It is a feature of altered skeletal muscle performance with a combination of paralysis, increased tendon reflex activity and hypertonia. It is also colloquially referred to as an unusual “tightness”, stiffness or “pull” of the muscles. Spasticity is a frequently encountered clinical condition.
Spasticity may be either ‘useful’ – by compensating decrease in motor strength- or ‘harmful’ – by limiting both passive and active motion and, in the extreme, by leading to irreducible contractures and deformities – or as in most cases – harmful and useful in the same patient!
A large population of adults and children in developing countries and in wealthy societies as well are suffering from this locomotor disability. Excess of spasticity leads to a disability that is marked by impaired locomotion and, if not controlled, handicapping deformities, discomfort, and pain. When spasticity is disabling, an effective therapeutic armamentarium is currently available. If spasticity fails to be controlled by relaxant medications and physical therapy and escapes the rehabilitation programs, neurosurgical procedures aiming to diminish the excess of tone and rebalance the agonist and antagonist muscle groups can be the remedy. They may help improve function and limit irreversible deformities. Complementary orthopedic corrections are often required though.
Spasticity should only be treated when an excess of tone leads to further functional losses, impairs locomotion and motricity, or induces deformities. Spasticity is often treated with the drug baclofen, which acts as an agonist at GABA receptors, which are inhibitory. Spastic cerebral palsy is the most common form of CP, which is a group of permanent movement problems that do not get worse over time and hence benefits from surgical interventions.