Perimenstrual Repetitive Greater Occipital Nerve Blockade for Menstrual Migraine: A Randomized, Double-Blind, Placebo-Controlled Trial

Menstrual migraine (MM) is a highly prevalent and challenging migraine subtype triggered by fluctuations in estrogen and progesterone levels, particularly estrogen withdrawal during the perimenstrual period

• This hormonal withdrawal sensitizes the trigeminovascular system and promotes the release of neuropeptides such as calcitonin gene-related peptide (CGRP)
• Currently, there are no licensed prophylactic medications specifically developed for MM, making alternative and non-systemic treatments necessary

This study investigates the efficacy of a targeted peripheral neuromodulation approach using bilateral greater occipital nerve (GON) blockade. The underlying clinical rationale is that GON blockade timed to the perimenstrual period can modulate nociceptive transmission at the trigeminocervical complex (TCC) and decrease peripheral nerve excitability, thereby limiting the impact of cyclic hormonal fluctuations on the trigeminovascular system

. In this trial, a Latin square experimental design is utilized to ensure balanced randomization between the active treatment and placebo groups

• Unlike single-injection protocols, the intervention is specifically synchronized with the patients' menstrual cycles, involving injections twice a month over a three-month period (seven days before menstruation and on the first day of menstruation)
• By evaluating this specific timing and repetitive protocol, the study aims to establish whether perimenstrual-targeted GON blockade can serve as an effective, non-systemic, short-term prophylactic strategy for patients suffering from this refractory migraine subtype.