Imagine not being able to control the movements of your body. This is a situation many movement disorder patients face on a daily basis. Abnormal movement disorders are caused by a variety of neurological diseases that either inhibit movement or cause excessive, involuntary movement. Movement disorders are chronic and progressive and can strike at any age. Causes are variable, and treatment is dependent upon the underlying disorder, according to Emory University.
Causes
Abnormal movement disorders are caused by autoimmune diseases, certain medications, infections, neurological injury, genetics and neurological diseases, according to Medline Plus. The Minnesota Academy of Family Physicians explains that neurological diseases, like Parkinson's disease, are characterized by progressive nerve cell destruction, primarily in the basal ganglia, a structure in the brain. The basal ganglia controls the timing of movement; therefore, damage to any part of the basal ganglia can either inhibit movement or cause excessive, involuntary movement. In addition to basal ganglia damage, movement disorders are also caused by injury to the cerebellum, or brain stem, two areas involved in the coordination of movement.
Hypokinesia
Hypokinesia is a term used to describe movement disorders that cause an inhibition of movement. Hypokinetic disorders are caused by the destruction of dopamine producing cells within the substantia nigra of the basal ganglia, according to The Minnesota Academy of Family Physicians. Types of hypokinesia include bradykinesia, rigidity, freezing and apraxia. Bradykinesia is characterized by slow, small movements. In people who suffer from this condition, walking becomes a shuffle and swallowing becomes difficult. In rigidity muscle becomes stiff and immovable. Freezing is a disorder in which a movement is halted for a few seconds, and apraxia is the inability to produce voluntary movements. Bradykinesia, rigidity, freezing and apraxia are all disorders associated with Parkinson's disease.
Hyperkinesia
Excessive, involuntary movements characterize hyperkinetic disorders. Hyperkinetic disorders are caused by damage to any portion of the basal ganglia, according to The Minnesota Academy of Family Physicians. Tremor is an example of a hyperkinetic disorder in which sustained, rhythmic movements are created, most frequently in the hand. Dystonia is a disorder in which involuntary muscle contractions produce a twisting of joint movement, or abnormal postures. Myoclonus is a sudden, involuntary muscle contraction, and chorea is a sudden, violent, involuntary movement of a limb. Tics are small, brief muscle contractions or vocal sounds and are an affliction found in Tourette’s syndrome.
Treatment
Treatment of movement disorders is based upon the underlying cause of the hyper- or hypokinetic disorder. In general, medications are used to promote the production of dopamine to lessen hypo- or hyperkinetic states. Deep brain stimulation is used to lessen abnormal brain activity. Botulism toxin is an affective medication used to dampen abnormal muscle contractions and limb postures, according to The National Institute of Neurological Disorders and Stroke, and "The Lancet Neurology."
Prognosis
Movement disorders are progressive and unpredictable and rarely result in recovery. While some patients become severely disabled, others experience only minor impairments. The severity of the condition depends upon the cause of the movement disorder, according to The National Institute of Neurological Disorders and Stroke.
References
- Emory University: Movement Disorders
- Medline Plus: Movement Disorders
- Minnesota Academy of Family Physicians: Movement Disorders
- The National Institute of Neurological Disorders and Stroke: Parkinson's Disease Information Page
- "The Lancet Neurology"; Treatment of Hyperkinetic Movement Disorders; Joseph Jankovic; 2009
