Localized proton NMR spectroscopy in the striatum of patients with idiopathic spasmodic torticollis.

Single voxel proton spectroscopy was used to study brain metabolism in idiopathic spasmodic torticollis. Peak metabolite ratios in long echo time (135 ms) spectra were evaluated in the basal ganglia of 16 patients (29-65 years). Eight of them were untreated; the other eight were examined 4-6 weeks after administration of botulinum toxin type A. As compared with 60 control spectra, patients showed a significant, therapy-resistant decrease in N-acetyl-L-aspartate (NAA)/choline (Cho). NAA/creatine (Cr) and Cho/Cr were close to normal in the post-treatment group but significantly reduced in untreated patients. This result is consistent with the hypothesis that striatal Cr is reversibly elevated in chronic muscle stimulation. The right and left striatum were affected to the same extent.