Patients with neurologic motor conditions, such as cerebral palsy and muscular dystrophies, are a unique and challenging patient population who commonly experience malnutrition and growth failure. Although each patient and their family share similar concerns and problems, they are fundamentally distinct, both in the manifestation and experience of disease. The care needed to maximize medical and social functioning requires an open, nonjudgmental, and adaptable practice.
The origin of malnutrition in these children is often complex and multifactorial. Unfortunately, tools used to assess nutritional status in typical children are often not valid in the assessment of children with special needs. In addition, few controlled studies validate our current standard of medical practice as it relates to providing adequate nutrition to these children. There are few guidelines to help the practitioner determine when poor growth can be equated with poor health.
How we as physicians approach these patients has a dramatic impact on their quality of life. Many families feel that communication with the practitioner is poor, that their input is not considered important, that they are not provided all the information on treatment options, and that practitioners do not take into account the needs of the family. In addition, many parents of special needs children are made to feel guilty or shameful about the child’s nutritional status, leading to yet more barriers to provide the best quality care to these children. Physicians must be sensitive to the goals and needs of the family, and balance that with the nutritional needs of the child. Nutritional plans should be developed in partnership with the family and that plan should be communicated to other providers.
Cerebral Palsy and Growth Failure
Cerebral palsy has been defined as a permanent disorder of the development of movement and posture, causing limitation of activity. Cerebral palsy is attributed to nonprogressive disturbances that have occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, perception, cognition, communication, and behavior. These children are often affected by epilepsy and develop secondary musculoskeletal problems. The population of children with cerebral palsy is large and growing. The incidence of cerebral palsy has been estimated at 3.6 children per 1000 live births. Approximately 8% of premature infants born between 22 and 32 weeks of gestation will have some component of cerebral palsy. These children often require extensive and sophisticated medical care over multiple subspecialties. Coordination of this care is often difficult and, in many situations, left up to the parent. Unfortunately, growth and nutrition are often lower on the list of medical priorities.
Growth failure is very common in patients with cerebral palsy in the United States. The North American Growth in Cerebral Palsy Project evaluated patients with cerebral palsy between the ages of 2 and 18 years. In patients with moderate to severe cerebral palsy (gross motor function classifications system III–V), 47% had weight below the 5th percentile and 68% had length less than the 2.5th percentile for age and sex. Linear growth failure affects approximately 23% of children with cerebral palsy and between 29% and 46% of children with cerebral palsy are undernourished. Median weight-for-age in children with spastic diplegia is below the 10th percentile for the National Center for Health Statistics (NCHS) reference population, and unfortunately becomes increasingly divergent as these children age. The U.S. Department of Health and Human Services has made it a priority to promote the health and well-being of people with disabilities, to prevent secondary conditions, and to eliminate disparity between people with and without disabilities. With recognition of the problem comes the challenge to find solutions that will promote health in this population.
Causes of Growth Failure
Although children with cerebral palsy have decreased linear growth for many reasons, nutritional status plays a major role. The nutritional components of growth failure include dysphagia, inappropriate dietary intake, increased nutrient losses, and altered energy needs.
The general motor dysfunction of cerebral palsy also manifests in difficulty with feeding and dysphagia. Approximately 86% of patients with quadriplegia and 37% of patients with diplegia or hemiplegia have feeding problems. Studies have suggested that up to 38% of children with cerebral palsy also have direct aspiration. In addition to the underlying oropharyngeal swallowing difficulties related to cerebral palsy, feeding is a complex system for these children, involving positioning of the child, presentation of differing textures, interactions of the parent/care giver with the child, and time. The time commitments of these families to feeding can be overwhelming, with 38% requiring more than 3 hours a day and 3% requiring more than 6 hours a day committed to feeding their children. All of these factors lead children with cerebral palsy to have a lower caloric intake than typical children. Evaluation of caloric intake may also be made more difficult because caregivers tend to overestimate the number of calories that the child eats and underestimate the amount of time that it takes to provide those calories.
Non-nutritive factors involved with growth failure include the severity of neurologic injury, ambulatory status, cognitive ability, endocrine abnormalities, and inherent genetic factors. Endocrine factors include abnormalities of growth hormone secretion. Linear growth in children with cerebral palsy diverges further from the growth seen in typical children as they get older. Studies have demonstrated a lack of pubertal growth spurt in children with cerebral palsy. Although children with cerebral palsy tend to experience early adrenarche, they enter puberty later and puberty lasts longer. Other studies have demonstrated decreased IGF-1 and growth hormone in girls with cerebral palsy, even with nutritional adjustment.
Benefits of Nutritional Rehabilitation
In evaluating and managing the nutritional status of children with special needs, the practitioner must focus on the benefit to overall health that appropriate nutrition can provide. Malnutrition will affect the overall health of these children by leading to increased healthcare utilization, decreased social participation, declining motor function, poor bone health, and ultimately a decreased life expectancy.
In patients with low body fat compartments, overall motor function is decreased, including the respiratory musculature. In a recent study, increases in mid-arm circumference, triceps skin fold, and the ratio of mid-arm circumference and knee height was associated with less motor decline. Malnutrition may also lead to decreased cerebral development and further delay in cognitive development. Diminished immune function impairs wound healing and affects susceptibility to infection.
Children with cerebral palsy who are malnourished have been found to have decreased social participation and increased irritability. In one study, triceps skinfold Z score correlated with child healthcare utilization, child participation in usual activities, and family activities. Each standard deviation increase in triceps skinfold was associated with a 20% reduction in doctor visits, 50% reduction in hospitalization, 22% reduction in days missed from school, and 33% reduction in missed activities for the family over 4 to 8 weeks. To reverse the devastating trend of malnutrition in this population, we also need to acknowledge the multiple causes of malnutrition and growth failure in patients with cerebral palsy and develop plans in conjunction with the family to address feeding and provision of calories.
Developing a Nutritional Plan
There are a number of steps in the development of a complete nutritional plan for patients with special needs. The first step is to fully assess the nutritional status of the patient using history, anthropometrics, and laboratory testing as a guide. Secondly, the provider should estimate caloric requirements, free water requirements, macronutrient and micronutrient needs, and identify the appropriate foods and supplements to achieve these nutritional goals. The third step involves the method used to provide the nutrition by studying the patient’s oropharyngeal swallowing function, as well as assessing for supplemental tube placement. Finally, the nutritional plan is put into place and closely monitored for response.
The initial nutritional assessment should include a detailed feeding and growth history, accurate anthropometric measurements, comparison of current nutrient intake versus estimated requirements, review of biochemical data, and implementation/modification of nutrition support regimen as indicated.
Ideally, a 3-day food record will be completed and brought to the initial visit for review. In lieu of this, a detailed diet history can be obtained during the visit by reviewing everything the child eats and drinks in a typical 24-hour period. An inventory of the child’s accepted foods and beverages (types and textures) is important in developing an oral component to the nutritional plan. For children who are receiving tube feedings, the clinician should document formula type, quantity, and method of administration. Other important components to the initial dietary history include fluid intake; use of multivitamins, minerals, or other additives; and the presence of food allergies and/or intolerances.
In addition to a thorough diet history, information on the child’s feeding capabilities and/or potential barriers to oral eating are also vital components of the nutritional assessment. This should include questioning on ability to sit and/or feed unassisted; degree of head control; the presence or absence of coughing, gagging, or choking while eating or drinking; the presence of chewing/swallowing difficulties; fatigue/lethargy during meals; and the amount of time the family spends on feeding, including the average length of mealtimes. It is essential to differentiate between what the child is actually consuming versus what is offered at meal and snack times. Studies have found that caregivers overestimate the quantitative assessment of oral intake by 44% to 54%.
Assessment of growth parameters in children with special needs can be challenging. The comparative standards presently available are based on data from the typical population, which is not a valid reference group for these children. Furthermore, obtaining accurate anthropometrics by standard techniques may not be feasible due to contractures, scoliosis, and rigidity.
Whenever possible, growth data should be obtained prior to the initial visit and plotted on the appropriate growth curve. Birth weight and length, as well as previous weight, length, and head circumference measurements should be compared to current anthropometric data to determine if growth faltering or abnormal weight gain or loss has occurred. Infants should be weighed on an infant scale and children older than 2 years of age should be weighed on a digital standing scale. If the child is unable to stand, the digital scale can still be utilized once weight of stroller, wheel chair, or person holding the child is “zeroed out.” Infants should be weighed naked and older children weighed in the lightest street clothing possible with shoes removed.
Infants and children younger than 2 years of age should be measured on a recumbent length board. For older children who are able to stand without crouching, standing height using a wall stadiometer will be measured (once shoes and/or braces have been removed). Because it is often difficult to obtain accurate height measurements in children with neurologic impairments due to contractures or inability to stand, tibial length (TL) * is a reliable and valid proxy measure for children up to 12 years of age.
* Estimated stature (cm) = (3.26 × TL) + 30.8 (+/− 1.4)Weight and height of children younger than 2 years of age should be plotted on the World Health Organization (WHO) Growth Charts. For children 2 years of age and older, data should be plotted on the Centers for Disease Control and Prevention (CDC) chart. There are no set standards for interpretation of growth data for children who are neurologically impaired. Although specific growth charts for children with cerebral palsy (based on age, sex, and Gross Motor Function Classification System [GMFCS] classification) have been developed, they may not represent the ideal or healthy weight for these children. Therefore, these special growth charts should be used only in conjunction with the WHO or CDC growth charts.
Review of multiple anthropometric measures and their trends will guide the level of nutritional intervention. A child may be considered well-nourished if he or she is gaining weight and growing appropriately, even if weight and/or height for age are tracking below the 5th percentile. Evidence of undernutrition (weight-for-height <80% of expected, body mass index [BMI] <5th percentile), growth failure (height-for-age <90% of expected), overweight (BMI >95th percentile), and individual nutrient deficiencies indicates the need for nutritional intervention.
Triceps skinfold thickness appears to be a better predictor of nutrition status than height and weight percentiles. Mid-arm circumference and triceps skinfold thickness can be used to help assess body fat and arm muscle area. Triceps skinfold thickness testing seems to be more accurate then weight-for-height determination in identifying undernourished children. Triceps and subscapular skinfold thickness provides information on body fat stores. However, studies comparing the use of doubly labeled water to measure body composition with skinfold studies demonstrated that skinfold measurements underestimated fat mass and fat-free mass.
Using skinfold calipers, triceps skinfold thickness can be measured on the left arms of both infants and children. Midarm circumference (MAC) should also be measured on same arm and will be tracked along with triceps skinfold thickness as a marker of nutritional status. Whenever possible, the same observer should obtain these measurements to improve validity. A triceps skinfold thickness of less than the 10th percentile for age and gender is an indicator that further intervention may be needed.
Body composition can be measured using dual X-ray absorptiometry (DXA) and has been validated for use in cerebral palsy. DXA can also be utilized to determine bone density. Typically, bone density is obtained at the lumbar spine and hip. In patients with contractures, this can be difficult. In children with cerebral palsy, bone density can be measured at the distal femur, projected in the lateral plane. Normative reference data are available for this technique.
The WHO Equations for Estimating Basal Metabolic Needs ( Table 92-1 ) and The Dietary Reference Intakes (DRIs) ( Table 92-2 ) are useful tools for estimating the patient’s caloric needs. Because both equations tend to overestimate the needs of the neurologically impaired child, an average of the two equations can be obtained and used in conjunction with the child’s usual caloric intake (obtained via diet history) as a guideline. Overall, close follow-up and monitoring is the key to generating appropriate weight gain while optimizing nutrition. If a child is gaining weight too quickly, the current caloric provision should be decreased by 10% increments. Conversely, if a child is clearly underweight or failing to thrive, then the calories should be increased by 10% increments.
|0-3||60.9W − 54||61W − 51|
|3-10||22.7W + 495||22.5W +499|
|10-18||17.5W + 651||12.2W + 746|
|18-30||15.3W + 679||14.7 + 496|