Tremors, loss of smell, and trouble sleeping, moving or walking are all well-known early signs of Parkinson’s disease (PD), according to the Parkinson’s Foundation. But a new study led by researchers from the Queen Mary University of London found hearing loss and epilepsy (seizures) could also be early signs of the disease.
Researchers analyzed early symptoms and risk factors for Parkinson’s using primary health care records from over a million people living in East London between 1990 and 2018. Unlike most studies that largely focus on affluent white populations, the study included data from diverse ethnic and socioeconomic groups: 45% of East London residents are black, South Asian or people of other ethnic groups, and 80% of the participants are from low-income neighborhoods.
They found that well-known early symptoms of the disease, including tremors and memory problems, can show up five and even 10 years before diagnosis, and that two other conditions – epilepsy and hearing loss – are early features of the disease as well.
“With increased capability and access to patient records, we’re able to make effective correlations of other signs, symptoms and traits in patients across the lifespan in a way that has a correlation with the occurrence of other diseases,” James Giordano, PhD, professor in the Department of Neurology and Biochemistry at Georgetown University Medical Center (who was not a part of the study), told Seasons. “Individuals who present throughout their life span with an increase in a seizure disorder, movement disorder, problems sleeping, all seem to have a higher correlation for PD.”
What else did the study find?
The authors analyzed 24 types of prediagnostic signs and risk factors of PD – dizziness, fatigue, constipation, insomnia, shoulder pain and tremor – based on previous studies. They also analyzed three different time periods: less than two years, two to less than five years, and five to 10 years before diagnosis.
They discovered that epilepsy was associated with Parkinson’s across all the time frames, and hearing loss was identified in the less-than-two-years and the two-to-less-than-five-years time periods, before PD diagnosis.
According to the study, researchers replicated their analysis using case-control data from the UK Biobank, a large biomedical database that contains health information from half a million UK participants. They found again that both epilepsy and hearing loss were linked with Parkinson’s diagnosis over the three different time periods.
“Both epilepsy and certain forms of sensory deficit such as tremors are early stages of the disease and perhaps may even be predictive of the evolution of the disease. All of this suggests there is a disruption in the neurological node and network integrity of systems that combine more than one neurological pathway or domain,” Giordano said. “One of the problems you see in the Parkinson patient is that fine motor control necessary for relative inhibition that regulates start and stop is absent, hence they shake, they have problems starting movement, and often they have problems stopping movement as well.”
The authors stated there was no association between ethnicity or economic deprivation and Parkinson’s diagnosis. They added the study had limitations because the data collected came from primary care records and some signs of Parkinson’s might not have been documented. In addition, the disease could have been misdiagnosed and information about patient medications was not known.
Why is this study important, and what does it mean for caregivers and seniors?
Giordano said this study is significant because it informs doctors of new signs and symptoms that can appear in patients who may have Parkinson’s disease. It also allows patients to get a timely diagnosis, which can help them manage their condition and improve their quality of life.
“The earlier we know about it, the earlier we can intervene, the more effectively you may be able to mitigate – if not prevent – certain signs or symptoms in their occurrence, and – in some cases – the more we can become creative in the therapeutic interventions that we apply,” he said.
However, he adds the findings may not necessarily apply to a patient who’s already diagnosed, being treated or is maintaining the disease:
“Once the disease has been diagnosed and the individual is actively expressing signs and symptoms, these new findings do not provide any indication that the presence or absence of these new networks of integrative features such as seizure disorder or loss of hearing in any way affects the time course and or the severity of Parkinson’s disease, only its occurrence.”
However, if someone is showing symptoms of epilepsy or loss of hearing, Giordano said, it can help caregivers and doctors determine the extent and type of care needed to manage a patient with PD.