Neuronal Dysfunction in Patients with Closed Head Injury Evaluated by In Vivo 1H Magnetic Resonance Spectroscopy

Abstract

With the use of localized, water-suppressed in vivo 1H magnetic resonance spectroscopy (MRS), the proton metabolic alterations of white matter in patients with closed head injury (CHI) and healthy controls are evaluated, and metabolic alterations with Glasgow Outcome Scale (GOS) scores are compared. Patients with CHI (n = 10) and healthy control subjects (n = 10) underwent MRS examinations using a stimulated-echo acquisition mode pulse sequence that provided 2 x 2 x 2 cm3 volume of interest in the left frontoparietal white matter. Proton metabolite ratios relative to creatine were obtained using a Marquart algorithm. The specific feature in patients with CHI was significant decrease of N-acetylaspartate (NAA)/creatine ratio compared with normal controls. No clear correlation of other metabolite ratios such as choline/creatine and inositols creatine was established. The level of NAA/creatine ratio was significantly correlated with GOS. Results of this preliminary study suggest that the reduction of NAA/creatine ratio may indicate neuronal loss in patients with CHI. The NAA/creatine ratio may serve as a metabolic criterion to predict the GOS of patients with CHI. Thus, in vivo 1H MRS may be a useful modality in the clinical evaluation of patients with CHI based on the proton metabolite concentrations of cerebral white matter.