Brain perfusion in patients with amnestic mild cognitive impairment (aMCI)

Amnestic mild cognitive impairment (aMCI) is considered a prodromal stage of dementia. Studies have shown that brain hypoperfusion, which is observed dementia onset and progression, is also seen in patients with aMCI. In this study, we examined the associations between aortic stiffness and brain perfusion in patients with aMCI. A total of 119 participants completed testing. 57 participants were diagnosed with MCI based on Peterson’s criteria. 62 participants were normal cognitive functioning. Total cerebral blood flow (TCBF) was obtained using the ultrasound-derived blood flows of the bilateral internal carotid and vertebral arteries. CBF was normalized (nCBF) to total intracranial volume, assessed using magnetic resonate imaging (MRI), to account for any differences in blood flow due to brain size. The two measures used to measure aortic stiffness were the carotid-femoral pulse wave velocity (cfPWV) and the carotid β-stiffness index (β-stiffness). There were no differences in participant characteristics. The aMCI group had a higher nCBF compared to the NC (p = 0.001). There were no differences in arterial stiffness (cfPWV p = 0.891; β-stiffness p = 0.160) between the groups. A line of best fit revealed there was no relationship between these measures and the nCBF in both NC (NC — nCBF = 38.78 + 0.39*β-stiffness, R 2 = 0.016, p = 0.336; NC — nCBF = 46.34 - 0.45*cfPWV, R 2 = 0.011, p = 0.420) and aMCI groups (aMCI — nCBF = 45.46 + 0.03*β-stiffness, R 2 = 0.001, p = 0.913; aMCI — nCBF = 48.85 - 0.34*cfPWV, R 2 = 0.023, p = 0.269) We observed a higher nCBF in the aMCI compared to the NC group that was not explained by either arterial stiffness measure. This data is surprising, but not novel, as previous studies have shown a hyperperfusion compensatory mechanism early in the MCI diagnosis. Future studies should identify potential mechanisms associated with compensatory mechanisms such as hyperperfusion, and how these mechanisms contribute to aMCI diagnosis and progression. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.