ABSTRACT
Introduction
The treatment of cluster headache (CH) is challenging in view of the few evidence-based treatments. The authors aim to summarize the evidence of efficacy and safety of greater occipital nerve blocks (GONBs) in CH.
Areas covered
The authors included papers indexed in PubMed and Web of Science from the beginning of indexing to 5 May 2020. They included both observational and randomized studies referring to patients with episodic and/or chronic CH. The authors identified 12 studies on 365 patients. Five studies (two randomized controlled trials) could be included in the meta-analyses. The pooled proportion of pain-free subjects at 1 month was 50% (95% CI 24–76%) with considerable heterogeneity (I2 = 88%; P < 0.01). The pooled relative risk ratio of pain freedom at 1 month in active versus control groups in the two included randomized controlled trials was 4.86 (95% CI, 1.35–17.55) without statistical heterogeneity (I2 = 0%; P = 0.39). Three studies showed decreased attack intensity, frequency, and duration after GONBs. The studies reported mild and transient adverse events.
Expert opinion
Despite several limitations and considerable heterogeneity, the available data support the efficacy and safety of GONBs for the treatment of CH. Further large randomized trials are needed to confirm efficacy and establish optimal treatment protocols.
Article highlights
Cluster headache relies on few evidence-based treatments.
We performed a systematic review and meta-analysis to summarize the evidence referring to greater occipital nerve blocks in cluster headache.
Despite their limitations and heterogeneity, the available data support the efficacy and safety of greater occipital nerve blocks for the treatment of cluster headache.
Further large randomized trials are needed to establish the optimal treatment protocols and indications for greater occipital nerve blocks in patients with episodic or chronic cluster headache.
Declaration of interest
S Sacco has financial relationship either as a lecturer or as a member of an advisory board with Abbott, Allergan, Novartis, Teva, Medsca and Eli Lilly. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.