Movement disorders are clinical syndromes with either an excess of movement or a paucity of voluntary and involuntary movements, unrelated to weakness or spasticity.
Movement disorders are synonymous with basal ganglia or extrapyramidal diseases.
Movement disorders are conventionally divided into two 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. E.g. Chorea, dystonia, tremors etc.
- Hypokinetic movement disorders refer to akinesia (lack of movement), hypokinesia (reduced amplitude of movements), bradykinesia (slow movement) and rigidity. E.g. Parkinson’s disease, atypical parkinsonian diseases like PSP, CBGD, MSA etc.