Multimodal brain imaging neurotransmitter marker study of TD: a review of TCM effect mechanisms and precise diagnosis and treatment combining traditional Chinese and western medicine.

OBJECTIVE: To systematically summarize findings from multimodal brain imaging and neurotransmitter marker studies in Tic disorders (TD), to explore potential neurobiological mechanisms underlying Traditional Chinese Medicine (TCM) interventions, and to propose a precision diagnosis framework integrating TCM and Western medicine. METHODS: This is a critical narrative review. A systematic literature search was conducted in PubMed, CNKI, and Wanfang databases up to October 2025 using keywords including "TD", "Tourette syndrome", "multimodal imaging", "neurotransmitter", and "TCM", ensuring comprehensive coverage. However, data synthesis followed a narrative, hypothesis-generating approach rather than a formal systematic review or meta-analysis framework. RESULTS: Structural MRI reveals basal ganglia volume reductions and cortical thickness abnormalities; functional MRI shows disrupted cortico-striato-thalamo-cortical (CSTC) connectivity and compensatory activation; DTI demonstrates white matter microstructural alterations; PET/SPECT identifies dopaminergic hyperactivity and serotonergic dysfunction; MRS indicates GABA-glutamate imbalance. TCM interventions (herbal formulas, acupuncture) modulate these imaging phenotypes with good safety profiles. However, most human imaging evidence for TCM remains correlational and preliminary, with animal models providing mechanistic hypotheses that require cautious translation. CONCLUSIONS: Multimodal biomarkers enable objective subtyping and treatment monitoring. Limitations include small sample sizes, cross-sectional designs, comorbidity confounding, and TCM-specific challenges (herbal quality control, blinding difficulties). Future research should prioritize large-scale longitudinal cohorts, standardized TCM randomized controlled trials, and low-cost biomarker translation for primary care implementation.