Dyskinetic cerebral palsy, also known as extrapyramidal cerebral palsy is characterised by impairment of voluntary movement because of the presence of interfering involuntary movements, and inappropriate co-contraction of agonist and antagonist muscles (dystonia). This group of disorders includes choreoathetotic cerebral palsy and dystonic cerebral palsy. The former is characterised by large amplitude, involuntary movements of mainly distal limbs (athetosis) with or without small amplitude, fleeting, asymmetric contractions of individual muscle groups (chorea).
Dystonic cerebral palsy predominantly affects proximal trunk and limb muscles, which may show slow, persistent movements, leading to the adoption of unusual postures, such as torticollis.