Interval saccades and fronto-parietal-occipital connectivity: Neural signatures of cognitive-sensorimotor impairment in Wilson's disease.

BACKGROUND

Eye movements intuitively reflect visual information processing and motor planning and execution. Studies confirm that Wilson's disease (WD) patients have abnormal eye movements, such as prolonged saccade latency and increased anti-saccade error rates, but the underlying mechanism remains unclear, a key gap in understanding copper-induced neural damage in WD. This study used non-invasive high-precision eye-tracking combined with fMRI to analyze abnormal eye movement characteristics and cognitive-sensorimotor integration disorder networks in WD patients with and without potential cognitive impairment risk.

METHOD: Montreal Cognitive Assessment (MoCA) was performed on 44 WD patients: 32 scored < 26, 12 scored ≥ 26, with no differences in age, disease duration, or UWDRS scores between groups. Eye movement data from the EyeKnow™ system showed MoCA scores negatively correlated with interval saccade latency and fastest completion time, and positively correlated with maximum interval saccade speed, anti-saccade accuracy, and average/maximum saccade speeds.

RESULT: 1.5 T fMRI revealed 10 connectivity abnormalities across 7 brain regions among patients with MoCA < 26, with the right superior parietal lobule-right lateral occipital cortex abnormality being particularly prominent. Correlation studies found sLOC.L - AG.L and sLOC.r - AG.r positively correlated with interval saccade completion time; SPL.r - aSMG.r positively correlated with interval saccade latency.

CONCLUSION

The study suggests interval saccades can serve as an important marker of cognitive-sensorimotor integration disorders in WD patients, involving collaborative participation of multiple frontal, parietal, and occipital brain regions.