Prevalence of feeding difficulties in children with CP

Feeding difficulties occur in 30–40% of children with CP,2 ,3 and are the commonest among children with severe motor impairment.2 In 2000, the Oxford Feeding Study evaluated 271 children with CP and feeding problems. Common feeding problems were need for help with feeding (89%), choking with food (56%), feeding time greater than 3 h per day (28%), constipation (26%) and frequent vomiting (22%).3 Inadequate nutrition caused by feeding difficulties may be further exacerbated by excessive losses caused by vomiting and GOR. The study also highlighted inadequacies in appropriate professional involvement to this group of children; two-thirds of children had never had a feeding or a nutritional assessment, and only 17% had received input from a dietician in the preceding 12 months.

Aetiology

Feeding difficulties in children with CP result from damage and disruption to the central nervous system (CNS) and enteric nervous system (ENS).

CNS control of feeding and swallowing is mediated via pathways involving cranial nerve nuclei, the brainstem and cortex. Sensory (afferent) input from cranial nerves V, VII, IX and X is relayed to the nucleus tractus solitarius (NTS) and then to specific regions of the brainstem known as central pattern generators (CPGs). Motor (efferent) signals from the CPG travel via the nucleus ambiguous and cranial nerve nuclei V, VII, IX, X and XII, and upper cervical nerves (C1–C3), controlling the movements of mastication, respiration and swallowing necessary to safe, effective feeding. Descending cortical pathways mediate the output from the NTS and CPG.4

The ENS comprises around 1 billion neurons and functions partly independently of the CNS. The ENS controls important functions such as motility, secretion and gastrointestinal blood flow. The CNS modulates the ENS. In children with neurological disorders, this interaction is disordered5 resulting in enteric dysfunction. This manifests primarily as foregut dysfunction. The foregut begins at the mouth and ends in the second part of the duodenum. The foregut is densely innervated by neurons of the ENS, making it vulnerable to abnormal efferent control, leading to electromechanical dissociation and associated dysmotility and symptoms.

These underlying problems may be further complicated by many other factors, some of which interact, and are shown in figure 1.

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Figure 1

Causal relationships between factors contributing to feeding difficulties and growth and general health in children with cerebral palsy.

Consequences of impaired feeding Inadequate growth and nutrition

Historically, poor nutritional status was believed to be unavoidable in children with severe neurodisability. We now understand that chronic feeding problems may cause malnutrition, dehydration and poor growth. When necessary, these can be avoided through appropriate intervention with dietetic input, with or without gastrostomy insertion. The contribution of specific brain injury does not adequately explain growth faltering in children with neurodisability. Equally, undernutrition does not explain all of the growth failure, especially linear growth failure, in children with CP.6 However, the pattern of early growth failure seen in children with CP reflects chronic undernutrition; poor weight gain is followed by suboptimal linear growth and eventual drop-off in head growth.7 Body mass index is a poor measure of body fat in children with CP.8 Skinfold thickness acts as a proxy estimate of body fat. Triceps skinfold thickness (TST) is relatively easy to perform; TST below the 10th percentile is a strong indicator of low body fat stores and therefore of undernutrition in children with CP.8

Neurodevelopmental outcome

It is possible that nutritional deficits may exacerbate the effects of primary brain injury in very young children with CP. Head circumference trajectory reflects brain growth. The positive relationship between head circumference and developmental outcome is widely acknowledged.9 Brain growth occurs most rapidly during the third trimester of pregnancy and the first 2 years of life, during which explosive neuronal growth and synaptogenesis occur. Postnatal rather than intrauterine head growth determines neurodevelopmental outcome.10 ,11 Poor postnatal head growth in ex-preterm infants aged 2 years, but not at term, is strongly associated with neurodevelopmental problems10 ,12 and CP.12 One small randomised double-blind control study of neonates with perinatal brain injury showed improved head growth and increased corticospinal axon diameter in those fed a high-energy and high-protein diet (120% of recommended average intake (RAI)) compared with those fed a standard energy and protein diet (100% RAI).13 The developmental outcome of this group of children has not yet been reported. Data from a small study of children with CP demonstrated improved gross motor skills following 6 months of nutritional rehabilitation.14 Studies of whether or not nutritional supplementation with macronutrients and micronutrients improves neurodevelopmental outcome in children with CP are underway.

Nutritional support of children with CP and dysphagia is essential during this 2-year formative period. However, this is also the period in which the parents of children with neurodisability are experiencing considerable challenges in ensuring their child receives appropriate calories.

General health

The North American Growth in Cerebral Palsy Project2 correlated feeding difficulties with adverse general health outcomes. Recurrent aspiration is a recognised consequence of dysphagia, and may lead to recurrent chest infections and chronic lung disease. Aspiration may result in recurrent respiratory infections, recurrent wheezing, intermittent stridor, atelectasis or desaturation requiring oxygen therapy. Acute aspiration pneumonia can be life threatening, and children may need expert management in intensive care.

Children with CP also experience gastrointestinal problems caused by disruption of the CNS-ENS axis. Foregut dysmotility resulting from transient relaxations of the lower oesophageal sphincter, delayed gastric emptying and abnormalities of oesophageal peristalsis result in GOR, affecting 15–75% of children with CP.15,–,17 Severe scoliosis may also contribute to GOR by causing raised intra-abdominal pressure. GOR commonly manifests as pain caused by resultant oesophagitis and recurrent vomiting, further compromising the nutritional intake in children with feeding difficulty. Chronic constipation occurs in 26–57% of children with severe disability.18,–,20 Factors such as prolonged immobility, skeletal abnormalities, extensor spasm, hypotonia and altered bowel motility are risk factors for constipation. Inadequate fluid and fibre intake also contribute. Opioids, anticonvulsants, antispasmodics, antihistamines and aluminium antacid preparations can further exacerbate problems.21 In addition to causing pain and discomfort, constipation may worsen feeding problems by causing recurrent vomiting, chronic nausea and early satiety.22 As stool softeners work by increasing the amount of fluid in the bowel, their effectiveness is often reduced in children with inadequate liquid intake.

Psychosocial impact and QoL

Feeding difficulties can have psychosocial impact for child and carer. Mealtimes provide potential opportunities for social interaction with family and friends. For the parents of a child with severe disability, feeding is usually an important part of parent-child social interaction. Dependence on a carer for feeding, prolonged feeding times, feeding-related behavioural difficulties, messy feeding and limited communication abilities all contribute to reduced opportunities for participation in feeding in the usual groups and settings (eg, peers at lunchtimes, and with the family in restaurants).

Twenty per cent of parents participating in the Oxford Feeding Study3 found mealtimes stressful. These findings are mirrored by a recent study examining feeding-related QoL in children with spastic quadriplegic CP.23 Parental stress resulting from adequately feeding their child was a prominent negative feature of focus group responses. Parents also reported that time spent preparing food and feeding their child, plus the preparation required for visits and trips limited the time available for other activities for the whole family.23 If oral feeding cannot support adequate growth, some parents may feel a sense of failure despite tremendous efforts to nourish their child. This may be compounded by negative interactions with health professionals. The majority of parents participating in the study of Morrow et al reported negative experiences when communicating with professionals regarding feeding issues. Parental responses indicated that they thought professionals did not consider their opinions to be important, that there was a general lack of information regarding treatment options and that they were made to feel guilty or ashamed, particularly with regard to their child's nutritional status.23 Parents also felt that healthcare staff took a very clinical approach, placing too much emphasis on weight.

Feeding dependence may have an impact on parents and other family members in other ways. For instance, particular ways of feeding are often considered essential for safe feeding by parents. This may make it difficult to leave their child in someone else's care, fearing that they are unequipped to deal with mealtime challenges, placing severe restrictions on parental and other family members' employment and social opportunities.

Assessment of children with neurodisability and feeding difficulties

The increased risk of nutrition and feeding-related morbidity warrants careful assessment and appropriate intervention in children with CP. The importance of effective multidisciplinary team (MDT) working cannot be overemphasised. The MDT should include, as appropriate, a paediatric gastroenterologist, paediatric surgeon, neurodisability or community paediatrician, or paediatric neurologist, paediatric radiologist, speech and language therapist (SLT), dietician, clinical nurse specialist, occupational therapist (OT), physiotherapist, psychologist and social worker. Open channels of communication with the child's family doctor, school, health visitor and community nurse facilitate appropriate exchange of information between all professionals around the child. Clinicians in regional services value close liaison with the child's local professionals. Figure 2 provides a summary illustration of the assessment and management of feeding difficulties in a child with CP.

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Figure 2

Assessment and management of feeding difficulties in a child with cerebral palsy.

Medical and developmental history

Information relating to the aetiology of the child's condition, severity of impairment, developmental progress, co-morbid conditions and drug therapies should be collected. A clear picture of the child's level of receptive language ability and overall cognitive ability, social communication skills, functional vision and motor ability is necessary to place the child's feeding ability and difficulties in a developmental context. Communication and cognitive impairments may reduce the child's ability to convey hunger, satiety, food preferences or discomfort during feeding. Children with visual impairment may be unable to anticipate food or drink approaching. Concurrently evaluating parental understanding of their child's ability is essential, as this helps clinicians understand parents' expectations about feeding. This information becomes very useful at the time of management formulation. A drug history may reveal that the child is on antiepileptic or antidrooling medications. These may reduce alertness, appetite and cause dryness of the mouth. Antiepileptic medications can be associated with increased risk of osteopenia. Nevertheless, suboptimal dosing and frequent seizures will interfere with feeding.

Feeding history

A detailed feeding history is essential. Current feeding should be placed in the context of the previous feeding history, and significant events. Thus, a feeding history starts with feeding ability and progress following birth, including any need for nasogastric tube feeding. The feeding trajectory of infants born preterm must be considered within the context of their corrected age appropriate gross and fine motor, cognitive and speech and language skills. Progress during significant events (such as hospital admissions due to illness and surgery) and times of change in feeding (eg, weaning) should be specifically enquired about. Any history suggestive of non-developmental, progressive feeding difficulty is a cause for concern, and warrants consideration and investigation of acquired disorders. Regarding current feeding, typical nutritional intake should be recorded, with details of quantities and consistencies of food ingested at snacks and mealtimes, and details of spillage or food vomited. The quantity of fluid ingested per day should be calculated in millilitres per kilogram body weight per day (50–100 ml/kg/day are adequate in temperate climates). Time taken to feed and feeding method are important. Other people involved in feeding the child (eg, carers, nursery or school staff) may give valuable perspectives on feeding. Involvement of a dietician in assessing the adequacy of the diet is extremely helpful. It is helpful for feeding to be observed by the MDT. Twenty-four hour food recall or a 3-day food diary is often used to provide nutritional information. Food diaries are a burden for families to complete and compliance is variable. Caution in interpretation is required as families may overestimate amounts consumed by overlooking spillage or vomiting. However, food diaries can be used to record food preferences for incorporation into dietary plans.

Growth history

The child health record, hospital, community or school records should be used to obtain a longitudinal record of weight and head circumference. Accurate height measurements are difficult to obtain in children unable to stand; it may not be possible to obtain previous accurate height recordings.

Physical examination

The purpose of examination is to identify the cause of feeding difficulties and factors which may interfere with feeding ability, complications of feeding difficulties and evidence of malnutrition. Muscle tone, truncal stability and head control, contractures, spasms and abnormal movements all impact on feeding ability. Evidence of chronic lung disease resulting from chronic aspiration may exist. Skin condition and examination of peripheral circulation provides information on nutritional status and helps identify those at risk of micronutrient deficiencies. Poorly nourished, poorly hydrated children often have prolonged capillary refill time and cold extremities.

Gross motor skills

Feeding and nutritional problems are more likely to occur in children with severe motor disability.3 Muscle tone, control of movements, degree of independence and persistence of reflexes which may interfere with feeding ability (eg, asymmetrical tonic neck reflex) should be assessed. Many children with CP have an element of dystonia. This is likely to further interfere with feeding ability and a trial of L-dopa may be appropriate. Mobility level is relevant to assessing energy requirements and dietary intake should be appropriate to energy expenditure.

Oral motor skills

Full assessment necessitates evaluation of oral motor skills at rest and during feeding. Assessment of jaw stability, movement and tone of the lips, cheeks and tongue is important. Significant overbites are common in children with CP and affect biting and chewing. Tonic biting may also be problematic. Jaw instability limits graded opening and closure, impairing manipulation of food in the mouth and leading to poor bolus formation and swallowing difficulty. Jaw thrusting and retraction may cause difficulties taking food from a spoon, drinking, retaining and manipulating food within the mouth, bolus formation and safe and effective swallowing. Consideration and management of mouth and jaw movements are central to any feeding plan.

The lips also play an important role in effective feeding. The lips may be hypotonic, hypertonic or have a mixed tone with constant movement at rest. Poor lip control can cause leakage of food and fluids, resulting in decreased intake and contributing to poor nutrition and dehydration. Normal cheek tone allows food to be contained within the mouth and supports lip and tongue movement. Poor cheek tone results in collection of food in the lateral sulci preventing formation of a cohesive food bolus.

By around 9 months, typically developing children have developed horizontal, vertical and lateral tongue movements. Children with neurological problems may never develop lateral tongue movements, compromising bolus formation, effective chewing and limiting the child's ability to manage age appropriate food textures. SLT assessment of tongue movement is an important component of oromotor skill assessment. Tongue thrusting causes food loss and difficulties in bolus formation and control. Tongue thrusting also makes spoon and cup placement difficult. Limited tongue movements also cause poor food control, slow or ineffective bolus formation and transit prior to swallowing and an inability to chew. Children with Worster–Drought syndrome have particular difficulty with oromotor and lip movements (including speech and blowing). Oromotor difficulties are often more severe than gross motor difficulties in this group of children.24

Swallowing

Careful assessment of swallowing is indicated in children with significant feeding difficulties. Ideally, clinicians should see the child eat and drink their usual food and fluid in the usual way in clinic. Safe and effective swallowing necessitates effective oral preparation of food, formation of a food bolus, oral transit and then propulsion of the bolus through the pharynx with the airway protected. Aspiration occurs when this process fails, allowing materials to pass below the vocal cords into the trachea and lungs. Aspiration occurs in as many as 68–70% of children with severe motor disability.25 ,26 Aspiration may be associated with specific clinical signs (table 1), or may occur silently.

As well as identifying aspiration, videofluoroscopy provides useful information on optimum feeding position, rate of feeding and appropriate textures. Identification of the phase during which aspiration occurs informs decisions about whether or not a child can eat and drink safely. For some children, oral feeding will not be a safe option, leading to recommendation of gastrostomy insertion. The reasons for doing the videofluoroscopy and possible outcomes should be clear to parents in advance of the assessment.

Seating/positioning

An assessment of the child's usual seating arrangement for feeding is helpful. This can often be carried out in clinics where the relevant equipment is available. Parents' mobile telephone video clips are useful for this purpose. Home and school visits by an OT are helpful to evaluate seating and the feeding environment. Head position affects the ability to swallow and maintain a safe airway. Minor alterations to the position of the head and body during feeding can improve feeding safety and ability. Ideally, the hips and knees should be at right angles to the body, and the feet supported or on a firm surface. This relies on some flexibility at the hips, knees, ankles, shoulders and spine. A midline head position should be maintained, with a slight chin tuck, avoiding neck extension. Depending on local set-up, an OT or a PT can advise on suitable specialist seating options. Seating suitability requires regular re-assessment as the child grows.

Management

Feeding intervention should aim to achieve appropriate nutrition and growth within the limits of the child's neurological condition. Intervention becomes necessary when there is evidence of potentially unsafe feeding, initial evidence of poor nutrition with or without growth failure. This may involve dietetic monitoring of the use of feeding intervention strategies which supplement the normal diet with glucose polymers with or without long-chain triglycerides to increase calorie intake, the use of hypercaloric or high-energy-density feeds, or gastrostomy tube (GT) insertion.

Feeding intervention strategies

Evidence to support the use of feeding intervention strategies for children with CP is limited, but suggests potential benefits from interventions including individualised positioning for feeding,27,–,29 alteration of food consistency30 and use of oral appliances.31,–,34 Evidence is conflicting concerning the use of oral sensorimotor treatment programmes. The only randomised control trialdid not suggest benefit35 but included only 20 children. One small study employing less robust methodology33and two case series36 ,37 reported some benefits, while a larger study found no improvements following use.38 Feeding devices (an electric feeder) are unlikely to be helpful in enhancing feeding efficiency.39 ,40 Most of the available studies use comparison or control groups and include relatively small numbers of children. There is an urgent need for adequately powered randomised control trials offering definitive guidance on best management.

Indications for gastrostomy feeding

GT feeding is indicated if oral feeding is unsafe, when nutrition cannot be maintained orally or daily feeding time is prolonged. What parents regard as a prolonged feeding time varies depending on parental opinion, but a definition of feeding time greater than 3 h per day is commonly used in clinical practice. Before GT insertion, a number of assessments are advisable. These include a contrast study to exclude hiatus hernia, assessment of respiratory function to determine the need for preoperative physiotherapy and antibiotics, lower oesophageal pH monitoring to identify significant GOR and videofluoroscopy to assess risk of aspiration. A simultaneous antireflux procedure, for example, fundoplication, may be indicated in children with significant GOR. Complications of gastrostomy feeding include anaesthetic complications, oesophageal laceration, pneumoperitoneum, peritonitis, colonic perforation and cologastric fistula formation. Later complications include stoma leakage, cellulitis, granulation tissue formation around the gastrostomy site and displacement. Gastrostomy insertion may worsen GOR, necessitating the use of antireflux medication or surgery. Further trials evaluating the efficacy of medical versus surgical management of GOR in children with gastrostomies are needed to establish best practice.41

An immobile child with low-energy requirements may be overfed via their GT. Close monitoring is essential to prevent excessive weight gain. One study examining body composition and total energy expenditure in 40 gastrostomy-fed children with spastic quadriplegic CP demonstrated significantly higher body fat content and lower lean body mass than a reference population of neurologically normal children.42 Commercially available enteral formulae developed for neurologically normal children may be associated with increased risk of overfeeding in immobile children with CP. A follow-on study of children with severe spastic quadriplegic CP and oral motor dysfunction examined the effects of a low-energy-dense, micronutrient-complete, high-fibre feed on growth and body composition. Appropriate growth was maintained without disproportionate rise in fat mass or fat percentage among trial participants.43

The use of gastrostomy feeding for children with CP has provoked some controversy. One study reported a negative impact of GT feeding on the survival of children with disabilities.44 A prospective longitudinal study showed no increase in respiratory morbidity or mortality in children with CP fed by GT.45 A parallel study demonstrated significant improvements in parental QoL following institution of GT feeding.46 These findings were not upheld by a prospective longitudinal study examining the impact of GT insertion on global and health-related QoL (HR-QoL) at 6 and 12 months following GT insertion.47 However, parents reported a positive impact of GT insertion on ease of feeding and medication administration, and felt that GT insertion had a positive impact on their child's health.47 In a further study, the majority of parents of children with gastrostomies reported benefits secondary to reduced feeding time, improved physical comfort and decreased burden of care. Reduced anxieties related to safety of feeding, nutritional status, adequate hydration and reduced dependence on one carer also contributed to positive views towards gastrostomies. Negative opinions resulted from complications of GT insertion, inadequate follow-up post insertion and a feeling of having been pressured into agreeing GT insertion.23

Sensitivity to the complex issues surrounding GT insertion is important when approaching the subject of GT feeding. Inclusion of the family in the decision-making process is vital. The MDT around the child must be made fully aware of the potential benefits and disadvantages to the child in order to support the family through the process. Disagreements between parents, carers (eg, those feeding the child at school or in respite care) and clinicians about the safety of oral feeding, and the need for GT insertion do occur. Clinicians should seek the advice of colleagues when necessary; referral to a regional feeding clinic or to a neurodisability specialist may be helpful. Very occasionally, it becomes necessary to consider whether the oral feeding desired by parents or carers or both is harmful for the child and in their best interests. Once again, discussion with colleagues and referral to a specialist clinic becomes helpful in helping parents see potential dangers for their child. When absolutely necessary, managing issues through child protection routes may require consideration.

The feeding environment

The mealtime environment may impact on the successfulness of feeding. Distracting visual or auditory stimuli can impair the child's ability to attend to feeding. Sudden noise may provoke muscle spasm or extension, increasing the risk of aspiration. Creation of a safe and comfortable feeding environment with plentiful interaction and communication opportunities helps to achieve a more enjoyable feeding experience for child and carer. The child's preferred communication method should be used during mealtimes. Augmentative communication aids may help the child to indicate choices, readiness for feeding, satiety or discomfort with feeding.

Behaviour

Children with CP have a higher incidence of behavioural and emotional problems than their normally developing peers.48 ,49 Consideration of the causes of any feeding-related behavioural difficulties is important, as factors such as pain, GOR, fear, sensory issues or past unpleasant feeding experiences may underlie aversive feeding behaviours. Avoidance of force feeding, waiting for the child's cues and increasing opportunities for interaction and encouragement are also important. An SLT can help implement good feeding practice. If these measures are unsuccessful, referral to a clinical psychologist may be appropriate. However, behavioural feeding difficulties can be challenging to ameliorate or eradicate; therefore, managing parental expectation is important.

Conclusion

Management of complex feeding difficulties requires careful and co-ordinated planning by all involved professionals. Any management plan must take into account the child's nutritional status, feeding abilities, medical condition and associated gastrointestinal problems, drug therapies, cognitive level, activity level and family members' opinions and circumstances. Careful multidisciplinary assessment and management of feeding difficulties is important in order to achieve appropriate growth and nutrition in children with neurodevelopmental disability. Failure to do so may result in inadequate growth, suboptimal neurodevelopmental outcome and poor general health. Management plans should be sensitive to individual family circumstances and priorities, while keeping child welfare paramount.