Preventive effect of greater occipital nerve block on patients with episodic migraine: A randomized double-blind placebo-controlled clinical trial.

Greater occipital block with a local anesthetic significantly decreases the number of attacks in episodic migraine, whereas no injection was superior to the placebo in regards to the duration and severity of the headaches.Trial Registration Information: Iranian Registry of Clinical Trials (IRCT). Registration number: IRCT2017070334879N1. https://www.irct.ir/trial/26537.