Neural correlates of verbal episodic memory in patients with MCI and Alzheimer's disease--a VBM study.

Objective: The hippocampus is a key area for episodic memory processes. Hippocampal atrophy is a hallmark feature of Alzheimer's disease (AD). We used a new and automatized morphometric technique to better characterize brain atrophy in subjects with different levels of cognitive deficit.

Methods: In this study 21 participants with Mild Cognitive Impairment (MCI), 12 patients with early AD and 29 elderly control subjects were subjected to high resolution MRI and a neuropsychological test battery. Brain volume across participants, measured by voxel-based morphometry (VBM), was correlated with verbal memory capacity, measured with a verbal memory test (VLMT).

Results: Atrophy in the anterior hippocampus, the ento- and perirhinal cortex as well as the parahippocampal gyrus, middle temporal gyrus and anterior cingulate cortex correlated closely with episodic memory performance.

Conclusions: These brain areas are known to subserve episodic encoding of verbal material. The data contribute to a better understanding of atrophic brain processes in subjects at risk for AD. A combination of neuropsychological testing and voxel-based morphometry may serve as a diagnostic tool in the future.