RCT :Thoracic Sympathetic Block for the Treatment of Complex Regional Pain Syndrome I of the Upper Limb

Inclusion Criteria: * Complex regional pain syndrome (IASP, 1994) involving an upper limb; * Pain scores in excess of five visual analog scale (VAS); * Poor outcome to treatment (less than 50% reduction in VAS scores) - Exclusion Criteria: * History of severe brain injury, epilepsy and stroke * Patients who had undergone sympathetic ganglion block for treatment of the affected limb, by any technique * Severe systemic disease * Addictive behavior, severe psychiatric disorders, psychiatric diseases untreated * Refusal to participate or not initial adherence to orientations * Refusal to be randomized in a treatment group or with contraindications to any of them pregnancy.