It’s estimated that around 70,000 Australians are living with Parkinson’s disease (PD), a condition for which there is no cure. That’s approximately one in every 340 people. With the ageing population set to increase over the coming decades, that number is predicted to rapidly rise. It’s statistics like these that led a team of Curtin University researchers to undertake ground-breaking research, using a different approach.
The overall aim of the project, which utilised data from an existing, broader collaborative research project, was to explore exactly what symptoms could be used to predict a PD sufferer’s decline in order to create targeted early interventions, as well as provide individuals with an idea of how their disease might progress.
“Many sufferers are faced with this reality of knowing that PD can be terribly degenerative and not knowing if, or when, that’s going to happen to them”, says PhD candidate and lead researcher, Andrew Johnson.
The research involved a sample of 114 WA men and women with PD aged between 39 and 85. But what’s different about the research is its method of analysis, which viewed data from a longitudinal perspective (over an extended period of time) as opposed to a cross-sectional perspective (at one specific point in time).
“Because the disease is progressive, by only exploring something in PD cross-sectionally, you’re effectively ignoring this hugely impactful aspect of PD”, says Johnson.
This longitudinal analysis produced some unexpected findings, in particular, that one ‘subtype’ of PD is more likely to lead to cognitive difficulties.
The two motor-related subtypes have quite different symptoms. Tremor Dominant (TD) produces prominent tremors, and Postural Instability & Gait Difficulty (PIGD) impacts on movement and balance. The research revealed that the latter subtype is more likely to lead to a disturbance in executive functions such as thinking, memory and planning abilities.
“We found that as postural symptoms get more and more dominant, individuals experience difficulties with spatial working memory, which is basically the ability to hold and manipulate spatial information for short periods of time”, Johnson explains.
Johnson believes that while the analysis and subsequent findings of the project are impactful and certainly a step in the right direction, more research is necessary to enhance existing findings and drive change.
To that end, he’s embarking on a new research project into subtyping, using data gathered over a six-year period, which investigates how tremor and postural symptoms change at different rates over time in PD, and the impact this has on the TD/PIGD subtyping process.