Cerebral palsy results from an injury to the immature brain. Although this injury is essentially non progressive the effects on the limbs do alter over time. The brain injury results in poor muscular control. This may manifest as spasticity (high muscle tone), weakness and poor coordination. Spasticity is the most common presentation.
The most widely utilised classification system for cerebral palsy is topographical (which limbs are involved). Quadraplegia means that both arms and legs are affected. Diplegia affects primarily the legs. Hemiplagia affects one side of the body (generally the arm more than the leg). The severity of involvement is variable. Very mild cases may not be apparent until the child is several years old.
The most useful recent development in the classification of cerebral palsy has been the creation of the Gross Motor Function Classification System (GMFCS)(Palisano 1997). This is based on the assessment of self-initiated movement with emphasis on function with regard to sitting and walking. This system was developed in relation to children in order to predict long term function. It has however also been utilized in adults and is a reliable tool for describing severity of involvement. Level I equates to almost normal function whilst level V patients are wheelchair bound and require help with all activities.