Which type of cerebral palsy is characterized by involuntary motor movement?

The type of cerebral palsy that is characterized by involuntary motor movement is athetosis. This condition is marked by unintentional, writhing movements that can affect various parts of the body. These involuntary movements are due to damage in the basal ganglia, which are areas of the brain responsible for coordinating movement. In individuals with athetosis, the movements can be slow and may increase during emotional responses, making it challenging for them to maintain stable posture or perform precise tasks.

By contrast, spasticity primarily involves muscle stiffness and tightness, resulting in exaggerated reflexes and difficulty with movement control. Ataxia is characterized by a lack of voluntary coordination of muscle movements, leading to balance and ambulation difficulties. Tremors typically involve rhythmic shaking in various body parts, which can occur at rest or during movement but do not fit the description of involuntary writhing motions found in athetosis. Thus, athetosis best represents the hallmark of involuntary motor movement among the forms of cerebral palsy listed.