Wei Wang
This project is a narrative review synthesizing mechanistic and clinical evidence of stellate ganglion block (SGB) for insomnia disorder, a prevalent chronic condition driven by persistent autonomic hyperarousal, sympathetic overactivity and HPA axis dysregulation. Standard insomnia treatments including CBT-I and hypnotics carry major accessibility and safety limitations; SGB, an ultrasound-guided cervical sympathetic nerve blockade, has emerged as a novel autonomic-targeted intervention but lacks comprehensive integrated evidence. The primary purposes are: (1) Summarize neurobiological evidence confirming autonomic dysfunction as the core pathology of hyperarousal insomnia; (2) Elaborate multi-pathway sleep-improving mechanisms of SGB including catecholamine suppression, HPA axis normalization, anti-inflammation and enhanced cerebral perfusion; (3) Systematically synthesize clinical efficacy, safety and subgroup outcomes of SGB as monotherapy for primary, refractory, perioperative, cancer-related and anxiety-comorbid insomnia; (4) Evaluate synergistic benefits of combined SGB + CBT-I/acupuncture treatments; (5) Identify widespread research limitations and propose standardized future trial frameworks to guide clinical application. We conduct systematic multi-database retrieval of mechanistic studies, RCTs, meta-analyses and observational cohorts, perform thematic narrative synthesis and tabulate key quantitative sleep and autonomic biomarker data. Expected outcomes include: an integrated multi-pathway physiological model of SGB anti-hyperarousal effects; consolidated clinical evidence showing consistent sleep improvements across insomnia subtypes and synergistic combined therapy benefits; a full summary of existing study flaws (small samples, protocol heterogeneity, short follow-up, geographic bias); clear clinical positioning of SGB as adjuvant therapy for treatment-resistant hyperarousal insomnia; and concrete recommendations for rigorous future neuromodulation trials. The final review manuscript, data extraction tables and supplementary materials will be archived on OSF to support open, reproducible sleep medicine research.