Neurometabolic changes in normal white matter may predict appearance of hyperintense lesions in systemic lupus erythematosus

Abstract

To determine if neurometabolic changes in the white matter (WM) of systemic lupus erythematosus (SLE) patients may predict the appearance of small hyperintense lesions on T2-weighted magnetic resonance imaging (MRI) inside the magnetic resonance spectroscopy (MRS) region of interest (ROI). We included 30 SLE patients and 23 controls. We performed single voxel proton MRS over the superior-posterior region of the corpus callosum. We measured signals from N-acetyl-compounds (NAA), choline (Cho) and creatine-phosphocreatin (Cr) and determined NAA/Cr and Cho/Cr ratios. After a minimum of 12 months, MRI and MRS were repeated in all patients and nine volunteers. Twenty patients had normal MRI and 10 patients had MRI hyperintense lesions in the MRS ROI at baseline. All patients had hyperintense lesions in the MRS ROI in follow-up MRIs. All SLE patients had increased Cho/Cr values at both MRS when compared with normal controls ( P = 0.001). In addition, there was an increase in Cho/Cr values when patients' baseline and follow-up MRS were compared ( P = 0.001). We observed a correlation between Cho/Cr ratios and number of WM lesions ( r = 0.69; P = 0.001). Increased Cho/Cr in normal appearing WM may be indicative of future appearance of hyperintense T2-weighted MRI lesions in SLE patients. Lupus (2007) 16, 963—971.