Motor dysfunction of the upper digestive tract in Pierre Robin sequence as assessed by sucking-swallowing electromyography and esophageal manometry

Diagnosis and Early Management of Robin Sequence

The results of a survey of twenty-four neonatal units in the United Kingdom and Ireland are presented. A structured ten-item questionnaire was used, and demonstrated the variation in how infants with RS are diagnosed and managed. Notably, the survey revealed that a minority of infants were diagnosed antenatally. There were significant discrepancies in diagnostic criteria used and 79% of the units referred the patients to tertiary services. A preference for minimally invasive approaches to managing upper airway obstruction, such as a trial of prone positioning before progressing to a nasopharyngeal airway, was reported by 96% of the centers. A narrative review was undertaken which discusses the current practices for diagnosis and early management of Robin sequence (RS). The challenges of antenatal diagnosis, strategies to enhance outcomes through early detection and controversies surrounding the management of neonatal upper airway obstruction associated with RS are included. The results of the survey and our comprehensive review of the literature emphasize that there remains uncertainty regarding the best approach to treating Robin sequence.

Airway and Feeding Outcomes in Pierre Robin Sequence: A Comparison of Three Management Strategies

BACKGROUND

Controversy remains regarding optimal management of Pierre Robin sequence (PRS). The goal of this study was to compare airway and feeding outcomes in infants with PRS who underwent surgical intervention, specifically mandibular distraction osteogenesis (MDO) or tongue-lip adhesion (TLA), or who had conservative management (CM) without surgery.

METHODS

All consecutive patients treated for PRS at a pediatric academic medical center, with at least one year follow-up, were included. Patients who underwent tracheostomy as an index procedure were excluded. Patients were divided into those who underwent MDO, TLA or CM. Feeding status and data from initial and follow-up polysomnograms were collected. Comparisons between groups were made using the Kruskal-Wallis test, followed by Mann-Whitney pairwise comparison with a Bonferroni correction, when appropriate.

RESULTS

67 neonates were included. 19 underwent TLA, 29 underwent MDO and 19 underwent CM. The proportions of syndromic patients were similar between groups. Patients undergoing CM had the lowest baseline AHI (9.1), but there were no significant differences between TLA (20.1) and MDO (25.4). At follow-up, the three groups had similar mean AHI (MDO 1.3, TLA 4.2, CM 4.5). A similar proportion of patients achieved AHI 5 or less (TLA 89.5%, MDO 96.6%, CM 84.2%). At one year, there were no significant differences in weight percentiles or in risk of failure-to-thrive between groups. One patient from the TLA group required a tracheostomy.

CONCLUSION

The three treatment modalities achieved high airway and feeding success rates. All three modalities should have a place in the armamentarium of the craniofacial surgeon.

Feeding and swallowing outcomes following mandibular distraction osteogenesis: an analysis of 22 non-isolated paediatric cases

Patients with mandibular hypoplasia and upper airway obstruction are at an increased risk of feeding and swallowing difficulties. Little has been described regarding these outcomes following mandibular distraction. The aim of this study was to evaluate the effect of mandibular distraction on feeding and swallowing function. A retrospective study was performed on 22 patients with non-isolated mandibular hypoplasia and severe upper airway obstruction treated with mandibular distraction. Median age at first mandibular distraction was 3.1 years (interquartile range 2.3-6.0 years) and the median follow-up time was 3.5 years (interquartile range 2.0-9.4 years). Prior to mandibular distraction, feeding difficulties were present in 18 patients. Swallowing difficulties were present in 20 patients, all of whom had problems in the oral phase of swallowing, while 11 patients had additional problems in the pharyngeal phase. Following mandibular distraction, at the time of follow-up, feeding difficulties persisted in 13 patients. Swallowing difficulties in the oral phase remained present in all 20 patients, while pharyngeal phase problems persisted in seven patients. In conclusion, feeding and swallowing difficulties are highly prevalent in non-isolated patients and often persist following mandibular distraction. Moreover, these can be the reason that decannulation cannot be accomplished. Hence, awareness and close follow-up by a specialized speech therapist is of paramount importance.

Nasopharyngeal Tube and Functional Treatment in Pierre Robin Sequence: A Tertiary Clinical Experience From 150 Cases

OBJECTIVES

To describe the initial care practices for children with Pierre Robin sequence (PRS) and analyze the factors predicting the severity of the obstruction breathing disorders.

DESIGN

A retrospective single-center study of 150 children with PRS.

SETTING

Single tertiary care center, Regional Competence Center for the diagnosis and treatment of PRS.

PATIENTS

A total of 150 children with PRS consecutively followed between 1986 and 2017. Group 1 comprises children without specific respiratory management; group 2, children requiring prone positioning to alleviate their respiratory distress symptoms; and group 3, children requiring nasopharyngeal airway tube (NT) or nonconservative surgical treatment.

MAIN OUTCOME MEASURES

Evolution and results of the initial treatment of PRS.

RESULTS

Forty-two percent (n = 63) were attributed to group 1, 39% (n = 50) to group 2, and 19% (n = 29) to group 3. Preterm birth, birth weight, or associated congenital malformations were not significantly different between the groups. However, the age of exclusive oral feeding was significantly different: 1 day (quartiles: 0-3) for group 1; 11 days (quartiles: 1-28) for group 2; 39 days (quartiles: 19-111) for group 3 (P < .0001). Considering the NT, its use relieves the upper airway obstruction, assessed by a respiratory polygraphy, in 14 children.

CONCLUSIONS

Nasopharyngeal airway tube has become our major first-line treatment, avoiding more complex procedures in most of the cases. The achievement of exclusive oral feeding seems to be a good predictor of the severity of respiratory symptoms in PRS.

A Standardized Extubation Schedule Reduces Respiratory Events After Extubation Following Mandibular Distraction in Infants

PURPOSE

The rational time for intubation during early mandibular distraction osteogenesis (MDO) in infants is unknown. To investigate the differences in clinical outcomes following MDO before and after a standardized extubation protocol implementation in infants.

METHODS

A retrospective cohort study was performed for infant patients under 1 year old undergoing MDO. The study population was composed of all patients presenting for evaluation and management who underwent MDO between November 2016 and February 2021. We divided them into 2 groups: the pre-protocol group and the protocol group. The inpatient charts of infants were assessed. The primary outcome was respiratory events after extubation. The secondary outcomes were duration of mechanical ventilation (MV), postoperative length of stay (LOS), and success rate of the first extubation. Other variables included age, sex, weight, height, and information related to diagnosis, distraction, anesthesia, and operation. The logistic regression model and linear regression model were used to calculate unadjusted and adjusted relative risk (RR) and mean difference (MD) for associations between 2 groups and the primary and secondary outcomes.

RESULTS

There were 142 infants in the pre-protocol group and 135 infants in the protocol group. The patients in the protocol group were heavier in weight than those in the pre-protocol group (P<.05). The Cormack-Lehane grade and the duration of operation and anesthesia were higher and longer in the pre-protocol group than in the protocol group (P<.05). Respiratory events after extubation were significantly more common in the pre-protocol group than in the protocol group [21.1 vs. 9.6%, adjusted relative risk 0.46 (95% CI 0.22-0.89), P <.01].

CONCLUSIONS

Among infants undergoing MDO, the standardization of extubation practices can reduce respiratory events after extubation compared with traditional management.

Risk Factors of Prolonged Mechanical Ventilation in Infants With Pierre Robin Sequence After Mandibular Distraction Osteogenesis: A Retrospective Cohort Study

Background: After mandibular distraction osteogenesis (MDO), most infants with Pierre Robin sequence (PRS) require mechanical ventilation to assist their breathing. However, the optimal duration of intubation during early mandibular distraction osteogenesis activation is poorly understood. This retrospective study was carried out to identify perioperative risk factors of prolonged mechanical ventilation in infants undergoing MDO. Methods: A total of 95 infants with PRS underwent MDO at Guangzhou Women and Children's Medical Center between 2016 and 2018, and the clinical records of 74 infants who met the selection criteria were analyzed. Of the 74 infants, 26 (35.1%) underwent prolonged mechanical ventilation, 48 (64.9%) did not. t-test, Wilcoxon Sum Rank test or chi-squared test were performed to compare variables that might associate with prolonged mechanical ventilation between the two groups, and then, significant variables identified were included in the multivariate logistic regression model to identify independent variables. Results: Univariate logistic regression analysis revealed that age, preoperative gonial angle, and postoperative pulmonary infection were associated with prolonged mechanical ventilation (all P < 0.05). Multivariate logistic regression analysis confirmed that the preoperative gonial angle and postoperative pulmonary infection were independent risk factors of prolonged mechanical ventilation (both P < 0.05). Conclusions: Infants with PRS and smaller preoperative gonial angle or postoperative pulmonary infection may be more likely to undergo prolonged mechanical ventilation after MDO. For others, extubation may be attempted within 6 days after MDO.

Functional outcomes in patients with facial dysostosis and severe upper airway obstruction

An increased risk of upper airway obstruction (UAO) is seen in up to 95% of patients with facial dysostosis. Secondary to respiratory problems are feeding difficulties and increased nutritional requirements. Little has been described regarding these outcomes in this patient population. Hence, a retrospective cohort study was performed to gather data on functional outcomes. Eighteen patients with facial dysostosis and severe UAO were included. The median follow-up time was 3.42 years. A tracheostomy tube was placed in 13 patients, of whom 10 subsequently underwent mandibular distraction. Three of the five patients without a tracheostomy underwent mandibular distraction as the primary surgical treatment; the remaining two patients were treated conservatively with oxygen supplementation. At presentation, 13 patients had feeding difficulties. Overall malnutrition was present in 16 patients during follow-up. At the end of follow-up, severe UAO was present in 12 patients, feeding difficulties in seven patients, and malnutrition in four patients, while two patients died. In conclusion, patients with facial dysostosis have a high prevalence of severe UAO, feeding difficulties, and malnutrition. Importantly, mandibular distraction has limited success in treating severe UAO in these patients. Close follow-up by a specialized craniofacial team is of paramount importance to manage the long-term consequences.

A retrospective study of patients with Robin sequence: Patient characteristics and their impact on clinical outcomes

INTRODUCTION

Robin sequence (RS) is a congenital set of abnormalities of the head and neck, consisting of a hypoplastic mandible (micrognathia), a tongue that is displaced posteriorly (glossoptosis), and obstruction of the airway. A clear set of diagnostic criteria for this complex condition has recently been established, but there is still no consensus in the literature with respect to managing the associated airway, feeding, and hearing difficulties. The objectives of the study are: 1) to describe the management of airway and feeding issues in children with RS; and 2) to evaluate the impact of airway and feeding strategies on important clinical outcomes.

METHODS

A retrospective chart review was conducted of all pediatric patients diagnosed with RS at London Health Sciences Centre from January 1995 until September 2017. The frequencies of all airway and feeding interventions were collected. Data were collected on several clinical outcomes including initial admission length, enteral feeding duration, tympanostomy tube insertion frequency, and hearing thresholds. Statistical analyses to evaluate the impact of airway and feeding strategies on clinical outcomes were carried out using independent samples t-tests and Chi-square tests, where appropriate.

RESULTS

Twenty-four patients were identified. Five patients (20.8%) required airway surgery and 18 patients (75.0%) required enteral feeding. Airway surgery was significantly associated with a longer ICU admission (15.8 vs. 4.3 days, p < 0.05), a longer overall hospital admission (73.0 vs. 25.2 days, p < 0.05), a delay in introducing oral feeds (222.8 vs. 11.5 days, p < 0.05), and a higher frequency of tympanostomy tube insertions (80% vs. 23.5% requiring ≥2 insertions, p < 0.05). Enteral feeding was significantly associated with a longer ICU admission (8.8 vs. 0 days, p < 0.05) and a longer overall hospital admission (43.9 vs. 5.6 days, p < 0.05).

CONCLUSIONS

This study demonstrates the substantial impact that airway and feeding difficulties have on RS patient morbidity, particularly with respect to length of hospital and ICU admission. This information has prognostic value and may be helpful in generating a management algorithm for this complex patient population.

Holoprosencephaly with Clefts: Data of 85 Patients, Treatment, and Outcome: Part 2: Management, Surgical Treatment, and Unexpected Aspects of Holoprosencephaly Cleft Patients

Context:

Cleft patients with holoprosencephaly (HPE) provide a wide clinical spectrum. Besides accessory agenesis of facial tissue structures, spanning from a single central incisor to the columella, up to the entire prolabium-premaxilla complex, brain deformities with various functional deficits may prevail, just like normal brain development. Making a precise diagnosis, just like choosing the most appropriate treatment plan often is challenging. A literature and chart review comprising 85 HPE cleft cases at the Cleft Clinic of the University of Pretoria, South Africa, was performed. It yielded pertinent diagnostic criteria and collected information about pregnancy history, brain development and survival rate as well as the initial perioperative management and the course of postsurgical midfacial growth.

Aims of Part 2:

The aim is to highlight how the here presented classification system of HPE cleft patients according to their clinical picture may facilitate the most appropriate treatment protocol.

Materials and Methods:

The classification system elaborated in Part I due to diagnostic criteria facilitated establishing classification related treatment protocol for 85 cleft cases with HPE.

Results:

According to diagnostic criteria, HPE cleft cases can be subdivided into (1) columella complex agenesis (Ag-Colum), (2) prolabium-premaxilla-columella complex agenesis in cleft lip-alveolus deformities (Ag-CLA), (3) prolabium-premaxilla-columella complex agenesis in complete hard and soft palate clefts (Ag-CLAP), and (4) “standard” uni-or bilateral CLA or CLAP (HPE-Std-cleft), including cases with an atrophic premaxilla with or without single central incisors. Relevant treatment protocols according to the particular classification are highlighted with figures and intra-operative pictures.

Conclusion:

This paper addresses the following aspects in cleft patients with HPE: A subdivision into four groups, the 3-in-1 surgical approach, the anteriorly directed midfacial growth and maternal HIV infection.

Management of Airway Obstruction in Infants With Pierre Robin Sequence

Background

Pierre Robin sequence (PRS)-related airway obstruction is often treated surgically; however, objective measures predicting the need for surgery are poorly defined.

Methods

A retrospective chart review was performed on 171 neonates with PRS. Infants were grouped based upon intervention modality: nonsurgical (conservative) or surgical [mandibular distraction osteogenesis (MDO) or tracheostomy]. Demographic data, physical examination findings, and study results were compared between groups to determine risk factors for surgical intervention, and to predict long-term success or failure of those interventions.

Results

The most significant, objective risk factor among those receiving surgery was a poor preintervention sleep study [obstructive index (OI): 42.4 versus 12.9 for the conservative treatment group; P < 0.001]. Only 11% of those treated conservatively had an OI >20, whereas 67.5% of those treated surgically met this severity measure. Of those receiving surgery, tracheostomy was associated with neurologic impairment (P = 0.030) and low birth weight (P = 0.046) compared with the MDO group. Together with syndromic status, these risk factors were useful for predicting failure of MDO to avoid subsequent tracheostomy (test sensitivity and specificity were 64.2% and 100.0%, respectively). No long-term differences in speech or micrognathia were detected between the 3 groups; however, those treated conservatively or with MDO had improved long-term feeding and airway obstruction outcomes compared with the tracheostomy group.

Conclusions

Surgical intervention for PRS-related tongue-based airway obstruction should be strongly considered with an OI >20. Tracheostomy should be reserved for complex patients with concomitant syndromic diagnosis, neurologic impairment, and low birth weight.

Severity of Retrognathia and Glossoptosis Does Not Predict Respiratory and Feeding Disorders in Pierre Robin Sequence

Pierre Robin sequence (PRS) may lead to life-threatening respiratory and feeding disorders. With the aim to analyse the association of the severities of retrognathia and glossoptosis with those of respiratory and feeding disorders, we retrospectively studied a series of 50 infants with retrognathia, glossoptosis, cleft palate, and airway obstruction. The patients were managed from birth to at least 6 years of age by a single pediatric team at the Armand Trousseau Hospital in Paris within a 12 years period (2000-2012). Retrognathia and glossoptosis were graded in the neonatal period according to a specific clinical examination. Ventilation assistance was required for 32/50 (64%) patients, and enteral feeding for 41/50 (82%). The grades of retrognathia and glossoptosis and the severity of respiratory disorders did not differ between patients with isolated PRS and syndromic PRS. Severe respiratory disorders were more common and long-lasting feeding (>12 months) was more frequently required in patients with syndromic PRS compared with isolated PRS (42 vs. 13%, p = 0.04 and 42 vs. 4%, p < 0.01 respectively). Using univariate analysis, neurological impairments and laryngomalacia were associated with severe respiratory disorders [Odds ratio (OR) 5.0, 95% CI 1.3-19.6; and OR 14.6, 95% CI 1.3-161.4; p < 0.05] as well as with long-lasting feeding (>12 months) disorders (OR 18.6, 95% CI 3.9-89.2 and OR 20.4, 95% CI 3,4-122.8; p < 10^-2). Syndromic SPR status was also associated with severe respiratory disorders (OR 4.9, 95% CI 1-32.5; p < 0.05). Using multivariate analysis, only syndromic PRS status was predictive for severe respiratory disorders (adjusted OR 8, 95% CI 1.47-44.57; p < 0.05); and only neurological impairments remained a significant risk for long lasting feeding disorders (>12 months) (adjusted OR 21.72, 95% CI 3.4-138.63; p < 10^-2). The grades of retrognathia and glossoptosis were not predictive factors for the severity of respiratory and feeding disorders. Conclusion: In children with PRS, the severity of clinical conditions may not correlate with anatomic variables but rather with laryngeal abnormalities, neurological impairement and syndromic PRS status.

Treatment of infants with Syndromic Robin sequence with modified palatal plates: a minimally invasive treatment option

Background

Infants with Robin sequence (RS) suffer from upper airway obstruction (UAO) and feeding problems. We developed an oral appliance with a velar extension in combination with functional treatment and appropriate feeding techniques, which was proven effective in isolated RS. As the above problems are particularly challenging in syndromic RS, we set out to evaluate our treatment concept also in these patients.

Methods

We searched our electronic departmental database to identify all children admitted to our department between 01/01/2003 and 31/12/2009 because of syndromic RS. UAO was quantified by cardiorespiratory sleep studies performed before and during treatment with a modified palatal plate. This appliance consists of a palatal part, covering the hard palate as well as the alveolar ridges and the potential cleft, and a velar extension shifting the tongue in a more anterior position, thereby opening the pharyngeal airway. It is adjusted by fiberoptic nasopharyngoscopy and controlled by cardiorespiratory sleep studies. Obstructive sleep apnea was defined as a mixed obstructive sleep apnea index (MOAI) >3/h. Feeding modalities before and after treatment and weight gain, determined as standard deviation score, were also evaluated.

Results

Of 68 children meeting inclusion criteria, 56 completed treatment (46 of these being infants). Underlying diagnoses included craniofacial dysostosis (N = 13) and synostosis syndromes (N = 5), unspecified dysmorphic syndromes (N = 23) and miscellaneous rare conditions (N = 27).

Median MOAI decreased from 8.5 (range 0.3–76.0) at admission to 1.1 (0.0–5.2) at discharge (p < 0.001). 51 children received only a TPP and 5 additionally continuous positive airway pressure (CPAP) or high-flow nasal cannula during sleep for mild residual OSA. Three children ultimately required tracheostomy. The number of exclusively gavage fed infants was reduced from 23 to 7. Conversely, the number of children fed exclusively by mouth increased from 18 to 30. Median SDS for weight decreased from −1.6 (−3.5–1.7) to −1.3 (−4.1-2.5). Twelve children had their treatment prematurely discontinued, e.g. due to laryngeal collapse/laryngomalacia. No patient died during treatment.

Conclusion

Treatment of UAO and feeding problems in these children with syndromic RS by a modified palatal plate with a velar extension was shown to be effective and safe. If confirmed in prospective studies, it may help to avoid more invasive interventions.

Contribuições da eletromiografia de agulha para o estudo da deglutição em seres humanos

RESUMO A Eletromiografia intramuscular é realizada pelo médico, a partir da fixação de eletrodos de agulha ou de fio fino para o estudo de músculos isolados ou músculos profundos. Esse estudo tem como objetivo identificar e descrever as contribuições da eletromiografia intramuscular, para a avaliação da deglutição em seres humanos. A busca, realizada no período entre abril e março de 2015, nos bancos de dados da PUBMED, BIREME E BANCO DE TESES DA CAPES, resultaram em 21 referências, das quais, apenas sete se enquadraram nos critérios de inclusão. Os artigos selecionados trazem contribuições importantes para o entendimento do comportamento eletrofisiológico e eletrofisiopatológico durante a deglutição e acredita-se que a escassez de estudos utilizando essa ferramenta em seres humanos deva-se ao incômodo e riscos causados pela introdução da agulha no ventre muscular e talvez a introdução de um fio fino (fine wire ou cooper wire), seja mais interesante para o auxílio diagnóstico de denervações e transtornos neuromusculares que comprometam a deglutição, pela possibilidade de reduzir drasticamente o incômodo causado pela agulha.

Pierre Robin sequence: Subdivision, data, theories, and treatment - Part 4: Recommended management and treatment of Pierre Robin sequence and its application

Context:

The disorder currently accepted as Pierre Robin syndrome/anomaly/sequence (PRS) has been plagued by controversy ever since initially being described. Controversy exists not only about the appropriate terminology and etiopathogenesis of the disorder but also about its management. Therefore, clinical findings and treatment outcomes of a large database of 266 PRS cases were compared with the current state of knowledge in the scientific literature related to history, clinical description, diagnostic criteria, epidemiology, theories of oligohydramnios, mandibular catch-up growth, midfacial hyperplasia, and early management.

Aims of Part 4:

To provide a systematic treatment protocol for Fairbairn–Robin triad (FRT) and Siebold Robin sequence (SRS) patients based on clinical findings and experience with 266 PRS cases.

Subjects and Methods:

A plethora of treatment modalities and their outcome in literature have been compared to those applied in this database and their outcomes.

Results:

The management of SRS/FRT depends on various factors including compromised airways, feeding difficulties, as well as the sequence of the reconstructive ladder.

Conclusion:

Based on the novel PRS subdivisions, a stepwise sequential treatment approach is outlined, addressing the particular needs of each disorder systematically.

Outcomes of Neonatal Bulbar Weakness

BACKGROUND AND OBJECTIVE

Neonatal bulbar weakness (BW) has various etiologies and a broad prognostic range. We aimed to report outcomes in a large series of children with neonatal BW and explore the association of orofacial electrodiagnostic data with outcome.

METHODS

We retrospectively reviewed the files of children who presented with facial, lingual, laryngeal, or pharyngeal weakness at birth and who underwent electrodiagnostic studies combining conventional needle electromyography (EMG) of orofacial muscles, blink responses, and EMG during bottle-feeding. Outcome measures included the need for prolonged respiratory assistance and enteral feeding, as well as sensorimotor and cognitive impairments.

RESULTS

Of 175 patients, 73% had developmental disorders, 25% suffered from acquired brain damage, and 2% had no apparent underlying disorders. Motor or mental impairment was observed in 71%; death occurred in 16%. Outcomes were not significantly different when comparing developmental disorders versus acquired brain damage or neurogenic versus normal detection EMG. Abnormal blink responses were associated with higher frequencies of respiratory assistance (P = .03), gastrostomy (P = .025), and death (P = .009); moderate or severe oropharyngeal incoordinations were associated with higher frequencies of respiratory assistance (P = .006), prolonged enteral feeding (P < .0001), and gastrostomy (P = .0002).

CONCLUSIONS

Orofacial electrodiagnostic studies provide supplementary information to help the pediatrician anticipate the management and prognosis of young infants with BW.

Pierre Robin sequence: Management of respiratory and feeding complications during the first year of life in a tertiary referral centre

OBJECTIVES

To review early clinical manifestations of Pierre Robin sequence (PRS) and their management during the first year of life in the University Hospitals Leuven.

METHODS

Retrospective series of 48 patients with PRS born between 2001 and 2011 and treated at a tertiary referral hospital. Review of the current literature about management of respiratory and breathing difficulties in the early life of PRS patients.

RESULTS

Of our cleft palate patients 15.3% presented with PRS. A syndrome was diagnosed in 14.6%, associated anomalies without a syndromic diagnosis in 56.3% and isolated PRS in 29.2% of the cases. Mortality rate directly related to PRS was 2.1%. Respiratory difficulties were observed in 83.3% and feeding difficulties in 95.6% of the patients. Respiratory problems were addressed in a conservative way in 75%, in a non-surgical invasive way in 42.5% and in a surgical way in 12.5%. A statistically significant relationship between the association of a syndrome or other anomalies, and a higher need for resuscitation and invasive treatment were found (chi-square test, p-values=0.019 and 0.034). Feeding difficulties were managed conservatively in 91.3%, invasively in 80.4% and surgically in 15.2%.

CONCLUSIONS

PRS is frequently associated with other abnormalities or syndromes. Therefore routine screening for associated anomalies in neonates with PRS is recommendable. Respiratory and feeding complications are highly frequent and possibly severe, particularly in patients with associated anomalies or syndromes, and should be recognized and addressed appropriately in an early stage. There is a potential role for the nasopharyngeal airway in reducing the need for the more traditional surgical interventions for respiratory problems.

Pierre Robin sequence: review of diagnostic and treatment challenges

Pierre Robin sequence is not a rare condition and paediatric specialists caring for respiratory related issues are likely to encounter cases in their practice. There have been a few recent reviews on the topic, mostly focusing on the surgical interventions performed for cases with severe airway obstruction. In the present review, we will highlight the different challenges that remain today in the global evaluation of infants afflicted with this condition through a thorough review of the medical literature, giving the clinician a full scope of the disease and of the various management options. The need for an improved objective evaluation of airway obstruction and for a better classification will be emphasized. We are therefore proposing a novel classification scheme that will better account for respiratory and feeding difficulties in these infants. Finally, many knowledge gaps persist regarding this condition, underlining the necessity for further research both in the genetic field and regarding the outcome of therapy.

Developmental and genetic perspectives on Pierre Robin sequence

Pierre Robin sequence (PRS) is a craniofacial anomaly comprising mandibular hypoplasia, cleft secondary palate and glossoptosis leading to life-threatening obstructive apnea and feeding difficulties during the neonatal period. The respiratory issues require careful management and in severe cases may require extended stays in neonatal intensive care units and surgical intervention such as lengthening the lower jaw or tracheotomy to relieve airway obstruction. These feeding and respiratory complications frequently continue well into childhood, affecting not only growth and development but also impacting on long term educational attainment. The diagnosis of PRS depends on readily recognizable clinical features but the phenotypic similarity of many PRS individuals conceals considerable etiological heterogeneity. Defects in the growth of the mandible sit at the core of PRS and the natural history of PRS can be classified into two major streams: primary defects of mandibular outgrowth and elongation and issues that are external to the mandibular skeleton but that secondarily impact on its growth. These altered developmental trajectories appear to be driven by a range of influences including defects in cartilage growth, neuromuscular function and fetal constraint. Various genetic and cytogenetic associations have been made with PRS and the diversity of these associations highlights the fact that there are numerous ways to arrive at this common phenotypic endpoint.

Airway, feeding and growth in infants with Robin sequence and sleep apnoea

OBJECTIVE

Robin sequence (RS) is associated with airway abnormalities that result in functional problems of obstructive sleep apnoea (OSA), feeding difficulties, and consequent poor growth. We evaluated the relationships between OSA severity, airway and feeding interventions, and weight at 12 months in infants with RS and OSA.

METHODS

Retrospective notes review of children with RS managed at our neonatal unit (1998-2010, inclusive).

RESULTS

Of 39 infants studied, 10 (25.6%) had mild/moderate OSA, and 29 (74.4%) severe. Infants with severe OSA required more airway interventions in hospital (82.8 vs 30.0%, p = 0.004) and at discharge (72.4 vs 20.0%, p = 0.007) than those with mild/moderate OSA; 30.0% of infants with mild/moderate OSA required continuous positive airway pressure (CPAP) during admission and 20.0% on discharge, but amongst those with severe OSA 82.8% required airway interventions as an inpatient, 17.2% underwent mandibular distraction osteogenesis, and 55.2% required CPAP on discharge. Those with severe OSA were also more likely to require tube feeding on discharge (89.7 vs 50.0%, p = 0.02). Overall, children were on a lower weight centiles at discharge compared to birth (-10.2 centiles) and at 12 months of age compared to birth (-14.8 centiles), but this occurred irrespective of OSA severity or need for airway interventions or tube feeding.

CONCLUSIONS

Infants with RS commonly have OSA, feeding and airway difficulties. Weight at 12 months appeared not to be influenced by OSA severity, feeding or airway problems, suggesting that current intervention/management strategy results in the severely affected infants growing as well as those affected less severely.

Rare syndromes of the head and face-Pierre Robin sequence

Pierre Robin sequence (PRS) is an association of clinical features consisting of mandibular hypoplasia, cleft secondary palate, and glossoptosis leading to obstructive apnea and feeding difficulties. PRS can occur as an isolated condition or can be found in association with a range of other features in a number of conditions including Treacher collins and Stickler syndromes. The frequent association of the PRS triad suggests a common underlying developmental mechanism which impacts on each of these tissues. Isolated PRS is typically sporadic but when familial usually exhibits autosomal dominant inheritance. The term PRS is applied on the basis of the pattern of malformation rather than etiology and growing evidence indicates that the initiating genetic lesion is variable. Various chromosomal anomalies have been associated with PRS including loci on chromosomes 2, 4, and 17. Associations with genes including SOX9, a number of collagen genes and work with animal models suggest the phenotype derives from a cartilage defect during early facial growth. However, alternative theories have been proposed and these highlight the difficulty of characterising congenital anomalies of craniofacial development in which multiple etiologies can result in very similar phenotypes.

Neonates with Tongue-Based Airway Obstruction

Objective. In this systematic review, the authors summarize the current evidence in the literature regarding diagnosis, treatment, and long-term outcomes in neonates with tongue-based airway obstruction (TBAO) and assess the level of evidence of included studies.

Data Sources. The terms Pierre Robin syndrome/sequence, micrognathia, retrognathia, and cleft palate were combined with airway obstruction, treatment, tongue-lip plication, and osteogenesis distraction to perform an Ovid literature search, yielding 341 references. The authors excluded references containing patients with isolated choanal/nasal obstruction, patients older than 12 months, and expert opinion papers, yielding 126 articles.

Review Methods. The authors searched 3 electronic databases and reference lists of existing reviews from 1980 to October 2010 for articles pertaining to the diagnosis, treatment, and outcomes of TBAO. Reviewers assigned a level of evidence score based on Oxford’s Centre for Evidence Based Medicine scoring system and recorded relevant information.

Results. Most studies were case studies and single-center findings. The lack of standardization of diagnostic and treatment protocols and the heterogeneity of cohorts both within and between studies precluded a meta-analysis. There was little evidence beyond expert opinion and single-center evaluation regarding diagnosis, treatment, and long-term outcomes of neonates with TBAO.

Conclusions. The variability in the phenotype of the cohorts studied and the absence of standardized indications for intervention preclude deriving any definitive conclusions regarding diagnostic tools to evaluate this patient population, treatment choices, or long-term outcomes. A coordinated multicenter study with a standardized diagnostic and treatment algorithm is recommended to develop evidence for the diagnosis and treatment of neonates with TBAO.

Pierre Robin sequence: an institutional experience in the multidisciplinary management of airway, feeding and serous otitis media challenges

OBJECTIVES

To evaluate the course and prognosis of airway obstruction, feeding difficulties and hearing abnormalities in patients with Pierre Robin sequence (PRS).

METHODS

A retrospective review was conducted, of 69 patients with PRS, attending between 1991 and 2010 at the Children's University Hospital in Dublin. Data regarding airway management, nutritional status and hearing difficulties was collected prospectively.

RESULTS

Airway obstruction requiring intervention other than positional therapy was seen in 39% (27) patients. Fifty nine percent (16/27) of these patients, who failed positional therapy, were successfully managed with a nasopharyngeal airway. Following failed intervention with nasopharyngeal airways, two patients had airway maintenance achieved with a successful glossopexy procedure. One patient had an adequate airway achieved with nasal continuous positive airway pressure. Eight patients (12%) required a surgical tracheostomy. Of those who required a tracheostomy, six patients had isolated PRS, one patient had PRS in association with Stickler syndrome and one patient had Nager acro-facial dystosis. Duration of tracheostomy tube ranged from 10 to 19 months, mean 13 months. Seventy percent (48 patients) required supplementary feeding in the form of nasogastric (NG) or gastrostomy tube. Forty-four patients were successfully managed with a temporary NG tube. One patient required a prolonged NG tube, and three required a gastrostomy tube. Twenty-one (30%) patients were successfully managed with a specialised Haberman bottle. Twenty-four patients (35%) who had their airway managed successfully by positional therapy, still required supplemental feeding. Thirty-one patients (45%) demonstrated a conductive hearing loss at some stage, which affected their speech and language development. Twenty-four patients (35%) required tympanostomy tube insertion once, while 7 (10%) of patients required ventilation tube insertion twice or more.

CONCLUSION

Airway management in the majority of PRS can be successfully achieved by conservative methods. Even in the presence of an adequate airway, many patients will require supplemental feeding. Early audiological assessment is necessary as many patients will need tympanostomy tube placement to ensure adequate speech and language development.

Treatment Modalities of Infants with Upper Airway Obstruction—Review of the Literature and Presentation of Novel Orthopedic Appliances

Objective

To present a new orthopedic method for treatment of infants with Pierre Robin sequence (PRS) and upper airway obstruction (UAO) as an alternative to other established nonsurgical and surgical techniques such as positioning, nasopharyngeal or endotracheal intubation, tongue-lip adhesion, extension, distraction, or tracheostomy.

Design

Review of the literature and presentation of novel orthopedic appliances.

Setting

Department of Orthodontics, Dental Clinic, Medical Faculty of the University of Wuerzburg, Germany, Department and Clinic of Pediatrics, Medical Faculty of the University of Wuerzburg, Germany, 2005 to 2008.

Patients

Seven patients with significant respiratory and feeding difficulties between 0 and 6 months of age. Both patients with nonsyndromic PRS and patients with syndromic PRS were included.

Interventions

The type of respiratory tract obstruction was defined by nasopharyngoscopy. Patients with type 1 obstruction received a plate with an epiglottic spur; whereas, patients with obstruction type 2, 3, or 4 received a plate with a pharyngeal tube.

Results

All patients were successfully treated with orthopedic appliances alone. Under plate therapy they showed good oxygen saturation and could consequently be better nourished orally.

Conclusions

The presented novel method is a noninvasive technique in treatment of infants with UAO.

Airway analysis: with bilateral distraction of the infant mandible

BACKGROUND

Mandibular distraction was proven to be a valuable tool for lengthening the hypoplastic mandible and relieving airway obstruction in infants. However, analysis of presurgical and postsurgical three-dimensional computed tomography and polysomnogram studies is lacking. The aim of this study was to describe the effect of distraction on the airway by evaluating the clinical, three-dimensional radiographic and polysomnogram studies before and after distraction.

METHODS

Seventeen infants with micrognathia who underwent internal curvilinear mandibular distraction from April 2005 through April 2008 at Lucile Packard Children's Hospital were included. Preoperative and postoperative computed tomography, polysomnograms, and feeding evaluations were obtained and compared after distraction.

RESULTS

The mean patient age before surgery was 105 days. All patients tolerated the distraction process with a mean mandibular advancement of 18.1 mm. One patient experienced a temporary marginal mandibular nerve palsy that resolved, and 1 postoperative wound infection was encountered. Preoperatively, the mean retroglossal oropharyngeal cross-sectional area was 41.53 mm. This was associated with a mean preoperative apnea-hypopnea index (AHI) of 10.57 and a minimum oxygen desaturation of 83%. After distraction, the mean airway increased to 127.77 mm. All patients had clinical improvement of their respiratory status; the mean postoperative AHI was 2.21, and the minimum oxygen desaturation was 90%. The result was a 209% cross-sectional airway increase. All patients progressed to oral feeds by 3.5 months postoperatively.

CONCLUSIONS

Mandibular distraction is effective at relieving anatomic airway obstruction in infants with micrognathia and obstructive sleep apnea while avoiding some previously reported associated complications.

Evaluation and management of neonatal dysphagia: impact of pharyngoesophageal motility studies and multidisciplinary feeding strategy

BACKGROUND AND OBJECTIVES

Abnormal swallowing (dysphagia) among neonates is commonly evaluated using the videofluoroscopic swallow study (VSS). Radiological findings considered high risk for administration of oral feeding include nasopharyngeal reflux, laryngeal penetration, aspiration, or pooling. Our aims were to determine pharyngoesophageal motility correlates in neonates with dysphagia and the impact of multidisciplinary feeding strategy.

METHODS

Twenty dysphagic neonates (mean gestation +/- standard deviation [SD] = 30.9 +/- 4.9 weeks; median 31.1 weeks; range = 23.7-38.6 weeks) with abnormal VSS results were evaluated at 49.9 +/- 16.5 weeks (median 41.36 weeks) postmenstrual age. The subjects underwent a swallow-integrated pharyngoesophageal motility assessment of basal and adaptive swallowing reflexes using a micromanometry catheter and pneumohydraulic water perfusion system. Based on observations during the motility study, multidisciplinary feeding strategies were applied and included postural adaptation, sensory modification, hunger manipulation, and operant conditioning methods. To discriminate pharyngoesophageal manometry correlates between oral feeders and tube feeders, data were stratified based on the primary feeding method at discharge, oral feeding versus tube feeding.

RESULTS

At discharge, 15 of 20 dysphagic neonates achieved oral feeding success, and the rest required chronic tube feeding. Pharyngoesophageal manometry correlates were significantly different (P < 0.05) between the primary oral feeders versus the chronic tube feeders for swallow frequency, swallow propagation, presence of adaptive peristaltic reflexes, oral feeding challenge test results, and upper esophageal sphincter tone. VSS results or disease characteristics had little effect on the feeding outcomes (P = NS).

CONCLUSIONS

Swallow-integrated esophageal motility studies permit prolonged evaluation of swallowing reflexes and responses to stimuli under controlled conditions at cribside. The dysfunctional neuromotor mechanisms may be responsible for neonatal dysphagia or its consequences. Manometry may be a better predictor than VSS in identifying patients who are likely to succeed in vigorous intervention programs.

Assessment of dysphagia in infants with facial malformations

In infants with facial malformation, dysphagia is frequent and can lead to respiratory and nutritional complications whatever the phenotype. The aim of our study was to assess the severity and mechanisms of dysphagia in infants with facial malformations in order to guide therapeutic management. Forty-two newborn infants with dysphagia and recognizable malformation patterns other than isolated Pierre Robin sequence had: (1) needle electromyography (EMG) of muscles of the face, tongue, and soft palate; (2) two-channel EMG during bottle feeding; and (3) esophageal manometry (EM). The results were compared by clinical dysphagia-grading groups and by age at cessation of enteral feeding. Although micrognathia (86%) and cleft or high-arched palate (76%) were common, the key clinical finding that correlated with the likelihood of respiratory complications was glossoptosis (p<0.01). EMG signs of denervation correlated with respiratory complications (p<0.05) and the duration of enteral feeding (p<0.01). EMG during bottle feeding showed disturbed motor organization at the pharyngeal level in 27 of 37 patients. The severity of pharyngeal incoordination correlated with the duration of enteral feeding (p<0.025). All 21 patients examined by EM had dysfunction at the esophageal level. Thus, in the assessment of upper digestive tract dysfunction, our clinical grading system, EMG, and EM yield convergent information that is relevant to the management of dysphagic infants with facial malformations. Much of the information is obtainable only from EMG.

Gastroesophageal reflux in severe cases of Robin sequence treated with nasopharyngeal intubation

OBJECTIVE

To study the prevalence of abnormal gastroesophageal reflux in infants with Robin sequence who had severe respiratory obstruction treated with nasopharyngeal intubation and to evaluate the efficacy of nonsurgical treatment.

DESIGN

Longitudinal prospective study.

SETTING

Hospital de Reabilitação de Anomalias Craniofaciais, University of São Paulo, Brazil.

PATIENTS

Twenty infants with severe isolated Robin sequence treated with nasopharyngeal intubation.

INTERVENTIONS

We performed 24-hour esophageal pH monitoring on each child at 2, 4, and 6 months of age. Respiratory and feeding status were evaluated. We considered abnormal gastroesophageal reflux as reflux index values above the 95th percentile of the Vandenplas reference for normal children.

RESULTS

The prevalence of reflux index above the 95th percentile at the first exam was 6/20, a value significantly higher than the reference (5/103, p < .01). At the second and third exams, reflux index values were decreased. Ninety percent of the infants showed improvement of respiratory difficulty and developed oral feeding capacity.

CONCLUSIONS

The prevalence of abnormal gastroesophageal reflux is higher in infants with severe cases of Robin sequence than in normal infants. Nonsurgical procedures improved respiratory and feeding difficulties of most of these infants.

Respiratory distress in Pierre Robin: successful use of pharyngeal tube

BACKGROUND/PURPOSE

The study describes a safe and least aggressive method to resolve airway obstruction in children born with a Pierre Robin sequence (PRS).

METHODS

In a retrospective study, we analyzed the assessment of airway obstruction at birth and for the following months. The definition of PRS was based on the anatomical anomaly triad cleft palate, micro/retrognathia, and glossoptosis with some degree of airway obstruction. We defined 3 categories of children depending on their difficulties of breathing or eating at birth.

RESULTS

From 1984 to 2004, 48 children were born in our hospital with a diagnosis of PRS. There were 32 children with nonsyndromic PRS (nsPRS) and 16 with syndromic PRS (sPRS): respectively, 40% (13) and 32% (5) had slight respiratory and/or feeding problems; 26% (8) and 56% (9), isolated feeding difficulties; 34% (11) and 12% (2), severe respiratory and feeding problems. Pharyngeal tube was used in 8 children with nsPRS and in 2 with sPRS. Neonatal surgery was not necessary. Primary palatoplasty was performed at almost the same time as for the patients with isolated cleft palate.

CONCLUSIONS

Children born with PRS have a good prognosis at birth provided that adequate respiratory support is given using either positive airway pressure mask or pharyngeal tube.

Robin sequence: a retrospective review of 115 patients

OBJECTIVES

Review a large series of patients with Robin sequence to document the incidence of (1) associated syndromic diagnoses; (2) co-morbid conditions; (3) frequency and type of operative management for airway compromise and feeding difficulties; and (4) possible differences in treatment between syndromic and nonsyndromic infants.

METHODS

Retrospective case-review of 115 patients with Robin sequence managed between 1962 and 2002 at two tertiary-care teaching hospitals for evaluation of demographic information, clinical findings, and treatment interventions.

RESULTS

Fifty-four percent (N=63) of patients were nonsyndromic. Syndromic patients included: Stickler syndrome (18%), velocardiofacial syndrome (7%), Treacher-Collins (5%), facial and hemifacial microsomia (3%), and other defined (3.5%) and undefined (9%) disorders. There was no statistical difference between the syndromic and nonsyndromic patients with regard to need for operative airway management (Fisher's exact test, p=0.264). Forty-two percent of patients required a feeding gastrostomy tube to correct feeding difficulties. Patients with a syndromic diagnosis were more likely to be developmentally delayed. Fifty-one (44%) patients underwent operative airway management: 61% underwent tongue-lip adhesion and 39% underwent tracheotomy. Fifteen percent of patients initially had tongue-lip adhesion subsequently required tracheotomy. While the preferred treatment for respiratory compromise differed between the two institutions, the percentage of patients requiring operative intervention was similar.

CONCLUSIONS

The pathogenesis of Robin sequence is multifactorial and syndromic in nearly half of the patients. Operative treatment of respiratory failure was required in 44% of infants; the rate was similar in both hospitals. The operative approach differed significantly between the institutions, however, based on the philosophy and training of the managing surgical specialty. Co-morbid factors such as baseline cardiopulmonary and neurologic status did not play a significant role in surgical decision making.

Prognosis of airway obstruction and feeding difficulty in the Robin sequence

OBJECTIVE

To evaluate the course and prognosis of airway obstruction and feeding difficulty in the Pierre Robin sequence (PRS).

METHODS

Retrospective review of 60 patients with PRS between 1993 and 2002 at the University of California, Davis Medical Center. Patients were placed into diagnostic subgroups: (1) Isolated PRS; (2) Syndromic PRS (known syndrome with PRS); (3) Unique PRS (unique anomalies with PRS). Data regarding severity, duration, and management of airway obstruction and feeding difficulty were collected.

RESULTS

Airway obstruction requiring intervention beyond positional therapy was seen in 28% isolated, 42% syndromic, and 58% unique PRS. One-third of patients who failed positional therapy were temporarily stabilized with a nasopharyngeal airway or endotracheal intubation. The remaining two-thirds of patients, who failed positional therapy required a surgical airway procedure. Four patients underwent mandibular distraction osteogenesis, resulting in successful decannulation or avoidance of tracheostomy. Thirteen patients underwent tracheostomy; mean duration of tracheostomy-dependence was 17.0 months in Isolated PRS and 31.7 months in Unique PRS (p < 0.01). Successful decannulation by age of 3 years was confirmed in 85% of patients who underwent tracheostomy. Tube feeding was required in 53% Isolated, 67% Syndromic, and 83% Unique PRS. Forty-two percent of PRS patients with a successful positional airway still demonstrated feeding difficulty. Short-term (0-3 months) and intermediate (4-18 months) tube feeding was more commonly required in Isolated and Syndromic PRS, while long-term (beyond 18 months) gastrostomy tube feeding was more commonly required in Unique PRS (p < 0.01). By 3 years of age, a successful oral diet was seen in 91% Isolated, 92% Syndromic, and 78% Unique PRS.

CONCLUSIONS

Diagnostic subgroups based on the presence of additional anomalies help families and physicians in understanding the severity and duration of feeding and airway difficulty in PRS. Two-thirds of PRS patients who fail positional therapy may ultimately require a surgical airway procedure. Feeding difficulty can be present in the absence of clinically significant airway obstruction. Families and physicians should be encouraged that by 3 years of age, most patients were successfully taking an oral diet without airway obstruction.

A case of severe Pierre Robin sequence with failure to thrive and tachycardia resolved after redo-fundoplication and hiatoplasty

We report an infant suffering from Pierre Robin sequence complicated by gastro-oesophageal reflux and failure to thrive, which were resistant to conservative therapy and a hemifundoplication. Gastro-oesophageal reflux was accompanied by supraventricular tachycardia, treated with propafenone. Tachycardia may be present in Pierre Robin sequence as a consequence of cardiac parasympathetic imbalance. The patient recovered completely from the gastro-oesophageal reflux and tachycardia after redo-fundoplication (Nissen) and a hiatoplasty were performed.

CONCLUSION

This case shows that a thorough search for gastro-oesophageal reflux is indicated in each case of Pierre Robin sequence with failure to thrive.

[Brainstem dysgenesis: Möbius, Cogan and Pierre Robin syndromes revisited]

We propose the term brainstem dysgenesis to designate patients with congenital dysfunction of the cranial nerves and muscle tone due to prenatal lesions or anomalies of the brainstem. In some patients, the dysgenesis is genetically determined and can be isolated or form part of a more extensive polymalformation syndrome (mutations of organizing or regulatory genes). In most patients with brainstem dysgenesis, however, the disorder is caused by prenatal destructive or disruptive lesions of vascular origin. Depending on the vessels involved and the magnitude of the lesion, clinical manifestations can range from intrauterine death to mild involvement of several cranial nerves. Clinical findings in some of these patients may coincide with those described in Möbius, Pierre Robin or Cogan syndromes and, if that is the case, the eponym will indicate the location of the brainstem lesion. Clinical manifestations in most patients with brainstem dysgenesis, however, do not fit into any of the aforementioned syndromes. In these circumstances the term brainstem dysgenesis should be used followed by a detailed description of each patient's clinical findings and/or the brainstem segment presumably involved. The prognosis of patients with brainstem dysgenesis due to prenatal destructive lesions depends on the magnitude of the vascular territory involved and, in most cases, is better than the initial clinical manifestations would indicate.

Laryngeal anatomic differences in pediatric patients with severe laryngomalacia

OBJECTIVES

To compare the aryepiglottic (AE) length in pediatric patients who have severe laryngomalacia (SL) and are undergoing aryepiglottoplasty with the AE length of a convenience sample of control patients without laryngomalacia.

DESIGN

Prospective case-control study.

SETTING

A tertiary-care pediatric hospital.

RESULTS

The mean AE fold length-glottic length ratio for patients with SL (0.380) was significantly lower than the mean ratio for controls (0.535) (P = .004 in 2-sample t test with unequal variance). For patients with SL, the aryepiglottoplasy procedure resulted in an average AE length increase-glottic length ratio of 0.330. Seven of the patients with SL were also diagnosed as having an underlying neurologic condition, and 18 had a diagnosis of gastroesophageal reflux disease. Two patients with SL required a tracheotomy for treatment of persistent airway obstruction.

CONCLUSIONS

In this series, patients with SL had lower AE fold length-glottic length ratios and more frequent occurrence of neuromuscular tone abnormalities (especially gastroesophageal reflux) than controls. These 2 findings may be related in that low intrauterine tone might contribute to anatomic underdevelopment.

Acoustic study of swallowing behaviour in premature infants during tube-bottle feeding and bottle feeding period

The premature infant has limited ability to integrate the swallowing-breathing cycle during feeding. The aim of this study was to assess the pattern of swallowing between the period of tube-bottle (TBF) and bottle (BF) feeding by means of cervical auscultation in premature infants. Twenty-three premature infants were enrolled (mean gestational age 34.7 +/- 1.7 weeks). Audiosignal recordings were made during TBF and BF with a small microphone set in front of the cricoid cartilage. The following parameters were calculated for 2 min and reported at 1 min: the percentage of time involved in swallowing (ST), the numbers of swallows (SN) and swallowing bursts (SB) and swallowing groups (SG). Individual histograms were established to show the individual pattern of swallowing behaviour and the distribution of groups, bursts and swallows over 2 min. Mean (STm), (SNm), (SBm), (SGm) values were calculated (+/- S.D.). Statistical analysis was used to compare the means and to establish correlations between parameters and curves. (STm), (SNm) and (SBm) increased significantly during BF compared with TBF for all premature infants and during follow-up. The histograms showed that in BF the groups were high in bursts. These findings and the histograms for each infant will allow determination of transition to bottle feeding without risk corresponding to the stage of maturation of swallowing function.

The neural crest: Basic biology and clinical relationships in the craniofacial and enteric nervous systems

The highly migratory, mesenchymal neural crest cell population was discovered over 100 years ago. Proposals of these cells' origin within the neuroepithelium, and of the tissues they gave rise to, initiated decades-long heated debates, since these proposals challenged the powerful germ-layer theory. Having survived this storm, the neural crest is now regarded as a pluripotent stem cell population that makes vital contributions to an astounding array of both neural and non-neural organ systems. The earliest model systems for studying the neural crest were amphibian, and these pioneering contributions have been ably refined and extended by studies in the chick, mouse, and more recently the fish to provide detailed understanding of the cellular and molecular mechanisms regulating and regulated by the neural crest. The key questions regarding control of craniofacial morphogenesis and innervation of the gut illustrate the wide range of developmental contexts in which the neural crest plays an important role. These questions also focus attention on common issues such as the role of growth factor signaling in neural crest cell development and highlight the central role of the neural crest in human congenital disease.

Watershed infarcts in the fetal and neonatal brainstem. An aetiology of central hypoventilation, dysphagia, Möibius syndrome and micrognathia

Watershed zone infarcts of the human cerebral cortex at the overlapping junctions of the anterior and middle cerebral arterial territories are well known. Another watershed zone exists in the brainstem tegmentum, between the terminal perfusion zones of the paramedian penetrating and long circumferential arteries, which are paired segmental vessels arising from the basilar artery. The vertebrobasilar circulation achieves its mature configuration and caudorostral flow by 9 weeks gestation. Systemic hypotension and other conditions of reduced basilar perfusion in the fetus, either early or late in gestation, may result in symmetrical longitudinal columns of infarction in the midbrain and tegmentum of the pons and medulla oblongata and laminar necrosis of the midbrain tectum. Within this zone are cranial nerve nuclei III-XII, the nucleus and tractus solitarius or central pneumotaxic center, as well as the nucleus ambiguus and other somatic motor nuclei that subserve muscles of swallowing, mastication and tongue movement. Watershed infarcts in the human fetal and neonatal brainstem are clinically expressed as multiple cranial neuropathies, failure of central respiratory drive and apnea, dysphagia and aspiration, Möbius syndrome and Pierre Robin sequence. MRI is sometimes helpful, but most of the involved neuroanatomical structures are beneath the resolution of present imaging techniques, and the diagnosis during life depends upon clinical neurological examination of the neonate, sometimes supported by evoked potential studies. Postmortem examination confirms the diagnosis and dates the lesions, but also contributes to better understand transient or persistent vascular insufficiencies in the fetal and neonatal brainstem.