Sustained attention instability as a cognitive biomarker in chronic spine pain: a 90- second visual attention test
Abstract
Background: Chronic spine pain is linked to self-reported cognitive complaints. This condition involves changes within fronto-parietal networks, including the dorsolateral prefrontal cortex (DLPFC) and posterior parietal cortex, which are related to cognitive impairment. However, objective markers are lacking. The 90-second Continuous Visual Attention Test (CVAT) quantifies key attention subdomains: reaction time (RT, alertness), RT variability (VRT, sustained attention), omission errors (focused attention), and commission errors (impulsivity). Considering that all other cognitive domains depend on attention, it is important to objectively assess these subdomains for a better understanding of these cognitive alterations. Objective: This study aimed to identify which specific attentional subdomains, measured by the CVAT, are impaired in adults with chronic spine pain. Methods: This prospective case–control study included 84 adults with chronic lumbar/cervical pain (≥3 months) and 118 healthy controls. A MANCOVA tested group differences on CVAT variables, controlling for age and sex, followed by Bonferroni-corrected ANCOVAs. To isolate cognitive variability from general processing speed, the coefficient of variability (VRT/RT) was also analyzed. Logistic regression assessed the predictive power of CVAT indices for pain status. Results: The MANCOVA showed a significant group effect (Pillai's Trace = 0.46, F(4,195) = 41.43, p < .001). Patients exhibited impairments in all measures (p < .001; η² = 0.093–0.44). The VRT deficit persisted when using VRT/RT. Logistic regression identified VRT as the strongest predictor of chronic spine pain (χ²(1) = 147.53, p < .001), correctly classifying 86.6% of participants. This finding remained when using VRT/RT (χ²(1) = 130.55, p < .001; 82.7% accuracy). Conclusion: Patients with chronic spine pain demonstrate attentional deficits, with sustained attention instability (VRT and VRT/RT) as the most robust marker. The CVAT detects this impairment, offering a practical tool for clinical assessment to inform treatment and monitor cognitive function in pain management.