Esophageal dysmotility/gastroesophageal reflux/delayed gastric emptying

Gastroesophageal reflux disease (GERD), or the reflux of gastric contents into the esophagus, is a common problem in children with CP, with an estimated prevalence of up to 75%. The reason for this high prevalence is likely multifactorial, primarily related to central nervous system impairment but also due to prolonged supine positioning in individuals with impaired mobility, and, for individuals receiving enteric tube feeds, the consistency of the diet being predominantly liquid. Both of these latter factors have been found to be contributors to GERD in normal infants, who have a similarly high prevalence. Esophageal manometry has demonstrated alterations in esophageal motility in some children with CP, particularly those with spastic tetraplegia.

Delayed gastric emptying has been reported in children with CP, with a prevalence of up to 67%. Inadequately treated delayed gastric emptying has been hypothesized to interfere with the treatment of reflux, although some studies have found no relationship between gastroesophageal reflux and delayed gastric emptying.

Vomiting and esophagitis are frequently noted symptoms of GERD in CP. Tooth erosion due to the effects of reflux has been observed in children with CP, and, if not recognized and treated, may impair oral feeding. GERD can also place the individual with CP at risk for chronic aspiration, especially when dysphagia is also present.

When GERD is present, conservative interventions to address positioning and the thickening of feeds, if appropriate and tolerated, may be appropriate first-line measures. In general, the same medications used for the treatment of reflux in neurologically unimpaired individuals, including proton pump inhibitors and histamine-2 receptor antagonists, are also appropriate for use in children with CP. Recent research supports a role for baclofen in the treatment of GERD. Baclofen, a GABA-B receptor agonist, inhibits triggering transient lower esophageal sphincter relaxation and also inhibits gastric emptying, reducing reflux. Baclofen is also frequently used to treat spasticity, and may be especially useful in children with CP who have spasticity and GERD. If the symptoms of GERD are noted to persist despite medical therapies, surgical management is sometimes considered. Children with CP, compared with other individuals with neurologic impairment, have been demonstrated to be more likely to require surgical intervention for treatment of reflux. Prophylactic fundoplication accompanying gastrostomy tube placement is occasionally advised because of concerns that gastrostomy, or the increase in feeding that often is enabled following gastrostomy, may worsen or precipitate GERD. However, a recent Cochrane review focusing on children with “neurologic impairment” generally and not specifically on those with a diagnosis of CP, indicated that robust scientific evidence is lacking as to whether fundoplication is beneficial in patients undergoing gastrostomy. Other surgical procedures for the treatment of GERD, such as gastrojejunostomy tube placement or esophagogastric separation, are also occasionally used, but again there are little data specific to children with CP, as opposed to individuals with nonspecific “neurologic impairment.”

Constipation

Constipation occurs in 26% to 90% of children with CP. The cause of constipation in CP is multifactorial and may include immobility as well as slow colonic transit time. Constipation is a significant problem in many children with CP and can contribute to other complaints, including pain, spasticity, feeding problems, irritability, poor appetite, and subsequent growth impairments. If not monitored and treated appropriately, ileus and permanent intestinal dysmotility can develop and, in extreme cases, can result in bowel perforation. Inquiring about the bowel habits and bowel program, if one exists, is an important area of the review of systems in evaluating a child with CP. Historical information may reveal extensive time periods between bowel movements, frequent episodes of diarrhea, and characteristics of bowel movements as hard and pelletlike sometimes requiring digital disimpaction, all of which suggests that evaluation of the bowel program is necessary. Abdominal radiographs are sometimes helpful in assessing stool load, but often historical information will be effective in identifying bowel motility issues.

Treatment of bowel dysmotility also depends on information obtained during the clinical encounter. In cases of suspected obstipation, a clean-out program may be recommended, with use of medications impacting the upper and lower gastrointestinal tracts. The presence of hindgut dysmotility may lead some practitioners to limit or avoid the use of enemas associated with electrolyte derangements, such as tap water enemas and phosphate enemas; likewise, the presence of foregut dysmotility may lead some to avoid the administration of mineral oil by mouth due to aspiration risk. Typically, in cases of no significant concerns for either hindgut or foregut dysmotility, oral polyethylene glycol at doses of up to 1 mg/kg in addition to rectal suppository or enema is used. Pending good results following clean-out, a daily bowel program should be customized for the child. This program often includes a combination of stool softeners or oral promotility agents and a diet with the appropriate amounts of fiber and fluid. Attainment of regularly scheduled soft, formed bowel movements with minimal incontinence is the primary goal of the bowel program and timed evacuations are helpful in achieving this.

Oropharyngeal dysphagia

The ability to form and manipulate a bolus and then to swallow it safely is a complex task that involves the coordination of multiple muscles that receive input from the cranial nerves (V, VII, and IX-XII). Severity of motor impairment, in general, is associated with dysphagia. Children classified at GMFCS level V (most severe) have been demonstrated to have more significant dysphagia than those at GMFCS level IV. An impairment in the ability to swallow often places the child at risk for aspiration, frequently leading to respiratory infection. Although esophageal reflux may also contribute to aspiration, direct aspiration as a result of oropharyngeal dysfunction is more strongly associated with respiratory infection than esophageal reflux. Up to 97% of nonambulatory children with CP and dysphagia have been demonstrated to be silent aspirators.

The need for accurate assessment of the risk of aspiration is a critical reason for a proper evaluation of swallowing. In general, evaluation of dysphagia in the child with CP is similar to that for other children with dysphagia. Because children with CP often have abnormal tone, attention to positioning is particularly important when trying to optimize oral feedings.

Other difficulties with self-feeding may occur because motor impairments can make such feeding difficult or even impossible. Children with oropharyngeal dysphagia may eat more slowly and this may lead to longer mealtimes. In children with severe spastic tetraplegia, feeding can be the most time-consuming basic care need. Children with dysphagia may prefer or be prescribed softer food textures and it is important to consider that softer foods may be less calorically dense, further contributing to inadequate caloric intake.

Enteric tube feeding

In children with CP in whom swallowing is not safe enough to allow oral feeding due to risk of aspiration, or in whom difficulties with feeding make it impossible or impractical to take in adequate calories by mouth, enteric tube feeds may be considered. This decision is often difficult, for the parent of the child for whom the procedure is being considered and for the practitioner caring for the child, because there are currently no randomized controlled trials addressing this issue. A recent longitudinal, prospective, multicenter cohort study, although not randomized or blinded, found statistically significant and clinically important increases in weight gain and subcutaneous fat deposition and reported that almost all parents noted a significant improvement in their child’s health after gastrostomy tube placement and a significant reduction in time spent feeding. Although promising, further studies are needed to gain a better understanding of optimal feeding management for children with CP.

Growth and nutrition in children with cerebral palsy

With the knowledge that increased caloric intake will likely be helpful in improving growth, the practitioner is still faced with the question of what is considered “appropriate” growth for the child with CP. This question may be more obvious in the case of the child with severe spastic tetraplegia, but in fact it is an important question across the spectrum of children with CP, with poor growth observed at all levels of severity. Children with mild CP are at risk, with undernourishment demonstrated in up to 30% of children with hemiplegia or diplegia. The analysis is further complicated as any assessment of appropriate caloric intake for growth needs to take into account that children with CP do not necessarily have the same caloric requirements as their peers in the general population. A high degree of variability in total energy expenditure (TEE) has been demonstrated in adults with CP, which appears largely attributable to high interindividual variation in energy expended in physical activity, thus making it difficult to provide general guidelines for energy requirements for this population. Ambulation status has been shown to be an important predictor of TEE and should be taken into account when estimating energy requirements. Formulas for calculating energy expenditure that take into account factors such as muscle tone, activity, and ambulation have been developed for adolescents with CP. In assessing linear growth in children with CP, one must take into account that height or length may be difficult to obtain reliably due to the presence of contractures; formulas using segmental measures have been developed. Body mass index (BMI; calculated as the weight in kilograms divided by height in meters squared) may not be a good indicator of nutrition in children with CP, primarily due to decreased muscle mass and decreased bone density. Because of these considerations, it may not be appropriate to use standard growth charts based on a nonneurologically impaired population. Growth charts for children with CP have been created, with some published in a usable form for clinicians.

Other indicators of nutrition frequently used in the general population, but found to be unreliable in children with CP, include serum prealbumin and albumin concentrations. There is little to no correlation of these values with anthropometric measures (eg, skinfolds, midarm fat area), growth (height), severity of CP, feeding dysfunction, or general health. Several measures of nutritional status, including weight-for-height percentiles, arm circumference, BMI, lean BMI, head circumference to arm circumference ratio, triceps and subscapular skinfold thickness, have been evaluated and triceps skinfold thickness less than 10% for age/sex has been identified as the best indicator of malnutrition in children with CP.

Micronutrient deficiencies in children with CP have been identified and associated with a low intake of iron, folate, niacin, calcium, vitamin E, and vitamin D, even among those who were receiving nutritional supplements. Similarly, decreased levels of vitamin D and calcium in nonambulatory tube-fed children with CP have been identified. (A detailed discussion of vitamin D and calcium and their relationship to bone growth in children with CP is provided in Houlihan and colleagues, this issue.)

Although most studies on malnutrition in children with CP focus on the problems associated with being underweight, some children with CP may be overweight. There is a rising prevalence of obesity (7.7%–16.5% during the past decade, and comparable to the general population during the same time period) in ambulatory children with CP. This is especially significant as heavier children with CP may be less well equipped to handle the impact of increased weight, as indicated by a decrease in gait speed and an increase in VO ₂ .

Growth in children with CP is unquestionably a complex issue, and currently there are few data to guide clinicians regarding what constitutes ideal, or even adequate, growth and nutritional status in this population. However complex, it is an issue worth tackling, because data suggest that improved growth correlates with improvements in gross motor function measure (GMFM) scores and in measures of social participation.