Abnormal brain perfusion detected in elderly Long COVID patients more than one year after initial mild infection

Motivation: Long COVID in aging has become a significant public health concern, but the neurological mechanisms of Long COVID symptoms remain elusive. Goal(s): This study aimed to assess abnormal brain perfusion related to cognitive impairments in Long COVID, who had initial non-hospitalized mild COVID-19.Approach: : 3D pCASL with Hadamard-encoded multiple PLDs was applied in 30 elderly Long COVID patients in comparison with 28 controls.Results: Both prolonged arterial transit time (ATT) and reduced ATT-corrected CBF (cerebral blood flow) were detected in Long COVID patients compared with controls, which was linked to cognitive deficits. Impact: This study demonstrates the usefulness of advanced MR perfusion techniques in evaluating Long COVID patients, where CBF and ATT showed distinctive patterns that correlated with cognitive decline, manifesting more than a year following the initial mild infection.