Fundamental bases of spasticity.- Neuroanatomical bases of spasticity.- Neurophysiological bases of spasticity.- Neurochemical bases of spasticity.- Assessment of spasticity.- Clinical features of spasticity.- Clinical assessment of spasticity.- Clinical neurophysiological assessment of spasticity.- Quantification of spasticity and limb function (based on clinical examination, and directed to adult patients).- Childhood spasticity assessment.- Nonsurgical treatment of spasticity.- Medical treatment of spasticity.- Physical treatments of spasticity and chemical blocks.- Neurostimulation for spasticity.- Spinal cord stimulation for spasticity.- Deep brain and cerebellar stimulation for spasticity.- Intrathecal Baclofen administration for spasticity using implantable pumps.- Pharmacological bases of intrathecal Baclofen administration.- CSF pharmacokinetic of intrathecal Baclofen administration.- Drug pump technical description, operative procedure and post-operative management.- Intrathecal infusion of Baclofen for spasticity: the RUSH and the US multicenter studies.- Intrathecal infusion of Baclofen for spasticity: The Toulouse and the French Multicenter Studies.- Neuro-ablative procedures for spasticity.- Selective peripheral neurotomies for the treatment of spasticity.- The different (open surgical, percutaneous thermal, and intrathecal chemical) rhizotomies for the treatment of spasticity.- Sectorial posterior rhizotomy for the treatment of spasticity in adults.- Sectorial posterior rhizotomy for the treatment of spasticity in children with cerebral palsy.- Selective functional rhizotomy for the treatment of spasticity in children.- Electrophysiological monitoring in selective posterior rhizotomy for spasticity: principles, techniques and interpretation of responses.-Surgery in the dorsal root entry-zone: microsurgical DREZ-tomy (MDT) for the treatment of spasticity.- Longitudinal myelotomy for spasticity.- Destructive stereotatic procedures for spasticity directed to the brain and the cerebellum.- Other treatments.- The spastic bladder and its treatment.- Orthopedic surgical corrections of spastic disorders.- Indications.- Indications for surgery to treat adults with harmful spasticity.- Indications for surgery to treat children with spasticity due to cerebral palsy.- Conclusions.