Hearing Loss and Epilepsy Identified As Early Signs of Parkinson’s Disease

UK Researchers have, for the first time, identified that hearing loss and epilepsy are early signs of Parkinson’s disease, making earlier diagnosis a greater possibility in the future.

In their pioneering study, published in the journal JAMA Neurology , researchers from Queen Mary University of London explored the early symptoms and risk factors for Parkinson’s disease among over a million people living in East London from 1990 to 2018. The area has one of the UK’s highest proportions of Black, South Asian, and mixed/ other ethnic groups, comprising around 45% of residents, compared with 14% in the rest of the UK. It also has some of the highest levels of deprivation in the UK; 80% of patients included in the study were from low-income households.

Lead author Dr Cristina Simonet, neurologist and PhD student at Queen Mary University of London, commented: “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 health care.”

Two New Early Features of Parkinson’s Uncovered

In their study, using electronic healthcare records the researchers identified that “known symptoms associated with Parkinson’s, including tremor and memory problems, can appear up to 10 and 5 years before diagnosis, respectively”.

In addition, they uncovered two previously unknown early features of Parkinson’s disease, epilepsy and hearing loss. They were able to replicate these findings using additional data from the UK Biobank.

Dr Alastair Noyce, reader in neurology and neuroepidemiology at Queen Mary University of London, and one of the study authors said: “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 researchwe’re hoping to identify people at high risk of Parkinson’s even before obvious symptoms appear.”

The researchers pointed out that although early signs of Parkinson’s have previously been described, “studies have largely focused on affluent white populations”.

They added: “The new study 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.”

Dr Simonet said: “People from minority ethnic groups and deprived areas have largely been under-represented in Parkinson’s research up till 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. Whilst 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.”

Increased Awareness Needed to Avoid Diagnosis Delay

Dr Noyce said: “People see their GPs with symptoms but often don’t get a diagnosis until 5 to 10 years after this. Tremor, for example, is one of the most recognizable symptoms of Parkinson’s – but was seen 10 years before eventual diagnosis in our study.”

Dr Simonet added: “It’s important that primary care practitioners are aware of the 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.”

In this East London population, conditions like hypertension and type 2 diabetes were associated with increased odds of developing Parkinson’s disease, the researchers said, adding that they also observed a stronger association with memory complaints within this population than previously described.

Dr Noyce emphasized: “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.” We may even “perhaps be in the position to slow down or cure Parkinson’s in the future”.