Middle meningeal artery (MMA)-directed interventions have been described for refractory headache syndromes, including migraine and aneurysmal subarachnoid hemorrhage-associated headache. We present a Neuro-Interventional Video demonstrating intra-arterial lidocaine-guided MMA coil embolization for severe refractory side-locked headache after ipsilateral internal carotid artery flow-diverter placement. The patient denied active headache or migraine immediately before flow-diverter treatment, but postprocedural headaches were documented at 1-month follow-up. The patient subsequently developed severe refractory side-locked right temporal headache without focal neurologic deficit or explanatory imaging correlate. Right external carotid angiography demonstrated a patent, moderately tortuous MMA. An SL-10 microcatheter was advanced into the frontal division beyond the orbital roof; hand injection demonstrated catheter tip position beyond orbital anastomotic branches. Intra-arterial lidocaine (27 mg) produced immediate improvement from 8/10 to 0/10 without neurologic or visual symptoms, followed by targeted coil occlusion of the selected frontal MMA territory. The accompanying video demonstrates patient selection, angiographic safety assessment, lidocaine response, coil deployment, and post-embolization confirmation. This single case is hypothesis-generating; the relative contributions of lidocaine and embolization and longer-term durability require further study.