The classic pattern of neurological disorders is not the only one affecting GI motility. Neurometabolic disorders are rare and complex disorders that result from inborn errors of metabolism that lead to impairment of the brain. Depending on the metabolic processes involved, neurometabolic diseases can be classified according to the tissue predominantly involved and the age of the child at presentation (37). Alexander disease is a cerebral degenerative disorder caused by a mutation in the GFAP gene encoding the main intermediate filament of astrocytes, resulting in progressive neurological and cognitive deterioration (38). There are four distinct forms of pathology: neonatal, infant, adolescent, and adult; they differ according to the clinical spectrum and neurological manifestations (39). These patients then require nutritional support because of weak sucking and severe swallowing difficulties (40). These patients often suffer from GERD in addition to the risk of malnutrition and cachexia associated with their neurological condition (41, 42). It has been observed that dysbiosis, or imbalance of gut microbiota, may contribute to the development of GERD by promoting the translocation of fermenting bacteria from the colon to the small intestine (43). This process can lead to the production of fermentative gases that exit from above, contributing to reflux symptoms. While increasing bicarbonate production may be a potential corrective nutritional intervention, other strategies aimed at modulating gut microbiota, such as probiotics or prebiotics, may also be effective in improving GERD symptoms (44, 45). Moreover, dietary interventions that target specific nutrients, such as fiber, may also improve gut health and reduce GERD symptoms (46).

X-linked adrenoleukodystrophy (X-ALD) is a neurometabolic disorder in which the brain, spinal cord, adrenal glands and testicles are the most affected organs (47). X-ALD represents the most prevalent peroxisomal disorder, originating from mutations occurring in the ABCD1 gene, which encodes the peroxisomal membrane protein ALDP, which plays a critical role in the transmembrane transport of very long-chain fatty acids (48). It is characterized by progressive symmetrical demyelination of the white matter (49). This condition determines progressive neurological damage leading to loss of swallowing ability and fecal continence (50). As in CP, in X-ALD there is no direct involvement of the GI system and consequently the GI problems are related to hypomobility and a loss of central co-regulation and control (47). Therefore, although CP represents static damage while X-ALD is characterized by dynamic progression, patient management might be similar.

Myotonic dystrophy is an autosomal dominant genetic disorder. It is caused by unstable expansion of a nucleotide triplet containing cytosine-thymine-guanine located in the 3′ untranslated region of chromosome 19q13.3 (51). Involvement of one of the various tracts of the GI system is common in these patients. Dysphagia, regurgitation, and delayed gastric emptying have been reported for the upper GI and abdominal swelling, diarrhea, or constipation for the lower GI (52). In this case, the pathogenesis of the clinical manifestations is local muscle damage; indeed, at the esophageal level, a decrease in muscle tone was observed that is directly proportional to the extent of GER (53); at the gastric level, the impairment of smooth muscle fibers leads to a slowing of gastric emptying, which can lead to gastroparesis (52). Decreased peristaltic activity in the gut can lead to paralytic ileus or anaerobic bacterial overgrowth, which can lead to osmotic diarrhea as a result of malabsorption (54). Paralytic ileus and bacterial colonization can then lead to serious complications such as toxic megacolon (55).

Duchenne muscular dystrophy (DMD) is a sex-linked recessive disease, whose gene is located on Xp21 (56). The GI manifestations in DMD are principally related to the degeneration of the GI smooth muscle that leads to atrophy (57). Gastric emptying time has been found to be significantly longer in patients with DMD than in healthy controls (57). GI damage is progressive and refractory gastroparesis has been frequently described in end-stage DMD patients (58, 59). This disorder can lead to severe gastric and small bowel dilation, leading to a paralytic ileus that often requires decompression surgery to avoid potentially fatal consequences. Similar complications may also occur in the distal segment of the intestine; in fact, reduced motility was observed not only in the stomach but also in the colon (60, 61).

Spinal muscular atrophy type 1 (SMA1) is an autosomal recessive neuromuscular disease mainly caused by a homozygous mutation or deletion in the SMN1 gene (62). GI symptoms observed in SMA1 patients include constipation and delayed colonic transit, GER, delayed gastric emptying, dysphagia and vomiting (63). These symptoms are caused by a defect in the central nervous system, even if pathogenetic role played by the enteric nervous system has been shown. In addition, there is often a significant loss of lean mass in these patients, and it is not possible to compare them to the general population. Specific growth curves and patterns that should be considered in children with SMA1 have been recently published by De Amicis et al. (64). Nutritional interventions can be used to support patients with SMA1 (65). One such intervention could be the supplementation with omega-3 fatty acids, that could improve mitochondrial function and energy metabolism, leading to improved muscle strength and function in some patients (66, 67).

Since survival rates of patients with SMA1 are significantly increasing thanks to the recent gene therapies, an individualized dietary therapy per each age should always be evaluated in order to provide proper growth and nutritional status. Each patient may have specific nutritional needs and metabolic aspects should be considered, with a subsequent strict nutritional and endocrine surveillance (65). Among these patients feeding can be continuous, discontinuous or an alternative administration of the two. A crucial aspect is deciding the proper moment to introduce an enteral nutrition by tube. Firstly, until an adequate weight for surgery is achieved, the placement of a nasogastric tube may be performed. Temporary enteral feeding should be continued until a definitive stoma can be placed.

They represent a group of genetic disorders characterized by defects in oxidative phosphorylation caused by mutations in nuclear or mitochondrial DNA genes encoding structural mitochondrial proteins (68). Mitochondrial diseases have a prevalence of about 12.5 per 100,000 inhabitants (69). Because mitochondria are ubiquitous, the clinical presentation is heterogeneous and multisystemic. Its symptoms may include fatigue, skeletal muscle weakness, growth retardation, blindness, ophthalmoplegia, nystagmus, hearing loss, hypoglycemia, diabetes mellitus, learning disabilities, intellectual disability, neuropsychiatric symptoms, cardiomyopathy. Regarding the GI, the muscular organs of the gastroenteric system are significantly involved, as the muscle necessarily requires mitochondrial metabolism to function, and GER, dysmotility and pseudo-obstruction are often described (18, 70).

Esophageal sphincter dysfunction has been commonly reported in MELAS (mitochondrial encephalopathy, lactic acidosis and stroke-like episodes), a mitochondrial disease (71, 72). GER and achalasia are common disorders described in patients with other mitochondrial diseases (73). Furthermore, GI involvement does not generally end at the esophageal level, and GI motility disorders with delayed intestinal transit and severe constipation are commonly reported (74). A study by Bhardwaj et al. analyzed gastric emptying and intestinal transit time in children with mitochondrial disorders and assessed response to prokinetic therapy (75). They found that about 70% of the enrolled patients had prolonged gastric emptying time and almost half had altered intestinal transit. The administration of prokinetics also did not lead to significant improvements.

In mitochondrial neurogastrointestinal encephalopathy (MNGIE), a rare autosomal recessive metabolic disease resulting from mutations in the TYMP nuclear gene, involvement of the GI tract is prominent, markedly delayed gastric emptying and a megacolon, often requiring urgent surgery, have been described (76). Gastroparesis and intestinal pseudo-obstruction are the extreme consequences of this dysmotility (77, 78). GI complications related to dysmotility are the leading causes of death in patients with MNGIE (79, 80). The lack of activity of thymidine phosphorylase causes the systemic accumulation of substrates of pyrimidine deoxyribonucleosides, which cause changes in the stability of mitochondrial DNA (81–84).

Mitochondrial abnormalities seen in MNGIE might contribute to gut bacterial overgrowth or gut microbiota dislocation and cause manifestations of GI dysmotility in these patients (79, 85). MNGIE is commonly associated with chronic intestinal pseudo-obstruction (CIPO), a syndrome of intestinal obstruction without the presence of anatomical or mechanical obstruction, which can result in severe intestinal motility failure (86). In most patients, CIPO leads to persistent malnutrition, and parenteral nutrition is often used (87). The cause could be interstitial Cajal cells (ICC) deficiency or an abnormal distribution of ICC networks, which have been reported in the small intestine and colon of pediatric patients and adults with intestinal pseudo-obstruction (88–90). Abnormalities in ICC number and structure have also been associated with other GI motility disorders such as gastroparesis (91, 92). Some studies suggest that ICCs act as specialized pacemaker cells of the GI (93, 94). As these cells are rich in mitochondria, they could be a target and consequently their deficiency could be the primary event preceding the muscular and neurogenic changes in the MNGIE gut (95). However, the factors contributing to ICC deficits could be caused by other metabolic disorders and GI dysmotility and require more detailed studies as currently available treatments for MNGIE are insufficient to resolve GI manifestations (79, 91).

It is then necessary to remember that in mitochondrial diseases the CNS is often affected and therefore some GI symptoms could be associated with a local muscle type problem but could have a central etiology; it is for example the case of dysphagia (96). Indeed, dysphagia may be related to central impairment, to peripheral nerve damage, or to smooth muscle cell involvement; So, the stronger the neurological involvement, the more likely it is that the root cause of gut problems is also central.

Symptoms such as abdominal pain, nausea, vomiting and diarrhea, which are frequently reported, should be considered in patients with Fabry disease (97–99). Fabry disease is a rare multisystem metabolic disease resulting from multiple types of mutations in the GLA gene that cause deficiency of the lysosomal enzyme alpha-galactosidase A, resulting in accumulation of glycosphingolipids, particularly globotriaosylceramide, in the lysosomes leads to (GL3) (98, 100, 101). The accumulation of these glycosphingolipids in cells, mainly in the vascular endothelium, leads to progressive cell death and dysfunction of important organs such as kidneys, heart, brain and skin (97, 100, 102). In children suffering from this disease, there are often symptoms associated with GI dysmotility due to autonomic dysfunction, such as abdominal pain, episodes of nausea and vomiting, bloating, and alternating constipation and diarrhea (100, 103, 104). It has been extensively described that abdominal pain and swelling increase immediately after a meal (97, 104). Dyspepsia and delayed gastric emptying can lead to food refusal and, in the worst case, in combination with other GI symptoms, also negatively affect body weight (99, 104, 105). Dysfunction of the autonomic nervous system responsible for gut motility and affecting GI circulation seems to play a central role alongside tissue inflammation related to GL3 accumulation (104, 106).

The therapy currently used for this disease is enzyme replacement therapy, which consists of administration of the recombinant human enzymes alpha-galactosidase A and Agalsidase beta (98, 101). Studies have shown that both enzyme replacement therapies have a GI effect, reducing abdominal pain and diarrhea (103, 107).

GI symptoms, particularly constipation and nausea, are also present in galactosemia type I (108). Galactosemia type I or classic galactosemia is a rare metabolic disorder occurring in neonates and consisting of a deficiency in galactose-1-phosphate uridylyltransferase (GALT) activity (109). Although identification through neonatal screening and prompt intervention to eliminate galactose from the diet eliminates possible acute or fatal symptoms (109, 110), most families still report GI problems in their children (108), probably due to the two different variants of GALT present in pathology and the various dietary restrictions suggested by physicians (111–113). Kelly et al. have suggested that excluding dairy products from the diet may have a negative impact on the gut microbiota of these children (114, 115), and it has been postulated that they may benefit from probiotic supplementation (108).

Artificial nutrition can help to manage the condition by providing sources of nutrition free from galactose. Specialized formulas that are free from lactose and galactose are available and can be used to meet the nutritional needs of individuals with galactosemia type I (116). Individuals with galactosemia type I may be at risk of nutrient deficiencies due to their restricted diet. It is important to monitor their nutrient intake carefully and supplement as necessary to ensure they are meeting their nutritional needs. Galactose can be found in many foods and ingredients, including some medications and supplements (109). It is important to read food labels carefully and avoid any products that contain galactose or lactose. In some cases, individuals with galactosemia type I may require enzyme replacement therapy or a liver transplant (117).

Type II glycogen accumulation disease, also known as Pompe disease, is an autosomal recessive disorder caused by alpha-glucosidase acid deficiency and results in abnormal accumulation of glycogen in the heart, skeletal and smooth muscles and in the nervous system (118–120). Since smooth muscle is involved, functional manifestations of the GI tract are directly related to the disorder; the most reported are abdominal pain, difficulty feeding and swallowing, GER, postprandial swelling, early satiety, abdominal discomfort, chronic diarrhea, and increased urgency (121–124). Autopsies of patients with Pompe disease revealed accumulation of glycogen in both the striated muscles of the tongue and the proximal esophagus, causing dysphagia, but also in the smooth muscles of the distal esophagus and small intestine, which could lead to other GI functional symptoms (125, 126). Although some cases of symptom improvement with enzyme replacement therapy (ERT) have been described (123, 124, 127), most patients still suffer from a variety of clinical symptoms, including GI symptoms, over the long term, since ERT appears to be inefficiently administered to target tissues (skeletal and smooth muscle) (118).

GI disorders, including diarrhea and constipation, have been described in patients with mucopolysaccharidosis (MPS) IIIB or Sanfilippo syndrome, a rare autosomal recessive lysosomal accumulation (128). The disease results in progressive severe CNS deterioration with severe neurological, cognitive and behavioral symptoms (129, 130). The United Kingdom Society for Mucopolysaccharidoses and Related Diseases has found that GI problems including constipation, diarrhea, food intolerance, recto-vaginal fistula, malabsorption, intestinal volvulus, intestinal congestion, ulcerative colitis, GI bleeding and pseudo-obstruction are commonly reported in these patients (131). A case of chronic diarrhea in MPS IIIB has also been described in the literature, in which abnormalities were found on intestinal endoscopy, partially overlapping with features of intestinal lymphangiectasia, for which the patient was on a low-fat diet and medium-chain triglyceride supplementation, thereby improving the condition of diarrhea (129). Furthermore, functional decline in children from the second decade of life leads to dysphagia and aspiration problems, necessitating nasogastric or gastrostomy feeding (132, 133). Unfortunately, no treatment has yet been discovered for this pathology, and GI complications, which are often underestimated, resulted in 6% of deaths (131).

Nutritional assessment of children with NI is part of multidisciplinary management performed by physicians, dieticians, nurses, speech therapists, physical therapists, psychologists, and occupational therapists. History-taking is the first step and aims to examine the evolution of eating stages and, if present, history of feeding problems since birth. Subsequent assessment of anthropometry is critical for assessing nutritional status and should be performed every 6 months in children with NI (3). Brooks et al. provided CP-specific growth curves stratified by sex, age and functional capacity according to the Gross Motor Function Classification System (GMFCS) (136). For the most common genetic disorders (e.g., Down Syndrome, Turner Syndrome, SMA1, Prader-Willi Syndrome, Rett Syndrome, Noonan Syndrome, Cornelia de Lange Syndrome, Rubinstein-Taybi Syndrome, Duchenne Muscular Dystrophy and Silver-Russell Syndrome) specific growth charts are generally available. However, assessment of height reflects adequate growth and nutritional status but can be challenging in children with malformations and spasticity (137).

Measuring segment length (knee height and tibial length) offers an alternative in children with skeletal deformities where back height cannot be measured (3). Other two measurements commonly used in normally developing children, such as weight-to-age and weight-to-height ratios (body mass index), overlook muscle and fat mass and are poor predictors of body composition in children with NI. Incorrect determination of body mass index could lead to overeating in children with NI, who were found to have a higher percentage of central body fat mass (138). The ESPGHAN position paper recommends routine skinfold thickness measurement and bioelectrical impedance analysis to estimate body composition independent of fat site (3).

Finally, the use of GMFCS growth charts for assessment of nutritional status in children with NI is not recommended as they are descriptive without reference standards (3). There is no clear definition of malnutrition in typically developing children or in children with neurological disorders (139, 140). For clinical practice, one or more of the following warning signs should be used to identify malnutrition in children with NI: physical signs of malnutrition, age-related z-score < 2, triceps plica thickness < 10 percentile for age-sex, mid-adipose muscle area am Upper arm <10 percentile and weight loss or failure to thrive (3).

The use of nutritional reference standards for children with normal development can be considered to estimate the caloric needs of children with NI. In certain clinical situations, such as pressure sores or in children with low calorie needs, it is recommended supplemental protein intake. Micronutrient intake should be in line with dietary reference values for normally developing children (3). The assessment of the micronutrient status (e.g., Vitamin B9, B12, vitamin D, calcium, phosphorus, iron) should be carried out annually. Finally, the use of indirect calorimetry to evaluate the basal metabolism, in addition to dual energy X-ray absorptiometry (DXA) and BMI, may allow examining the nutritional assessment of the child with NI (3, 141).

Nutritional difficulties in children with neurometabolic disorders are often associated with neurological sequelae of the disease. However, there is little evidence describing their frequency or severity (142). Dietary restrictions in congenital neurometabolic disorders can result in deficiencies in fatty acids, essential amino acids, and micronutrients. Close monitoring of nutritional fitness requires close monitoring of growth. Monitoring of weight gain and information on possible long-term consequences of overweight and obesity should be provided (143).

The severity of the main clinical features of dysmotility reflects the ability of a child with NI to adopt and tolerate a regular diet. In addition, the duration of the symptoms can influence the worsening of malnutrition (144). Adjusting nutrition to meet the needs of a neurologically impaired child with GI motility disorders is challenging. Different nutritional approaches include oral nutrition, enteral nutrition, and parenteral nutrition.

Maintaining feeding ability is an excellent strategy to increase calorie density in severely malnourished children. Due to the higher energy density of fats per gram (9 kcal/g) compared to proteins and carbohydrates (4 kcal/g), it is recommended to use typical household products such as oils and high-fat spreads in children, and high-calorie formulas in infants (135). Fasting stimulates autophagy through multiple mechanisms related to neurometabolic disorders (145). Abnormalities in mTOR signaling have been reported in Pompe disease after fasting; however, these abnormal signaling pathways were reversed by arginine supplementation (146).

Pharyngeal hypotension associated with generalized hypotension is a common finding in children with neurologically impaired (NI) genetic syndromes. In particular, children with 22q11 deletion syndrome (DiGeorge syndrome, velocardiofacial syndrome, and conotruncal anomaly-facial syndrome) have difficulty increasing the amount of food and changing the consistency of food (147). Therefore, offering small, frequent meals may be a common strategy (148). In children with Prader-Willi syndrome, pharyngeal hypotension leads to poor sucking. Using a nipple with a wider base can help the infant achieve a seal around the nipple and allow intraoral pressure to build up. Supporting the head in a neutral or slightly flexed position while applying intense pressure to the midline of the tongue may improve tongue tone (149).

A variety of esophageal dysmotility disorders can significantly interfere with oral feeding in children with NI. Patients should be encouraged to eat upright and minimize food intake for several hours before bedtime. Other esophageal motility disorders affect only the absorption of solid food. The diet should therefore allow for fluids and mixed foods, as well as fluid intake after each swallow if solid meals are tolerated (144). Children with delayed gastric emptying should eat finely divided food in 5 or 6 small meals per day. The diet should be low in fiber to prevent bezoar formation and low in fat to avoid exacerbating delayed gastric emptying (144). Studies conducted among infants report better gastric emptying with medium-chain triglycerides than long-chain triglycerides (150), while whey hydrolysate formulas have been shown to improve feeding tolerance and reduce gastrointestinal symptoms in some patients, with a faster emptying (151). In contrast, a higher fluid content in the diet should be encouraged as it is better tolerated. Regardless of the consistency of the food offered, the child should sit for 1–2 h after the meal (152). Finally, in children with NI and constipation, increasing fiber and fluid intake may be a useful strategy to improve this symptom (153). Reports of the use of mixed diets in patients with dysmotility have recently emerged, although pediatric data are still limited. Individual studies have shown an improvement in nausea and vomiting due to the higher viscosity of the mixtures (154, 155). A possible positive effect on stool frequency and consistency has been associated with the introduction of various dietary fibers (155). The positive influence of the mixed diet on the diversity and richness of the intestinal microbiome was described, with a significant increase in bacterial diversity and a corresponding decrease in harmful Proteobacteria in the analyzed stool samples (156). However, more research is needed to evaluate the composition and safety of mixed diets in children with dysmotility.

Finally, it has to be stated that completely abandoning oral nutrition in children is a clear indication of a failure in medicine, since the proper maturation of the entire digestive system represent the best solution for ensuring proper nutrient absorption and supply to the body (157). However, in some cases, children with NI may face difficulty in maintaining a full oral nutrition (3). In such cases, it is important to address the root cause of the problem through proper medical intervention and nutritional support.

Enteral nutrition is recommended for patients who cannot eat orally for more than 3 h a day, whose oral intake provides less than 60–80% of their individual needs, whose growth or weight gain are insufficient, and whose triceps thickness is consistently below the fifth percentile per age. Aspiration during oral feeding or severe chewing and swallowing disorders (dysphagia) are also indications for the start of enteral nutrition (3). Enteral feeding should be started before malnutrition develops, as early treatment achieves better growth patterns (158). A PEG placement is recommended for enteral feeding planned for more than 2 months (138). However, the choice of enteral approach depends on GI motility. Gastric feeding is preferred, as it allows for boluses of food and can tolerate a larger volume and osmotic load than the small intestine, providing greater flexibility in the choice of formula type and feeding schedule (144).

Different strategies should be tailored to each patient depending on the extent of the motility disorder or feeding tolerance. First, continuous jejunal nutrition may recommended, especially in patients with delayed gastric emptying due to the risk of aspiration (18). For children with poor volume tolerance and high calorie needs, continuous overnight feeding combined with daytime boluses is recommended (3, 65, 138). Breast milk is the first choice for infants, while hypoosmotic and hydrolyzed formulas can be considered in children with dysmotility from 1 year of age (18). The addition of dietary fiber to enteral formulas has been shown to accelerate intestinal transit time, but the fiber content should reflect a normal diet (159). Although data are incomplete and conflicting, supplementation of medium-chain triglycerides to enteral formulas has been shown to improve symptoms such as chronic diarrhea, stunted growth, and poor appetite (160).

In cases of cow’s milk protein allergy, constipation can be a sign in children with neurological disorders. A cow’s milk protein exclusion diet for 12 months reduced constipation symptoms in a cohort study of 145 children with neurological disabilities (161). A whey-based formula may be attempted if gastric emptying is delayed (162). Formula containing whole casein protein slows gastric emptying compared to formula with whey protein. However, breast milk results in faster gastric emptying than different types of formula (163).

A polymeric enteral formula with standard energy density should be recommended (164), but children with increased energy needs and poor tolerance to large volumes of liquids may need formulas with high energy density containing fibers or supplementation with glucose polymers and/or long-chain triglycerides (140). For children with severely reduced mobility, a low-calorie maintenance formula with a low-fat content plus fiber and micronutrients is indicated (3). Enteral mixtures based on whey protein hydrolysates could be indicated in cases of slow gastric emptying or allergies to cow’s milk proteins (162). Enteral nutrition can be performed as intermittent boluses or continuously (165). Children with increased caloric requirements or poor volume tolerance may benefit from a combination of continuous nocturnal enteral nutrition combined with multiple boluses during the day (166).

Enteral nutrition with special formulas can be an effective intervention for neurologically impaired children with feeding difficulties (167). These special formulas can provide adequate nutrition while also addressing specific nutritional needs that may arise due to the child’s underlying condition. For example, natural formulas, which contain whole food ingredients, may be preferred over synthetic formulas in some cases as they can help maintain a diverse microbiota and gut health, which is crucial in individuals with gut dysmotility (168). In addition, the inclusion of fiber in enteral formulas has been shown to improve bowel function and reduce the incidence of constipation (169). Fiber is an indigestible carbohydrate that can promote the growth of beneficial gut bacteria and improve overall gut health (16). It can also provide bulk to stool, which can aid in bowel movements and prevent constipation (170).

Blenderized diets have been used in children with NI as an alternative to commercial enteral formulas, and may also be easier to digest and reduce the risk of constipation or other GI issues (154, 155). This type of diet can be tailored to meet the specific nutritional needs of the child and may be preferred by families who want to avoid processed foods or have concerns about the ingredients in commercial formulas (171). They could provide a wider range of nutrients and flavors than commercial formulas. Blenderized diets. Additionally, some parents report improvements in their child’s behavior, cognition, and energy levels after switching to a blenderized diet (172). Parents should work closely with a dietitian to develop a nutritionally balanced plan and should be aware of the potential risks of infection or nutrient imbalances if the diet is not properly prepared or stored. It is important to add that blenderized diets may not be appropriate for all children with NI and should only be used under the guidance of a healthcare professional. Factors such as medical history, feeding difficulties, and medication regimen should be taken into consideration when making this decision. A combination of blenderized feeding and commercial formulae may minimize symptoms of tube feeding whilst supporting growth (156).

Furthermore, selecting natural food options that are easily digestible and offer a variety of macronutrients and micronutrients can help ensure optimal nutrition (168). For neurologically impaired children with PEG, some natural food options that can be incorporated into their diet include: fruits and vegetables that are rich in vitamins, minerals, and antioxidants and can be easily blended into their feeding regimen; whole grains such as rice, oats, and quinoa, which provide carbohydrates, fiber, and essential nutrients; lean protein sources such as chicken, fish, and eggs that provide essential amino acids; and healthy fats such as avocado, nuts, and seeds that are rich in omega-3 fatty acids. Dairy products such as milk, yogurt, and cheeses are also good sources of calcium for bone health (166, 173, 174). Formulas containing natural foods have been shown to enhance tolerance and feeding outcomes, improve family participation, and increase compliance during mealtimes (175). In all cases, it is essential to consult a registered dietitian to develop an individualized nutrition plan for all patients with NI who are receiving enteral nutrition.

Special formulas can also be tailored to meet the specific nutritional needs of individual patients, particularly in the first years of life (176). For example, children with spasticity and dystonia may benefit from formulas with a higher protein content to support muscle growth and maintenance (177). Similarly, children with malabsorption may require peptide-based enteral formulas to promote absorption of essential nutrients (178). It is important to note that the use of special formulas should be guided by a healthcare professional and tailored to meet the individual needs of each patient. A registered dietitian can work with families and healthcare teams to develop individualized nutrition plans that address the specific needs of each patient.

In neurologically impaired children who have contraindications for enteral nutrition, or in those with severe gastrointestinal dysmotility who cannot tolerate enteral nutrition, parenteral nutrition may be considered (144). This type of nutrition, especially in the long term, is associated more with degenerative pathologies, and therefore more with neurogenetic/neurometabolic ones. Patients with spasticity and dystonia are at a higher risk of enteral feeding-induced dystonia, which can present with symptoms such as sweating, pallor, inconsolable crying, and convulsions (173). Interruption of enteral nutrition typically leads to an almost immediate response, indicating anterior gut dysmotility. The sympathetic motor fibers that innervate the anterior gut are controlled by higher centers located in the spinal cord and brainstem. Therefore, it is more likely for intestinal dysmotility to occur in central neurological disorders than in spinal lesions. Further research is needed to determine whether the neural modulation of gut motility occurs through direct effects of neurotransmitters or neuroendocrine mechanisms. In cases where enteral feeding-induced dystonia persists, total parenteral nutrition may be considered, but only after all enteral feeding options, medication intake, and pain control have been explored (179). This is an ethical approach to ensuring that parenteral nutrition is only used as a last medical choice.