Parkinson’s disease - a common
challenge in elderly people
Parkinson's disease is a progressive neurodegenerative disorder named after British doctor James Parkinson
where 75% of dopamine producing brain cells in substantia nigra part of brain is damaged and they cannot produce enough dopamine. Dopamine (C8H11NO2) is a
neurotransmitter that regulates movement and emotional responses. So, lower
dopamine results in the motor symptoms of Parkinson’s disease, such as movement
problem, postural instability, tremor, rigidity, and walking problem. Non-motor
symptoms include sleep disorder/insomnia, mental/mood disorders, orthostatic
hypotension and hallucination/psychosis. Parkinson’s patients also have lewy
bodies i.e. abnormally accumulated proteins (mainly alpha synuclein) inside
their neuron cells.
Parkinson’s is of 3 types: primary or idiopathic (80%)
which has no known cause, secondary
which is from exposure to external/environmental toxins such as pesticides,
fungicides (maneb), herbicides (paraquat), insecticides (such as permethrin and
beta HCH), heavy metals etc., and genetic (15%) which is genetically
transferred. The most common genes involved are PARK2 (parkin), LRRK2 (leucine
rich repeat kinase 2) and GBA (glucocerebrosidase) [1]. Mutations in any of
these genes result in Parkinson’s. Recent research describes neuroepigenetics
or epigenetic modifications in brain to explain the unexplained detail of
Parkinson’s [2]. Another recent research in University of Copenhagen, Denmark,
describes IFNβ gene may play a role in Parkinson’s [3]. A research study from
National Center for Biological Sciences, Bangalore, found that Calcium can
regulate the Dopamine level in brain cells [4].
Currently
there is no permanent cure for Parkinson’s. Medications, exercise/physical
therapy and neurosurgery such as deep brain stimulation (when medications can’t
control the symptoms) can control the symptoms to some extent. The common
medication includes carbidopa-levedopa (Rytary, Sinemet), dopamine agonists (that
mimic dopamine effects in brain) such as pramipixole (mirapex) and ropinirole
(Requip), MAO-B (monoamine oxidase B) inhibitors (that prevent dopamine
breakdown) such as selegiline ( Eldepryl) and rasagiline (Azilect). In 2015 FDA approved carbidopa-levedopa
infusion drug Duopa that delivers in gel form directly to small intestine for
patients with more advanced stage of Parkinson’s.
References
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