Multiple Cranial Nerve Blocks as an Alternative Preventative Therapy for Chronic Migraine.

Abstract

The objective of this prospective cohort study is to evaluate the efficacy of multiple cranial nerve blocks (MCNBs) as a preventative therapy for chronic migraine. MCNBs, namely greater occipital nerve (GON) blocks, are frequently used for the acute and transitional treatment of migraine. There is little evidence on the efficacy of repeated MCNBs as a preventative treatment for chronic migraine. This single-center, prospective cohort study collected demographic and outcome data on chronic migraine patients who had MCNBs in the headache service between June 2017 and March 2019. Outcome measures included reduction in headache days, Headache Impact Test 6 (HIT6) scores and patient-reported effectiveness of the blocks. Outcomes for 64 patients with a diagnosis of chronic migraine or chronic migraine with aura (MWA) were collected. Average age at first block procedure was 41years (range 21-72) with a female predominance of 54/64 patients (84%). About 37/64 patients (58%) had repetitive occipital nerve blocks only, and 27/64 patients (42%) had occipital and trigeminal nerve blocks. Mean (±SD) reduction in headache days post-MCNBs was 5.4 (±5.0) days and mean (±SD) reduction in HIT6 scores was 5.3 (±10.3). About 42/64 patients (66%) responded to the MCNBs with at least a 30% reduction in headache days. Mean (±SD) duration of effect was 5.7 (±5.4) weeks. About 13/64 of the patients transformed to low-frequency episodic migraine on follow-up. About 22/64 patients (34%) showed no reduction in headache days or HIT6 scores. About 9/112 (8%) instances of minor post block complications were documented with a total of 501 injections. This study demonstrates that repetitive MCNBs could provide effective prevention in patients with chronic migraine.