Virtual Reality IDs Navigation Issues in Early Alzheimer Disease
Classification accuracy superior to cognitive tests considered highly sensitive to early disease
WEDNESDAY, June 12, 2019 (HealthDay News) -- An entorhinal cortex-based virtual reality navigation task can differentiate patients with mild cognitive impairment at low and high risk for developing dementia, according to a study published in the June issue of Brain.
David Howett, from the University of Cambridge in the United Kingdom, and colleagues studied 45 patients with mild cognitive impairment (26 with cerebrospinal fluid [CSF] Alzheimer disease biomarker data: 12 biomarker-positive and 14 biomarker-negative) and 41 healthy control participants. Participants took an immersive virtual reality path integration test as a measure of entorhinal-based navigation.
The researchers found that behavioral performance was correlated with magnetic resonance imaging measures of entorhinal cortex volume. Biomarker-positive patients showed larger errors in the navigation task compared with biomarker-negative patients, whose performance was similar to that of control participants. There was a positive correlation between path integration performance and Alzheimer disease molecular pathology, with levels of CSF amyloid-β and total tau contributing independently to distance error. There was a negative correlation between path integration errors and the volumes of the total entorhinal cortex and of its posteromedial subdivision. The path integration task's differentiation of biomarker-positive versus biomarker-negative patients (area under the curve, 0.90) had higher diagnostic sensitivity and specificity than the best cognitive tests (area under the curve, 0.57).
"This study provides evidence that navigation tasks may aid early diagnosis of Alzheimer's disease, and the basis of this in animal cellular and behavioral studies provides the opportunity to answer the unmet need for translatable outcome measures for comparing treatment effect across preclinical and clinical trial phases of future anti-Alzheimer's drugs," the authors write.