Efficacy and safety of greater occipital nerve block with a small volume of lidocaine and methylprednisolone in tertiary headache center

Background: The greater occipital nerve block (GON-B) is used in clinical practice for treating different forms of headache. There is no standardized procedure to perform GON-B. This study evaluates the efficacy and feasibility of a low-volume GON-B protocol utilizing a pre-mixed solution of lidocaine (10 mg) and methylprednisolone (40 mg) across various headache disorders. Methods: This observational case series included patients receiving their first GON-B from November 2019 to February 2021. Participants were diagnosed with migraine, cluster headache, cervicogenic headache, or paroxysmal hemicrania. The primary outcome was the degree of response to the GON-B. Results: Thirty-nine patients with migraine underwent a first GON-B. Regarding headache frequency, 26% achieved substantial response and 33% partial response. For headache intensity, 26% reported substantial and 49% partial improvement. Migraine patients experienced a significant reduction in median monthly headache days from 25 to 13 (p=0.001) and in headache intensity from a median of 8 to 6 on the Numerical Rating Scale (NRS) scale (p<0.001). Of the 27 patients receiving a second GON-B, 33% had a substantial response, 48% a partial response, and 19% no response. Results from subsequent sessions were consistent with these findings. Ten patients with cluster headache underwent GON-B, showing a significant reduction in pain intensity from a median NRS score of 10 to 5 (p=0.008). Two patients with cervicogenic headache showed a partial response to GON-B, with pain intensity decreasing from 8 to 6 and 8 to 7 over 30 monthly episodes. A patient with paroxysmal hemicrania received seven GON-B injections, reducing daily attacks from 30 to 10 and pain intensity from 7 to 6 on the NRS scale. Conclusions: These outcomes affirm GON-B potential in interrupting pain pathways, even at a low dose, in a wide range of headache disorders.