Dynamic brain glymphatic changes and cognitive function in COVID-19 recovered patients: a DTI-ALPS prospective cohort study.

OBJECTIVE

This study aimed to evaluate brain glymphatic function in COVID-19 recovered patients using the non-invasive Diffusion Tensor Imaging-Analysis Along the Perivascular Space (DTI-ALPS) technique. The DTI-ALPS technique was employed to investigate changes in brain glymphatic function in these patients and explore correlations with cognitive function and fatigue.

MATERIALS AND METHODS

Follow-up assessments were conducted at 1, 3, and 12 months post-recovery. A total of 31 patients completed follow-ups at all three time points, with 30 healthy controls (HCs) for comparison.

RESULTS

Compared to HCs, COVID-19 recovered patients showed a significant decline in MoCA scores at 3 months post-recovery ( < 0.05), which returned to near-normal levels by 12 months. Mental fatigue, measured by the Fatigue Assessment Scale (FAS), was significantly higher in COVID-19 patients at all follow-up points compared to HCs ( < 0.05). The DTI-ALPS index in both hemispheres showed significant differences at 3 months post-recovery compared to HCs ( < 0.001), indicating increased glymphatic activity. Longitudinal analysis revealed a peak in the DTI-ALPS index at 3 months post-recovery, which then decreased by 12 months. Correlation analysis showed a significant negative correlation between the Bilateral brain hemisphere DTI-ALPS index and MoCA scores (right side:  = -0.373,  = 0.003; left side:  = -0.255,  = 0.047), and a positive correlation with mental fatigue (right side:  = 0.275,  = 0.032; left side:  = 0.317,  = 0.013).

CONCLUSION

This study demonstrates dynamic changes in brain glymphatic function in COVID-19 recovered patients, with a peak in activity at 3 months post-recovery. These changes are associated with cognitive function and mental fatigue, suggesting potential targets for addressing neurological symptoms of long COVID. The non-invasive DTI-ALPS technique proves to be a valuable tool for assessing brain glymphatic function in this population.