Proton magnetic resonance spectroscopy of the thalamus in chronic complex regional pain syndrome (CRPS) type-1 patients

Abstract

AbstractRecent reports have suggested that reduced thalamic blood flow and functional alterations in thalamic pain processing circuits may be important components in chronic neuropathic pain. The purpose of the present study was to examine neural activity in the thalamus in chronic CRPS (complex regional pain syndrome) type-1 patients, using proton magnetic resonance spectroscopy (1H-MRS). We performed 1H-MRS with a 1.5T MR system on a 2 × 2 × 2-cm voxel in the thalamus bilaterally, in five CRPS type-1 patients and six normal control subjects. We measured the N-acetylaspartate to creatine (NAA/Cr) ratio, which reflects neural activity, using 1H-MRS. The mean NAA/Cr ratio in the thalamus contralateral to the side of pain decreased significantly, compared to the mean NAA/Cr ratio of the ipsilateral side and the normal control subjects. Our results using 1H-MRS suggest that chronic CRPS type-1 seems to be associated with abnormal balance of neural activity of the thalamus.