Hypertonia

Hypertonia is an upper motor neuron dysfunction marked by an abnormal increase in tightness of muscle tone and a reduced ability of a muscle to stretch (i.e. an increased stiffness). Hypertonia is usually a feature of spasticity in particular muscles. These features are common in cerebral palsy.

A form of hypertonia unrelated to spasticity is known as Paratonia which is associated with dementia.