THE USE OF TOPICAL 4-PERCENT LIDOCAINE IN SPHENO-PALATINE GANGLION BLOCKS FOR THE TREATMENT OF CHRONIC MUSCLE PAIN SYNDROMES - A RANDOMIZED, CONTROLLED TRIAL

To assess the efficacy of 4% topical lidocaine in spheno-palatine bloc ks, a randomized controlled trial was carried out on patients with chr onic muscle pain syndromes. Sixty-one patients (42 with fibromyalgia ( FM) and 19 with myofascial pain syndrome (MPS)) completed the trial. O utcome measures included pain intensity, a daily pain diary, headache frequency, sensitivity to pressure using a dolorimeter, anxiety, depre ssion, and sleep quality. Patients were randomized to receive either 4 % lidocaine or sterile water (placebo) 6 times over a 3-week period. B oth subjects and investigators were blind to treatment allocation. The results showed that 4% lidocaine had no superiority over placebo in a ny of the outcome measures. Twenty-one subjects (35%) showed a decreas e in pain which was greater than 30% of their baseline value. Of these 21 subjects, 10 received lidocaine and 11 received placebo. These dat a suggest that, in this population, 4% lidocaine is no better than pla cebo in the treatment of chronic muscle pain.