M. Salim  ( Department of Anaesrhesiology, Military Hospital, Rawalpindi. )

Myofascial pain may be defined as pain originating from trigger points which are small circumscribed areas of focal hyper- irritability in myofascial structures which result in referred pain. Alternative terminology for myofascial pain is interstitial myofibrositis, fibrositis, myositis, myofascitis, myalgia, muscular rheumatism, etc¹. Different treatment modalities have been proposed² such as spray stretch technique, pressure technique, injection with local anaesthetics and steroids. The study was undertaken to evaluate and compare the level of pain relief obtained by trigger point injection and TENS.

Twenty-six subjects included in this study were patients referred to pain clinic. They were suffering from myofascial pain and had 1-3 distinct ‘trigger points’. The trigger areas were identified by palpation or by, acupunc­ture point detector (Pointers F. 1 I.T.O. Co. Japan). In 13 patients 0.5%, 2 ml pain lignocaine was injected in each trigger point followed by passive muscle stretch. In other group of 13 patients TENS was applied for 20-30 minutes with frequency and voltage which was tolerable to individual patient. They were also followed by passive muscle stretch. Half an hour after treatment an unaware observer interviewed each subject and obtained an estimate of pain on 0-10 Verbal PainAnalogue Scale and Salim’s subjective scale³. These subjects were again interviewed after 3 days. All the 13 patients who had injection of analgesic were benefitted and only 4 patients showed improvement with TENS. More patients benefitted with local analgesia injec­tion as compared to TENS.

Patients having chronic pain problems rarely obtain permanent pain relief with a single injection. A series of injections coordinated with suitable exercises of affected muscles produce the best long term result.

1. Garrette, D.K. Myofascial syndrome, in pain management. By CA. Warfield, Philadel­phia, Lippincott, 1990, pp. 167-71.
2. Ready, LB. and Kozody, R. Trigger point injection vs jet infection: the treatment of myofascial pain. Journal of Pain, Amsterdam, Elsevier. 1983; 15:201-6
3. Khan, M.A.R. and Salim, M. Anis and Salcem. Clinical Anaesth. for students. Pain management, Rawalpindi The Army Press, 1989,241-45.