Intramuscular and nerve root stimulation vs lidocaine injection of trigger points in myofascial pain syndrome

Objectives: To compare the efficacies of an intramuscular stimulation technique and 0.5% lidocaine injection to trigger points in myofascial pain syndrome. Participants: Forty-three people with myofascial pain syndrome of the upper trapezius muscle. Interventions: Twenty-two subjects were treated with intramuscular stimulation and another 21 with 0.5% lidocaine injection at all the trigger points on days 0, 7 and 14. Results: Intramuscular stimulation resulted in a significant reduction in Wong-Baker FACES pain scale scores at all visits and was more effective than trigger point injection. Intramuscular stimulation also resulted in significant improvement on the Geriatric Depression Scale - Short Form. Local twitch responses occurred in 97.7% (42/43) of patients. All the passive cervical ranges of motion were significantly increased. Post-treatment soreness was noted in 54.60% of patients in the intramuscular stimulation group and 38.1 % in the trigger point injection group, respectively, and gross subcutaneous haemorrhage (> 4 cm(2)) was seen in only one patient in the trigger point injection group. Conclusion: In managing myofascial pain syndrome, after one month intramuscular stimulation resulted in more significant improvements in pain intensity, cervical range of motion and depression scales than did 0.5% lidocaine injection of trigger points. Intramuscular stimulation is therefore recommended for myofascial pain syndrome.