Spastic hemiparesis (hemiplegia): lesion in corticospinal system of one cerebral hemisphere. Often caused by intrauterine cerebral infarct or hemorrhage. Hemiparesis may manifest as early hand preference (less use of weaker side). Seizures frequent when lesion affects cortex.

Spastic diplegia or diparesis: prominent spasticity in both legs, hyperactive reflexes, upgoing toes. Causes: bilateral germinal matrix hemorrhage or periventricular leukomalacia associated with prematurity; perinatal ischemia in watershed parasagittal zone.

Spastic quadriplegia: most severe variant of CP, often with moderate-to-severe mental deficiency. Diffuse malformation or damage to brain, e.g., multicystic leukomalacia following severe ischemia, lissencephaly. Seizures frequent and difficult to control.

Hypotonic CP: child floppy but tendon reflexes hyperactive; usually with severe mental deficiency and diffuse brain involvement.

Dyskinetic CP: athetosis, choreoathetosis, dystonia due to basal ganglia pathology. Causes: neonatal hyperbilirubinemia (kernicterus), severe anoxia. Abnormal movements usually start after age 1 year. Treatment rarely effective.

Ataxic CP: maldevelopment of cerebellum or its pathways; some with cognitive impairment. Does not respond well to physical or drug therapy; may improve with age.

Mixed CP: combination of dyskinetic and spastic CP, or ataxia and athetosis.