Applying the new research diagnostic criteria: MRI findings and neuropsychological correlations of prodromal AD.

OBJECTIVE

We describe the neuroimaging characteristics of prodromal AD (PrdAD) patients diagnosed using the new research criteria in a clinical setting. In order to further characterize these patients, we also study the relationship between neuropsychology, CSF biomarkers and magnetic resonance imaging (MRI) findings.

METHODS/PATIENTS: 76 participants--24 controls (CTR), 20 amnesic patients, and 32 Alzheimer's disease (AD) patients--were included in the study. PrdAD was defined on the basis of an objective episodic memory deficit and an AD CSF profile. Structural MRI was performed in all participants.

RESULTS

After FWE correction, voxel-based morphometry (VBM) analysis of PrdAD patients versus CTR showed significant clusters of decreased gray matter (GM) volume in the left hemisphere regions including the parahippocampal gyrus, uncus, precuneus, and middle frontal gyrus. We did not find differences in brain atrophy between PrdAD and mild AD patients. Some significant associations were found between CSF levels and episodic and semantic fluency tests in the PrdAD group. Correlations in the PrdAD group revealed that patients with higher scores on delayed free recall had significantly greater GM volume in the left superior temporal gyrus (t = 6.64, p < 0.0001).

CONCLUSIONS

PrdAD patients presented mainly medial temporal GM atrophy, which was related with significant episodic memory impairment. The cognitive deficit observed in PrdAD patients was also associated with CSF biomarker levels.