What is "movement disorder"

n. (context medicine English) Any abnormality that concerns control of skeletal muscle, from involuntary twitching or lack of coordination to loss of function.

Movement disorders can be defined as neurologic syndromes in which either an excess or movement or a paucity of voluntary and automatic movements, unrelated to weakness or spasticity. The term movement disorders is used synonymously with basal ganglia or extrapyramidal diseases. Conventionally movement disorders are divided into two major categories: 1. Hyperkinetic movement disorders also called dyskinesias refers to excessive, often repetitive, involuntary movements that intrude into the normal flow of motor activity. 2. Hypokinetic movement disorders refers to akinesia (lack of movement), hypokinesia (reduced amplitude of movements), bradykinesia (slow movement) and rigidity. In primary movement disorders the abnormal movement is the primary manifestation of the disorder. In secondary movement disorders it is an manifestation of other systemic or neurological disorder.