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

Abstract

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.

Keywords: headache; injection; migraine; saline; splenius capitis.

Figure 1

(A) Sympathetic nerve entrapment point (SNEP) injection of 4.0 mL of isotonic saline into the splenius capitis muscle using a 23 gauge, 1 inch needle. (ShinChang Medical Corp, Gumi, Republic of Korea) (B) Deeply localized (DL) SNEP injection. The tender points in the T7/T8 interspinous space are identified after the patient is completely relaxed. Isotonic saline (4 mL) is then injected at a point half a finger-breadth from the spinous process using a 23 gauge, 1 inch needle.

Figure 2

Flowchart of the patient selection process.

Figure 3

Changes according to assessment points during the 24 month follow-up of 12 patients. Compared with the baseline values, statistically significant reductions in the headache frequency and duration, highest intensity of headache experienced during the previous and current weeks (VAS1 and VAS2, respectively), and Headache Impact Test-6 scores were observed at all assessment points following SNEP injection (p < 0.001). Assessment point 1, at baseline (before injection); assessment point 2, at 1 month; assessment point 3, at 3 months; assessment point 4, at 6 months; assessment point 5, at 12 months; assessment 6, at the 24 months follow-up visit after the first injection. Abbreviations: VAS, visual analogue scale; SNEP, sympathetic nerve entrapment point.