Global Health Asia-Pacific September 2020 September 2020 | Page 42

Cover Story
Are we facing a Parkinson’s pandemic?
Those afflicted could double to 12 million by 2040 due to genetic and environmental factors, though
the cause of the disease is still unknown
For most
of human
history, PD has
been a rare
disorder. But
demographic
changes and the
by-products of
industrialisation,
such as
pesticides
and heavy
metals, are now
contributing to
an impending
Parkinson’s
pandemic.
With the daily death toll still mounting from
COVID-19, it’s understandable that the
global community would be laser focused
on the threats from infectious diseases. This is natural
after all, given that they’ve been responsible for some
of the most devastating epidemics in human history
� the 191� �u, �bola, SA�S, and M��S, to name just
a few.
But what the current preoccupation with COVID-19
is making us forget is that chronic diseases, those
that can’t be transmitted from person to person, still
pose the biggest threats to human health, especially
in high-income nations. And many of these continue to
skyrocket around the world.
Data collected by the World Health Organization
(WHO) show that in 2016 six of the top seven causes
of death worldwide were all non-communicable
diseases: heart disease, stroke, chronic obstructive
pulmonary disease, Alzheimer’s, lung cancer,
and diabetes. Lower respiratory infections, a
communicable disease, was ranked fourth.
Though not in the top seven, a number of other
chronic disorders are poised to increase their
global burden in the coming years. One of these
is Parkinson’s disease (PD), the fastest growing
neurological disorder in the world.
A 201� report reminds us that the once rare
condition has now become commonplace. Indeed,
experts warn that we are on the cusp of a potential
global crisis.
For most of human history, PD has been a rare
disorder. But demographic changes and the byproducts
of industrialisation, such as pesticides and
heavy metals, are now contributing to an impending
Parkinson’s pandemic, said experts writing in the
Journal of Parkinson’s Disease.
PD is a progressive nervous system disorder
that affects movement. Symptoms start gradually,
sometimes with a barely noticeable tremor in just
one hand and can later cause stiffness or slowing of
movement. In the early stages, a patient’s face may
show little or no expression, and the arms may not
swing when walking. Speech can become soft or
slurred.
PD symptoms typically worsen over time, and,
while the disease cannot be cured, medications can
significantly improve symptoms. Occasionally, surgery
can help regulate certain regions of the brain and
improve symptoms.
In people with PD, certain nerve cells, or neurons,
in the brain gradually break down or die. Many of the
symptoms are due to a loss of neurons that produce
a chemical messenger in the brain called dopamine.
When dopamine levels decrease, it causes abnormal
brain activity, leading to symptoms of PD.
One theory posits that neurons die because they’re
unable to clear damaged cell components that start
building up.
Unfortunately, its cause is still unknown, but several
factors seem to play a role. One is genes. �esearchers
have identified specific genetic mutations that can
cause the disease, although this is still uncommon.
Abnormalities in the gene ����2, for instance, seem
to affect lysosomes, the cellular components that are
responsible for clearing waste, in a way that makes
them work ine�ciently.
�nvironmental triggers are another possible cause.
�xposure to certain toxins or environmental factors
may increase the risk of later PD. Though establishing
a clear-cut causal link isn’t feasible, both the industrial
solvent trichloroethylene and the pesticide paraquat
have been associated with the neurodegenerative
condition.
“Other factors that may lead to the disease include
family history of the disease, drinking well water, prior
head injuries, or living in the rural area,� said Dr Ooi
Phaik Yee, a consultant neurologist with Gleneagles
Hospital in �uala �umpur at a conference organised
for World Parkinson’s Day.
Neurological disorders are now the leading
cause of disability globally, and the fastest growing
neurological disorder in the world is PD. Between
1990 and 2015, the number of people with PD soared
worldwide to over six million.
Driven mostly by ageing, this number is projected
to double again to over 12 million by 2040. Other
factors, such as declining smoking rates and
increasing industrialisation, could raise the burden to
over 1� million. Smoking has been shown to lower the
risk of PD.
Based on a 2018 report by the Department of
Statistics Malaysia, the number of patients with �D
in that country is expected to increase sixfold from
the current estimated 20,000 to 120,000 by 2040,
40 SEPTEMBER-OCTOBER 2020 GlobalHealthAsiaPacific.com