Health In Focus
  • Shedding tears can help diagnose people with Parkinson's disease
  • Tears can be a reliable, inexpensive and noninvasive biological marker of Parkinson's disease
  • A protein called alpha-synuclein in the tears of people helps in diagnosing with Parkinson's disease

Tears act as a biological marker in diagnosing and treating Parkinson's disease (PD) early.

Tears contain various proteins that are produced by the secretory cells of the tear gland, which are stimulated by nerves to secrete these proteins into tears.
Your Tears can Tell If You Have Parkinson's Disease or Not

For this reason, the research team investigated tears because Parkinson's disease can affect nerve function outside of the brain, said Mark Lew, MD, of the Keck School of Medicine of the University of Southern California in Los Angeles, a Fellow of the American Academy of Neurology and this study's author.

The preliminary study was presented at the American Academy of Neurology's 70th Annual Meeting, Los Angeles.

Link Between Tears and Parkinson's Disease

"We believe our research is the first to show that tears may be a reliable, inexpensive and noninvasive biological marker of Parkinson's disease," said Lew.

The research team hypothesized that any change in nerve function could be easily seen in the protein levels of tears.

In this study, tear samples from about 55 people who have PD were taken and were compared with tear samples taken from about 27 people who did not have PD, but were of the same age and gender.

Later, tears were analyzed for the levels of four proteins. The results revealed that the levels of a particular protein, alpha-synuclein in the tears of people with Parkinson's disease varied when compared to the control group.

Also, the levels of another form of alpha-synuclein called oligomeric alpha-synuclein, which are implicated in nerve damage in PD were also found to vary when compared with the controls.

There is also a possibility that the secretory cells could produce these different forms of alpha-synuclein by themselves, as they can be secreted into tears directly.

Importance of Proteins in Tears

The findings show that the total levels of alpha-synuclein were decreased in those who had PD, with an average of 423 picograms of that protein per milligram (pg/mg) than those without PD who has an average of 704 pg/mg.

However, levels of oligomeric alpha-synuclein were increased in individuals who had PD with an average of 1.45 nanograms per milligram of tear protein (ng/mg) when compared to 0.27 ng/mg in those without Parkinson's.

A picogram is 1,000 times smaller than a nanogram.

Lew also stated, "Knowing that something as simple as tears could help neurologists differentiate between people who have Parkinson's disease and those who don't in a noninvasive manner is exciting. And because the Parkinson's disease process can begin years or decades before symptoms appear, a biological marker like this could be useful in diagnosing, or even treating, the disease earlier."

Further research is required to be conducted on larger groups of people to check if these protein changes can be detected in tears in the earliest stages of PD, i.e., even before the symptoms could start.

Facts About Parkinson's Disease

Parkinson's disease (PD), a chronic and progressive disease of the nervous system that causes a gradual loss of muscle control. Parkinson's mostly affects people who are over 60 years.
  • Worldwide, approximately 7 to 10 million people suffer from Parkinson's disease.
  • Around 18 out of 1,000 people who are over 65 are affected with Parkinson's disease.
  • About 1 to 2 out of every 1,000 people have Parkinson's disease.
  • Men are one and a half times more likely to have Parkinson's disease than women.
  • People with an affected first-degree relative, such as a parent or sibling have a 4 to 9 percent higher chance of developing Parkinson's disease.
There is no cure for Parkinson's disease. However, a combination of therapies like physiotherapy and speech therapy can help control the symptoms and maintain the quality of life.

Parkinson's disease can be prevented by consuming a well-balanced diet. The diet should be rich in a variety of foods such as vegetables and fruits, omega-3 fatty acids, tea, caffeine, and wine, as they provide neuroprotection.

Vitamins C, D and E supplementation can also help in slowing down the progress of Parkinson's disease.

References :
  1. What is Parkinsons - (
  2. 10 Early Warnings Signs - (
  3. Understanding Parkinsons - (
  4. Parkinsons Disease - (
Source: Medindia

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