Purpose: To investigate whether there are metabolite changes in basal ganglia of children with complete healing of rheumatic fever (RF), history of Syndenham chorea (SC) and obsessive compulsive-tic disorder (OCTD) developed after RF when compared with healthy controls and each other. Material and methods: A total of 49 children with history of RF and 31 healthy controls were included into the study. All patients and control group underwent a detailed neuropsychiatric evaluation. Children with the history of RF were classified into-three groups as; group 1: with history of RF without neuropsychiatric complications (NCRF), group 2: only with history of SC (HSC), group 3: with HSC and OCTD (OCTD). After MR imaging, single voxel MR spectroscopy was performed in all subjects. Voxels (15 x 15 x 15 mm) were placed in basal ganglia. N-acetyl aspartate (NAA)/creatin (Cr), and choline (Cho)/Cr ratios were calculated. Results: OCTD were detected in 13 children with HSC. NAA/Cr ratio was found to be decreased in these children when compared with NCRF (n:29), HSC without OCTD (n:7) and control groups (n:3 1). No significant difference was found in metabolite ratios of children with HSC without OCTD when compared with NCRF and control groups. There were no significant differences in Cho/Cr ratio between patient and control groups. Conclusion: Although MR imaging findings was normal, MR spectroscopy findings (decreased NAA/Cr ratio) in our study support the neuronal loss in basal ganglia of children with OCTD and could indicate the development of permanent damage. (C) 2003 Elsevier Ireland Ltd. All rights reserved.