LONDON - Hearing loss and epilepsy have been identified as early signs of Parkinson’s disease, according to a new study that looked at the most diverse population to date.

Queen Mary University of London researchers say it is important doctors are aware of the signs, and when symptoms can appear, so patients can get a timely diagnosis and early help to manage their condition and improve quality of life.

Using health records from more than one million people living in east London between 1990 and 2018, researchers found that known symptoms associated with Parkinson’s, including tremor and memory problems, can appear up to 10 and five years before diagnosis respectively.

They also uncovered two new features of the condition – epilepsy and hearing loss, and were able to repeat these findings using additional data from the UK Biobank database.

Lead study author Dr Cristina Simonet, neurologist and PhD student at Queen Mary University of London, said: “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.

“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.”

Previous studies describing early signs of Parkinson’s have largely focused on richer white populations, with little representation of patients from ethnic minorities and those living in areas of high social deprivation.

The experts suggest their research provides further evidence of risk factors and early signs of Parkinson’s, using data from such a diverse and deprived urban population for the first time.

In east London, conditions such as high blood pressure and type 2 diabetes were associated with increased odds of developing Parkinson’s.

The region has one of the highest proportions of black, south Asian and mixed/other ethnic groups, which make up around 45% of residents in the area, in comparison to 14% in the rest of the UK.

It also has some of the highest levels of deprivation in the UK, and 80% of patients included in the study were from low-income households.

The researchers also observed a stronger association between memory complaints within this population than previously described.

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 is a large research project funded by Parkinson’s UK that aims to identify people at high risk of developing the condition.

The research, funded by Barts Charity, is published in JAMA Neurology.