Objective: We investigated the efficacy and tolerability of greater occipital nerve block with lidocaine plus betamethasone in adults with chronic migraine in whom two or more previous preventive treatments were unsuccessful.

Methods: Ten participants were enrolled in a 24-weeks, randomized, double-blind, placebo-controlled, crossover trial conducted at a single tertiary headache center in Copenhagen (Denmark). After a 4-week run-in period, participants underwent treatment with bilateral greater occipital nerve block with lidocaine plus betamethasone (GONb) or lidocaine plus saline (placebo) with a 4-week interval wash-out phase between the 8-week crossover periods. The primary aim was to compare the number of migraine days during crossover periods after GONb or placebo. This trial is registered at ClinicalTrials.gov (NCT02686983).

Results: This study was stopped before achieving the a priori sample size, due to a slow enrollment. Ten participants were recruited, completed the study and were included in the analyses. At the baseline, the mean number of monthly migraine days was 22.9 (range, 14-30). No difference between GONb and placebo on the reduction of monthly migraine days was observed (p = 0.147; 95% CI between 0.6 and 3.7 days). Adverse events were recorded in two patients after GONb, compared with three patients after placebo.

Conclusions: GONb is not beneficial in patients with difficult-to-treat chronic migraine.