Effectiveness of Novel Sympathetic Nerve Entrapment Point Injections for Chronic Migraine: A Pilot Study

No studies to date have investigated the ability of sympathetic nerve entrapment point saline (SNEP) injections to achieve long-term pain relief in patients with migraine. Therefore, this study aimed to investigate the safety and long-term efficacy of repeat splenius capitis (SC) SNEP injections in patients with migraine (with/without tension-type headache). This retrospective, single-arm study included 12 patients with migraine. Isotonic saline was injected into their SC approximately six times for 3 months. Headache frequency, duration (hour/week), intensity (using the visual analog scale), and quality of life (using the Headache Impact Test-6) were assessed during the follow-up visits for up to 24 months after the first injection. Changes before and after treatment were assessed using repeated-measures analysis of variance. Significant reductions in headache frequency, duration, and intensity were observed at all assessment points after SNEP injections when compared with the baseline values (p < 0.05), while the patients' headache-related quality of life also improved. Treatment was continued for up to 3 months to maintain these improvements, and no worsening of status or adverse effects were observed in any of the patients over the following 24 months. Our results show that SNEP injections may offer persistent, substantial, and clinically relevant benefits in patients with migraine.