Annals of Rehabilitation Medicine

Original Article: J Korean Acad Rehabil Med. 2007;31(6):750-755.; Comparison on Treatment Effects of Pharmaceutic Agents for Trigger Point Injection.; Han, Soo Jeong , Lee, Kyung Hwan; Department of Rehabilitation Medicine, School of Medicine, Ewha Womans University, Korea. foammy@hanmail.net

Abstract: Objective
To compare the effect of pharmaceutic agents which were used in trigger point injection and to establish a relationship between ultrasonographic change in injected muscle and post-injection soreness by a double blinded study. Method: Twenty-seven patients who were diagnosed as myofascial pain syndrome with their trigger point in upper trapezius muscle were recruited. They were assigned to four groups by age and sex: lidocaine injection (n=8), normal saline injection (n=6), 20%dextrose injection (n=6), and BTX-A injection (n=7). One physiatrist palpated a trigger point at upper trapezius muscle and injected blinded agents with same volume (1 ml). Ultrasonography for injected muscle was done by 2 weeks after injection. Visual analog scale was evaluated up to twenty three weeks. Results: Mean score of visual analog scale was decreased in all groups. Among the four agents, 0.5% lidocaine and BTX-A showed significant decrement in visual analog scale (p＜0.05). Ultrasonographic depth of muscle was increased in BTX-A and 20% dextrose injected group at the end of injection (p＜0.05). There were no significant different treatment effect in four pharmaceutic agents. Conclusion: In all four groups, trigger point injection showed therapeutic effect for myofascial pain syndrome. Among the four agents, 0.5% lidocaine and BTX-A could reduce pain significantly up to twenty three weeks. Mechanical pressure on muscle fiber was thought to be one of the causes of post-injection soreness. (J Korean Acad Rehab Med 2007; 31: 750-755)

Keywords :Myofascial pain syndrome, Trigger point, Botulinum toxin type A, Lidocaine, Ultrasonography