Background: Mild cognitive impairment (MCI) is a recently described transitional clinical state between normal aging and Alzheimer's disease (AD). With the assumption that amnestic MCI patients had pathologic changes corresponding to an early phase and probable AD patients to a later phase of the disease progression, we could approximate the temporal course of proton magnetic resonance spectroscopy ( 1 H-MRS) alterations in AD with a cross-sectional sampling scheme.