Investigating the oxidative stress-vascular brain injury axis in mild cognitive impairment of the Alzheimer's type.

INTRODUCTION

Oxidative stress may contribute to brain injury in the Alzheimer's disease (AD) continuum. The antioxidant glutathione (GSH) can be assessed with magnetic resonance spectroscopy (MRS). Because the relationship between GSH and vascular brain injury is unknown in the AD continuum, we address this gap in mild cognitive impairment (MCI).

METHODS

3T Magnetic resonance imaging (MRI)/MRS data were obtained from 31 patients with MCI. GSH and total N-acetylaspartate (tNAA; neuroaxonal integrity marker) were measured in posterior cingulate cortex (PCC) and frontal white matter (FWM). Cerebrovascular injury was assessed using white matter hyperintensity (WMH) volume. Global and regional brain tissue integrity were assessed using normalized brain (NBV) and hippocampal volumes.

RESULTS

Significant associations were reported in FWM between GSH/total creatine (tCr) and tNAA/tCr, and between GSH and both WMH and NBV. tNAA, GSH/tCr, and tNAA/tCr were higher in PCC than in FWM.

DISCUSSION

Our results suggest that oxidative stress contributes to vascular brain injury in MCI.

HIGHLIGHTS

Neuronal, vascular, and oxidative injuries occur in the Alzheimer's disease (AD) spectrum. Glutathione (GSH) is the main endogenous antioxidant in the brain. Brain GSH can be measured with magnetic resonance spectroscopy (MRS). We measured brain GSH level in people with mild cognitive impairment (MCI). Low GSH level was associated with vascular brain injury, neuroaxonal damage, and atrophy.