Parkinson's protein test could lead to earlier and better diagnosis

The test works by looking at alpha-synuclein, a protein that changes shape and clumps together in the condition.

Diagnosing Parkinson's

Currently, people with Parkinson's are diagnosed by a specialist based on symptoms such as tremor, slowness, stiffness and balance issues. 

However, Parkinson's symptoms vary widely from person to person and can be similar to other conditions, especially in the early stages. This means it can take time to rule out other conditions, and many experience delays before receiving a diagnosis, or are misdiagnosed.

A test looking at alpha-synuclein

In the brain cells of people with Parkinson's, the alpha-synuclein protein changes shape and forms toxic clumps known as Lewy bodies. Detecting these changes could lead to a definitive diagnostic test for Parkinson's.

A team at the Oxford Parkinson's Disease Centre has developed a highly-sensitive method to measure the clumping of alpha-synuclein in cerebrospinal fluid (CSF) - a clear fluid that surrounds the brain. The test is called alpha-synuclein real-time quaking-induced conversion (αSyn-RT-QuIC).

The team used this pioneering new technique to analyse CSF samples from: 

• 74 people with Parkinson’s
• 24 people with a similar condition called multiple system atrophy (or MSA)
• 45 people with idiopathic REM sleep behaviour disorder (RBD), who have a higher than average risk of Parkinson's
• 55 people without these conditions.

What they found

The results, published in the scientific journal Brain, found the test correctly identified Parkinson's in 89% of cases. It was able to rule out Parkinson's correctly in 96% of those without the condition. Read the full research results on the Oxford Academic website.

Importantly, it was able to tell the difference between people with MSA and those with Parkinson's - which is something that can be difficult to do based on symptoms alone.

The test was also able to identify abnormal alpha-synuclein in people with RBD who later developed Parkinson's. This suggests the test might be useful for predicting the condition before symptoms appear. 

Dr Beckie Port, Research Communications Manager at Parkinson's UK, said: 

"We know that people may well have been misdiagnosed with, and treated for, another condition before receiving their correct diagnosis of Parkinson's. The months leading up to a diagnosis by a health professional can cause huge anxiety. 

"This could be a significant development towards a future early diagnostic test for Parkinson's. Such a test would enable the newly diagnosed to access vital treatment and support to manage their Parkinson's symptoms sooner.

"An early diagnostic test could also speed up research into new drugs that slow the condition, which could prevent people from ever developing symptoms associated with Parkinson's."