Proton MR spectroscopy in Wilson disease: analysis of 36 cases

Abstract

Background and purpose: Wilson disease (WD) is rare but one of the few metabolic disorders that can possibly benefit from effective available treatments. The literature regarding proton MR spectroscopy (MRS) in WD is scarce and controversial. The purpose of this study was to determine the brain metabolic changes due to WD by using MRS. To our knowledge, this is the first time that MRS was performed in such a large sample of patients with WD.

Methods: Thirty-six patients with WD and 37 healthy volunteers were examined with MRS in the parieto-occipital cortex, frontal white matter, and basal ganglia (BG). Ratios of the following metabolites were calculated in relation to creatine (Cr): N-acetylaspartate (NAA), choline (Cho), myo-inositol (mI), and glutamine/glutamate (Glx). The mean peak line width was measured on each spectrum.

Results: Compared with control subjects, patients with WD had significantly decreased NAA/Cr ratios in the three studied areas (P < .005) and an increased mI/Cr ratio in the BG (P < .001). Cho/Cr and Glx/Cr did not differ between the groups. The mean peak line in the BG was wider in patients than in control subjects.

Conclusion: WD is unequivocally associated with MRS changes that could possibly be assigned to neuronal loss (in the three studied areas), to gliosis, and to iron and/or copper deposition in the BG.

Fig 1.

Axial T2-weighted fast spin-echo images (TR/TE = 3000/88.8, echo train length = 22) show the VOIs for MRS. A, In the BG. B, In the FWM. C, In the POC.

Fig 2.

Representative STEAM spectra (TR/TE = 2000/30) in the BG. A, Spectrum in a patient with WD shows reduction of the NAA peak relative to the Cr peak, with augmentation of the mI peak. B, Spectrum in a control subject obtained in the same location.

Fig 3.

Scatterplot shows NAA/Cr and mI/Cr ratios in the BG in patients with WD and in control subjects.