Scientists have discovered a new Parkinson’s marker that can identify sufferers years before any of the traditional symptoms begin. Researchers at King’s College London have found that damage to the serotonin system in the brain acts as an “excellent marker” for the disease.
The breakthrough has been hailed “fascinating” by experts, who say it fills a “crucial gap” in existing knowledge of Parkinson’s. Despite the fact that the condition is currently incurable, identifying it early can improve outcomes for patients and slow its progression.
This is not always easy since the telltale signs, such as tremors and slow movement, begin years after Parkinson’s has taken hold. According to the NHS, Parkinson’s is the second most common neurodegenerative disease, with Alzheimer’s taking the top spot.
Parkinson’s is a daily struggle for 148,000 people in the UK, which equates to one in 350 of the country’s population. In the US, there are around half a million sufferers of the condition, helping to put it in the spotlight and demonstrate the importance of continued research.
Heather Wilson is the lead author of the study and is based at the Institute of Psychiatry, Psychology and Neuroscience. She said: “We found serotonin function was an excellent marker for how advanced Parkinson's disease has become. Crucially, we found detectable changes to the serotonin system among patients who were not yet diagnosed.
“Therefore, brain imaging of the serotonin system could become a valuable tool to detect individuals at risk for Parkinson's disease, monitor their progression and help with the development of new treatments.”
Parkinson’s disease is the result of alpha-synuclein protein in the brain, but in most people it’s unclear as to why is occurs. In some cases it develops due to a genetic mutation, but this is a small proportion, leaving only speculation about environmental factors for others.
Scientists from King’s College London looked at 14 carriers of the rare gene mutation in order to study early warning signs. Half of them had not yet shown any symptoms of Parkinson’s, despite the inevitability of doing so in later life.
All of the participants underwent a scan that shows serotonin in the brain. This was then compared to data collected on 65 people with non-genetic Parkinson’s and 25 healthy volunteers. This is when the scientists discovered the serotonin system begins to malfunction a long time before symptoms occur.
Previous studies have suggested that the dopamine system is the first area to be affected by Parkinson’s, so the new research opens up another area of investigation. It could lead to the development of new screening tools to establish which individuals are at the greatest risk.
Dr Beckie Port, research manager at Parkinson’s UK, said: “This is one of the first studies to suggest that changes in serotonin signalling may be an early consequence of Parkinson’s. Detecting changes that are happening in the brain in these early stages is a crucial gap in Parkinson’s research at the moment.”