Latest findings prove Parkinson's is two distinct diseases

It has long been discussed that Parkinson's, due to its varied presentation in those living with the condition, is two diseases. Now, a team of researchers at Aarhus University have used advanced imaging scans to prove that this is the case.

The findings, published in Brain in August, shared that Parkinson's begins, for some, with the enteric nervous system, located in the intestines, before moving to the brain. However, for others it begins directly in the brain, affecting a person's dopamine system first, and moves to the intestines and other parts of the body later. This sheds light on why the microbiome of people with Parkinson's is different to that of healthy people.

In addition to showing the differences between the brain-first and body-first types of Parkinson’s, the team suggested that a known risk factor for Parkinson, isolated REM sleep behavior disorder (iRBD), could be specifically associated with body-first disease.

They also pointed out that diagnosing the brain-first Parkinson's is likely much harder as much damage has been done in the brain before the first motor symptoms appear.

Their findings impact the tailoring of therapies for those with Parkinson's, and may offer novel lines of enquiry for research into prevention.

Notably, a recent study in multiple sclerosis (MS) presented by Stephanie Kurten at the recent ECTRIMS/ACTRIMS joint conference, also noted as having a different microbiome without clear causal routes as yet, found that the enteric nervous system may also play a role in the demyelination of nerve cells in the brain known to cause MS.

The research, questioning whether MS actually begins in the gut, and this new evidence that one form of Parkinson's certainly does, suggests the gut/central nervous system links being explored in neurological conditions may be essential to our understanding, treatment and eventual prevention, of these conditions.

A helpful summary article on this can be found in Diagnostic Imaging.