PO-56 | The role of bilateral greater occipital nerve block in resistant chronic migraine with medication overuse

Leonardo Troilo, Letizia Curto, Giulia Procopio, Antonia Di Chirico, Gabriele Siciliano, Sara Gori, Filippo Baldacci | Neurology Unit, Department of Clinical and Experimental Medicine, University of Pisa-AOUP, Pisa, Italy

Background: Chronic migraine (CM) is a disabling neurological disorder, defined by headache occurring on ≥15 days/month for more than three months, with migraine features on at least 8 of those days. Its management is complicated by medication overuse (MO), which not only decreases the effectiveness of preventive strategies but also worsens the overall prognosis and quality of life. Moreover, a substantial subset of patients is classified as having resistant CM, defined by failure of multiple prophylactic treatments. In this context, greater occipital nerve block (GONB) has emerged as a promising, low-cost, minimally invasive treatment option.

Methods: This ongoing study investigates the short- and medium-term efficacy of bilateral GONB in patients with highly resistant CM (i.e. patients with at least four previous failures including three classes of oral preventive drugs and anti-CGRP monoclonal antibodies or onabotulinumtoxin A and concurrent MO. At baseline (T0), patients underwent comprehensive assessment including monthly headache days, symptomatic medication intake, pain intensity (VAS), and several validated questionnaires: MIDAS, HIT-6, PHQ-9, GAD-7, PSQI, rMEQ, ESS, fatigue scale, and evaluation of cutaneous allodynia. GONB was performed bilaterally using lidocaine with or without corticosteroids. Follow-up visits were scheduled at one week (T1) and one month (T2), assessing changes in VAS, headache days, drug intake, and questionnaire scores.

Results: Preliminary findings suggest a significant reduction in VAS scores at T1, indicating early pain relief. At T2, patients showed a decrease in symptomatic medication intake and HIT-6 scores, suggesting improved functional impact.

Conclusion: GONB appears to be a safe and effective short-term treatment option in patients with highly resistant CM and MO. It may contribute not only to pain reduction but also support withdrawal from overused medications.