Ladek et al. (2026)
- Authors: Anja-Maria Ladek, Leonie Priebe, Thomas Harrer, Ellen Harrer, Georg Michelson, Thomas S. Knauer, Diogo X. Dias-Nunes, Christian Y. Mardin, Antonio Bergua, Bettina Hohberger
- Institutes: Department of Ophthalmology, Universitätsklinikum Erlangen, Germany, Department of Human Medicine, Paracelsus Medical University, Salzburg, Austria, Department of Internal Medicine 3-Rheumatology and Immunology, Universitätsklinikum Erlangen, Germany, Deutsches Zentrum Immuntherapie and Center for Rare Diseases Erlangen, Germany
- Publisher: Biomedicines
- Link: DOI
Summary
This research introduces a novel, objective way to measure the cognitive fatigue and ‘brain fog’ that ME/CFS patients experience. By using virtual reality to track reaction times, the study provides a potential tool for clinicians to quantify symptoms that were previously only measurable through subjective patient reports. This could lead to better diagnostic clarity and a standardized way to monitor treatment success more accurately.
What was researched?
This study investigated whether reaction time metrics during 3D visual tasks in a virtual reality environment could serve as an objective biomarker for cognitive impairment and fatigue in ME/CFS.
Why was it researched?
ME/CFS diagnosis currently relies on subjective questionnaires, which can make it difficult for physicians to track disease severity or the effectiveness of treatments. Researchers aimed to find a tangible, objective measurement for cardinal symptoms like cognitive fatigue and impaired information processing speed.
How was it researched?
A total of 120 participants, including 60 ME/CFS patients and 60 healthy controls, performed three rounds of a 3D stereoptic game using a virtual reality-oculomotor test system. The researchers analyzed reaction times and the capacity to improve performance over repeated gaming rounds while adjusting for age and gender as potential confounding factors.
What has been found?
ME/CFS patients showed consistently slower reaction times compared to controls across all difficulty levels. Unlike the healthy group, ME/CFS patients failed to significantly improve their speed in later rounds, which researchers believe reflects the impact of mental fatigue. Notably, these objective results did not correlate with the patients’ own subjective self-assessment scores, suggesting that traditional questionnaires may not capture the full extent of cognitive slowing.
Discussion
The primary limitation was a lack of age-matching between the patient and control groups, although statistical models were used to normalize the data. The findings suggest that 3D VR tasks provide a more nuanced and taxing assessment of cognitive load than standard 2D tests.
Conclusion & Future Work
The study concludes that 3D virtual reality performance is a promising tool for objectively quantifying fatigue in ME/CFS. Future research should combine these performance metrics with biological markers to further validate the tool’s diagnostic and monitoring power in clinical settings.