The spastic mouse. And the search for an animal model of spasticity in human beings.

An animal model of chronic spasticity would be valuable. There has been little success at producing such a model, however, because there is no frequently occurring natural disease in animals and, after experimental injury, the animals tend to die or recover. Spasticity in animals or humans is one of the many manifestations of an upper motor neuron syndrome; there is no such thing as pure spasticity. Spasticity in animals and humans involves abnormal functions at many levels of the neurologic and muscular systems. Animal models of spasticity may not be directly applicable to human spasticity, because the animal brain is so different from the human brain. Genetically spastic mice are a homogeneous population that have an abnormally functioning neurotransmitter within the central nervous system. This model has been shown to develop abnormalities of muscle growth that ultimately lead to contracture. The spastic mouse shows some promise for investigation of the abnormalities of muscles and joints that occur in spastic humans.