After the neurophysiological evaluation, patients will receive an intrathecal baclofen bolus of 50 µg or placebo (randomization). After the intrathecal baclofen or placebo injection, a clinical and neurophysiological examination, of neuropathic pain and spasticity and spasms, will be repeated at 1, 2 and 4 hours after the bolus administration. Moreover, Kumru et al. (2013) reported that the 50 µg intrathecal baclofen bolus reduced the pain perception threshold and evoked acute pain perception in patients with SCI.