Parkinson’s disease could be diagnosed via skin samples, research suggests.
No tests definitively show a patient has the brain disorder, with doctors assessing individuals based on their symptoms and medical history.
While Parkinson’s is incurable, treatments can help to relieve a patient’s discomfort and improve their quality of life.
These are most effective during the early stages of the disease, however, a lack of a test means many Parkinson’s cases are missed.
Misfolding of the protein alpha-synuclein has long been linked to Parkinson’s onset. With previous research suggesting the protein is also in skin tissue, scientists from Iowa State University took samples from 50 individuals, half of whom had the disease.
Testing for alpha-synuclein, the team correctly identified 24 out of the 25 Parkinson’s patients.
“Since there’s no easy and reliable test available for the early diagnosis of Parkinson’s disease at present, we think there will be a lot interest in the potential use of skin samples for diagnosis,” said lead author Professor Anumantha Kanthasamy.
More than 145,000 people over 20 in the UK are thought to have been living with Parkinson’s in 2018. In the US, nearly 1 million people have the disease.
To help improve diagnoses, the Iowa scientists analysed 50 skin samples from anonymous donors of the Arizona Study of Aging and Neurodegenerative Disorders.
Half of the samples came from Parkinson’s patients, while the remaining half were donated by people without any brain disorder.
Misfolded alpha-synuclein proteins are known to accumulate in a Parkinson’s patient’s brain. They have also been detected in other organs, like skin.
The scientists ran the samples through a test that was originally developed to detect mad cow disease.
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Results, published in the journal Movement Disorders, revealed testing for alpha-synuclein identified 24 out of the 25 Parkinson’s patients.
Just one of the 25 controls was incorrectly flagged as potentially having the disease.
“These results indicate tremendously high sensitivity and specificity which is critical for a diagnostic test,” said co-author Dr Charles Adler, from the Mayo Clinic Arizona.
As well as helping an individual be diagnosed, identifying a Parkinson’s patient during the early stage of their disease may enable them to take part in clinical trials, helping scientists to better understand the condition.
“The clinical diagnostic accuracy for early-stage Parkinson’s has been quite poor, only around 50-70%,” said co-author Dr Thomas Beach from the Banner Sun Health Research Institute, Arizona.
“Since clinical trials really need to be done at an early stage to avoid further brain damage, they have been critically hampered because they have been including large percentages of people who may not actually have the disease.
“Improving clinical diagnostic accuracy is, in my view, the very first thing we need to do in order to find new useful treatments for Parkinson’s.”
An existing patient may be offered a supportive treatment, like physiotherapy. They could also be prescribed medication to ease tremors and other movement issues. If these fail to help, a type of surgery called deep brain stimulation may be carried out.
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