Image copyright Science Photo Library Image caption The accumulation of the protein alpha-synuclein (shown in red) is thought to cause the progressive degeneration of the neurons that leads to the symptoms of Parkinson's disease

A test of how sticky a protein molecule is could help diagnose the early stages of Parkinson's disease, a study from the University of Edinburgh suggests.

Scientists said early work on a small number of samples proved very accurate.

Sticky clumps of the molecule are found in the brain cells of people with Parkinson's - and in those of some dementia sufferers.

A Parkinson's disease charity said the results were "hugely promising" but larger studies were now needed.

The study is published in the journal Annals of Clinical and Translational Neurology.

Using samples of spinal fluid from 38 patients, researchers looked for a protein molecule called alpha-synuclein using a highly-sensitive technique.

The molecule is found in healthy brains but it is only when the protein sticks together in lumps that it causes problems, making brain cells die or stopping them performing properly.

These sticky clumps are called Lewy bodies and are found in the brains of those with Parkinson's and those of some dementia patients.

In their tests, the Edinburgh researchers correctly identified 19 out of 20 samples from patients with Parkinson's and three samples from people who were thought to be at risk of the condition.

Healthy samples from 15 people were also correctly identified.

Image copyright Dr Tilo Kunath MRC Centre Regenerative Medicine

What is Parkinson's disease?

Parkinson's disease is a progressive brain condition caused by the loss of nerve cells

Its symptoms include tremors, muscular rigidity, poor balance and depression

It is not known what causes the condition and there is currently no accurate test for it

As a result, patients often have to wait years for a diagnosis, which is based on physical symptoms, medical history and simple mental and physical tests

Dr Alison Green, from the University of Edinburgh, said the technique had already been used successfully to test for Creutzfeld Jacob Disease (CJD), another degenerative brain condition.

"We hope that with further refinement, our approach will help to improve diagnosis for Parkinson's patients," she said.

She said scientists were interested in whether it could be used to identify people with Parkinson's, or those with a type of dementia caused by Lewy bodies, in the early stages of their illness.

"These people could then be given the opportunity to take part in trials of new medicines that may slow, or stop, the progression of the disease," she said.

She said the technique was not able to pick up other types of dementia such as Alzheimer's disease.

Dr Beckie Port, senior research communications officer at Parkinson's UK, said there was an urgent need for a simple and accurate test, and she called the research "hugely promising".

"Further research is needed to test more samples to see if the results continue to hold true, but this could be a significant development towards a future early diagnostic test for Parkinson's," she said.