movement disorders

Movement Disorders can be defined as neurological syndromes in which there is either an excess of movement (termed “hyperkinetic movements”) or a paucity of voluntary or automatic movements (termed “hypokinetic movements”) these are unrelated to weakness or spasticity.

Hyperkinesias have also been called dyskinesias or abnormal involuntary movements. The six major categories of hyperkinetic movement disorders are: restless legs, tremor, chorea, dystonia, myoclonus and tics. However, there are other ‘minor’ or less common hyperkinetic movement disorders such as akathisia, hemifacial spasms, hyperekplexia, myokimia, myorhythmia, and stereotypy.

These hyperkinetic disorders can be, involuntary, automatic (i.e. learned motor behaviors performed without conscious effort such as the act of walking or swinging of arms during walking), voluntary (planned or self-initiated), semi-voluntary (induced by an inner sensory stimulus such as a need to scratch an itch; or an unwanted feeling or compulsion such as those seen in restless legs or akathisia).

Hypokinesia (decreased amplitude of movement) is sometimes used alternatively with bradykinesia (slowness of movement), and akinesia (loss of movement). Parkinsonism is the most common cause of hypokinetic movements but there are other less common causes of hypokinetic movements such as: cataplexy and drop attacks, catatonia, hypothyroid slowness, rigidity, and stiff muscles.

Most, but not all, movement disorders are a result of basal ganglia dysfunction—what we term as “extrapyramidal disorders”. Movement disorders can also come from injury of the cerebral cortex, cerebellum, brainstem, spinal cord, peripheral nerve, and other areas.