Abstract
Quantitative evaluation of tic disorders (TDs) is challenging as there are few objective indicators that can be used for the assessment of treatment outcomes. 18F-Fluorodeoxyglucose (FDG) is a radioactive tracer that is able to cross the blood-brain barrier and can be detected by positron emission tomography/CT (PET/CT). In the present study, it was hypothesized that FDG PET/CT scan can be applied to reflect the severity of tic symptoms in a rat TD model, where signals detected in the brain striatum can be used to evaluate the efficacy of tic treatment with traditional Chinese medicine (TCM). A rat model of TD was established by treatment with iminodipropionitrile. Rats were divided into the following four groups (n=10 each): i) Control; ii) TCM; iii) haloperidol; and iv) model only. Observations of stereotypic behavior in rats were subsequently scored and micro-PET/CT was used to evaluate the rate of FDG uptake. Stereotypy scores were found to be significantly higher (P<0.05) in the TD rat model (P<0.05) compared with those in control rats. Both stereotypy scores (P<0.05) and standardized FDG uptake values (SUV; P<0.05) were revealed to be significantly reduced in the TD model rats after treatment with TCM or haloperidol. SUV correlated positively with stereotypy score (R=0.926; P<0.05) and the SUV scores were found to be significantly different among control group, TCM group, haloperidol group and model only group (P<0.05). These data suggest that the application of FDG in the striatum can be used to evaluate the effectiveness of TCM treatment for TDs.