Developments in breath testing for the detection of Parkinson’s
Original article: Sensor Array for Detection of Early Stage Parkinson’s Disease before Medication, Chemical Neuroscience: July 10, 2018.
A novel sensor, which analyses particles in exhaled breath, may have the potential of accurately identify as yet untreated people with Parkinson’s from those without the condition.
Why is it important?
The method and findings, if replicated and extended, could represent a novel method for the early detection of Parkinson’s. The cost effective nature of the device and testing which does not require highly skilled operators are key advantages for such techniques if they are to be eventually rolled out in settings beyond the neurology clinic.
- Novelty 80% 80%
- Proximity 60% 60%
- Deliverability 70% 70%
“This is very exciting technology. The early detection of Parkinson’s is not only important from the stand point of treating the people affected by the condition, but also for the research community. A diagnositic aid like a breath analysis device could be extremely informative, telling us a great deal about the early stages of the condition. In addition, it will be interesting to see if this technology can be used to monitor Parkinson’s over time – picking up fluctuations in the condition in a longitudinal study. Such a tool would be of tremendous value, particularly in the context of a clinical trial.”
Accurately diagnosing Parkinson’s, and detecting it as early as possible, has a direct impact on the choice of treatment, and could also help early efforts toward neuroprotection. Given current methods, the success of early diagnosis upon first presentation may be as low as 26%, so more tools and methods to detect the first signs of Parkinson’s are needed. Can analyzing the breath be informative in this respect? A novel technology focuses on analyzing the spectrum of exhaled particles called volatile organic compounds, which make up what the researchers term the volatolome. Moreover, it is relatively cost effective and does not require the use of highly skilled operators.
Using nanomaterial sensors paired with a computer algorithm, in a novel device designed to analyse the volatolome, these researchers had previously been able to discriminate with reasonable accuracy between people with Parkinson’s and controls. However, as the Parkinson’s group were treated with medication in that study, one of the criticisms was that the sensor may have been picking up particles related to the medications themselves. This would limit the scope and utility of such a sensor. So, the Israel based group sought to take this work a step further, and focus on as yet untreated individuals.
The researchers compared samples from 29 people with untreated Parkinson’s and 19 controls. Participants in this study sat comfortably, wearing a plastic nose clip. Using a carbon based breath filtration system, into which they breathed for 3 minutes, the breath was cleared of environmental contaminants in a so called “lung washout”. They were then asked to inhale deeply and exhale into a tube, the contents of which were analysed.
Although no single volatile organic particle stood out as clearly different between the two groups, the overall composition of exhaled breath discriminated between the groups with an accuracy of 81%, detecting Parkinson’s at a rate of 79% and correctly identifying controls at a rate of 84%.
How does the method compare to other existing tests? The breath sensory array performed worse than brain imaging focusing on the midbrain which has an accuracy of 92%, but marginally better than the UPSIT smell test which accurately detects Parkinson’s at a rate of 62%, distinguishes controls at 89% and has an overall accuracy of 73%. The researchers point out that a compound called benzaldehyde was higher in the Parkinson’s group (although this was not quite statistically significant), while another, acetophenone appeared to be lowered, paralleling a pattern seen in people with multiple sclerosis.
As this is a small study, future work will have to focus on a much larger sample of newly diagnosed but not yet treated people with Parkinson’s, to establish whether this technology can be a useful add-on to existing methods.
Finberg, J. P. M., Aluf, Y., Loboda, Y., Nakhleh, M. K., Jeries, R., Abud-Hawa, M., . . . Haick, H. (2018). Altered Volatile Organic Compound Profile in Transgenic Rats Bearing A53T Mutation of Human alpha-Synuclein: Comparison with Dopaminergic and Serotonergic Denervation. ACS Chem Neurosci, 9(2), 291-297: https://pubs.acs.org/doi/abs/10.1021/acschemneuro.7b00318
Original article: Sensor Array for Detection of Early Stage Parkinson’s Disease before Medication, Chemical Neuroscience: July 10, 2018. Finberg, J. P. M., Schwartz, M., Jeries, R., Badarny, S., Nakhleh, M. K., Abu Daoud, E., . . . Haick, H.