New discovery could help diagnose Parkinson’s years before symptoms appear

A study published in npj Parkinson’s Disease has found that early-stage Parkinson’s disease is associated not only with a reduced sense of smell, but also with changes in how affected individuals perceive different odors.

The researchers compared data from 94 participants, some of whom had Parkinson’s disease while others had impaired smell for reasons unrelated to the condition. Participants were asked to evaluate a range of odors according to several criteria, while the researchers analyzed their involuntary responses to the smells, including their patterns of inhalation.

The findings showed that Parkinson’s disease affects more than the ability to distinguish between odors; it also appears to alter the way odors are perceived. Combined with distinctive patterns of physiological responses to different smells, this feature enabled the researchers to distinguish Parkinson’s disease from other causes of impaired smell with an accuracy of 94%, whereas conventional smell tests failed to make the distinction.

The scientists believe this approach could represent a significant advance in the early diagnosis of Parkinson’s disease. By identifying disease-related changes through the sense of smell long before symptoms such as tremors and muscle rigidity emerge, the method could potentially enable therapeutic interventions at earlier stages, when they may be more effective.

In a related development, researchers recently developed a low-cost electrochemical sensor capable of detecting changes in dopamine levels in tears. The technology could pave the way for the early detection of diseases such as Parkinson’s before symptoms become apparent.

Meanwhile, a study published in the scientific journal BBIH reported that certain viral infections may increase the risk of developing Parkinson’s disease.