Parkinson’s May Begin in Gut and Spread to the Brain Via the Vagus Nerve

A major epidemiological registry-based study from Aarhus University and Aarhus University Hospital indicates that Parkinson’s disease begins in the gastrointestinal tract; the study is the largest in the field so far.

The chronic neurodegenerative Parkinson’s disease affects an increasing number of people. However, scientists still do not know why some people develop Parkinson’s disease. Now researchers from Aarhus University and Aarhus University Hospital have taken an important step towards a better understanding of the disease.

New research indicates that Parkinson’s disease may begin in the gastrointestinal tract and spread through the vagus nerve to the brain.

This image shows the course and distribution of the glossopharyngeal, vagus, and accessory nerves.
The research has presented strong evidence that Parkinson’s disease begins in the gastrointestinal tract and spreads via the vagus nerve to the brain. Many patients have also suffered from gastrointestinal symptoms before the Parkinson’s diagnosis is made. The image is for illustrative purposes only.

“We have conducted a registry study of almost 15,000 patients who have had the vagus nerve in their stomach severed. Between approximately 1970-1995 this procedure was a very common method of ulcer treatment. If it really is correct that Parkinson’s starts in the gut and spreads through the vagus nerve, then these vagotomy patients should naturally be protected against developing Parkinson’s disease,” explains postdoc at Aarhus University Elisabeth Svensson on the hypothesis behind the study.

A hypothesis that turned out to be correct:

“Our study shows that patients who have had the the entire vagus nerve severed were protected against Parkinson’s disease. Their risk was halved after 20 years. However, patients who had only had a small part of the vagus nerve severed where not protected. This also fits the hypothesis that the disease process is strongly dependent on a fully or partially intact vagus nerve to be able to reach and affect the brain,” she says.

The research project has just been published in the internationally recognised journal Annals of Neurology.

The first clinical examination

The research has presented strong evidence that Parkinson’s disease begins in the gastrointestinal tract and spreads via the vagus nerve to the brain. Many patients have also suffered from gastrointestinal symptoms before the Parkinson’s diagnosis is made.

“Patients with Parkinson’s disease are often constipated many years before they receive the diagnosis, which may be an early marker of the link between neurologic and gastroenterologic pathology related to the vagus nerve ,” says Elisabeth Svensson.

Previous hypotheses about the relationship between Parkinson’s and the vagus nerve have led to animal studies and cell studies in the field. However, the current study is the first and largest epidemiological study in humans.

The research project is an important piece of the puzzle in terms of the causes of the disease. In the future the researchers expect to be able to use the new knowledge to identify risk factors for Parkinson’s disease and thus prevent the disease.

“Now that we have found an association between the vagus nerve and the development of Parkinson’s disease, it is important to carry out research into the factors that may trigger this neurological degeneration, so that we can prevent the development of the disease. To be able to do this will naturally be a major breakthrough,” says Elisabeth Svensson.

[divider]About this Parkinson’s disease research[/divider]

Facts

  • Parkinson’s disease is a chronic and neurodegenerative disease which affects approx. 1 out of every 1,000 people.
  • The first signs of the disease are most often seen between the ages of 50-60.
  • The researchers carried out a registry study involving 14,883 patients who had undergone a vagotomy.
  • The research project was supported by the Danish Parkinson’s Disease Association and PROCRIN (Program for Clinical Research Infrastructure).

Funding The research was funded by the Danish Parkinson’s Disease Association.

Source: Elisabeth Svensson – Aarhus University
Image Credit: Image is credited to the Gray’s Anatomy and is in the public domain
Original Research: Abstract for “Vagotomy and subsequent risk of Parkinson’s disease” by Elisabeth Svensson PhD, Erzsébet Horváth-Puhó PhD, Reimar W Thomsen PhD, Jens Christian Djurhuus DMSc, Lars Pedersen PhD, Per Borghammer DMSc and Henrik Toft Sørensen DMSc in Annals of Neurology. Published online June 2015 doi:10.1002/ana.24448


Abstract

Vagotomy and subsequent risk of Parkinson’s disease

Objectives: Parkinson’s disease (PD) may be caused by an enteric neurotropic pathogen entering the brain through the vagal nerve, a process that may take over 20 years. We investigated the risk of PD in patients who underwent vagotomy, and hypothesized that truncal vagotomy is associated with a protective effect, while super-selective vagotomy has a minor effect.

Methods: We constructed cohorts of all patients in Denmark who underwent vagotomy during 1977-1995 and a matched general population cohort, by linking Danish registries. We used Cox regression to compute hazard ratios (HRs) for PD and corresponding 95% confidence intervals [CIs], adjusting for potential confounders.

Results: Risk of PD was decreased in patients who underwent truncal [HR = 0.85, 95% CI= 0.56–1.27; follow-up of >20 years: HR = 0.58, 95% CI: 0.28–1.20] compared to super-selective vagotomy. Risk of PD was also decreased following truncal vagotomy when compared to the general population cohort [overall adjusted HR = 0.85, 95% CI 0.63–1.14; follow-up >20 years, adjusted HR = 0.53 [95% CI: 0.28–0.99]. In patients who underwent super-selective vagotomy, risk of PD was similar to the general population [HR = 1.09, 95% CI: 0.84–1.43; follow-up of >20 years: HR = 1.16, 95% CI: 0.80–1.70]. The statistical precision of the risk estimates was limited. Results were consistent after external adjustment for unmeasured confounding by smoking.

Interpretation: Full truncal vagotomy is associated with a decreased risk for subsequent PD, suggesting that the vagal nerve may be critically involved in the pathogenesis of PD.

“Vagotomy and subsequent risk of Parkinson’s disease” by Elisabeth Svensson PhD, Erzsébet Horváth-Puhó PhD, Reimar W Thomsen PhD, Jens Christian Djurhuus DMSc, Lars Pedersen PhD, Per Borghammer DMSc and Henrik Toft Sørensen DMSc in Annals of Neurology. Published online June 2015 doi:10.1002/ana.24448

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  1. shanhong Lu MD, PhD I agree. Removing the vagal nerve is likely fraught with risk of unforeseen adverse events.

    1. If disease can spread via nerves in the body…this opens up a host of questions concerning many diseases where the etiology has not yet been identified. I wonder if there is any other research or medical evidence of this with other nerves?

  2. While a link between PD and gastrointestinal stress may have been revealed by incidences of vagal nerve surgery it is also possible there are other deterrents to PD illuminated by this research, calling for further research. Status of the gut (stomach, intestines and colon) condition of the entire neuroendocrine system, and the health of the parasympathetic nervous system. (important de-stressor, and re-generator). It will be great to see more studies on this important topic. Our work with Moving For Life has shown increased body awareness, improved abdominal tonus, and strengthening of the immune system – it would be great to extend this model to other elders including those with Parkinson’s disease. .

  3. My dads entire family history is riddled with Parkinsons. Not supposed to be genetic, but i haven’t a clue why then it never skips a generation. Gaste roenterologists will tell you there are manypossible causes for a gastric problem, and diagnosis is mainly done by elimination possibilities.
    I don’t see the data for their theory, and am interested about the nutritional keys they found. Diet controlled PD? I am hopeful…

  4. Our work with Quantitative EEG and biofeedback has shown positive results for PD and dementia and its clear that the NIR improves cortical blood flow and removes toxic proteins and improves CNS efficiency. The biofeedback helps to reregulate CNS activity which again improves immune functioning. The NIR frequency range also kills some of the viruses which contribute to these problems, e.g., MRSA.

  5. Is there possibility that Restless legs could be a pre-cursor to Parkinsons? Doctors give parkinson’s med (Sinemet) for Restless legs. Just wondering.

  6. My mother has never had any gastrointestinal problems. She has had essential tremors since she was 5 years old. She was diagnosed with Parkinson’s 2 years ago. Her symptoms intensified after the death of my father and brother. I don’t know how much I trust this research.

    1. PD is a wildly multifactorial disease, and different etiological mechanisms can lead to the same outcome. Besides, not perceiving gastrointestinal problems does not necessarily mean that they are not there – they may simply not have manifested. Plus, a pathogen that affects, say, CNS tissue, alghtough entering through the intestinal tract, does not necessarily need to exhibit any effect in the gut. Moreover, the actual article says “This intriguing finding suggests that an intact vagal nerve is important in the pathogenesis of PD”. If you can understand it, you should actually read it.

  7. Before my husband was dx with Parkinson’s he suffered from severe gastrointestal condition that actual made him loose his job. He lost over 80 pounds in less then 6 months and lost so much muscle mass that he had to use a walker. He couldn’t eat or drink.

    1. Agree… Vagus nerve removal is not a cure. As with most conditions there is always going to be a problem with the elimination of toxic build up within the body. The paths of elimination must be kept functional. The role of the gastrointestinal tract is vast, we are walking food com-posters, but the foods we throw down out necks is woeful.
      Become educated as far as what lives within you and what it takes to create a balanced inner micro biom

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