Beyond Movement: Uncovering Cognitive and Psychological Aspects of Parkinson's Disease

Parkinson's disease is widely recognized for its motor symptoms such as tremors, rigidity, and slowness of movement. However, recent research emphasizes that non-motor symptoms, specifically cognitive decline and anxiety, significantly impact patients' quality of life and often go unnoticed in clinical settings. A study led by Marit Ruitenberg at Leiden University highlights the importance of early detection and new testing methods to identify these invisible symptoms.

One promising approach involves analyzing practice effects in neuropsychological tests—improvements in test results due to familiarity or repeated exposure. While typically considered as noise or methodological artifacts, these effects may provide valuable insights into cognitive functioning. Ruitenberg's research indicates that individuals with Parkinson's exhibiting smaller practice effects over a year are more prone to cognitive decline, suggesting that this phenomenon could serve as a non-invasive predictor.

This initial exploratory study involved both Parkinson's patients and healthy controls completing the same cognitive assessments twice, separated by one year. Results showed healthy controls had more pronounced and consistent practice effects, whereas Parkinson's patients with reduced practice effects were at higher risk for future decline. Further research is necessary to refine these findings, including exploring shorter intervals between tests to increase practicality.

In addition to cognitive challenges, anxiety presents as a common yet often overlooked symptom in Parkinson's. Approximately 30% to 50% of patients experience anxiety, which overlaps with physical symptoms like tremors and blood pressure changes, making diagnosis difficult. An interdisciplinary collaboration between Leiden University and the University of Waterloo aims to better understand anxiety manifestations through large datasets, network analyses, and virtual reality experiments. The goal is to develop more targeted treatments tailored to specific anxiety types—be it general anxiety, episodic anxiety, or avoidance behaviors.

Ultimately, these research efforts aim to facilitate earlier intervention and support for Parkinson's patients. By focusing on invisible symptoms, healthcare providers can improve quality of life and better address the comprehensive needs of individuals living with this neurodegenerative condition. Continuous scientific investigation remains crucial for translating these insights into practical clinical tools.

Source: https://medicalxpress.com/news/2025-10-motor-skills-cognitive-psychological-symptoms.html