Definitions and Epidemiology
Pediatric feeding disorders may be defined as problems with the developmentally appropriate intake of food. This broad category includes difficulties that objectively result in nutritional or medical risk (e.g., refusal of dietary protein leading to protein energy malnutrition), as well as those perceived as problematic by the child’s family that result in stressful mealtimes without objective medical consequence. These do not include eating disorders (i.e., anorexia and bulimia) or obesity. Pediatric feeding disorders may be associated with medical disease (often gastrointestinal), malnutrition or failure to gain weight, developmental delays affecting skill acquisition, and interpersonal disorders. Feeding problems have been characterized simply along axes of ability and desire,1 by biophysical etiology,2 or by criteria that focus on interpersonal relationships.3 Children with feeding disorders are best assessed and managed by interdisciplinary teams that address all sides of the problem, given that distinct facets of the disorder require individual expert assessment and intervention.
Feeding disorders occur in children with an incidence as high as 25% in normal children,4 with a higher incidence in those with neurologic disability.5–7 While children with feeding disorders require evaluation by a gastroenterologist due to the high coincidence with gastrointestinal disorders,1,8 skill acquisition and behavioral components are often present and require behavioral evaluation and management beyond what a gastroenterologist may provide.9
An individual patient’s feeding disorder is unique. Environmental and family social-dynamic issues are different for each individual with the same underlying pathology (e.g. hypoplastic left heart syndrome). Furthermore, feeding, the airway, and the upper gastrointestinal tract exist in a reciprocal relationship system where problems with one of these components may produce problems in the others (Figure 3–1); such may be seen in an infant with pulmonary disease, where cough and tachypnea may aggravate reflux and feeding problems, respectively. Additionally, the central nervous system, with respect both to basic motor and sensory function and to its higher order processes such as personality development, exists in the background of this relationship and can both contribute to, and be affected by, problems of the airway, upper GI tract, and feeding ability (Figure 3–1).
Interplay between airway, gastrointestinal tract, and feeding ability. Feeding ability has a reciprocal relationship with the airway and the upper gastrointestinal tract, where one affects the others. In the background, the central nervous plays a role, in regard to both the motor and sensory function and the higher order personality and social dynamic issues.
Achievement of normal feeding is a function of skill acquisition as permitted by the child’s internal and external environments. The progression of feeding that occurs over infancy is governed by neuromuscular and anatomic maturation that limit the manner of feeding at any specific age.10 A newborn is limited by neurologic immaturity and unique anatomy that helps isolate the oral cavity from the airway. These limitations prevent the processing of solids, but maximize the efficiency of suckling from a nipple. As the infant grows, the oral cavity enlarges and neuromuscular maturation occurs, manifested as lateral motion of the tongue, as well as improved head and truncal stability that allows the introduction of smooth solids. As the oral cavity grows, the larynx descends, and teeth appear, which together with further skill acquisition allow the introduction of more complex solids and table foods into the diet by 1 year of age. A strong element of social bonding drives the progression across feeding milestones, and infants learn to respond to positive reinforcement. Early exposure to various tastes may also play a role in flavor programming and the later acceptance of a varied diet.11
Swallowing is a complex behavior that requires coordination of cranial nerves (V, VII, IX, X, and XII), cervical nerves (1 and 2), and corresponding sensory and motor endpoints to coordinate the oral and pharyngeal phases (Table 3–1). Similar to data on abnormal visual cortex development associated with early onset blindness,12 children who miss developmental “critical periods” in infancy often fail to progress across feeding milestones, presumably due to abnormal cortical development allowing coordination of swallowing function. Such a patient typically would not progress across textures and may be subject to developing profound feeding disorders with possible social and/or medical consequences.
|Afferent||Trigeminal (V)||Oral cavity, anterior 2/3 of tongue||None|
|Facial (VII)||None||Anterior 2/3 of tongue|
|Glossopharyngeal (IX)||Posterior 1/3 of tongue||Posterior 1/3 of tongue|
|Efferent||Trigeminal (V)||Muscles of mastication|
|Facial (VII)||Lips and face|
|C1 and C2|
|Vagus (X)||Larynx and esophagus|
|Efferent||Trigeminal (V)||Tensor veli palatini|
|Glossopharyngeal (IX)||Palate, pharynx, larynx|
|Trigeminal (V)||Hyoid and laryngeal movement|
|C1 and C2|
Interruption of this graded exposure and corresponding development occurs in many infants and children with congenital or transient disease states that interfere with progression of feeding skills. An infant with complex congenital heart disease may not be well enough to take initial oral feedings for several months after birth, resulting in a situation where graded food exposures have not occurred. This directly impairs neuromuscular development, not to mention the social bonding that typically occurs with feeding. Recognition of such a feeding disorder is the first step in properly addressing it and establishing realistic and developmentally appropriate expectations.
In the clinical setting, a feeding disorder may present as a nutritional consequence of an inadequate diet (e.g., poor weight gain and protein energy malnutrition), a medical consequence of prior or active disease (e.g., obstructive lung disease, eosinophilic esophagitis, seizures, and heart failure), a consequence of dysphagia (e.g., choking, aspiration pneumonia, or failure to advance across textures), or a psychodynamic problem (e.g., tantrums, disruptive mealtime behaviors, unmet parental expectations, and feeding schedule that result in grazing). Most patients with feeding problems exhibit a complex, mixed presentation of several such issues. Such inherent complexity benefits from a multidisciplinary approach that utilizes specialists to assess each facet of the feeding disorder, including a gastroenterologist, a nurse, a dietitian, a speech and language pathologist, an occupational therapist, and a behavioral psychologist.
The phases of normal feeding must each be carefully evaluated to understand the nature of the problem.2 These include the pre-oral phase during which foods are identified, selected, and then placed within the oral cavity. The oral phase follows, processing the alimentary bolus by chewing with subsequent transit to the pharynx. The pharyngeal phase coordinates the passage of the bolus into the esophagus with ongoing respiration. The esophageal phase requires orderly transit, with peristaltic contractions moving the bolus into the stomach. The gastrointestinal phase involves temporary storage of the meal within the stomach, which enlarges to accommodate the meal and gradually releases it into the intestine in a manner that maximizes nutrient digestion and absorption.
It is easy to see how perturbation of any of these phases may result in a feeding disorder. The problem may be clear and limited, such as the ineffective esophageal phase of a patient with achalasia. Conversely, the problem may be more complex, as in an ineffective pre-oral phase of an infant with blindness, a depressed mother, or other sensory or environmental deprivation.
Families may not understand the underlying complexity of feeding disorders and may simply want things to be better. In particular, parents may not understand that they may have contributed to developing and/or sustaining the feeding disorder. It is critical for the clinician to probe the parents’ understanding of the feeding disorder by simply asking, “What problem may I help you with?” It is also critical to understand the parents’ beliefs about the underlying cause by following up the question, “Why do you think this is happening?” Failure to begin the work-up with these two simple questions may establish unrealistic expectations that will limit the progress that can be made over time. The family of a child who has already had a comprehensive multidisciplinary assessment that was negative may still believe a medical etiology is being missed. They may not be ready to address underlying interpersonal issues that are the likely etiology. Failure to both acknowledge and move beyond a family’s initial perceptions will result in inability to establish the trust required to guide the family through management of a feeding disorder.
It is common for children with feeding disorders to have had previous extensive medical evaluations, often at different institutions. Review of these medical records should be done prior to the clinic evaluation, sometimes with a limited telephone conversation with the family. This may be helpful in deciding which diagnostic elements may be required, including videofluoroscopic swallow study (VSS), EGD, meal observations, or consultation and assessment with other subspecialists who are not routinely part of the team, such as neurology, genetics, or otolaryngology.
Diagnosis of a feeding disorder must include diagnosis of underlying and comorbid disorders. The former may include almost any pediatric disorder; the latter may include failure to gain weight, gastroesophageal reflux disease (GERD), and dysphagia. Conceptually, the physician leading the team must simultaneously evaluate three major issues: nutrition, upper GI tract dysfunction, and dysphagia (Figure 3–2).
Conceptual algorithm for management of feeding disorder with or without dysphagia. Three important questions for the gastroenterologist to consider are detailed in the diagram. Failure to gain weight may be assessed through traditional assessments of caloric retention, maldigestion, malabsorption, or increased caloric demands. Use of caloric supplementation and/or structuring of meals to foster appetite may be considered. Vomiting and GERD may require acid suppression, management of dietary protein intolerance, fluoroscopic studies, assessment of non-GI causes (e.g., brain MRI and renal ultrasound), pH probe testing, or impedance testing. Aspiration requires careful documentation of pulmonary health history, limiting oral feedings per findings from swallowing evaluations, possible imaging of the chest, and pulmonary consultation. Failure of controlling any of the above may require institution of nasogastric (NG) tube or gastrostomy tube (GT) feedings. Failure to control symptoms may indicate need to jejunal feeding via nasojejunal (NJ) tube, placement of gastrojejunostomy (GJ) tube feeding, or thoughtful consideration of a fundoplication.