A new test could help diagnose Parkinson's disease in its early stages

There is currently no definitive diagnostic test for Parkinson's, leading to a high rate of misdiagnosis, particularly due to overlapping symptoms with conditions such as dementia with Lewy bodies, multiple system atrophy, and pure autonomic failure.

Researchers hope to improve early diagnosis of Parkinson's disease, file photo

A simple, minimally invasive skin biopsy could help diagnose Parkinson's disease and other progressive nervous system conditions in their early stages, scientists say.

The test proposed by the researchers looks for phosphorylated alpha-synuclein (P-SYN), an abnormal protein associated with certain degenerative brain disorders. The results of the studies so far indicated that 93% of those with Parkinson's had a positive skin biopsy for P-SYN, compared to the control sample.

The findings, published in the journal Jama, give researchers hope of using biopsies for early diagnosis of Parkinson's disease and speeding up drug development, reports The Independent.

Around 10 million people suffer from Parkinson's worldwide and in the UK 153,000 people are thought to be living with the condition.

The disease is difficult to diagnose in its early stages because there is currently no test, and symptoms such as tremors, mild memory and thinking problems, and sleep problems vary from person to person and can often be confused with other diseases.

Previous research has shown that this technique is able to distinguish between Parkinson's and multiple system atrophy, offering hope for managing these diseases “which appear clinically similar but have very different prognoses.”

The study followed 428 people, aged 40 to 99, with a clinical diagnosis of Parkinson's disease, dementia with Lewy bodies, multiple system atrophy and pure autonomic failure, with three skin biopsies collected from each patient. 3 mm, through neck, knee and ankle puncture. Those with dementia with Lewy bodies and multiple system atrophy and pure autonomic failure tested 96 percent and 98 percent and 100 percent positive for the abnormal protein, the researchers said.

Lead study author Roy Freeman, director of the Center for Autonomic and Peripheral Nerve Disorders at Beth Israel Deaconess Medical Center in the US and professor of neurology at Harvard Medical School, said the team was delighted with the accuracy of this diagnostic test.

“Parkinson's disease and its subgroup of progressive neurodegenerative diseases show a gradual progression, but alpha-synuclein is present in the skin even in the earliest stages,” Roy Freeman said.

The researchers believe, however, that further research is needed to validate the results and to characterize them “potential role of skin biopsy for detection of P-SYN in clinical care”.

Commenting on the study, Dr Katherine Fletcher, Research Communications Lead at Parkinson's UK, said: “This study is one of many looking to find a simple way to more accurately and objectively identify and measure neurodegenerative conditions like Parkinson's. (…) However, the test still needs to be perfected to better understand its accuracy and sensitivity to detect the different conditions and at what stage they are”.

“Research into these types of tests is extremely important not only to improve diagnosis, but also to help accelerate the search for new and better treatments that will transform the lives of those living with Parkinson's.” Dr. Katherine Fletcher also stated.