New study results from the Technion Institute of Technology in Israel indicate that a portable breath test may have the capability to identify people with Parkinson’s disease (PD) before they know they have it or begin treatment.
A new medical device evaluates a person’s exhaled breath. The test uses an array of 40 sensors to analyze compounds in the breath and has successfully been able to identify people with Parkinson’s who have not yet begun treatment.1,2 Although further studies will be needed on a larger scale, this is an important step for improving techniques for early diagnosis.
Parkinson’s disease is a chronic neurodegenerative condition that affects neurons in the brain that control motor movement and other brain functions. The majority of people with Parkinson’s develop it after age 60. By the time they experience symptoms, their disease has generally progressed beyond the initial stages. Earlier diagnosis of PD could identify those who will develop the disease before they are symptomatic. This could improve their opportunity to try a more varied choice of neuroprotective therapies that could slow the symptomatic progression of the disease.1,2
Avenues of early diagnosis that have been previously studied include earlier versions of the breath test, smell tests, and ultrasound/brain scans. Earlier devices could detect people with Parkinson’s disease already receiving treatment, a later stage than the one successfully explored in the latest research.
How the breath test works
The breath analyzer uses electronic breath sensors to detect volatile molecules in exhaled breath.1 Exhaled breath is made up of carbon dioxide, nitrogen, oxygen, water, and inert gases. There are also volatile molecules produced by the body or absorbed from the environment. Volatility measures the rate that a substance evaporates (vaporizes) at normal temperatures. In study results it has proven to identify people with de novo Parkinson’s.3 According to industry guidelines, de novo PD refers to either people newly diagnosed with Parkinson’s disease or those not yet receiving L-dopa medication. The device uses gold nanoparticles or single-walled carbon nanotubes. Each sensor has an attached chemical that can bind with the volatile organic compounds in the exhaled breath. They are expected to be useful to identify biomarkers by recognizing compounds that are characteristic of PD. This binding results in a change to the electrical resistance of the sensor.3
Hope to identify those at risk but not yet diagnosed
The original test was used to detect differences in the exhaled breath of people already being treated for Parkinson’s disease and healthy controls. The new study evaluated the sensors ability to detect differences in the breath of those with early-stage Parkinson’s who were not yet taking any medications.4 Ultimately, the hope is that the breath test could be used to screen for people at risk for Parkinson’s.
The study looked at 29 people recently diagnosed with idiopathic Parkinson’s disease who were not taking any medications and 19 controls of similar ages. Idiopathic PD has no known cause. According to findings published in the ACS Chemical Neuroscience journal the results noted that the sensors were able to select early-stage Parkinson’s patients with a sensitivity of 79 percent, a specificity of 84 percent, and an accuracy of 81 percent, all statistically significant. These measurements determine the “power” of diagnostic tools. Accuracy is defined as the ability to correctly differentiate between diseased and healthy subjects. Specificity is the ability to correctly identify healthy subjects, and sensitivity is the ability to correctly identify diseased subjects.1,2,3,4
Breath screening is one of the most noninvasive screening techniques available for early detection and could be made widely available if it becomes portable. Earlier diagnosis has great potential for people with PD and other neurodegenerative conditions. It can provide access to treatments that start before there is extensive cell death of dopamine-producing neurons in the substantia nigra area of the brain.1 Since PD is a chronic condition with no cure presently available, earlier treatment may delay or prevent the progression of the disease, giving hope to the PD population and researchers seeking to improve their lives.
Finberg JPM, Schwartz M, Jeries R, et al. Sensor Array for Detection of Early Stage Parkinson's Disease before Medication. ACS Chem Neurosci. 2018. Published July 10, 2018. https://pubs.acs.org/doi/10.1021/acschemneuro.8b00245. Accessed online August 7, 2018.
Paddock, C. Parkinson's disease: Breath test for early diagnosis steps closer. Published July 31, 2018. https://www.medicalnewstoday.com/articles/322635.php. Accessed online August 9, 2018.
Sensor Array for Detection of early Stage Parkinson’s Disease before Medication. American Chemical Society News Service PressPac Published July 25, 2018. https://www.acs.org/content/acs/en/pressroom/presspacs/2018/acs-presspac-july-25-2018/breath-test-for-early-stage-parkinsons.html. Accessed online August 9, 2018.
Pena, A. Simple Breath Test May Aid in Early Diagnosis of Parkinson’s, Study Reports. Published July 31, 2018. https://parkinsonsnewstoday.com/2018/07/31/new-breath-test-parkinsons-may-aid-early-diagnosis-study/. Accessed online August 7, 2018.