A comparative trial of botulinum toxin type A and methylprednisolone for the treatment of myofascial pain syndrome and pain from chronic muscle spasm

Abstract

Myofascial pain syndrome (MPS) is a common illness, characterised by acute or chronic focal pain, muscle stiffness and fatigue. The pathophysiology of MPS remains unclear. Previous preliminary studies have demonstrated therapeutic efficacy of the muscle relaxant botulinum toxin type A (BTX-A) in the treatment of MPS. A single-centre, randomised trial compared the effects of BTX-A with the steroid methylprednisolone (both administered intramuscularly with 0.5% bupivacaine), in 40 patients suffering from chronic myofascial pain in the piriformis, iliopsoas or scalenus anterior muscles. Thirty days after receiving an injection of either BTX-A or steroid followed by post-injection physiotherapy, pain severity had decreased significantly from baseline in both treatment groups, with no significant difference between the two treatment groups. However, the baseline pain score was significantly higher in the BTX-A treatment group compared with the steroid group (7.9 vs. 7.3), and the reduction in pain score between baseline and 30 days post-injection was greater in the BTX-A group compared with the steroid group (-3.9 vs. -3.5; P=0.06). At 60 days post-injection, the pain severity score for the BTX-A-treated patients was statistically significantly lower than the pain score for the steroid-treated population (2.3 vs. 4.9). Furthermore, the reduction in pain score in the BTX-A group at 60 days post-injection was greater than at 30 days (-5.5 vs. -3.9), whereas the effect of the steroid had begun to wane. These results indicate the superior efficacy of BTX-A over conventional steroid treatment in patients suffering from MPS, when combined with appropriate physiotherapy.

Brief review: Piriformis syndrome: etiology, diagnosis, and management

“…The somatic component underlying PS is a myofascial pain syndrome of the PM. 2,7,14,29,30 The symptomatology of the PS can also be contributed from a few muscles in the Fig. 1 The piriformis muscle (1) and neighboring muscles, nerves, and vessels: 2, gluteus minimus; 3, gluteus medius; 4, gluteus maximus; 5, quadratus femoris; 6, superior gluteal nerve; 7, inferior gluteal nerve; 8, posterior cutaneous femoral nerve; 9, superior gluteal artery; 10, inferior gluteal artery and vein; 11, internal pudendal artery 91 vicinity.…”

Ct-guided piriformis muscle injection for the treatment of piriformis syndrome

“…It is thought that the piriformis muscle tendon may be tethering the sciatic nerve, and causing irritation of the nerve because of pressure or decreased blood flow to the nerve. Some investigators consider the piriformis syndrome to be a form of myofascial pain syndrome (23). It may also follow total hip replacement (4) or lumbar disc surgery (19).…”

Ultrasound-guided injection of botulinum toxin A in the treatment of iliopsoas spasticity

“…Willenborg et al [21] used US to locate the muscle and verified the correct position of the needle by electrostimulation. The computed tomographyguided technique described in 2000 by Porta et al had several disadvantages, including high costs, long examination time, use of ionizing radiation, and the need for sedation especially in young patients [22]. In 2003, Westhoff et al [6] described a US-guided technique with an anterior approach, which allowed the needle to be positioned quickly, safely, and without the use of ionizing radiation.…”