Hippocampal metabolic abnormalities in mild cognitive impairment and Alzheimer's disease

Abstract Mild cognitive impairment (MCI) defines a group of otherwise healthy elderly subjects with a markedly elevated risk of developing Alzheimer's disease (AD). In the search for biomarkers of MCI, we assessed whether MCI shares neurochemical abnormalities with AD in areas affected early in the course of the disease. As a secondary study aim, we tested to what extent neurochemical findings reflect neuropsychological deficits. Proton spectroscopy was performed in 19 MCI patients, 18 AD patients and 22 age and gender matched controls (CON) within the parietal gray and white matter (PWM and PGM) and the hippocampus (HIP). The cognitive test battery used included measures compiled by the Consortium to Establish a Registry for Alzheimer's Disease (CERAD). The N -acetyl-aspartate to creatine ratio (NAA/Cr) was significantly reduced in the HIP of MCI and AD compared with CON ( p p p p p 1 H MRS may enable an objective staging of the neurodegenerative process underlying the age-dependent cognitive deficits eventually leading to dementia.