Assessing the effectiveness of greater occipital nerve block in chronic migraine: a systematic review and meta-analysis.

BACKGROUND & AIMS: Chronic migraine poses a global health burden, particularly affecting young women, and has substantial societal implications. This study aimed to assess the efficacy of Greater Occipital Nerve Block (GONB) in individuals with chronic migraine, focusing on the impact of local anesthetics compared with placebo. METHODS: A meta-analysis and systematic review were conducted following the PRISMA principles and Cochrane Collaboration methods. Eligible studies included case-control, cohort, and randomized control trials in adults with chronic migraine, adhering to the International Classification of Headache Disorders, third edition (ICHD3). Primary efficacy outcomes included headache frequency, duration, and intensity along with safety assessments. RESULTS: Literature searches across multiple databases yielded eight studies for qualitative analysis, with five included in the final quantitative analysis. A remarkable reduction in headache intensity and frequency during the first and second months of treatment with GONB using local anesthetics compared to placebo has been reported. The incidence of adverse events did not differ significantly between the intervention and placebo groups. CONCLUSION: The analysis emphasized the safety and efficacy of GONB, albeit with a cautious interpretation due to the limited number of studies and relatively small sample size. This study advocates for further research exploring various drugs, frequencies, and treatment plans to enhance the robustness and applicability of GONB for chronic migraine management.

Ultrasound-Guided Combined Greater Occipital Nerve Block at the C2 Level with Trapezius Trigger Point Injection and Supraorbital-Supratrochlear Nerve Block: More Effective on Allodynia and Disability in Chronic Migraine.

Background: Chronic migraine (CM) patients with cutaneous allodynia (CA) show a poor response to treatment. Long-term studies have yet to be conducted to demonstrate the efficacy of blocks on CA. This study evaluated the improvement in allodynia and disability in CM treated with ultrasound (US)-guided blocks. Methods: In this prospective, non-randomized comparative study, 60 CM patients with CA were evaluated for the clinical effectiveness of the therapy using the numeric rating scale (NRS), headache impact test-6 (HIT-6), brush allodynia test, and allodynia symptom checklist (ASC-12). At the first visit, tenderness in the nerve or trapezius muscle was confirmed in the intervention group. US-guided greater occipital nerve block (GONB), GONB, and trapezius muscle injection (TPI), or GONB, TPI, and peripheral trigeminal nerve block (PTNB), respectively, were performed four times once a week for a month. Initial and third-month assessments were performed. Results: The ASC-12 scores decreased in the GONB+TPI+PTNB and GONB groups more than the GONB+TPI group (mean rank, respectively, 26.86, 27.40, 38.39; P = 0.018). The decrease in HIT-6 scores was greater in the GONB+TPI+PTNB group than in the GONB group (mean rank, respectively, 21.98, 39.95, P < 0.017) in the first month. In the third month, the GONB+TPI+PTNB group scored HIT-6 significantly lower than GONB and GONB+TPI (mean rank: 18.84, 38.73, 35.61; P < 0.001). Conclusions: GONB+TPI+PTNB was more successful in alleviating allodynia and disability.

Serum CGRP Changes following Ultrasound-Guided Bilateral Greater-Occipital-Nerve Block.

Background: Calcitonin-gene-related peptide (CGRP) and CGRP receptors are expressed in trigeminal nerve cells, and treatments targeting CGRP are effective in migraines. For headaches that do not respond to pharmacological treatment, minimally invasive techniques such as greater-occipital-nerve block (GONB) can help relieve the pain and reduce the frequency of headaches. Our study assessed the efficacy of ultrasound-guided greater-occipital-nerve block (USgGONB) in chronic migraines (CM) and its relationship to serum CGRP levels. Methods: Forty chronic migraineurs who underwent bilateral USgGONB using 40 mg triamcinolone and 1 mL lidocaine were recruited and interictal serum CGRP samples were collected immediately before and one month after GONB. The clinical response was evaluated using headache diaries before and one month after USgGONB. The patient response was determined after USgGONB according to the reduction in headache days as a good responder (>50% reduction), poor responder (<50%) or non-responder. Results: Monthly headache days after GONB showed a significant reduction (median, 10 days; range, 8−14.7) compared to before the block (median, 18 days; range, 17−22; p < 0.001). Across all patients, interictal serum CGRP levels after USgGONB were significantly lower than before the block (median, 40 pg/mL (range, 25−60) vs. 145 pg/mL (range, 60−380) (p = 0.001). The pre-treatment interictal CGRP levels showed a significant difference (p = 0.003), as their levels in non-responders (median, 310 pg/mL; interquartile range, 262−350) were significantly higher than those seen in responders, whether poor responders (median, 135 pg/mL; interquartile range, 100−200 pg/mL) or good responders (median, 140 pg/mL; interquartile range, 80−150 pg/mL). Conclusion: the study showed the beneficial effect of USgGONB in chronic migraines that was associated with lowering interictal CGRP levels, implying a potential role for CGRP in the mechanism of action of GONB in CM, and the interictal CGRP level may be used as a predictor for the response to GONB.