Sensory thalamic neurostimulation for chronic pain.

Among all kinds of pain, deafferentation pain is the most physically and mentally debilitative; this affliction is often resistant to medications and to the effects of ablative neurosurgical procedures. Since the introduction of neurostimulation as a method of treatment of pain, stimulation of the sensory thalamic relay nucleus has been proven effective in the majority of cases of patients suffering from deafferentation pain. The method used for thalamic stimulation and the results obtained in a series of 89 patients treated from October 1978 to October 1985 will be presented. Postherpetic trigeminal pain has the best chance of responding to thalamic stimulation with a long-term success rate of 80%. This is also true for anesthesia dolorosa of any origin (after ablative surgery, nerve lesions, paraplegia). In the opposite, only 50% of patients with either brachial plexus avulsion or thalamic pain syndrome will have a significant benefit from thalamic stimulation. It would appear that the success of thalamic stimulation in these disorders may be dependent upon the extent of the central lesion from the periphery up to the thalamic regions (dorsal horn destruction, lesions of the thalamus).