Impaired ability to eat related to problems gathering food and getting ready to suck, chew, or swallow it.

Behavior or an act aimed at harming a person, animal, or physical property (e.g., acts of physical violence; shouting, swearing, and using harsh language; slashing someone's tires).

A motor disorder characterized by a velocity-dependent increase in tonic stretch reflexes with increased muscle tone, exaggerated (hyperexcitable) tendon reflexes.

A seizure is an intermittent abnormality of nervous system physiology characterized by a transient occurrence of signs and/or symptoms due to abnormal excessive or synchronous neuronal activity in the brain.

Severe mental retardation is defined as an intelligence quotient (IQ) in the range of 20-34.

Abnormal coordination of muscles involved in speech.

A delay in the achievement of motor or mental milestones in the domains of development of a child, including motor skills, speech and language, cognitive skills, and social and emotional skills. This term should only be used to describe children younger than five years of age.

A type of Developmental delay characterized by a delay in acquiring motor skills.

Complete lack of development of speech and language abilities.

A reduced ability to participate in the back-and-forth flow of social interaction appropriate to culture and developmental level, which is normally characterized by an influence of the behavior of one person on the behavior of another person. This results in difficulty interacting with others through emotional, physical, or verbal communication.

A condition in which there is increased muscle tone so that arms or legs, for example, are stiff and difficult to move.

Head circumference below 2 standard deviations below the mean for age and gender.