Table 5.
Arterial spin labeling MRI correlates of episodic memory
| Author, year | Study groups | Episodic memory test | Imaging analysis method | Imaging correlates of episodic memory |
|---|---|---|---|---|
| Preclinical AD | ||||
| Fleisher, et al 2009 [115] | 13 CNC (positive family history of AD and at least one copy of the APOE ε4; high risk), 10 CNC without these risk factors | Face-name association | CBF and BOLD signal response in MTL | Decreased CBF and BOLD response during encoding in the high risk group. |
| Bangen, et al 2014 [116] | 16 CNC with high, 55 with low vascular risk | CVLT-II | CBF in caudate, thalamus, MTL, posteromedial and frontal cortices | Trend for positive correlation between MTL CBF and memory in high vascular risk group. |
| Zlatar, et al 2016 [117] | 21 APOE ε4 carrier, 38 noncarrier CNC | WMS-R, CVLT-II | Voxel-wise analysis | R anterior cingulate, L HC, parahippocampal gyrus, insula, putamen, middle temporal, supramarginal, R middle and superior temporal gyri CBF negatively correlated with verbal memory in APOE ε4 carriers. |
| Bangen, et al 2017 [118] | 15 Aβ+, 47 Aβ- CNC (florbetapir PET) | AVLT | CBF in HC, PCG, precuneus and postcentral gyrus | HC, PCG and precuneus CBF negatively correlated with recall in Aβ+ CNC. |
| Hays, et al 2017 [119] | 35 subjective cognitive decline, 35 CNC | CVLT-II, WMS-R | Voxel-wise analysis | PCG, corpus callosum, HC, L medial and inferior temporal, fusiform gyri, R inferior frontal gyrus CBF negatively correlated with verbal memory in subjective cognitive decline CNC. |
| Preclinical AD and MCI | ||||
| Bangen, et al 2012 [120] | 16 MCI (8 APOE ε4 carriers), 29 CNC (14 APOE ε4 carriers) | Picture encoding | CBF and BOLD signal response in MTL | No CBF or BOLD difference between CNC and MCI; and APOE ε4 carriers and noncarriers. |
| Wierenga, et al 2012 [121] | 20 MCI (9 APOE ε4 carriers), 40 CNC (13 APOE ε4 carriers) | WMS-R, CVLT-II | Whole brain CBF | L parahippocampal and fusiform gyri CBF positively correlated with verbal memory in APOE ε4 carriers. |
| MCI | ||||
| Xu, 2007 et al [122] | 12 aMCI, 14 CNC | RAVLT, scene encoding | Voxel-wise analysis | Reduced R precuneus, cuneus and PCG CBF during the task. CBF positively correlated with RAVLT in the overall sample. |
| Xie, 2016 et al [123] | 65 aMCI, 62 CNC | Scene encoding | Voxel-wise analysis and CBF in PCG, precuneus, HC, parahippocampal gyrus | Reduced MTL, temporal pole, precuneus, PCG, L lingual and fusiform gyri, cuneus, superior occipital lobe CBF during the task. |
Abbreviations: CNC, cognitively normal control; AD, Alzheimer's disease; APOE ε4, apolipoprotein E ε4; Aβ, amyloidβ; MCI, mild cognitive impairment; aMCI, amnestic mild cognitive impairment; CVLT-II, California Verbal Learning Test-II; WMS-R, Wechsler Memory Scale-Revised; AVLT, Auditory Verbal Learning Test; RAVLT, Rey Auditory Verbal Learning Test; CBF, cerebral blood flow; BOLD, blood-oxygen-level dependent; MTL, medial temporal lobe; HC, hippocampus; PCG, posterior cingulate gyrus; R, right; L, left.