It may occur in situations where the individuals motor intention spreads to either nearby or distant muscles, taking away from the original goal of the movement. Overflow is often associated with dystonic movements and may be due to a poor focusing of muscle activity and inability to suppress unwanted muscle movement. Co-contraction refers to a voluntary movement performed to suppress the involuntary movement, such as forcing ones wrist toward the body to stop it from involuntarily moving away from the body.In evaluating these signs and symptoms, one must consider the frequency of repetition, whether or not the movements can be suppressed voluntarily (either by cognitive decisions, restraint, or sensory tricks), the awareness of the affected individual during the movement events, any urges to make the movements, and if the affected individual feels rewarded after having completed the movement. The context of the movement should also be noted; this means that a movement could be triggered in a certain posture, while at rest, during action, or during a specific task. The movements quality can also be described in observing whether or not the movement can be categorized as a normal movement by an unaffected individual, or one that is not normally made on a daily basis by unaffected individuals. Differential diagnosis
Diseases that feature one or more hyperkinetic movements as prominent symptoms include:

Huntingtons disease
Hyperkinesia, more specifically chorea, is the hallmark symptom of Huntingtons disease, formerly referred to as Huntingtons chorea. Appropriately, chorea is derived from the Greek word, khoros, meaning "dance."
The extent of the hyperkinesia exhibited in the disease can vary from solely the little finger to the entire body, resembling purposeful movements but occurring involuntarily. In children, rigidity and seizures are also symptoms. Other hyperkinetic symptoms include:

Head turning to shift eye position
Facial movements, including grimaces
Slow, uncontrolled movements
Quick, sudden, sometimes wild jerking movements of the arms, legs, face, and other body parts
Unsteady gait
Abnormal reflexes
"prancing," or a wide walkThe disease is characterized further by the gradual onset of defects in behavior and cognition, including dementia and speech impediments, beginning in the fourth or fifth decades of life. Death usually occurs within 10–20 years after a progressive worsening of symptoms. Caused by the Huntington gene, the disease eventually contributes to selective atrophy of the Caudate nucleus and Putamen, especially of GABAergic and acetylcholinergic neurons, with some additional degeneration of the frontal and temporal cortices of the brain. The disrupted signaling in the basal ganglia network is thought to cause the hyperkinesia. There is no known cure for Huntingtons disease, yet there is treatment available to minimize the hyperkinetic movements. Dopamine blockers, such as haloperidol, tetrabenazine, and amantadine, are often effective in this regard. Wilsons disease
Wilsons disease (WD) is a rare inherited disorder in which patients have a problem metabolizing copper. In patients with WD, copper accumulates in the liver and other parts of the body, particularly the brain, eyes and kidneys. Upon accumulation in the brain, patients may experience speech problems, incoordination, swallowing problems, and prominent hyperkinetic symptoms including tremor, dystonia, and gait difficulties.