[Invasive techniques in chronic pain control]

A wide range of invasive techniques are available for pain treatment. Treatment must be adapted to the severity of the underlying disease and the intensity of pain. Very few controlled studies concerning these techniques have been performed, and it is therefore difficult to assess their short and long term efficacy. Optimal effectiveness will be obtained if the indication is correct. This non exhaustive revue presents the indications, techniques and results of neural conduction blocks as peripheral blocks, Alcock canal block, zygapophysial joint blocks and also central blocks illustrated by epidural and intrathecal injections and finally sympathetic nervous system blocks as celiac plexus block, stellate ganglion block and intravenous blocks for complex regional pain syndromes. The indications, techniques and results of thermal neurolyse (radiofrequency, thermocoagulation), transcutaneous electrical nervous stimulation (TENS) and implant central stimulation are also presented. A multidisciplinary approach is used to evaluate the risk/benefit ratio of these invasive techniques for each patient.