Movement disorders are clinical syndromes with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity.^[1] Movement disorders are synonymous with basal ganglia or extrapyramidal diseases.^[2] Movement disorders are conventionally divided into five major categories- hyperkinetic and hypokinetic.

Hyperkinetic movement disorders refer to dyskinesia, or excessive, often repetitive, involuntary movements that intrude upon the normal flow of motor activity.

Hypokinetic movement disorders refer 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, the abnormal movement is a manifestation of another systemic or neurological disorder.^[3]

Classification

Diagnosis

Step I : Decide the dominant type of movement disorder^[5]

Step II : Make differential diagnosis of the particular disorder^{[citation needed]}

Step II: Confirm the diagnosis by lab tests^{[citation needed]}

• Metabolic screening
• Microbiology
• Immunology
• CSF examination
• Genetics
• Imaging
• Neurophysiological tests
• Pharmacological tests

Treatment

Treatment depends upon the underlying disorder.^[6] Movement disorders have been known to be associated with a variety of autoimmune diseases.^[7]

History

Vesalius and Piccolomini in 16th century distinguished subcortical nuclei from cortex and white matter. However Willis' conceptualized the corpus striatum as the seat of motor power in the late 17th century. In mid-19th-century movement disorders were localized to striatum by Choreaby Broadbent and Jackson, and athetosis by Hammond. By the late 19th century, many movement disorders were described, but for most no pathologic correlate was known.^[8]