ABSTRACT
INTRODUCTION
Choroid plexus (ChP) enlargement is a neuroimaging biomarker of neuroinflammation and neurodegeneration. However, evidence of ChP structural and perfusion alterations in long coronavirus disease (COVID) and their clinical relevance remains limited.
METHODS
This study included 86 long COVID, 67 recovered COVID, and 26 COVID-negative healthy controls (HCs). ChP volume and cerebral blood flow (CBF) were quantified, and their associations with Alzheimer's disease (AD) symptoms and plasma biomarkers were examined.
RESULTS
Both patient groups showed higher ChP volume and lower CBF than HC. Relative to recovered COVID, long COVID patients had a larger ChP volume, but no significant difference in CBF. ChP volume correlated positively with glial fibrillary acidic protein (r = 0.35) and phosphorylated tau217 (p-tau217; r = 0.54), while CBF correlated negatively with p-tau217 (r = –0.56). Both ChP volume and CBF were associated with cognitive decline measured with Mini-Mental State Examination and Clinical Dementia Rating.
DISCUSSION
These findings suggest that ChP differences in long COVID are associated with AD-related cognitive decline and increased plasma biomarkers.
Highlights
- Long coronavirus disease (COVID) patients show choroid plexus (ChP) enlargement and reduced cerebral blood flow.
- ChP alterations are associated with Alzheimer's disease (AD)-related symptoms and plasma biomarker changes.
- ChP alterations on magnetic resonance imaging may serve as imaging markers for tracking neurological symptoms and AD-related pathology in post-COVID patients.

