The way you draw a spiral could reveal whether you will get Parkinson's disease.

Researchers at Rmit University in Melbourne, Australia, asked volunteers to draw a spiral on a sheet of paper.

By analyzing their speed and how hard they pressed the pen on the paper, the team could tell which volunteers had Parkinson's disease.

They could also tell how severe their diagnosis was.

The current study builds on previous research which found that Parkinson's patients tend to move their pen more slowly when sketching, and use less pressure on the page.

By analyzing how long it took them to draw the spiral and how hard they pressed on the paper with the pen, the team at Rmit University could tell how severe their diagnosis was

And yet, researchers have not yet been able to find a way to measure these factors.

In a new study, recently published in Frontiers in Neurology, a team of researchers in Australia set out to develop an automatic system to contribute to the diagnosis of Parkinson's, and to assess its severity, from the comfort of a community doctor's office.

'Our aim was to develop an affordable and automated electronic system for early-stage diagnosis of Parkinson's disease, which could be used easily by a community doctor or nursing staff,' explains Poonam Zham, a researcher involved in the study.

Parkinson's disease is a neurodegenerative disorder that causes shaking, muscle rigidity and difficulty with walking.

Many treatments for Parkinson's are only effective when doctors diagnose the disease early, and a patient's treatment options depend on their stage of the disease.

However, noticeable symptoms tend to arrive when it is already too late, and it is difficult to know how far along the patient is.

Given the physical symptoms, using a pen and paper can be a strong marker for determining their status.

But since writing words depends on language proficiency and education, the team at Rmit felt a sketch would offer a more accurate account.

The researchers developed specialized software and combined it with a tablet computer that can measure writing speed, and a pen that can measure pressure on a page.

They used the system to measure pen speed and pressure during a simple spiral sketching task in a sample of healthy volunteers and Parkinson's patients with different levels of disease severity.

In a world-first, the system also mathematically combines pen speed and pressure into one measurement, which the team calls the Composite Index of Speed and Pen-pressure (CISP) score.

The system measured slower pen speeds, pen pressures and CISP scores in the Parkinson's patients, compared with the healthy volunteers, and all three measurements clearly indicated whether a participant had Parkinson's or not.

On their own, pen speed and pressure were not sufficiently different between patients with different levels of Parkinson's severity, for the system to distinguish between them.

However, using the new CISP score, the system could tell whether the patients had level one or level three Parkinson's, using a particular disease severity scale.

'The system can automatically provide accurate Parkinson's diagnosis and could also be used by community doctors to monitor the effect of treatment on the disease,' says Zham.

'This simple device can be used by community doctors for routine screening of their patients every few years after the patients are above middle-age.'