Swallowing disorders in cerebral palsy: a systematic review of oropharyngeal Dysphagia, nutritional impact, and health risks

Abstract

Cerebral palsy (CP) is a permanent disorder affecting movement and posture due to nonprogressive brain issues, often leading to various sensory, cognitive, and musculoskeletal challenges. Among these complications, oropharyngeal dysphagia (OPD) is prevalent, impacting up to 85% of children with CP and resulting in significant nutritional deficits. This systematic review aims to explore the prevalence and types of OPD in CP patients, its effects on nutritional status, and its associated health complications, emphasizing the need for thorough assessment and intervention to mitigate risks. The review adheres to PRISMA guidelines, searching five major databases (PubMed, Web of Science, Embase, Cochrane Library, and Scopus) without time range restrictions to capture studies addressing swallowing disorders and their impact on nutritional status in CP. This review has been registered on Open OSF (n) 3KUQX. Individuals with CP often experience swallowing impairments, including delayed pharyngeal transit and aspiration. Research indicates that 81.5% of kids with CP suffer from dysphagia, commonly associated with reduced motor skills and general health. Moreover, as a result of these swallowing difficulties, nutritional complications may occur, with elevated levels of gastroesophageal symptoms causing malnutrition and growth delays, which require thorough evaluations and personalized interventions for successful treatment. Tools like the Videofluoroscopic Swallowing Study were identified as primary methods for evaluation, but assessment remains limited by methodological inconsistencies. This systematic review underscores the significant health impacts of OPD in children with CP, which affects nutrition and overall well-being. Future research should address the need for standardized evaluation methods and effective interventions to balance nutritional needs with practical mealtime strategies.

Introduction

Cerebral palsy (CP) is a nonprogressive neurological disorder affecting movement and posture, often accompanied by oropharyngeal dysphagia (OPD), a significant contributor to malnutrition and health complications [1, 2]. Data from developed countries indicate that the occurrence of CP is 2–3 per 1000 live births, with a much higher rate of 40–100 per 1000 in premature babies born before 28 weeks of gestation [3,4,5,6,7,8]. Motor impairments in CP affect oral and pharyngeal coordination, leading to aspiration and pulmonary complications [9,10,11,12]. In fact, OPD affects up to 85% of children with CP and is connected to reduced food consumption [13,14,15,16,17]. The operational definition of OPD is impairment in the swallowing function, as described in the International Classification of Functional Health Disorders (ICF) as "related to the ingestion and handling of solids or liquids from the mouth into the body" [18, 19]. The ICF defines eating and drinking as a combination of the upper extremity function, social and cultural elements, and the swallowing function. OPD disrupts all phases of swallowing: oral, pharyngeal, and esophageal. Primitive reflexes like sucking and chewing remain, impairing bolus formation and safe swallowing [20, 21]. These difficulties are exacerbated by inadequate nourishment and hydration, resulting in extended, stressful mealtimes [22,23,24]. The severity of dysphagia correlates with motor and cognitive impairments. Therefore, effective treatment necessitates a multidisciplinary approach that considers gastrointestinal, respiratory, nutritional, and motor abilities, as well as behavioral and familiar factors [25,26,27,28,29,30]. A comprehensive assessment of both swallowing and nutrition is essential for optimal rehabilitation [31]. Table 1 provides an overview of the psychometric and diagnostic tools (including clinical and instrumental assessments of dysphagia) used to assess dietary and swallowing issues [32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67]. Given these challenges, understanding the swallowing process and its impact on nutrient intake is crucial. Swallowing is a complicated process involving synchronized muscle and nerve action in the oral cavity, throat, and esophagus to safely deliver food and liquids to the stomach [12, 68,69,70]. Children with CP commonly experience trouble eating due to physical and functional implications. This reduces energy, muscular mass, and immune function, raising the risk of infections and other repercussions [71,72,73]. Furthermore, swallowing dysfunctions can result in symptoms such as pharyngeal itching, coughing, hypersensitivity, choking, and vomiting, which can bring problems such as pneumonia, weight loss, cognitive impairment, and higher death rates [74,75,76]. Patients with CP may also have gastroesophageal reflux disease (GERD), which causes symptoms such as heartburn and regurgitation [76,77,78,79,80,81]. Despite OPD being a severe complication in CP, there is a notable lack of standardized assessment tools and integrated intervention strategies addressing both motor and nutritional aspects. Current diagnostic practices vary widely, often relying on fragmented methodologies that fail to capture the multidimensional nature of OPD, encompassing motor, sensory, and nutritional aspects. Additionally, integrated intervention strategies that address both swallowing dysfunction and its nutritional consequences remain underexplored. The scarcity of evidence-based guidelines for multidisciplinary management further underscores the need for a systematic synthesis of available knowledge. This systematic review is timely, addressing critical gaps by consolidating evidence on OPD's prevalence, clinical burden, and the lack of standardized, multidisciplinary approaches for its management. It aims to provide a clearer understanding of the disorder’s impact on nutrition, growth, and related health outcomes. Furthermore, it seeks to identify existing limitations in diagnostic practices and propose directions for future research, fostering the development of standardized approaches and integrated care models. Given the profound health implications of untreated OPD, a thorough synthesis of available data is essential to guide clinical decision-making and policy formulation.

Table 1 shows the psychometric tool and diagnostic instruments for dietary and swallowing issues

Materials and methods

Search strategy

A literature search was conducted using PubMed, Web of Science, Cochrane Library, Embase, and Scopus databases, employing the keywords: (Oropharyngeal Dysphagia) AND/OR (Cerebral Palsy) AND/OR (Nutritional status). The investigation was carried out with no limitations of time, enabling a thorough examination of the changing knowledge about OPD in children with CP. Searches were conducted independently by two reviewers (AC, DM) using Boolean operators and controlled vocabulary (e.g., MeSH terms), to enhance transparency and accuracy in identifying relevant studies. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) flow diagram was utilized to outline the process (identification, screening, eligibility, and inclusion) for selecting relevant studies addressing the prevalence, types, and assessment of OPD and swallowing disorders in patients with CP as well as its impact on nutritional status and related health complications, as illustrated in Fig. 1 [82].

Fig. 1

PRISMA 2020 flow diagram of evaluated studies

The Prisma Check list was also used to guarantee the scientific rigor of the paper (as shown in the supplementary materials). All articles were screened based on titles, abstracts, and full texts by the two researchers (AC, DM), who independently performed data extraction, article collection, and cross-validation to reduce the risk of bias (e.g., missing result bias, publication bias; time lag bias; language bias). These researchers read full-text articles deemed eligible for the study, and in case of disagreement on inclusion and exclusion criteria, the final decision was made by a third researcher (RSC). Moreover, the agreement between the two reviewers (AC and DM) was assessed using the kappa statistics. The kappa score, with an accepted threshold for substantial agreement set at > 0.61, was interpreted to reflect excellent concordance between the reviewers. This criterion ensures a robust evaluation of the inter-rater reliability, emphasizing the achievement of a substantial level of agreement in the data extraction process. The list of articles was then refined for relevance, reviewed, and summarized, with key topics identified from the summary based on the inclusion/exclusion criteria. This review was registered with a DOI (https://doiorg.publicaciones.saludcastillayleon.es/https://doiorg.publicaciones.saludcastillayleon.es/10.17605/OSF.IO/8HJK4) on the Open Science Framework (OSF).

PICO Evaluation

We applied the PICO model (Population, Intervention, Comparison, Outcome) to create our search terms.

In this review, the population focuses on individuals with CP who show symptoms of OPD and other swallowing problems. The intervention concentrates on different ways to evaluate OPD and associated swallowing issues, such as diagnostic assessments and screening instruments designed to identify swallowing difficulties in the group, as well as rehabilitation techniques. Due to the observational nature of the studies reviewed, we did not incorporate a particular comparison group. Nonetheless, research papers were chosen by looking at how swallowing issues affect the nutritional status and overall health of children and adults with CP in comparison to typical standards for their age group. In conclusion, our outcome measures address the effects of OPD on nutritional status, growth patterns, and health problems like gastroesophageal reflux (GER) and respiratory infections, explaining how swallowing difficulties can lead to additional health issues in children with CP. By organizing our evaluation using the PICO framework, we aimed to fully grasp the intricate nature of OPD in CP patients, highlighting its frequency, variations, and health effects to assist healthcare providers and caregivers in conducting focused evaluations and treatments to enhance nutritional and health results in this at-risk group.

Inclusion criteria

This systematic review focused on studies targeting individuals with CP who had been diagnosed with OPD or similar swallowing disorders. Studies were considered eligible if they provided quantitative or qualitative data on the prevalence, types, or assessment methods of OPD in this population. Specifically, eligible studies are to those that explicitly included individuals with CP and reported swallowing assessments based on standardized diagnostic instruments such as videofluoroscopic swallowing studies (VFSS), fiberoptic endoscopic evaluation of swallowing (FEES), or validated clinical tools designed for dysphagia assessment. To ensure comprehensive coverage, we included studies examining the relationship between swallowing difficulties and nutritional health indicators, such as eating habits, growth patterns, and associated health conditions like GERD or respiratory complications. Only research articles published in peer-reviewed journals were considered, with no restrictions on the date of publication. Furthermore, the review exclusively included studies conducted on children with CP, focusing solely on human populations. Articles had to be published in English to be eligible.

Exclusion criteria

Studies not centered on individuals with CP or lacking a definitive diagnosis of OPD were omitted. The omission also included articles that did not evaluate or discuss swallowing disorders in individuals with different neurological conditions, or those that did not examine or consider oral phase dysphagia with regard to nutritional status. Moreover, we excluded non-English publications or those without peer-review status, to maintain the credibility and dependability of the results. Exclusions were made for studies that focused mainly on surgical or invasive procedures and lacked relevant data on swallowing assessments or nutritional outcomes, as our review centers on non-invasive assessment techniques and their impacts on health. Systematic, integrated, or narrative reviews were also excluded; however, their reference lists were reviewed and included when relevant. Furthermore, diagnostic tools were excluded if they were found to overlap significantly with other included tools in terms of functionality, lacked adequate validation in clinical or research environments, or if there was insufficient evidence supporting their use specifically for the evaluation of oral phase dysphagia. Tools not directly addressing swallowing function or those designed for broader assessments unrelated to OPD were also omitted. This approach ensures that the included tools are both highly specific and clinically relevant for the target population. Finally, we did not include conference abstracts, opinion pieces, and editorials because they lack the necessary level of detail for a systematic review.

Results

Quality of included studies—Risk of bias

We assessed the risk of bias using appropriate tools based on the design of the included studies [83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123]. Of the forty-one studies, three were a randomized controlled trial (RCT) [88, 120, 123]. For this one, we used the updated Cochrane Risk of Bias (RoB 2) tool, which covers five domains: i) bias arising from the randomization process, ii) bias due to deviations from the intended intervention, iii) bias due to missing data on the results, iv) bias in the measurement of the outcome and v) bias in the selection of the reported result (Fig. 2) [124]. Our assessment identified mainly some concerns about the overall risk of bias and in particular in the selection of the reported result (D5). Gisel et al. [88], and Abd-Elmonem et al. [120], expressed some concern about the risk of bias in the randomization process (D1). This could introduce selection bias, potentially leading to imbalances in baseline characteristics between intervention groups. It could confound the observed effects and make it difficult to attribute changes solely to the intervention. On the other hand, Gisel et al. [88], and Khamis et al. [123] showed some concern risk in D3 (missing outcome data). The majority of the studies presented a low risk in the outcome measure (D4) and in the deviations from intended interventions (D2). Overall, while the RoB 2 assessment suggests reasonably sound methodology for these three studies, the identified biases, particularly in randomization, missing data, and reporting, warrant careful consideration when interpreting the synthesized evidence. These biases could potentially inflate or deflate the observed effects and limit the generalizability of the findings.

Fig. 2

Risk of Bias (RoB) of included RCT studies

For the thirty-eight [76, 80,81,82,83, 83, 84, 84, 85, 85, 86, 86, 87, 87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119, 121, 122] non-randomized studies we applied the ROBINS-I tool. ROBINS-I assesses bias in seven areas: i) bias due to confounding, ii) bias in participant selection, iii) bias in classification of interventions, iv) bias due to deviations from intended interventions, v) bias due to missing data, vi) bias in outcome measurement, and vii) bias in selection of the reported outcome (Fig. 3) [125]. The evaluation of bias with the ROBINS-I tool in different studies shows a generally moderate methodological standard, highlighting several areas of concern that may impact the accuracy of the results. For instance, bias in participant selection (D2) was a recurring issue in multiple studies, such as Lagos-Guimarães et al. [83], which showed a serious risk of bias in this domain. This could result in an unrepresentative sample that undermines the generalizability of the findings. Similarly, Remijn et al. [84] demonstrated moderate risks in both participant selection (D2) and confounding (D1), suggesting potential discrepancies in how baseline differences between intervention groups were managed. These biases may lead to distorted effect estimates, affecting the validity of their conclusions. Several studies, including those by Benfer et al. [85], and Benfer et al. [90], showed a minimal bias in various aspects. Nonetheless, they did highlight a moderate risk related to missing data (D5), which could impact the credibility of their results. Missing data, especially when systematic, could introduce imbalances or reduce the statistical power of the studies, thereby impacting the robustness of their findings. Conversely, concerns were significantly raised by Asgarshirazi et al. [89] regarding a study that faced a high risk of bias in participant selection (D2) and result reporting (D7), potentially compromising the reliability of its findings. This means that only certain results, perhaps those that are statistically significant or more favorable, are reported, while others are not. This can significantly distort the overall picture of the intervention's effects. Adding to the complexity of the evaluation, research conducted by Otapowicz et al. [86], Wang et al. [95], Oftedal et al. [97], and McAlister et al. 2022 [108] highlighted doubts concerning how interventions were classified (D3), as well as showing moderate/serious risks of data being absent (D5). This scenario highlights the difficulties in reaching firm conclusions from these inquiries. Furthermore, it is important to mention that many studies have shown moderate to severe problems in different areas, indicating systemic methodological issues that could have a significant effect on the accuracy and validity of the results. In summary, while these studies provide valuable insights, the identified biases, particularly in participant selection, confounding, missing data, and selective reporting, highlight the need for cautious interpretation of their results. These biases may potentially distort the observed effects, limiting the applicability of the findings to broader populations or clinical settings.

Fig. 3

Cochrane Risk of Bias in Non-randomized Studies of Interventions (ROBINS-I)

Synthesis of evidence

In total, 1771 articles were found: 290 articles were removed due to duplication after screening; 56 articles were excluded because they were not published in English; 1171 articles were excluded based on title and abstract screening. Finally, 213 articles were removed based on screening for inadequate and untraceable study designs (as shown in Fig. 1). Forty-one research articles met the inclusion criteria and were therefore included in the review. These studies are summarized in Table 2.

Table 2 shows the main findings of the studies included in the review

CP does not have any cure, and only a few therapies assist in the management of the condition. The primary goal of therapy is symptom management. Therefore, the studies discussed in this review investigate the prevalence, types, and assessment of OPD and swallowing disorders in patients with CP as well as its impact on nutritional status and related health complications. Twelve articles deal with the challenges and management of dysphagia and swallowing disorders in CP [83,84,85,86,87,88,89,90,91,92,93,94]. Fourteen articles explore the nutritional status and gastroesophageal symptoms in CP [95,96,97,98,99,100,101,102,103,104,105,106,107,108] whereas the other fifteen papers examine the assessment techniques and rehabilitation strategies for the nutritional outcome in individuals with CP [109,110,111,112,113,114,115,116,117,118,119,120,121,122,123].

Impact of Dysphagia on Nutrition and Swallowing Disorders in Cerebral Palsy: Challenges and Management

Dysphagia and swallowing difficulties in CP pose intricate challenges affecting health and quality of life, necessitating specific management approaches. In the first five studies, it is consistently found that dysphagia is very common among people with CP and is frequently linked to both reduced functioning and a lower quality of life. Different levels of dysphagia symptoms are seen depending on the seriousness and stage of swallowing difficulties, with more noticeable problems seen in individuals with severe motor restrictions. In an initial cross-sectional examination, 81.5% of 103 children with CP experienced dysphagia, with 31% displaying tracheal aspiration during videofluoroscopy, but none contracted aspiration pneumonia, highlighting the procedure's safety within this group [83]. This study revealed a high prevalence of OPD in children with CP, with 81.5% of participants exhibiting some degree of swallowing dysfunction. This high prevalence is clinically significant, as OPD is associated with adverse health outcomes such as growth delays due to inadequate nutritional intake and an increased risk of GER. An observational study comparing mastication in 8 children with spastic CP found notable delays in chewing and less synchronized tongue movements in comparison to typically developing children. This highlights the importance of using mastication observation, evaluation, and ultrasound assessments for personalized analysis [84]. In a study of 130 children with CP, Benfer et al. found that 67.7% had pharyngeal dysphagia, which was linked to lower gross motor function. Coughing was a frequent but not specific indicator, and parent reports were moderately accurate [85]. A cross-sectional study of 67 children with spastic CP found that over half of them had swallowing difficulties associated with severe speech problems and significant cognitive impairment, particularly when the throat was affected [86]. Yi and his team studied 117 adults with CP and found that dysphagia symptoms had a significant impact on their quality of life, with chewing problems and choking on food commonly reported; decreased functional status and increased age also affected quality of life scores [87]. Seven additional studies show important problems with eating and swallowing in individuals with CP, affecting their nutrition, growth, and overall health. Typical discoveries include a high occurrence of swallowing difficulties, ongoing dangers inhaling food or liquid, and connections between feeding struggles and motor function issues, indicating that customized, collaborative treatments are crucial for enhancing safety and nutritional results. In a randomized controlled trial, 27 children with CP and moderate eating issues didn't show significant improvements in eating efficiency or growth outcomes after receiving 10–20 weeks of oral sensorimotor therapy. Weight and skinfold measurements did not change despite the absence of catch-up growth, indicating that the severity of impairment is better reflected in eating efficiency than in response to treatment [88]. Another cross-sectional study involving 50 children with CP and gastrointestinal issues found that GERD was present in 66% and OPD in 82%, especially among those with significant motor difficulties. After 6 months of receiving nutritional rehabilitation and therapy, only 46% showed weight gain, suggesting minimal progress [89]. In a group of 53 children diagnosed with CP at 18–24 months and 36 months, the prevalence of OPD stayed consistent, with 30% demonstrating progress. The severity of OPD was strongly predicted by gross motor function linked with lower weight and BMI, underscoring the importance of screening focused on gross motor skills to inform intervention approaches [90]. A study following 179 children with CP found that the prevalence of OPD decreased from 79.7% at 18–24 months to 43.5% at 60 months. The progress was mainly seen in kids with minor motor difficulties, highlighting the chance for natural improvement in less severe instances and the need for targeted treatments in more severe cases [91]. Seo and colleagues found that in 17 adults with dyskinetic CP and cervical dystonia, videofluoroscopic assessments showed a high prevalence of difficulties with chewing, tongue movements, and laryngeal elevation. Challenges in the pharyngeal stage were associated with the severity of cervical dystonia rather than the Gross Motor Function Classification System (GMFCS) level, highlighting the need for dysphagia screening in adults with severe cervical dystonia to improve treatment strategies [92]. Mouilly and his team studied 65 children with CP (ages 2–17) and found that growth delays were linked to gross motor dysfunctions and feeding problems through anthropometric analysis. Around 65% of individuals suffered from incorrect mouth openings and other facial deformities, leading to poor nutritional levels [93]. In comparison research, eleven children with spastic CP showed significant difficulties with eating and swallowing, such as heightened activity in the suprahyoid muscles and irregular coordination between breathing and swallowing, when compared to a control group. These issues, especially inhalation after swallowing, were found to be associated with more severe dysphagia scores, emphasizing the importance of focused interventions combining respiratory and swallowing techniques [94]. The findings from this subsection underscore the pervasive impact of dysphagia on individuals with CP, revealing significant challenges across various aspects of nutrition, motor function, and quality of life. Studies highlight the high prevalence of swallowing difficulties, their correlation with gross motor impairments, and their implications for growth and health outcomes. While some progress is observed in less severe cases, targeted and interdisciplinary management strategies remain essential for addressing the multifaceted needs of this population.

Health risks Associated with OPD and Gastroesophageal Symptoms in Individuals with Cerebral Palsy

Ensuring proper nutrition for people with CP is a significant difficulty, influenced by distinct gastroesophageal symptoms and obstacles that require focused evaluation and rehab efforts. In the initial five studies on nutritional status in children with CP, it was consistently observed that they experience significant challenges in terms of nutrition and growth. These difficulties are influenced by age, severity of motor functions, and changeable lifestyle factors. Managing nutritional health in this population is complex due to growth abnormalities, changes in body composition, and a high occurrence of feeding and gastrointestinal problems. Wang and his team [95] assessed the nutrition status of 377 children with CP between the ages of 2 and 18 in West China, revealing that 42.4% were stunted, 21.5% were underweight, and 18.5% were overweight or obese. Older children and those with severe motor impairments showed more prominent nutritional deficiencies, which were closely linked to GMFCS and Manual Ability Classification System (MACS) levels, indicating age and motor functions as important factors for personalized nutritional strategies [95]. Bell et al. [96] conducted a longitudinal study on 240 young children with CP in Australia, ages 18 months to 5 years, and found a connection between dietary intake, sedentary behavior, and growth results. Adjustable aspects such as eating habits and exercise were associated with better body composition and development, underscoring the opportunity for lifestyle changes to improve health, well-being, and engagement [96]. A different long-term research project tracked 161 children with CP between 18 and 60 months old, revealing that children in GMFCS levels IV and V exhibited less fat-free mass and a higher body fat percentage than children with milder impairments. Energy consumption and regular physical exercise in children with GMFCS level I had a positive effect on body composition, highlighting the importance of personalized diet and exercise routines [97]. Another paper compared behavioral interventions for feeding difficulties in children aged 1–12 with CP and autism. Behavioral methods, including escape extinction and differential reinforcement, successfully decreased food rejection and boosted consumption in both groups, emphasizing the significance of behavioral techniques in managing feeding difficulties in CP [98]. A cross-sectional study looked at GERD and dental erosion in 46 children with CP aged 3–13, finding higher rates of GERD-related dental erosion and reduced saliva in those with GERD. Logistic regression analysis found a link between GERD and dental erosion, highlighting the importance of managing GERD to prevent oral health problems in this high-risk group [99]. Dysphagia, GER, and other feeding issues are frequently seen in children with CP, affecting their nutritional health and overall well-being. The degree of feeding and swallowing problems is linked to the severity of motor deficits, requiring customized evaluation and treatment strategies to effectively manage these complex issues. During a prospective cohort study of 29 children with CP aged 2 to 10 years, 3,899 reflux episodes were observed through 24-h multiple intraluminal impedance-pH monitoring, with 70% being non-acidic. This indicates that numerous instances of reflux in individuals with chronic pancreatitis may go unnoticed with just pH monitoring, impacting the treatment of GER and potentially exacerbating respiratory and nutritional issues [100]. In another study, 99% of the 166 children with severe CP, who had an average age of 9 years, displayed symptoms of dysphagia. Surprisingly, 76% of these individuals faced some level of challenge with swallowing, with 15% requiring tube feeding due to severe difficulties. The level of dysphagia was discovered to be strongly correlated with motor challenges rather than parental reports of feeding problems. This suggests parents may not be aware of the problem and stresses the need for early dysphagia screening [101]. In the research by Schepers et al. [102], it was observed that among 77 children with CP (average age: 7 years), those positioned in higher levels of the Eating and Drinking Ability Classification System (EDACS) experienced significantly fewer dysphagia restrictions, with EDACS explaining 55% of the variability. These results indicate that including dysphagia limitations in the thorough assessment of swallowing can assist in determining suitable feeding approaches [102]. In a study that looked at different age groups, dysphagia was common in a large portion of 82.5% of the 40 children with CP, while GER was present in 40% and constipation in 60% of the subjects. Kids with dysphagia and digestive issues displayed unique eating patterns that impacted their growth and overall nutrition. People with GER drank more fluids, while people with constipation had a lower intake of fiber and fluids, indicating the need for specific dietary interventions for different gastrointestinal symptoms [103]. A longitudinal study that followed 23 children with CP for 30 months found that issues with feeding remained stable, with minor changes in the occurrence of coughing. Children with significant difficulties in mouth movements experienced more eating difficulties/problems than those with minor or no issues/difficulties, highlighting the pervasive and enduring nature of feeding problems in CP and underscoring the necessity for ongoing support for children with severe disabilities [103]. The last four studies emphasize the intricate connection between CP, dysphagia, and nutritional status, suggesting that as motor and eating impairments worsen, nutritional difficulties also escalate. Performance in eating and drinking, length of mealtime, and need for help are key factors that affect nutrition results in individuals with CP, regardless of age. In a cross-sectional study of 17 children with spastic CP, mealtime duration measures were reliably associated with feeding performance. Children with unilateral brain involvement had shorter mealtimes and higher feeding scores, indicating a connection between motor impairment severity and feeding efficiency [104]. In a study by Zhao and colleagues, high levels of undernutrition were discovered in a group of 1,151 children, especially among those with severe limitations in motor skills and eating habits. The likelihood of moderate to severe undernutrition significantly increased in children with GMFCS and EDACS levels IV and V [106]. Oliveira and colleagues [107] conducted a study on 56 adult CP patients hospitalized for a year, finding that more severe dysphagia and dietary restrictions resulted in worse nutritional outcomes, despite no significant weight change over time [107]. Finally, a study by McAllister et al. [108] involving 2,035 adults demonstrated a link between severe EDACS levels and lower body weight and body mass index. 86% of patients with EDACS level V required gastrostomies, highlighting the importance of regular dysphagia screening and nutritional support for this group [108]. Overall, a strong association between motor impairments and OPD severity was found, with delayed pharyngeal transit time and laryngeal elevation issues commonly reported. Furthermore, key findings highlight the significant challenges in nutritional health, growth, and feeding efficiency, all closely linked to the severity of motor impairments and gastrointestinal complications. The need for personalized approaches to nutrition, lifestyle modifications, and targeted behavioral interventions is evident. Moreover, the association between GER, dysphagia, and oral health emphasizes the importance of comprehensive evaluation and early screening to mitigate long-term health risks.

Diagnostic Tools for evaluating Nutritional Outcome in Cerebral Palsy: Assessment Techniques and Rehabilitation Strategies

Assessing nutritional improvements in individuals with CP requires a comprehensive approach combining certain evaluation methods with customized rehab plans to address their unique needs. The studies discussed in this paragraph emphasize the notable frequency of dysphagia and related nutritional difficulties in children with CP. Every research highlights the importance of complete evaluations and specialized interventions for this group of people. Santoro et al. [109] analyzed 40 children with CP and found that problems with oral motor skills cause issues with eating, malnourishment, and higher chances of inhaling food or liquid. The authors recommend a comprehensive evaluation from multiple disciplines, which involves neurological assessments, in order to create customized intervention plans [109]. Kantarcigil and colleagues [110] concentrated on assessing the dependability of asynchronous telehealth assessments for dysphagia in a sample of 19 children, aged between 6.9 and 17.5 years old. Findings revealed significant agreement between remote and in-person evaluations, demonstrating that telehealth is a viable choice for assessing dysphagia in areas with limited access to healthcare services [110]. Araujo and their team [111] examined the nutritional status of 187 children with CP. The study revealed that 10% of children were below the 10th percentile in weight when using CP-specific growth charts, showing that general pediatric norms frequently overestimate malnutrition. Furthermore, there were noteworthy connections discovered among dysphagia, constipation, and inadequate nutritional status [111]. Alacam et al. [112] conducted a study with 84 children, with 42 having CP and 42 being healthy controls, using the Nordic Orofacial Test-Screening. The results showed higher dysfunction scores in the CP group, especially in facial expression and swallowing, highlighting the importance of specialized orofacial therapies [112]. Costa and his group [113] evaluated 33 students at a special needs school, finding that every single one showed signs of oropharyngeal dysphagia, with 90.6% experiencing compromised swallowing safety and significant levels of malnutrition and dehydration. This research emphasizes the significance of utilizing multidisciplinary methods to effectively address the complex needs of this group [113]. A prospective study with 151 children with CP (average age 6.11 years) investigated how different dysphagia classification systems are related to functional profiles. Findings showed that 15.2% of participants had prominent swallowing difficulties, with clear connections between the EDACS, communication and gross motor skills, emphasizing the need for a comprehensive evaluation [114]. A study validating the EDACS system for evaluating eating and drinking skills in CP patients involved 151 participants. The research discovered a noteworthy 78% agreement among speech and language therapists, showcasing the system dependability and possibility for broad clinical use [115]. In a cross-sectional study the feeding and swallowing difficulties of 89 children with CP, aged averagely 6 years old, were evaluated. A screening tool with four items based on parent responses had a high sensitivity (81%) and specificity (79%) in identifying feeding problems, allowing for prompt interventions for affected children [116]. In a study comparing the Exeter Dysphagia Assessment Technique (EDAT) with comprehensive clinical assessments, 18 children with CP were evaluated. The EDAT showed substantial consistency (minimum 78%) in different feeding abilities, providing a non-intrusive and easy-to-use option for assessing dysphagia in kids [117]. A prospective study evaluated how well EDACS can identify the risk of aspiration in 131 children with CP, who had a median age of 4.4 years. The EDACS effectively detected the risk of aspiration, showing a sensitivity of 78% and specificity of 92%. This research backs the suggestion to utilize both EDACS and the Pediatric Eating Assessment Tool for the best clinical decision-making on swallowing studies [118]. Su et al. [119] studied 16 severely affected children with CP at levels IV and V, comparing the Mann Assessment of Swallowing Ability (MASA) with videofluoroscopic swallowing studies. Findings demonstrated that although MASA did not distinguish between aspirators and nonaspirators, it was able to predict oral dysfunction, suggesting its restricted usefulness in evaluating aspiration [119]. An experiment with random allocation tested the effects of oral sensorimotor stimulation on 71 children between 12 and 48 months old who have spastic quadriplegia. The intervention resulted in notable enhancements in oral motor function and physical growth in comparison to traditional therapy, underscoring its effectiveness in improving feeding abilities [120]. Sousa and colleagues [121] conducted research on 28 patients with spastic quadriplegic CP who were under the age of 13. The research discovered that 75% used different feeding methods, with 57% classified as eutrophic. Thus, a significant relationship was found between dietary intake and nutritional status, underscoring the necessity of personalized nutritional advice [121]. Yilmzaz and his team [122] evaluated functional feeding abilities in a group ranging from 4 to 25 years old using the Modified Functional Feeding Assessment Scale. While parents did not notice major feeding problems, the findings showed significant struggles in different feeding abilities, emphasizing a difference between what parents thought and the actual issues [122]. A last randomized controlled trial assessed the viability of the babiEAT intervention in 14 infants with CP and oropharyngeal dysphagia. Both babiEAT and standard care were deemed satisfactory by parents, but they expressed greater satisfaction and perceived effectiveness with babiEAT. Additionally, babiEAT improved fluid intake efficiency and food texture acceptance without raising the risk of aspiration [123]. Overall, the evidence emphasizes the critical role of comprehensive diagnostic approaches and individualized treatment plans in addressing the high prevalence of dysphagia and nutritional difficulties among children with CP. Emerging tools, such as telehealth for dysphagia assessments and standardized instruments like EDACS and EDAT, show promise in improving diagnostic accuracy and clinical decision-making. The importance of tailored approaches, including oral sensorimotor stimulation and individualized dietary planning, was also evident, demonstrating potential for improving both nutritional outcomes and quality of life in this population. Key insights of the results section are presented in Fig. 4.

Fig. 4

Key insights of results

Discussion

This systematic review examined the prevalence, types, and assessment of OPD and swallowing disorders in patients with CP as well as its impact on nutritional status and related health complications. The results concerning dysphagia and swallowing issues in people with CP highlight the intricate and diverse nature of these difficulties, mirroring trends seen in previous research [126,127,128]. Our review consistently found high prevalence rates of dysphagia in CP, with some studies reporting rates exceeding 80% [83, 89, 101, 103] as showed in Fig. 5. This is consistent with previous literature using videofluoroscopy as the diagnostic tool, which has also reported high prevalence. However, it is important to note that studies using other methods, such as FEES may report different prevalence rates. While VFSS allows for visualization of all phases of swallowing and is considered the gold standard, FEES offers advantages in portability and the ability to assess sensory function, but is limited in visualizing the oral phase. The connection between dysphagia and the extent of motor disabilities, as demonstrated in various studies within our review [85, 90, 101], is also consistent with prior work [129, 130]. This relationship underscores the impact of motor control on the complex coordination required for safe and efficient swallowing. Studies have shown that problems with swallowing can hinder both quality of life and overall health [78, 87, 131]. Specifically, difficulties with chewing, as reported in several of the included studies [84, 87, 92], can lead to reduced food intake and subsequent nutritional deficiencies. Similarly, the frequent occurrence of coughing and aspiration [83, 85, 94] highlights the risk of respiratory complications, which can further impact health and well-being. This is consistent with existing literature highlighting the link between aspiration and increased risk of pneumonia in individuals with neurological impairments [132, 133]. Several studies have pointed out that traditional interventions may not be sufficient in improving eating efficiency or growth outcomes in individuals with CP [88, 89], indicating that standard therapies may not tackle the root complexities of dysphagia. For instance, the study by Gisel et al. [88] found no significant improvements in eating efficiency or growth outcomes after oral sensorimotor therapy, which aligns with findings from other research suggesting that more intensive or combined interventions may be necessary [134, 135]. This highlights the need for further research to explore the effectiveness of different therapeutic approaches, including combinations of oral motor exercises, postural adjustments, and dietary modifications. The results underscore the importance of thorough evaluations, which should include clinical observations and instrumental assessments like videofluoroscopy and ultrasound, to create tailored treatment strategies that address the specific challenges associated with chewing and swallowing [136]. Moreover, the high occurrence of gastroesophageal symptoms in children with CP and their relation to nutritional health highlight an important aspect that needs more attention in clinical practice. The ongoing recognition of GERD and OPD as major concerns indicates a need for holistic approaches to address both swallowing disorders and nutritional deficits [137]. This is particularly relevant considering the high prevalence of GERD (66% in one study) [89] and its potential to exacerbate swallowing difficulties. The prevalence of undernutrition and obesity in this group is a result of how motor functions, feeding habits, and health outcomes are interconnected, highlighting the significance of personalized lifestyle changes and dietary interventions. In summary, these results add to the current understanding by emphasizing the ongoing issues related to dysphagia in CP and promote a change towards inclusive, collaborative treatment strategies. New rehabilitation strategies need to focus on constantly assessing and adjusting to the specific requirements of individuals with CP, with the goal of enhancing their well-being and quality of life. It is important to note that, even with differences in environmental factors, dietary practices, and access to healthcare, research consistently demonstrates that OPD impacts a similar percentage of children with CP in various nations. This consistency emphasizes the core characteristics of swallowing challenges in CP and indicates that OPD is strongly linked to the neurological and physiological obstacles that come with the condition rather than outside influences. The widespread occurrence of OPD showcases the importance of standardized evaluation and treatment plans that can be used globally, guaranteeing that all children with CP receive the required assistance to address their feeding concerns securely.

Fig. 5

Prevalence of OPD and Dysphagia in Children with CP

A Multidisciplinary Approach to Dysphagia in CP: from Diagnosis to Personalized Intervention Strategies

Beyond the established principles of early detection and multidisciplinary care, this review underscores the critical need for more structured and individualized approaches to dysphagia management in CP. A key advancement would be the development and implementation of standardized diagnostic protocols for OPD. Current practice often varies significantly, hindering consistent diagnosis and treatment planning. Standardized guidelines, incorporating clinical observations, instrumental assessments like VFSS and FEES, and validated questionnaires, while accounting for individual motor, cognitive, and communicative abilities, would greatly enhance diagnostic accuracy and facilitate inter-clinician communication [138, 139]. This, in turn, allows for the creation of truly tailored interventions. For example, specific postural adjustments like side-lying or chin tuck, depending on the nature of the swallowing impairment, can significantly improve swallowing safety. Similarly, adaptive utensils, such as angled spoons or non-slip grips, can empower individuals with limited motor control to participate more actively in mealtimes. Texture-modified diets, ranging from pureed to mechanically altered, should be carefully prescribed by a dietitian in collaboration with the speech-language pathologist, ensuring both nutritional adequacy and swallowing safety. Furthermore, fostering robust multidisciplinary collaboration is paramount [140]. An ideal care model would involve regular joint meetings between neurologists/developmental pediatricians (managing the underlying neurological condition), speech-language pathologists (addressing swallowing mechanics and oral motor skills), dietitians (optimizing nutritional intake and managing dietary modifications), and, crucially, the caregivers. These meetings would facilitate shared goal setting, consistent implementation of strategies across settings, and ongoing monitoring of progress. For instance, if a child is identified as having difficulty with the pharyngeal phase of swallowing during VFSS, the speech-language pathologist can implement specific exercises and strategies, while the dietitian adjusts the diet to appropriate consistencies, and the caregivers are trained on safe feeding techniques and positioning to reinforce these strategies at home. Finally, future research should explore the potential of emerging technologies to address challenges, particularly in low-resource settings. Portable videofluoroscopy offers the possibility of bringing instrumental assessments to remote communities, while artificial intelligence (AI)-driven diagnostic tools could enhance the efficiency and accessibility of dysphagia screening, potentially identifying individuals at risk earlier and allowing for more timely intervention. By analyzing patient data and clinical inputs, AI algorithms could quickly and accurately detect early signs of swallowing dysfunction, facilitating faster and more reliable diagnoses. This would be particularly valuable in areas with fewer specialized clinicians, allowing for more widespread and efficient identification of at-risk individuals. Furthermore, the integration of these technologies could drive cost-effectiveness by reducing the need for frequent in-person specialist consultations and enabling remote monitoring. These technological advancements, coupled with standardized protocols and robust multidisciplinary collaboration, hold significant promise for transforming the landscape of dysphagia management in individuals with CP.

Strengths and Limitations

This thorough review provides a strong summary of current research on OPD in children with CP, offering important perspectives for clinical practice and guiding future research. The review's rigorous search strategy, which utilized several reputable databases without time limitations, is a key strength as it enables a comprehensive analysis of the changing understanding of OPD and swallowing disorder in this group. The utilization of the PRISMA guidelines improves transparency and methodological rigor by providing detailed information on the study selection process. Having several evaluating studies independently, along with calculating inter-rater reliability using the kappa statistics, enhances the trustworthiness of the data extraction process and minimizes potential bias. Moreover, incorporating both quantitative and qualitative research enhances the results of the analysis by covering a diverse array of experiences concerning swallowing disorders and its effects on nutritional status and health issues. Analyzing a particular group, which includes children and adults with CP, guarantees that the findings are relevant to this vulnerable population. This underscores important care strategies for healthcare professionals and caregivers. Nevertheless, some constraints are present in this systematic review. The exclusion of non-English studies may have led to the omission of significant research, which could limit the generalizability of the findings. This limitation may lead to an inadequate representation of the worldwide research environment for various populations and contexts. Additionally, omitting non-English studies might unintentionally create a geographical or cultural bias, thereby limiting the relevance of the findings to a particular group of countries or populations. The evaluation of bias through tools such as ROBINS-I and RoB 2, though necessary, raised issues pertaining to study design, particularly concerning the selection and reporting biases in certain studies that were included. Furthermore, the reliance on observational studies, which lack comparison groups, may reduce the ability to draw definitive conclusions about the causal relationships between swallowing disorders and nutritional outcomes. To address these gaps, future research should aim to include studies in a broader range of languages and prioritize high-quality randomized controlled trials or cohort studies with comparison groups to strengthen the evidence base and improve clinical recommendations.

Conclusions

This systematic review unequivocally confirms the widespread prevalence and significant clinical ramifications of OPD and related swallowing disorders in individuals with CP. The consistently high prevalence of dysphagia observed across studies, frequently exceeding 80%, underscores the critical need for improved clinical practice. These swallowing difficulties are not isolated issues; they profoundly impact nutritional status, growth, overall health, and quality of life, often compounding risks such as GER and respiratory complications. Therefore, this review strongly advocates for several key actions. First, clinicians should prioritize the implementation of standardized diagnostic protocols for OPD in CP, incorporating both clinical observation and instrumental assessments like VFSS and, where appropriate, FEES, to ensure accurate diagnosis and facilitate effective treatment planning. Second, truly integrated multidisciplinary care models are essential. This necessitates close collaboration among neurologists/developmental pediatricians, speech-language pathologists, dietitians, physical therapists, and, crucially, caregivers, to ensure consistent and holistic management. Finally, this review highlights the transformative potential of emerging technologies. Portable VFSS can improve access to instrumental assessments, especially in resource-limited settings, while AI-driven diagnostic tools offer the promise of more efficient and objective screening, enabling earlier identification and intervention. By implementing these practical steps (standardizing diagnosis, fostering multidisciplinary collaboration, and embracing technological advancements) clinicians and researchers can profoundly improve the lives of individuals with CP and dysphagia, mitigating health risks and enhancing overall well-being.