Mapping gray matter loss with voxel-based morphometry in mild cognitive impairment

We used voxel-based morphometry to comprehensively and objectively map gray matter loss in 22 patients with amnestic mild cognitive impairment, defined as progressive isolated episodic memory decline. Compared with 22 age-matched healthy controls, patients had highly significant gray matter loss predominantly affecting the hippocampal region and cingulate gyri (posterior and subcallosal part of the anterior), and extending into the temporal neocortex. Compared with 16 age-matched patients with mild Alzheimer's disease, gray matter density was significantly preserved in mild cognitive impairment in the posterior association cortex. This pattern of gray matter loss in mild cognitive impairment agrees with but considerably expands upon previous region-of-interest based MRI studies, and is highly consistent with the course of neurofibrillary tangles across aging and Alzheimer's disease.