CP Terminology and Definitions

Describing cerebral palsy by motor type, topography, function and proportions in a total population

  • Spasticity – 85%
  • Dyskinesia – 7%
  • Ataxia – 6%
  • Hypotonia – 2%

Classification by Motor Type

ACPR(a) +Reid, 2011
Spasticty: Overactive muscles that display a velocity-dependent resistance to stretch. Spasticity can cause secondary impairments such as loss of muscle length, joint dislocation and pain 85 – 91%
Dyskinesia: Dyskinesia is either athetosis or dystonia. Athetoid CP is hypotonic with hyperkinesias characterized by involuntary writhing-stormy movement and can co-occur with chorea. In contrast, dystonic CP is hypokinetic, involving involuntary, abnormal twisting postures or repetitive movements with hypertonia. Tone is typically fluctuating 4 – 7%
Ataxia: Ataxia results in tremors with a shaky quality. Ataxic CP involves a loss of muscular coordination where movements have abnormal force, rhythm, and accuracy 4 – 6%
Hypotonia: Pure, generalized hypotonia (decreased muscle tone) is the least common CP motor type. Some argue that pure hypotonia should not even be considered a cerebral palsy 2%
(a) Australian Cerebral Palsy Register.
  • Hemiplegia – 38%
  • Diplegia – 36%
  • Quadriplegia (Tetraplegia) – 26%

Classification by Topography

Hemiplegia: Hemiplegia/monoplegia is the involvement of one side of the body. The upper limb is usually more affected than the lower limb. Strong early hand preference or hand disregard is sometimes the first sign of a problem. 38%
Diplegia: Diplegia is where both the legs are affected and are more affected than the upper limbs. 36%
Quadriplegia(Tetraplegia) Quadriplegia refers to the presence of spasticity in all four limbs; where the affect on the arms is equal or more than the legs. Trunk and oro-facial involvement is also to be expected. In rare cases, one limb is spared and this is referred to as triplegia. 26%
(a) Australian Cerebral Palsy Register.

Classification by Gross Motor Function at 2-4 Years

Level I: Floor sits independently, hands-free. Walks without assistive devices. 32%
Level II: Floor sits independently, hands-free with balance affected. Walks using an assistive mobility device. 27%
Level III: Floor sits using w-sitting. Walks short distances indoors using a hand-held mobility device with assistance. 12%
Level IV: Floor sits when placed, uses hands for balance. Rolls, creeps or crawls for short distances. 14%
Level V: Unable to sit independently. 14%
(a) Proportion in Australia with each level of Gross Motor Function Classification System.

Classification by Manual Ability at 4-18 Years(a)

Level I: Handles objects easily and successfully
Level II: Handles most objects but with somewhat reduced quality and/or speed of achievement.
Level III: Handles objects with difficulty; needs help to prepare and/or modify activities.
Level IV: Handles a limited selection of easily managed objects in adapted situations
Level V: Does not handle objects and has severely limited ability to perform even simple actions.
(a) Manual Ability Classification System

Classification by Communication Function

Level I: Effective Sender and Receiver with unfamiliar and familiar partners.
Level II: Effective but slower paced Sender and/or Receiver with unfamiliar and/or familiar partners.
Level III: Effective Sender and Receiver with familiar partners.
Level IV: Inconsistent Sender and/or Receiver with familiar partners.
Level V: Seldom Effective Sender and Receiver even with familiar partners.
(a) Communication Function Classification System

(1) Bax M, Goldstein M, Rosenbaum P, et al. 2005. Proposed definition and classification of cerebral palsy, April 2005. Dev Med Child Neurol 47:571-576./