Chronic migraine is a highly disabling disorder often refractory to pharmacological therapy. Greater occipital nerve block (GONB) is an established interventional strategy; however, traditional landmark-guided techniques may limit accuracy and safety. Ultrasound guidance allows precise visualization of the nerve at both proximal (C2 level) and distal (occipital) locations, potentially improving outcomes. Current literature presents variability in technique and uncertainty regarding the optimal injection site.

Twelve studies comprising 658 patients were included. US-GONB significantly reduced pain intensity (MD: –3.48) and monthly headache frequency (MD: –9.12), with sustained benefits up to three months. Both single- and repeated-frequency protocols demonstrated effectiveness, with repeated injections producing greater improvements. Proximal and distal approaches were similarly effective in reducing pain, but proximal injections achieved greater reductions in monthly headache frequency (–10.83 vs –6.36 days; P = 0.006). US-GONB also reduced headache duration and analgesic use. Adverse events were generally mild; however, proximal blocks were associated with higher rates of sensory changes and vasovagal symptoms.