or by stress or anxiety.
- Some people may have many of the features of
Parkinson's disease, but the cause is another medical condition. This is
termed 'Parkinsonism'. Stroke disease, dementia with Lewy bodies and the
side effects of some drugs are common causes.
- There are also some less common neurological
conditions that may mimic PD, but have additional signs and symptoms and so
are called 'Parkinson's Plus Syndromes'. These include Multiple System
Atrophy (MSA) and Progressive Supranuclear Palsy (PSP).
- Overall, PD is one of the most common
disabling neurological conditions in older people, though it can also
develop in younger adults. About one person in a hundred aged over 65 will
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