The phenomenon of spasticity: a pathophysiological and clinical introduction to neuromodulation therapies.

Spasticity is part of the complex clinical picture which results from the upper motor neuron impairment. The underlying mechanisms that produce the automatic overactivity of the muscle groups may manifest themselves as either passive movements dependent on the exerted velocity or persistent muscle overactivity in the form of spastic dystonia. The therapeutic management of spasticity is closely related to the aims of rehabilitation; these include avoidance of complications, restoration of movement, re-education of motion and gait, development of self-dependency, and social integration, as well as modification and reorganization of the cortical brain map. The latter is achieved through long-term learning processes which are subserved by new neurophysiological dynamics. and the mechanisms of neuroplasticity which develop during neural regeneration.