[99mTc]TRODAT-1/[123I]IBZM SPECT studies of the dopaminergic system in Tourette syndrome.
The good clinical effectiveness of dopamine depleter and receptor antagonists on tics suggests dopaminergic hyperactivity in Tourette syndrome (TS). In this case-control study of 10 TS patients and 15 age-matched healthy controls, we evaluated (i) presynaptic and postsynaptic striatal dopaminergic function using [(99m)Tc]TRODAT-1/[(123)I]IBZM single photon emission computed tomography (SPECT) and (ii) correlations between dopamine transporter (DAT)/D2 receptor binding sites and tic severity scores. Patients 1-5 were pretreated with haloperidol and were drug free for at least 3 months before SPECT imaging. Patients 6-10 were drug-naïve. We found no significant difference in DAT and D2 receptor binding sites between TS patients and healthy controls nor any association between striatal DAT or D2 receptor binding sites and tic severity assessed using the Modified Rush Videotape Rating Scale. Our findings provided no direct evidence of abnormally available striatal DAT or dopamine D2 receptors in TS. However, functional abnormalities of the dopaminergic system, e.g., alterations in the synaptic release of endogenous dopamine, cannot be completely ruled out.
Hwang
Wen-Juh
WJ
Department of Neurology, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 70428, Taiwan. wjhwang@mail.ncku.edu.tw
Yao
Wei-Jen
WJ
Fu
Ying-Kai
YK
Yang
An-Shoei
AS
D000293:Adolescent; D000328:Adult; D001549:Benzamides; D003342:Corpus Striatum / Q000000981:diagnostic imaging* / Q000503:physiopathology; D050483:Dopamine Plasma Membrane Transport Proteins / Q000502:physiology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007457:Iodine Radioisotopes; D008279:Magnetic Resonance Imaging; D008297:Male; D009460:Neurologic Examination; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2 / Q000502:physiology*; D017661:Receptors, Presynaptic / Q000502:physiology; D013569:Synapses / Q000502:physiology; D015899:Tomography, Emission-Computed, Single-Photon; D005879:Tourette Syndrome / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014326:Tropanes
D001549:Benzamides; D050483:Dopamine Plasma Membrane Transport Proteins; D007457:Iodine Radioisotopes; D015609:Organotechnetium Compounds; D011759:Pyrrolidines; D017448:Receptors, Dopamine D2; D017661:Receptors, Presynaptic; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1; C055743:3-iodo-2-hydroxy-6-methoxy-N-((1-ethyl-2-pyrrolidinyl)methyl)benzamide