Can constipation be the key to the early diagnosis of Parkinson’s disease?

When Parkinson’s disease, one of the most common neurological disorders, is diagnosed, the disease’s progression cannot be reversed, leaving doctors with one option: treating the symptoms. However, a research team at the Hebrew University of Jerusalem found a potential way to diagnose the disease up to 20 years earlier, using what may seem like an unusual method: investigating and understanding the physiological process behind constipation.

“Consider a 55- to 60-year-old patient who suffers from constipation,” said Goldberg. “We may someday develop a test based on the neural changes that we have discovered to determine whether there is a neural factor at play that could indicate Parkinson’s.”

How does Parkinson’s work?

Dopamine cells fail to reach the brain, leading to cell loss.

The number of cells lost in the process is huge at the time the disease is usually diagnosed, which is why recovery is so difficult. This leads to visible motor symptoms in the patient that indicate the presence of the disease.

Constipation is one of the few non-motor symptoms of Parkinson’s. In fact, it is quite common and can be an important indicator of the disease if it is analyzed early – around the age of 20.

The hypothesis is based on the discovery of Lewy bodies, tiny deposits of protein residues within brain cells. The discovery was led by Dr. Friedrich Lewy in 1912.

In the early 2000s, researchers looked at the path Lewy bodies take in the brains of patients with Parkinson’s. Although nothing conclusive came out of this, they suggested that the accumulation of protein residues was not occurring at random locations in the brain, but at intentional locations, in locations that control the healthy functioning of parts of the body.

In particular, they saw that one of the first places Lewy bodies were found was the area that controls gastrointestinal movement, potentially explaining the connection.

The research substantiated this hypothesis by over-expressing the alpha-synuclein protein, a specific protein that is known to increase the activity of Lewy bodies in the area of ​​the brain that controls gastrointestinal activity, in the brain of laboratory mice. A model to slow down the digestive system after the expression of the alpha-synuclein protein in the brain stem. (Credit: J. GOLDBERG / J. ROEPER)

They found that by expressing the protein in excess, the electrical activity of brain cells decreased – the cells literally shrunk. They were then able to associate this with human brains in the early stages of Parkinson’s.