Greater occipital nerve blocks in chronic cluster headache: a prospective open‐label study

Background and purpose Greater occipital nerve blockade ( GONB ) has been shown to be effective in episodic cluster headache. However, its use in chronic cluster headache ( CCH ) is less certain. The study aims to prospectively assess the efficacy and consistency of response to GONB in a large series of CCH patients. Methods CCH patients who had a unilateral GONB and were referred to the N ational H ospital for N eurology and N eurosurgery were studied prospectively. Headache characteristics were collected using headache diaries. Responders were considered to be patients with a complete or partial response lasting at least 7 days. In a subgroup of responders the outcomes of serial GONB performed at 3‐monthly intervals were also analysed. Results Eighty‐three CCH patients were studied. After the first GONB , a positive response was observed in 47 (57%) patients: 35 (42%) were rendered pain free, 12 (15%) had a partial benefit and one patient obtained <50% improvement. The duration of a positive response lasted a median of 21 days (range 7–504 days). There was a transient worsening of condition in 6% of patients. The overall rate and average duration of response remained consistent after the second [ n  = 37; 31 responders (84%); median duration 21 days], third [ n  = 28; 20 responders (71%); median duration 25 days] and fourth [ n  = 14; 10 responders (71%); median duration 23 days] injections. Conclusion GONB seems to be an efficacious treatment with reproducible effects in CCH patients. Performed three monthly, GONB may have a useful role in the management of CCH .