Definition There are various terms which refer to specific movement mechanisms that contribute to the differential diagnoses of hyperkinetic disorders. As defined by Hogan and Sternad, “posture” is a nonzero time period during which bodily movement is minimal. When a movement is called “discrete,” it means that a new posture is assumed without any other postures interrupting the process. “Rhythmic” movements are those that occur in cycles of similar movements. “Repetitive,” “recurrent,” and “reciprocal” movements feature a certain bodily or joint position that occur more than once in a period, but not necessarily in a cyclic manner. Overflow refers to unwanted movements that occur during a desired movement. It may occur in situations where the individual's 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 one's 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 movement's 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: Huntington's disease<unk> , more specifically chorea, is the hallmark symptom of Huntington's disease, formerly referred to as Huntington’s chorea. Appropriately, chorea is derived from the Greek word, khoros, meaning “dance.” The extent of the<unk>  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 walk The 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<unk> . There is no known cure for Huntington's 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. Wilson's disease Samuel Alexander Kinnier Wilson, the neurologist most known for his description of what came to be known as Wilson's disease. Wilson's 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. Psychiatric disturbances such as irritability, impulsiveness, aggressiveness, and mood disturbances are also common. Restless leg syndrome Restless leg syndrome is a disorder in which patients feel uncomfortable or unpleasant sensations in the legs. These sensations usually occur in the evening, while the patient is sitting or lying down and relaxing. Patients feel like they have to move their legs to relieve the sensations, and walking generally makes the symptoms disappear. In many patients, this can lead to insomnia and excessive daytime sleepiness. This is a very common problem and can occur at any age. Similarly, the syndrome akathisia ranges from mildly compulsive movement usually in the legs to intense frenzied motion. These movements are partly voluntary, and the individual typically has the ability to suppress them for short amounts of time. Like restless leg syndrome, relief results from movement. Post-stroke repercussions A multitude of movement disorders have been observed after either ischemic or hemorrhagic stroke. Some examples include athetosis, chorea with or without hemiballismus, tremor, dystonia, and segmental or focal myoclonus, although the prevalence of these manifestations after stroke is quite low. The amount of time that passes between stroke event and presentation of<unk>  depends on the type of hyperkinetic movement since their pathologies slightly differ. Chorea tends to affect older stroke victims while dystonia tends to affect younger ones. Men and women have an equal chance of developing the hyperkinetic movements after stroke. Strokes causing small, deep lesions in the basal ganglia, brain stem and thalamus are those most likely to be associated with post-stroke<unk> . Dentatorubral-pallidoluysian atrophy DRPLA is a rare trinucleotide repeat disorder (polyglutamine disease) that can be juvenile-onset ( 40 years). Late adult-onset DRPLA is characterized by ataxia, choreoathetosis and dementia. Early adult-onset DRPLA also includes seizures and myoclonus. Juvenile-onset DRPLA presents with ataxia and symptoms consistent with progressive myoclonus epilepsy (myoclonus, multiple seizure types and dementia). Other symptoms that have been described include cervical dystonia, corneal endothelial degeneration autism, and surgery-resistant obstructive sleep apnea.
Hyperkinesia
Dyskinesia
Abnormal posturing
Hypertonia
Clonus
Lusitropy
Spasticity
Copropraxia