Dopamine D-2 receptor imaging in Gilles de la Tourette syndrome

Objectives - To examine postsynaptic dopamine D-2 receptors in Tourette syn drome (TS). Material and methods - Seventeen patients and a control group w ere investigated using single photon emission computed tomography (SPECT) a nd iodobenzamide (I-123-IBZM). Results - In neuroleptic treated patients (n = 7) I-123-IBZM-binding was significantly reduced compared to both normal controls (P < 0.0001) and unmedicated patients (P < 0.001). In unmedicated patients (n = 10) mean binding ratio did not differ from that of control gr oup. Patients in advanced stages of the disease, however, revealed signific antly reduced relative striatal binding compared to patients in the early s tages (P < 0.005) and normal controls (P < 0.0001). Conclusion - The result s lend further support to the hypothesis that the dopamine receptor is invo lved in TS pathology. During the natural course of the disease ties often i mprove in early adulthood. It is suggested that this spontaneous recovery f rom ties may be associated with reduced receptor binding capacity.