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Hyperkinetic Movement Disorders



The term ataxia refers to a group of progressive neurological diseases that affect coordination and balance. Ataxias are often characterized by poor coordination of hands and eye movements, speech problems and a wide-based and unsteady gait. Ataxia can result from stroke, tumor, infection, trauma or degenerative changes in the cerebellum. They are generally classified into two groups: hereditary and sporadic ataxias. Hereditary ataxias affect the cerebellum and spinal cord and are passed from one generation to the next through a defective gene. A common hereditary ataxia is Friedreich's (recessive) ataxia. Sporadic ataxias occur spontaneously in individuals with no known family history of ataxia.

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Chorea refers to involuntary movements that are irregular, purposeless and unpredictable in timing. Any body part may be affected. When mild, a person may look fidgety and can often incorporate the chorea into other purposeful movements. Chorea is the hallmark of an inherited disorder called Huntington's disease.

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Dystonia is the third most common movement disorder, after essential tremor and Parkinson's disease. It is characterized by sustained co-contractions of opposing muscle groups that cause twisting or repetitive movements and abnormal postures. Dystonia is classified according to the number of muscle groups affected. It may be may be focal and limited to one area (such as the face, neck, larynx/vocal cords, or limbs), or it may be generalized and affect the whole body. These conditions can be both painful and debilitating. Aside from medications, dystonias are frequently treated with Botox injections. Patients with regional and generalized dystonias and normal MRI scans may benefit from deep brain stimulation therapy. The following are examples of focal dystonias:

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Hemifacial Spasm

Hemifacial spasm (HFS) is characterized by involuntary contraction of facial muscles. HFS usually occurs only on one side of the face. Like blepharospasm, the frequency of contractions in hemifacial spasm may range from intermittent to frequent and constant. The unilateral blepharospasm of HFS may be particularly troublesome, interfering with routine tasks such as driving. In addition to medication, patients may respond well to treatment with Botox. HFS may be due to vascular compression of the nerves going to the muscles of the face. For these patients, surgical decompression may result in long-lasting improvement of symptoms.

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Huntington's Disease (HD)

Huntington's disease is a hereditary degenerative brain disorder. Its most common symptom is chorea (involuntary movements). The chorea slowly progresses and becomes more severe over time. In addition, HD slowly reduces the individual's ability to walk, think, talk and reason. Since HD is a hereditary disorder, the diagnosis is made through gene testing of the blood. There is no cure for HD, and there is no known way to stop the progression of the disorder. The goal of treatment is to minimize complications associated with disease progression and improve the patient’s overall quality of life.

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Myoclonus refers to involuntary movements that are sudden and brief. They can be classified as positive or negative. Positive myoclonus is caused by sudden muscle contractions, while negative myoclonus is caused by sudden loss of muscle contractions. In general, myoclonus cannot be suppressed and can occur in any part of the body.

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Restless Legs Syndrome

Restless legs syndrome is a disorder where patients feel uncomfortable or unpleasant sensations in the legs. These sensations occur usually 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.

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Tardive Dyskinesia / Tardive Dystonia

Tardive dyskinesia or tardive dystonia, both referred to as "TD," refers to a wide variety of involuntary sterotypical movements caused by the prolonged use of dopamine receptor-blocking agents. The most common dopamine receptor-blocking agents are antipsychotics and anti-nausea agents. The classic form of TD refers to stereotypic movements of the mouth, where patients look like they are chewing gum. However, TD can take the form of other involuntary movements such as chorea, dystonia or tics.

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Tics/Tourette’s Syndrome (TS)

Tics are involuntary movements that are stereotyped, meaning that they tend to recur with the same or a very similar pattern in the same muscles. They most commonly involve the face, mouth, eyes, head, neck or shoulder muscles. Tics can be motor (pertaining to movement) or vocal (pertaining to speech). Tics usually vary in severity over time and worsen in times of stress.

When both motor and vocal tics are present and persist for more than one year, a diagnosis of Tourette's syndrome (TS) is likely. TS is an inherited neurobehavioral disorder characterized by both motor and vocal tics. Many individuals with TS also may develop obsessions, compulsions, inattention and hyperactivity. TS starts in childhood.

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Tremor is the shaking of one or more body parts and is the most common type of involuntary movement. There are many reasons for people to have tremor; many people notice tremor when they are excited or scared. However, when tremors become persistent, it may be a sign of something else.

Essential tremor (ET), also known as benign essential tremor, or familial tremor, is the most common movement disorder. It is estimated that 5 percent of people worldwide have this condition. It can affect people of any age and tends to run in families. ET is a tremor that usually affects the hands and arms but can also affect the head, voice, chin, trunk and legs. Both sides of the body tend to be equally affected. The tremor is called an action tremor, meaning that the tremor typically becomes noticeable in the arms when they are being used. Patients often report that the tremor in ET improves significantly with alcohol. First-line medical treatments for ET are beta-blockers. For patients in otherwise good health who fail to respond adequately to medication, deep brain stimulation and thalamotomy can be highly effective.

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Wilson's Disease

Wilson’s disease (WD) is a rare inherited disorder in which patients have a problem with copper metabolism. In patients with WD, copper accumulates in the liver and then in other parts of the body, particularly the brain, eyes and kidneys. When the copper starts to accumulate in the brain, patients may experience tremor, speech problems, incoordination, dystonia gait difficulties and swallowing problems. Psychiatric disturbances such as irritability, impulsiveness, aggressiveness and mood disturbances are also common. UMHS has a research protocol for patients with Wilson’s disease.

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