No change in striatal dopamine re-uptake site density in psychotropic drugnaive and in currently treated Tourette's disorder patients: a [I-123]-beta-CIT SPECT-study

Background: There is evidence that Tourette's disorder (TD) is associated w ith abnormalities in the dopaminergic system involving the dopamine transpo rter (DAT). Data from [I-123]-beta -CIT single photon emission computed tom ography (SPECT) studies and postmortem findings concerning DAT densities in TD patients are not conclusive. The objective of our study was to measure DAT densities with [I-123]-beta -CIT binding in TD patients who were either psychotropic drug naive or currently treated with antipsychotics (AP) and healthy controls. Method: Altogether 20 TD patients were investigated. A to tal of 15 patients were psychotropic drug naive and five were currently tre ated with AP. Ten psychotropic drug naive patients were compared with ten a ge and sex matched healthy subjects. Five currently treated patients were c ompared with five age and sex matched psychotropic drug naive TD patients. The investigation was carried out using [I-123]-beta -CIT (2-beta -carbomet hoxy-3-beta (4-iodophenyl)-tropane and SPECT. Regions of interest (ROI) wer e drawn over the striatum and the cerebellum. Results: The DAT densities me asured by the striatal/cerebellar (S/C) binding ratio did not differ betwee n drug naive TD patients and the controls. The difference between currently AP treated and psychotropic drug naive TD patients did not reach the level of significance. There was no correlation between the ratio and severity o f ties and illness. Conclusion: Our study with psychotropic drug naive TD p atients contributed to clarify the inconsistent results concerning the DAT. (C) 2001 Elsevier Science B.V. All rights reserved.