A breath test to detect early stage Parkinson’s disease



Parkinson’s disease affects 7-10 million people worldwide each year and is the second, most common cause of age-related neurodegenerative disorders after Alzheimer’s disease.  The symptoms include tremors, loss of smell and neuropsychiatric problems. By the time most people experience symptoms, they have already lost many of the dopamine-producing neurons affected by the disease. Thus, diagnosing it earlier, say at a routine doctor’s visit could increase the treatment options available and help the patients begin neuroprotective therapy sooner.

A new study published in ACS Chemical Neuroscience show that researchers have tested a sensor to detect that could early-stage Parkinson’s disease from the breath of patients.  

A device previously developed by John P.M. Finberg, Hossam Haick and their colleagues could detect differences in the exhaled breath of people already being treated for Parkinson’s disease and the healthy controls. For detecting this, they developed an array of 40 sensors based on gold nanoparticles or single-walled carbon nanotubes, with each sensor being attached to a different chemical that could in turn bind to certain volatile molecules in the breath. This binding changed the electrical resistance of the sensor, thereby yielding a measurement.

As an extension of this research, they wanted to see if the device could detect differences in the breath of patients with early-stage, not-yet-treated Parkinson’s disease.

The researchers tested the device on the exhaled breath of 29 newly diagnosed patients who had not yet begun taking medication for their illness. When comparing the sensor output to that of 19 control subjects of similar age, they found that the array detected early Parkinson’s disease with 79 percent sensitivity, 84 percent specificity and 81 percent accuracy, which was better than a diagnostic smell test and almost as good as an ultrasound scan of the brain.

Although the device needs to be improved and validated by larger studies, the researchers say that it has potential as a small, portable system to screen at-risk individuals without the need for highly trained specialists.