Efficacy of Adding a Distal Level Block to a C2 Level Greater Occipital Nerve Block under Ultrasound Guidance in Chronic Migraine.

Objective: To investigate the benefit of adding a distal level greater occipital nerve (GON) block to the proximal level GON block under ultrasound guidance in patients with chronic migraine (CM) with cutaneous allodynia (CA). Methods: Seventy-eight patients with CM were included. A single US-guided GON block was performed at proximal and distal levels in patients with CM with CA and only at the proximal level in patients with CM without CA. Thirty (38.5%) patients with bilateral pain received bilateral GON blocks, and 48 (61.5%) with unilateral pain received unilateral GON blocks. The patients were evaluated using Numeric Rating Scale (NRS) scores before treatment and 1 and 4 weeks after treatment and through Headache Impact Test-6 (HIT-6) scores before treatment and 4 weeks after treatment. Results: The NRS scores significantly decreased at first and fourth weeks, and the HIT-6 scores significantly decreased at fourth week (p < 0.001) compared with preintervention scores in all groups. No significant difference was found between the groups regarding the postinterventional first and fourth week when the decreases of NRS and HIT-6 scores were compared (p = 0.599). There were no significant differences in the effectiveness of unilateral and bilateral GON blocks (p > 0.001). Conclusion: A single US-guided GON block is an effective and safe treatment option in patients with CM, providing a positive effect on pain and quality of life for 4 weeks. The addition of a distal level GON block to the proximal level GON block provides no extra benefit to patients with CM with CA.