There are a number of symptoms that may indicate the early stages of Parkinson's, according to a study.
Hearing loss and epilepsy have been confirmed as early warning signs of the condition, with researchers adding the two symptoms to the list already including memory problems and tremors - which can appear as much as five and ten years prior to diagnosis respectively.
The study's findings, published in the medical journal JAMA Neurology, indicated the two additional risk factors are early symptoms of the disease, with both also recognised long before an official diagnosis.
Analysing one of the most diverse populations to date, researchers at the Queen Mary University of London examined the health record of one million participants between 1990 and 2018.
Early detection of related symptoms if vital to allow an early diagnosis which can in turn allow patients to manage their condition and quality of life.
Following the initial study, researchers repeated their findings looking at additional data from the UK Biobank database.
The Parkinson's early signs study
Earlier studies looking at the early signs of Parkinson's largely focused on richer white populations, with little representation of patients from ethnic minorities and those living in areas of deprivation.
"This is the first study focusing on the pre-diagnostic phase of Parkinson's in such a diverse population with high socioeconomic deprivation but universal access to healthcare," said the lead study author Dr Cristina Simonet, neurologist and PhD student at Queen Mary University of London.
"People from minority ethnic groups and deprived areas have largely been under-represented in Parkinson's research up until now, but to allow us to get a full picture of the condition we need to ensure research is inclusive and represents all those affected.
"Our results uncovered novel risk factors and early symptoms: epilepsy and hearing loss.
"While previous research has hinted at the association, such as epilepsy being more prevalent in Parkinson's patients than in the general population, more research is now needed for us to fully understand the relationship.
"In the meantime, it's important that primary care practitioners are aware of these links and understand how early the symptoms of Parkinson's can appear, so that patients can get a timely diagnosis and doctors can act early to help manage the condition."
Parkinson's risk factors and findings
The research provides further evidence of early signs and risk factors of the disease, the experts state. Using a more diverse range of data allows for more diverse findings for the first time.
Conditions such as high blood pressure and type 2 diabetes were associated with the risk of developing Parkinson's, according to the data analysed from east London.
The region has one of the highest populations black, south Asian and mixed/other ethnic group - making up around 45 per cent of the population over all. This compares to the 14 per cent average across the UK.
The area also has one of highest levels of deprivation in the UK, with 80 per cent of patients included in the study from low-income households.
This allowed the researchers to observe a stronger association between memory complains within this popular than previously described.
Why the study is important?
Dr Alastair Noyce, reader in neurology and neuroepidemiology at Queen Mary University of London, who is also an author on the new research, said: "People see their GPs with symptoms but often don't get a diagnosis until five to 10 years after this.
"Tremor, for example, is one of the most recognisable symptoms of Parkinson's - but was seen 10 years before eventual diagnosis in our study. This is too long for patients to wait.
"If we're able to diagnose Parkinson's earlier, we have a real opportunity to intervene early and offer treatments that could improve quality of life for patients.
"This study confirms that many of the symptoms and early features of Parkinson's can occur long before a diagnosis.
"Through our ongoing PREDICT-PD research, we're hoping to identify people at high risk of Parkinson's even before obvious symptoms appear - which means that we could do more than just improve quality of life for patients, and perhaps be in the position to slow down or cure Parkinson's in the future."
PREDICT-PD , a large research project funded by Parkinson's UK, aims to identify those at high risk of developing the disease.
The research, funded by Barts Charity, is published in JAMA Neurology.
Don't miss the latest news from around Scotland and beyond - Sign up to our newsletter here.
