Cerebral Palsy: Introduction and Diagnosis (Part 1)

Martha Wilson Jones, MSN, RN, CPNP; Elaine Morgan, BSN, RN, CRRN, PNP; Jean E. Shelton, MD; Christine Thorogood, MD


J Pediatr Health Care. 2007;21(3):146-152. 

In This Article

Classification of Cerebral Palsy

One method to classify CP is to describe the predominant motor characteristics, which include spastic, hypotonic, athetotic, dystonic, and ataxic, as well as the topographical pattern of limb involvement, such as monoplegia, diplegia, triplegia, hemiplegia, or quadriplegia. A second method divides CP into two major physiologic classifications, pyramidal (spastic) and extra pyramidal (nonspastic), indicating the area of the brain that has been affected as well as the resulting predominant motor disorder.

Pyramidal/spastic CP results from defects or damage occurring in the brain's corticospinal pathways, also described as upper motor neuron damage. Spastic CP accounts for nearly 70% to 80% of all cases of CP, with cognitive impairments seen in approximately 30% (Taft 1995, Thorogood 2001). Although increased muscle tone is the predominant feature observed, hyperreflexia, clonus, extensor Babinski response, and persistent primitive reflexes are commonly seen (see Table 2 ).

Extrapyramidal (nonspastic) CP is caused by damage to nerve cells outside of the pyramidal tracts in the basal ganglia or the cerebellum. It is typically divided into two subtypes, dyskinetic and ataxic. Dyskinetic CP is then further divided into athetoid and dystonic (Blair and Stanley 1985, Dormans and Pellegrino 1998, Rosembaum 2003). It accounts for 15% to 20% of all cases of CP, with dyskinetic accounting for 10% to 15% and ataxic approximately 5% (Sanger et al 2003, Taft 1995, Thorogood 2001). The resulting disability is global with abnormal tone regulation, postural control, and coordination (Dormans & Pelligrino, 1998) (see Table 2 ).

Hypotonic CP often is mentioned in classifications of CP because of the resulting motor delays observed. This entity also is referred to as central hypotonia. To classify hypotonia as CP, myopathy and neuropathy must be ruled out as potential causes. These infants are floppy, exhibit a marked decrease in overall muscle tone, and will have significant delays in motor milestones. Because of weak facial and oral muscles, there often are associated problems with feeding (Molnar 1992, Taft 1999). CP with hypotonia has persistent primitive reflex patterns and hyperreflexia, which distinguishes it from lower motor neuron causes of hypotonia.

It is possible to see many different combinations of types of CP depending on the area of brain damage; this can be confusing to parents when different professionals call their child's CP either "mixed" or by different names. However, when the types overlap, it can be difficult to precisely label the resulting disability within the typical subtypes (Kuban and Leviton 1994, Taft 1999).


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.
Post as: