Today, levodopa remains the most effective and widely prescribed pharmacological treatment for the disease.It is often coupled with certain enzyme inhibitors, such as carbidopa (that stop the breakdown of levodopa prior to entering the brain), allowing more of it into the brain and increasing the amount of dopamine produced.
Given the prevalence of the disease is estimated to double by 2030, the search for a cure is critical.
2017 marks the 200th anniversary since the 1817 publication of Dr James Parkinson’s seminal work, An Essay on the Shaking Palsy – the first complete medical description of the disease.
Other early drug treatments included derivatives of ergot, a fungus that affects rye.
Today we know these mimick the effects of dopamine in the brain and many of the modern dopamine-mimicking Parkinson’s drugs are based on these compounds.
But it wasn’t until the discovery of dopamine’s role in the disease in the 1960s that drug therapy made significant progress.
Before that, there was Parkinson’s technique (described above), as well as some other dubious methods recommended by French neurologist Jean-Martin Charcot in the later 19th century.
In 1960, Herbert Ehringer and Oleh Hornykiewicz discovered that dopamine was depleted in the brain of those with the disease.
Dopamine itself is not able to cross the blood-brain barrier – a protective barrier that stops pathogens and other larger molecules from entering the brain through the blood.
Parkinson’s disease is the second most common neurodegenerative disease after dementia, affecting more than ten million people worldwide.
In Australia alone, more than 70,000 people have the disease – that’s one in every 340 Australians.