Predicting Gross Motor Function in Cerebral Palsy

Cerebral palsy is a syndrome of various motor impairments manifested during early childhood.¹ The notion that the condition is usually related to birth-related injury has been dispelled by sound epidemiological studies.² Prenatal factors such as brain malformations and in utero injuries are significant contributors.³ Premature birth and multiple gestation pregnancies also play significant roles in the development of cerebral palsy.^{4 - 7}

The medical and neurological classifications of cerebral palsy have focused on limb involvement and types of tone abnormalities, such as spasticity, choreoathetosis, and dystonia.^{8 - 9} However, little is known of the prognosis for gross motor function in children diagnosed as having cerebral palsy, particularly during the early stages when the diagnosis is first made. Consequently, clinicians have limited evidence with which to respond to anxious parents who wonder, "What does the future hold?"or who ask direct questions, such as, "Will my child ever walk?"

The article by Rosenbaum et al¹⁰ in this issue of THE JOURNAL provides important prognostic information that clinicians can use in their communication with families. The study followed up a large cohort of children diagnosed as having cerebral palsy of varying severity over a 4-year period. This study deserves sound marks on all accounts: solid research design, validated measures, sound study execution, and rigorous data analysis. Of note, the authors relied on broad-based assessments of motor function, which had been validated on large cross-sectional groups of children with cerebral palsy. These validated tools have the advantage of being easily used by examiners with minimal training and clinical experience, and also have the benefit of stratifying individuals with this condition into severity groups. These attributes add up to an excellent set of tools from which to derive longitudinal data and solid scientific information on which to base prognosis for gross motor function.

Based on 2632 motor function assessments in 657 children with cerebral palsy aged 1 to 13 years, the authors generated methodologically sound motor development curves that have ecological and statistical validity. The ability to predict rates and limits of motor function for a given level of cerebral palsy severity is a major advance in predictive capacity. Statistical patterns of gross motor development are desirable for their probabilistic underpinnings. Stratification by severity of motor impairment allows for a more accurate classification of the likely motor progression of a child. As the authors point out, the curves should help clinicians counsel families regarding their child's possible gross motor outcomes. The study results also provide a sound basis on which to examine the effects of interventions on what amounts to the natural history of the condition.

Rosenbaum et al also appropriately emphasize that the observation of independent, unaided motor function levels is only part of the total picture in patients with cerebral palsy. Quality and efficiency of movement, along with cognitive, emotional, and environmental factors are extremely important in function and outcome. The authors also mention the new World Health Organization's International Classification of Functioning, Disability and Health,¹¹ recognizing that cerebral palsy is a medical condition that usually results in some level of disability. Future clinical and research efforts in cerebral palsy and related conditions should not only assess capacities (as this study does), but also should address actual day-to-day activity levels and incorporate how well individuals are able to participate in life and societal activities. Only by addressing all of life's functional dimensions can a true prognosis be discussed and individualized treatment plans devised. This is true for cerebral palsy and for many other illnesses and disabilities. For instance, our group¹² recently adapted the World Health Organization disability classification approach as a service delivery model for patients with spina bifida.

Clinicians who deliver the diagnosis of cerebral palsy (or other diagnoses that affect development of the nervous system) to parents have to be careful not to use this kind of prognostic information improperly. Planning interventions and judging progress over time are helpful in adjusting a family's expectations regarding how much therapy is appropriate for a given child. The unstated goal of improving motor function at all costs (financial and otherwise) sometimes is not appropriate. Older children with cerebral palsy need time to develop social, intellectual, and emotional skills, and also need time to simply be children and to play. On the other hand, the study results should not be overapplied by those who might desire cost-cutting and wish to limit services. As the authors point out, "It is extremely important that parents, therapists, program managers, third-party payers, and other decision makers not assume further therapy is unhelpful or unnecessary when the curves appear to level off. Continuing efforts should be made to address ways both to increase independent activity and to promote participation of children with disabilities, as well as to address secondary impairments that may arise."

Applying a prognosis to a diagnosis and communicating this information to the patient, or his/her family in the case of childhood-acquired conditions, is an important responsibility for physicians. The goal is to help manage the difficult questions that arise for patients and families. At the heart of the matter is really "What does this mean for our lives" or "Will our lives ever be the same?" or when a child is involved, "This is not what we hoped for our child." Ultimately, physicians are not responsible for predicting the future, but should assist those in need and nurture the human spirit. Along with providing technical and scientific expertise, clinicians can help families with a child with cerebral palsy avoid the false hope that all of their (and their newly diagnosed child's) problems will disappear, and more important, help them reshape their hope¹³ that through the human spirit and with the help of each other, life's challenges will be met.