Convergent and Discriminant Validity of Default Mode Network and Limbic Network Perfusion in Amnestic Mild Cognitive Impairment Patients

Background: Previous studies reported default mode network (DMN) and limbic (LIN) brain perfusion deficits in patients with amnestic mild cognitive impairment (aMCI), frequently a prodromal stage of Alzheimer’s disease (AD). However, the validity these measures as AD markers has not yet been tested using MRI arterial spin labeling (ASL). Objective: To investigate convergent discriminant DMN LIN aMCI. Methods: We collected core (amyloid-? 42 [A?42], phosphorylated tau 181 levels cerebrospinal fluid [CSF]), neurodegenerative (hippocampal volumes CSF total tau), vascular (white matter hyperintensities), genetic (apolipoprotein E [APOE] status), features (memory functioning on Paired Associate Learning test [PAL]) 14 aMCI patients. Cerebral blood flow (CBF) was extracted from ASL correlated to assess validity. Discriminant assessed carrying out same analysis AD-unrelated features, i.e., somatomotor visual networks’ perfusion, cerebellar volume, processing speed. Results: Perfusion reduced (F = 5.486, p 0.039) 12.678, 0.004) APOE ?4 carriers compared non-carriers. A?42 (r 0.678, 0.022) memory (PAL, number errors, r –0.779, 0.002). No significant correlation detected tau, neurodegeneration, nor features. Conclusion: Our results support aMCI, indicating between CBF amyloidosis, ?4, impairment.