There may be more than one type of Parkinson's Disease

Research suggests that one form of the neurological condition begins in the brain and the other in the nervous system.

Anna Sharratt 3 minute read October 2, 2020
Parkinson's Disease

A new study suggests that Parkinson's disease may have a connection to gut health. Getty

Silke Appel-Cresswell studies how bacteria in the gut play a part in the development of Parkinson’s Disease, a neurodegenerative disease.

“There is evidence that in one subgroup of the disease, there are symptoms in the gut decades before people develop the movement problems associated with Parkinson’s,” says the associate professor for Medicine and Neurology at the University of British Columbia. “We want to see what goes wrong with the gut,” she says.

It’s why she’s excited by a new study by Danish scientists making the gut-brain connection, and theorizing that Parkinson’s Disease may not be one disease but actually two.

Researchers discovered through the brain imaging of 37 patients that one group of patients had damage in the brain prior to damage in the intestines, and heart MRI scans of other patients showed nervous system damage of the intestines and heart before the brain was affected.

They believe there are two subtypes of the disease: one is a brain-first (top-down) type, where a “pathology” begins in the brain and spreads to the autonomic nervous system, and a body-first (bottom-up) type, “where the pathology originates in the enteric or peripheral autonomic nervous system and then spreads to the brain,” according to the study. The researchers also found that REM sleep behavior disorder, in which people physically act out dreams, rather than remaining still during REM, is linked to the body-first type of Parkinson’s.

“This will inform how we look, how we split groups up and seemingly explains controversial findings in the past,” says Appel-Cresswell. She says past studies have had conflicting results, likely the result of tracking people with two different forms of the disease and very different symptoms and disease progressions.

REM sleep behavior disorder, in which people physically act out dreams is linked to the body-first type of Parkinson’s

Parkinson’s is a neurodegenerative disease that affects over 100,000 Canadians. It is caused by the death of nerves in the brain that produce dopamine. When this begins to happen, patients begin to experience symptoms of tremor, mobility issues, rigid muscles, fatigue, and poor balance. There is no cure for Parkinson’s though certain medications, physical therapy and speech therapy can help alleviate symptoms.

Should the two-subtype theory hold, it could unlock new ways of identifying patients at risk of Parkinson’s and target therapies for each type, according to Julie Wysocki, director of the Parkinson Canada Research Program.

Currently, medications used to treat Parkinson’s work to improve patients’ quality of life but do not slow the progression of the disease.

“It’s a huge barrier not knowing what causes [Parkinson’s],” she says. “We can absolutely identify therapies if we can diagnose things earlier.”

Still, research is still in its early stages, and a cure for the disease is still a long way off, says Wysocki. But she foresees more researchers investigating this line of thinking. “There’s enthusiasm for these results.”

Appel-Cresswell says that the study needs to be replicated in order to determine whether the two subtypes of the disease exist. But she’s buoyed by the fact that the mystery that is Parkinson’s Disease is slowly unravelling, and that new research could open doors to personalized medicine, with each subtype treated differently.

“This is really important as a concept,” she says.

If you or someone you care about is living with Parkinson’s Disease, connecting with a support network can help to not only learn ways to better manage their health, but also share experiences with others. Some Canadian resources include the Parkinson Canada, Parkinson’s Resource Centreand in the U.S., The Michael J. Fox Foundation for Parkinson’s Research.


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