Study Rationale: Cognitive decline is common in people with Parkinson’s disease (PD), and changes in thinking and performance on objective cognitive tests reported by individuals and their family are used for PD diagnosis. We showed that several of these objective tasks are biased against first-generation immigrants with PD. However, it is unclear whether culture also influences individuals’ self-assessment of their abilities. Cognitive testing is also important in the context of deep brain stimulation (DBS) therapy, which carries a cognitive risk. Again, the relationship between diversity and cognitive decline after DBS is unknown.
Hypothesis: We will examine whether cultural bias extends to the reporting of cognitive difficulties and whether cognitive changes after DBS—and our ability to predict these outcomes—vary as a function of diversity.
Study Design: We will use existing clinical data from neuropsychological assessments conducted in Toronto, where 50% of residents are first-generation immigrants. First, we will compare individuals born in Anglosphere countries (Canada, UK, USA) to immigrants born elsewhere in terms of the type and severity of reported change in cognition and in daily activities, and in terms of the degree to which this self-reporting corresponds to objective testing. Second, we will compare the changes in test performance following DBS between these groups and devise a statistical model to predict cognitive outcome in all individuals, while considering the potential influence of multiculturalism.
Impact on Diagnosis/Treatment of Parkinson’s disease: Our findings will enhance clinicians’ awareness of potential cultural differences in individuals’ subjective reports, improving the diagnosis of cognitive decline. Our results will also increase the accuracy of the estimated cognitive risk of DBS in individuals, while considering the potential influence of multiculturalism.
Next Steps for Development: Results can be readily integrated in clinical practice through increasing clinicians’ knowledge of cultural differences, and application of the predictive model to individuals with PD.