Objective: The assessment of efficacy of injection therapy with local anesthetic and dry needling of myofascial trigger points in the treatment of myofascial pain syndrome. 

Materials and Methods: 89 patients with active myofascial trigger points in trapezius muscles were randomly distributed to 2% lidocaine injection (LA) and dry needling (DN) groups. After injection all patients were assigned to do trapezius stretching exercises at home. Pressure pain threshold values (pressure value as mm/Hg at which the patient feels pressure pain with algometer) and subjective pain intensity values (Visual Analogue Scale (VAS), Likert pain score) were recorded at three weeks and three months visits for the follow-up of therapy. Depression and anxiety were assessed using the Beck Depression Inventory (BDI) and the State Trait Anxiety Inventory I and II (STAI). 
 

Results: Post treatment evaluations demonstrated a significant increase in pressure pain threshold values, and significant decrease in the VAS and Likert scores (p<0.01) in both groups and there was no difference between groups with respect to these responses. After three weeks of treatment compared with DN, the decrease in trigger points was more evident in the LA group (p<0.05). Decreases in BDI and STAI I-II scores were significant only in the LA group (p<0.01, p<0.05 respectively).
 

Conclusion: Trigger point injection with LA or DN were both found to be effective but the clinical response started earlier and improvements regarding the psychological profile were obtained only in LA group.