‘E-nose’ could someday diagnose Parkinson’s disease by ‘smelling’ skin

Scientists have developed an e-nose that may help in diagnosing Parkinson’s Disease through smell.

Researchers have developed a portable, artificially intelligent olfactory system or ‘e-nose’ that could potentially diagnose the disease. Scientists discovered that patients with Parkinson’s Disease secrete increased serum, an oily waxy substance that is produced by glands in the skin. There is also an increased production of yeast, enzymes and hormones which all combine to omit a particular odour.

Researchers developed an e-nose combining gas chromatography (GC) with a surface acoustic wave sensor that measures gaseous compounds as they interact with a sound wave and algorithms.

Jun Liu, Xing Chen and colleagues wanted to develop a fast, easy to use and inexpensive GC system that could diagnose through smell, making it suitable for point-of-care testing. The team collected sebum samples from 31 Parkinson’s Disease patients and 32 healthy people by swabbing their upper backs with gauze. They analysed volatile organic compounds emanating from the gauze with the e-nose.

The team discovered three odours, octanal, hexyl acetate and perillic aldehyde, that were different between the two groups. Researchers noted that the model was 91.7 per cent sensitive when identifying patients but specificity was only 50 per cent which indicated a high rate of false positives. When the machine learning algorithms were used to analyse the entire odour profile, this accuracy increased to 79.2 per cent.

According to the researchers, for the e-nose to be ready for the clinic, it needs to be tested on many more people to improve the accuracy, and they also need to consider factors such as race.

Parkinson Disease diagnosis

Parkinson’s Disease causes motor symptoms such as tremors, rigidity and trouble walking. It also causes non-motor symptoms such as depression or dementia. Currently, there is no cure for the condition but early diagnosis and treatment can improve a patient’s quality of life and relieve the symptoms.

It is normally not diagnosed until patients develop motor symptoms and by that stage, they have already lost essential neurons.