Comparison of the clinical efficacy of bilateral and unilateral GON blockade at the C2 level in chronic migraine.

The main purpose of this study was to retrospectively compare the unilateral and bilateral application of proximal greater occipital nerve (GON) block at the C2 level in the treatment of chronic migraine disease. In chronic migraine patients who underwent GON blockade, the average number of migrainous painful days per month, the average duration of pain in attacks, the highest visual analogue scale (VAS) score in pain intensity for one month, and total analgesic use were recorded before and after the block. According to the GON block protocol applied by our clinic, the patients were treated for GON block 4 times a month, once a week. The data obtained were recorded before the treatment, in the 1st and 3rd months after the last injection, and the results were compared using the chi-square, Fisher, Mann-Whitney U, and Wilcoxon-signed rank tests. During the 3-month follow-up, the groups did not differ significantly in terms of the number of days with headache in 30 days, the average duration of headache, the highest VAS score in 30 days, and total analgesic use in 30 days. In both groups, the findings decreased in the 1st month and increased in the 3rd month compared to pre-treatment. However, results of both the 1st and 3rd months were significantly lower than pre-treatment (p<0.05), and there was a clinical benefit compared to pretreatment. While the GON block at the C2 level was effective in the treatment of chronic migraine, the superiority of bilateral application to unilateral application was not detected.