 The repetitive transcranial magnetic stimulation rTMS is used in pain treatment for several years. The aim of the study is to assess, in a rigorous scientific protocol, analgesic effect of the neuronavigated rTMS assisted by robotic arm on chronic neuropathic painful subjects. The crossover study is randomized, double blinded and controlled sham rTMS and it includes a large homogeneous population suffering of central neuropathic pain. 