Hard to swallow: Developmental biological insights into pediatric dysphagia

Evaluation of the Efficacy of Focal Vibration Therapy-Novafon as an Assistive Therapeutic Tool for Children With Feeding and Swallowing Disorders

BACKGROUND

Paediatric dysphagia refers to any feeding and/or swallowing problem that affects nutritional or liquid intake safety or adequacy. There is a prominent lack of available evidence-based effective therapeutic tools to facilitate the rehabilitation of feeding and/or swallowing disorders in children.

OBJECTIVE

The purpose of this study was to assess the effectiveness of focal vibration therapy-Novafon as an assistive therapeutic intervention for children with feeding and swallowing difficulties.

METHODS

The study involved 122 children with dysphagia who were divided into two groups: (1) 61 children who received conventional dysphagia therapy (cCDTh) and (2) 61 children who received conventional dysphagia therapy in combination with Novafon therapy (cCDTh+NTh). All children were evaluated for pre-, mid- and post-dysphagia therapy with the Gugging Swallowing Screen (GUSS) and Pediatric Eating Assessment Tool-10 (PEDI-EAT-10) in different Cypriot school and health settings.

RESULTS

PEDI-EAT-10 total scores for both groups observed that the cCDTh+NTh group had a significant decrease in the overall median between pre- and post-dysphagia therapy total score (Median = 3.00) compared to the cTDTh score (Median = 7.00). GUSS total scores between the two groups showed an increase in overall medians but the cCDTh+NTh group (Median of pre-therapy = 16.50, mid-therapy = 19.00 and post-therapy = 20.00) noted a higher increase in medians compared to the cCDTh group (Median of pre-therapy = 15.00, mid-therapy = 16.00 and post-therapy = 17.00).

CONCLUSION

The present study highlights that focal vibration therapy using Novafon may serve as an effective and supportive approach within conventional dysphagia therapy for children. Further research is necessary to enhance the evidence-based literature on the use of Novafon in paediatric dysphagia.

Pediatric Dysphagia Risk Screening Instrument (PDRSI) in Children With Cerebral Palsy

This study aimed to evaluate whether the Pediatric Dysphagia Risk Screening Instrument (PDRSI) was a suitable test for children with cerebral palsy (CP) and assess the instrument's Turkish validity and reliability. One-hundred twenty-six children with CP participated in this study. "Cronbach's alpha (ɑ)," "Cronbach's ɑ when one item is deleted," "inter-item correlation," and "corrected item-to-total correlation" were used to assess internal consistency. In addition, inter-rater agreement tests (Cohen's kappa coefficient) were conducted for reliability. Construct validity was used to assess the validity. Moreover, flexible fiberoptic endoscopic evaluation of the swallowing method was used to describe the receiver operating characteristic curve analysis and calculate the sensitivity and specificity of T-PDRSI. It was found that the PDRSI had adequate validity and reliability. The PDRSI can be used in children with CP as a valid and reliable instrument with high sensitivity and specificity.

Motion reconstruction and finite element analysis of the temporomandibular joint during swallowing in healthy adults

There is a close physiological connection between swallowing and the temporomandibular joint (TMJ). However, a shortage of quantitative research on the biomechanical behavior of the TMJ during swallowing exists. The purpose of this study was to reconstruct the movement of the temporomandibular joint (TMJ) based on in vivo experiment and analyze the biomechanical responses during swallowing in healthy adults to investigate the role of the TMJ in swallowing. Motion capture of swallowing, computed tomography (CT), and magnet resonance images (MRI) were performed on six healthy subjects. The movements of the TMJ during swallowing were reconstructed from the motion capture data. The three-dimensional finite element model was constructed. The dynamic finite element analysis of the swallowing process was performed based on the motion data. The range of condylar displacement was within 1 mm in all subjects. The left and right condyle movements were asymmetrical in two-thirds of the subjects. The peak stresses of the discs were relatively low, with a maximum of 0.11 MPa. During swallowing, the condylar displacement showed two trends: slow retraction and slow extension. The tendency to extend could lead to a gradual increase in stress on the disc.

Development of eating skills in infants and toddlers from a neuropediatric perspective

Early infant feeding and swallowing are complex motor processes involving numerous muscles in coordination, e.g. the orofacial muscles as well as the muscles of the pharynx, larynx and esophagus. The newborn's reflexive drinking develops into the ability to ingest pureed complementary food as infancy progresses. Finally, in the last part of the first year of life, a differentiated eating, chewing and swallowing process develops allowing the voluntary intake of different foods of the family diet. The dietary schedule for the first year of life, which describes the recommended nutrition of infants in Germany, corresponds to these milestones in eating development. Disturbances in gross motor development, sensory processing issues, and organic and behavioral problems are known to interfere with the development of eating skills. Swallowing disorders (dysphagia) in children can have a detrimental effect on food intake and pose a serious risk to growth and development. Their prevention treatment requires a multidisciplinary approach with the aim of enabling the child to eat independently in the long term.

Development and validation of the caregiver Burden from infant home NGT care instrument

OBJECTIVE

To design and validate an age and condition-specific health status instrument to best reflect the parental experience caring for these children with complex needs and home Nasogastric Tube (NGT) placement.

STUDY DESIGN

Combined Qualitative and Quantitative design, testing and implementation for item production and reduction, followed by formal validation by evaluating validity, reliability, and establishing a clinically meaningful change score.

SETTINGS

Tertiary care, multi-disciplinary aerodigestive center.

PARTICIPANTS

All caregivers whose infant met criteria for eligibility for discharge home from the NICU or Special Care Nursery (SCN) with NGT in place were offered inclusion in this group. Intervention/Exposure: Structured qualitative interviews of these caregivers to explore and define these concepts and domains, to item generate and then reduce, and then psychometric analyses.

METHODS

Structured, moderated qualitative interviews with parents/caregivers of children who have undergone home NGT care of their children for item creation, design, and then reduction. Reliability was assessed by Cronbach alpha analysis. Construct validity and clinically meaningful change score was assessed using various query methods.

MAIN OUTCOME MEASURES

Cronbach's alpha to assess reliability, a priori hypotheses validity analyses, and minimally important clinical difference calculation.

RESULTS

Scaled scores of this condition specific instrument ranged from 14 to 74 where higher scores indicate better QOL related to managing the NGT. Cronbach's alpha with all 14 items was 0.93. Validity was assessed by a self-assessment question to discriminate between change (95% CI: 8.5-14.1; p < 0.0001) as well as by other comparators to identify the instrument's ability to discriminate among populations where parents felt a difference in experience. The minimally important difference was calculated at 18 points.

CONCLUSION

This represents the initial validation of the first condition and age-specific health status instrument to assess parent experience of caring for infants requiring a home NGT for dysphagia.

Localization of TRPV3/4 and PIEZO1/2 sensory receptors in murine and human larynges

Objective

The primary aim of this study was to identify expression of TRPV3 and TRPV4 chemoreceptors across perinatal and adult stages using a murine model with direct comparisons to human laryngeal mucosa. Our secondary aim was to establish novel cell expression patterns of mechanoreceptors PIEZO1 and PIEZO2 in human tissue samples.

Study design

In vivo.

Methods

We harvested murine laryngeal tissue to localize and describe TRPV3/4 endogenous protein expression patterns via immunofluorescence analyses across two developmental (E16.5, P0) and adult (6 weeks) timepoints. Additionally, we obtained a 60-year-old female larynx including the proximal trachea and esophagus to investigate TRPV3/4 and PIEZO1/2 protein expression patterns via immunofluorescence analyses for comparison to murine adult tissue.

Results

Murine TRPV3/4 expression was noted at E16.5 with epithelial cell colocalization to supraglottic regions of the arytenoids, aryepiglottic folds and epiglottis through to birth (P0), extending to the adult timepoint. Human TRPV3/4 protein expression was most evident to epithelium of the arytenoid region, with additional expression of TRPV3 and TRPV4 to proximal esophageal and tracheal epithelium, respectively. Human PIEZO1 expression was selective to differentiated, stratified squamous epithelia of the true vocal fold and esophagus, while PIEZO2 expression exhibited selectivity for intermediate and respiratory epithelia of the false vocal fold, ventricles, subglottis, arytenoid, and trachea.

Conclusion

Results exhibited expression of TRPV3/4 chemoreceptors in utero, suggesting their importance during fetal/neonatal stages. TRPV3/4 and PIEZO1/2 were noted to adult murine and human laryngeal epithelium. Data indicates conservation of chemosensory receptors across species given similar regional expression in both the murine and human larynx.

Pediatric dysphagia overview: best practice recommendation study by multidisciplinary experts

BACKGROUND

Currently, there is no comprehensive and multidisciplinary recommendation study covering all aspects of pediatric dysphagia (PD). This study aimed to generate PD management recommendations with methods that can be used in clinical practice to fill this gap in our country and in the world, from the perspective of experienced multidisciplinary experts.

METHODS

This recommendation paper was generated by a multidisciplinary team, using the seven-step process and a three-round modified Delphi survey via e-mail. First, ten open-ended questions were created, and then detailed recommendations including management, diagnosis, treatment, and follow-up were created with the answers from these questions. Each recommendation item was voted on by the experts as overall consensus (strong recommendation), approaching consensus (weak recommendation) and divergent consensus (not recommended).

RESULTS

In the 1st Delphi round, a questionnaire of 414 items was prepared based on the experts' responses to ten open-ended questions. In the 2nd Delphi round, 59.2% of these items were accepted as pre-recommendation. In the 3rd Delphi round, 62.6% of 246 items were accepted for inclusion in the proposals. The final version recommendations consisted of 154 items.

CONCLUSIONS

This study includes comprehensive and detailed answers for every problem that could be posed in clinical practice for the management of PD, and recommendations are for all pediatric patients with both oropharyngeal and esophageal dysphagia.

Endoluminal Functional Lumen Imaging Probe Is Safe in Children Under Five Years Old

BACKGROUND

Endoluminal functional lumen imaging probe (EndoFLIP) is a minimally invasive, novel device that uses high-resolution impedance planimetry to measure important parameters of the gastrointestinal lumen that aid in the diagnosis of esophageal disorders. EndoFLiP is approved by the US Food and Drug Administration (FDA) for children 5 years and older. We sought to compare its safety and luminal characteristics between children under 5 years of age with children 5 years and older.

METHODS

A single-center retrospective review was performed to identify all patients < 21 years of age who underwent esophagogastroduodenoscopy (EGD) with EndoFLIP between October 2017 and November 2020. Results: Sixty-seven EGDs with EndoFLIP were performed in 56 patients, including 14 that were done in children < 5 years and 53 in children ≥5years. The median age in the < 5-year group was 1.7years (interquartile range [IQR], 0.9-4.4) and the youngest patient was 1 month old. The median age in ≥5-year group was 14.3 years (IQR, 8.2-16.2). Median procedure times were similar (32 minutes [IQR, 25-48] for the < 5-year group; 28 minutes [IQR, 20-33] for ≥5-year group; P  = 0.08). There were no adverse events or unplanned hospitalizations in either group. At 30 mL inflation, the pressure of the lower esophageal sphincter (LES) was statistically different between the 2 groups (P = 0.02).

CONCLUSION

EndoFLIP appears to be safe for use in our small cohort of children < 5 years of age and may be an important tool in the management of esophageal disorders in this age group. There was no difference in procedure time between our 2 age groups and there were no procedure-related complications.

Selective disruption of trigeminal sensory neurogenesis and differentiation in a mouse model of 22q11.2 deletion syndrome

22q11.2 Deletion Syndrome (22q11DS) is a neurodevelopmental disorder associated with cranial nerve anomalies and disordered oropharyngeal function, including pediatric dysphagia. Using the LgDel 22q11DS mouse model, we investigated whether sensory neuron differentiation in the trigeminal ganglion (CNgV), which is essential for normal orofacial function, is disrupted. We did not detect changes in cranial placode cell translocation or neural crest migration at early stages of LgDel CNgV development. However, as the ganglion coalesces, proportions of placode-derived LgDel CNgV cells increase relative to neural crest cells. In addition, local aggregation of placode-derived cells increases and aggregation of neural crest-derived cells decreases in LgDel CNgV. This change in cell-cell relationships was accompanied by altered proliferation of placode-derived cells at embryonic day (E)9.5, and premature neurogenesis from neural crest-derived precursors, reflected by an increased frequency of asymmetric neurogenic divisions for neural crest-derived precursors by E10.5. These early differences in LgDel CNgV genesis prefigure changes in sensory neuron differentiation and gene expression by postnatal day 8, when early signs of cranial nerve dysfunction associated with pediatric dysphagia are observed in LgDel mice. Apparently, 22q11 deletion destabilizes CNgV sensory neuron genesis and differentiation by increasing variability in cell-cell interaction, proliferation and sensory neuron differentiation. This early developmental divergence and its consequences may contribute to oropharyngeal dysfunction, including suckling, feeding and swallowing disruptions at birth, and additional orofacial sensory/motor deficits throughout life.

Acute Paediatric Tracheal Deviation and Neck Lump Secondary to Food Bolus Impaction

Acute presentations of paediatric tracheal deviation secondary to neck masses are rare. The differentials are broad and the child may be compromised. Stabilising and resuscitating the child are the primary aims.

This case describes a six-year-old boy with a history of neurodevelopmental delay and progressive dysphagia, presenting with an acute history of soft food bolus impaction, significant tracheal deviation and a firm neck lump. We discuss the diagnostic difficulties of the presentation, the work-up and the management of this rare case in the setting of a university hospital in the United Kingdom, with no paediatric intensive care on site.

Evaluating dysphagia in infants with congenital heart disease using Fiberoptic Endoscopic Evaluation of Swallowing

OBJECTIVE

Dysphagia is common in infants with congenital heart disease (CHD). However, there is minimal published data regarding its management outside of the perioperative period. The objective of this study is to describe the role of Fiberoptic Endoscopic Evaluation of Swallowing (FEES) in the diagnosis and management of dysphagia in infants with CHD.

METHODS

Infants with CHD who underwent FEES exam for evaluation of swallowing dysfunction between February 2015 and February 2021 at a university-based, tertiary care urban pediatric hospital were studied. Demographic data, presenting symptoms, medical history, and dysphagia history were examined. The validated Dysphagia Outcome and Severity Scale (DOSS) was used to standardize and compare dysphagia severity.

RESULTS

62 FEES exams were performed on 48 patients. All 48 patients were diagnosed with dysphagia and had a mean dysphagia severity score (DOSS) of 2.68. Patients with wet laryngeal congestion on presentation had worse mean DOSS score and were more likely to demonstrate aspiration on FEES exam (p < 0.01). There was no significant difference in mean DOSS or presence of aspiration when comparing infants who had cardiothoracic surgery, vocal cord paralysis, or lower respiratory tract illness with those who had not (p > 0.05).

CONCLUSION

A FEES exam is an effective and well-tolerated procedure for evaluating swallowing dysfunction in pediatric patients with CHD and its use reduces radiation exposure for this vulnerable population. Wet laryngeal congestion was found to be predictive of more severe dysphagia and aspiration. There is no significant association between severity of dysphagia or aspiration on FEES exam and history of cardiac surgery, vocal cord paralysis, or lower respiratory tract illness.

Advances in Swallowing Neurophysiology across Pediatric Development: Current Evidence and Insights

Purpose of Review

This review article analyzes current evidence on the neurophysiology of swallowing during development and offers expert opinion on clinical implications and future research directions.

Recent Findings

In the past five years, basic and clinical research has offered advances in our understanding of pediatric swallowing neurophysiology. Animal models have elucidated the role of brainstem circuits and the peripheral and central nervous system in neonatal swallowing. Recent human studies have further showcased that fetal and infant swallowing require cerebral inputs in order to develop functionally. Finally, neurophysiological and neuroimaging studies are starting to better define these cerebral inputs, as well as neuroplastic adaptations that may be needed for optimal feeding development.

Summary

The neural development of swallowing is a complex and dynamic process. Continued research is needed to better understand influences on swallowing neural development, which can be essential for improving prevention, diagnosis, and interventions for pediatric dysphagia.

Aberrant early growth of individual trigeminal sensory and motor axons in a series of mouse genetic models of 22q11.2 deletion syndrome

We identified divergent modes of initial axon growth that prefigure disrupted differentiation of the trigeminal nerve (CN V), a cranial nerve essential for suckling, feeding and swallowing (S/F/S), a key innate behavior compromised in multiple genetic developmental disorders including DiGeorge/22q11.2 Deletion Syndrome (22q11.2 DS). We combined rapid in vivo labeling of single CN V axons in LgDel^+/− mouse embryos, a genomically accurate 22q11.2DS model, and 3D imaging to identify and quantify phenotypes that could not be resolved using existing methods. We assessed these phenotypes in three 22q11.2-related genotypes to determine whether individual CN V motor and sensory axons wander, branch and sprout aberrantly in register with altered anterior–posterior hindbrain patterning and gross morphological disruption of CN V seen in LgDel^+/−. In the additional 22q11.2-related genotypes: Tbx1^+/−, Ranbp1^−/−, Ranbp1^+/− and LgDel^+/−:Raldh2^+/−; axon phenotypes are seen when hindbrain patterning and CN V gross morphology is altered, but not when it is normal or restored toward WT. This disordered growth of CN V sensory and motor axons, whose appropriate targeting is critical for optimal S/F/S, may be an early, critical determinant of imprecise innervation leading to inefficient oropharyngeal function associated with 22q11.2 deletion from birth onward.

Mother-to-Child Transmission of Arboviruses during Breastfeeding: From Epidemiology to Cellular Mechanisms

Most viruses use several entry sites and modes of transmission to infect their host (parenteral, sexual, respiratory, oro-fecal, transplacental, transcutaneous, etc.). Some of them are known to be essentially transmitted via arthropod bites (mosquitoes, ticks, phlebotomes, sandflies, etc.), and are thus named arthropod-borne viruses, or arboviruses. During the last decades, several arboviruses have emerged or re-emerged in different countries in the form of notable outbreaks, resulting in a growing interest from scientific and medical communities as well as an increase in epidemiological studies. These studies have highlighted the existence of other modes of transmission. Among them, mother-to-child transmission (MTCT) during breastfeeding was highlighted for the vaccine strain of yellow fever virus (YFV) and Zika virus (ZIKV), and suggested for other arboviruses such as Chikungunya virus (CHIKV), dengue virus (DENV), and West Nile virus (WNV). In this review, we summarize all epidemiological and clinical clues that suggest the existence of breastfeeding as a neglected route for MTCT of arboviruses and we decipher some of the mechanisms that chronologically occur during MTCT via breastfeeding by focusing on ZIKV transmission process.

Transcriptional dysregulation in developing trigeminal sensory neurons in the LgDel mouse model of DiGeorge 22q11.2 deletion syndrome

LgDel mice, which model the heterozygous deletion of genes at human chromosome 22q11.2 associated with DiGeorge/22q11.2 deletion syndrome (22q11DS), have cranial nerve and craniofacial dysfunction as well as disrupted suckling, feeding and swallowing, similar to key 22q11DS phenotypes. Divergent trigeminal nerve (CN V) differentiation and altered trigeminal ganglion (CNgV) cellular composition prefigure these disruptions in LgDel embryos. We therefore asked whether a distinct transcriptional state in a specific population of early differentiating LgDel cranial sensory neurons, those in CNgV, a major source of innervation for appropriate oropharyngeal function, underlies this departure from typical development. LgDel versus wild-type (WT) CNgV transcriptomes differ significantly at E10.5 just after the ganglion has coalesced. Some changes parallel altered proportions of cranial placode versus cranial neural crest-derived CNgV cells. Others are consistent with a shift in anterior-posterior patterning associated with divergent LgDel cranial nerve differentiation. The most robust quantitative distinction, however, is statistically verifiable increased variability of expression levels for most of the over 17 000 genes expressed in common in LgDel versus WT CNgV. Thus, quantitative expression changes of functionally relevant genes and increased stochastic variation across the entire CNgV transcriptome at the onset of CN V differentiation prefigure subsequent disruption of cranial nerve differentiation and oropharyngeal function in LgDel mice.

Abnormal Nutritive Sucking as an Indicator of Neonatal Brain Injury

A term neonate is born with the ability to suck; this neuronal network is already formed and functional by 28 weeks gestational age and continues to evolve into adulthood. Because of the necessity of acquiring nutrition, the complexity of the neuronal network needed to suck, and neuroplasticity in infancy, the skill of sucking has the unique ability to give insight into areas of the brain that may be damaged either during or before birth. Interpretation of the behaviors during sucking shows promise in guiding therapies and how to potentially repair the damage early in life, when neuroplasticity is high. Sucking requires coordinated suck-swallow-breathe actions and is classified into two basic types, nutritive and non-nutritive. Each type of suck has particular characteristics that can be measured and used to learn about the infant's neuronal circuitry. Basic sucking and swallowing are present in embryos and further develop to incorporate breathing ex utero. Due to the rhythmic nature of the suck-swallow-breathe process, these motor functions are controlled by central pattern generators. The coordination of swallowing, breathing, and sucking is an enormously complex sensorimotor process. Because of this complexity, brain injury before birth can have an effect on these sucking patterns. Clinical assessments allow evaluators to score the oral-motor pattern, however, they remain ultimately subjective. Thus, clinicians are in need of objective measures to identify the specific area of deficit in the sucking pattern of each infant to tailor therapies to their specific needs. Therapeutic approaches involve pacifiers, cheek/chin support, tactile, oral kinesthetic, auditory, vestibular, and/or visual sensorimotor inputs. These therapies are performed to train the infant to suck appropriately using these subjective assessments along with the experience of the therapist (usually a speech therapist), but newer, more objective measures are coming along. Recent studies have correlated pathological sucking patterns with neuroimaging data to get a map of the affected brain regions to better inform therapies. The purpose of this review is to provide a broad scope synopsis of the research field of infant nutritive and non-nutritive feeding, their underlying neurophysiology, and relationship of abnormal activity with brain injury in preterm and term infants.

Pathophysiology of aspiration in a unilateral SLN lesion model using quantitative analysis of VFSS

OBJECTIVE

The purpose of this study was to elucidate the pathophysiology of aspiration in previously studied female infant piglets after a unilateral superior laryngeal nerve (uSLN) lesion.

METHODS

Videofluoroscopic swallow studies (VFSS) were acquired from 15 female piglets ages 2-3 weeks (9 with uSLN lesion and 6 controls). VFSS were analyzed at 30 frames/second sampling rate. Quantitative measures were conducted and compared between groups using published methodologies for VFSS assessment in adult and infant humans. Measures included the: 1) number of lingual-palatal contacts (LPC) (i.e. pre-swallow), 2) total pharyngeal transit time (TPT), 3) offset of swallow (offP), as well as onset of: 4) pharyngeal stage (onP), 5) pharyngoesophageal segment opening (oPES), 6) maximum PES opening (maxPES), 7) airway closure onset (oAC), and 8) maximum airway closure (maxAC). Measures 5-7 were determined relative to onP. Bolus residue was rated by severity (0 (none) to 3 (severe)). A gamma regression was used to compare continuous measures between lesioned and control groups.

RESULTS

The number of LPC (p = .006), TPT (p = .023) and timing of maxAC (p = .041) were significantly greater in the uSLN lesion than the control group.

CONCLUSIONS

Outcomes of this study replicated prior published findings and elucidated that piglets with right uSLN lesions exhibited delayed maxAC. Noteworthy was the use of clinically relevant quantitative videofluoroscopic measures in piglets for comparison to future studies in human pediatric populations.

Why Does the Face Predict the Brain? Neural Crest Induction, Craniofacial Morphogenesis, and Neural Circuit Development

Mesenchephalic and rhombencephalic neural crest cells generate the craniofacial skeleton, special sensory organs, and subsets of cranial sensory receptor neurons. They do so while preserving the anterior-posterior (A-P) identity of their neural tube origins. This organizational principle is paralleled by central nervous system circuits that receive and process information from facial structures whose A-P identity is in register with that in the brain. Prior to morphogenesis of the face and its circuits, however, neural crest cells act as "inductive ambassadors" from distinct regions of the neural tube to induce differentiation of target craniofacial domains and establish an initial interface between the brain and face. At every site of bilateral, non-axial secondary induction, neural crest constitutes all or some of the mesenchymal compartment for non-axial mesenchymal/epithelial (M/E) interactions. Thus, for epithelial domains in the craniofacial primordia, aortic arches, limbs, the spinal cord, and the forebrain (Fb), neural crest-derived mesenchymal cells establish local sources of inductive signaling molecules that drive morphogenesis and cellular differentiation. This common mechanism for building brains, faces, limbs, and hearts, A-P axis specified, neural crest-mediated M/E induction, coordinates differentiation of distal structures, peripheral neurons that provide their sensory or autonomic innervation in some cases, and central neural circuits that regulate their behavioral functions. The essential role of this neural crest-mediated mechanism identifies it as a prime target for pathogenesis in a broad range of neurodevelopmental disorders. Thus, the face and the brain "predict" one another, and this mutual developmental relationship provides a key target for disruption by developmental pathology.

Prenatal Ultrasound Measurement of Fetal Stomach Size Is Predictive of Postnatal Development of GERD in Isolated Cleft Lip and/or Palate

OBJECTIVE

To determine whether prenatal ultrasound measurement of fetal stomach size, as a surrogate marker of fetal swallowing, is predictive of postnatal development of gastroesophageal reflux disease (GERD) in cases of isolated cleft lip and/or palate (CL/P).

DESIGN

This is a retrospective case-control study. The outcome of interest is postnatal diagnosis of GERD in isolated CL/P. The exposure of interest is prenatal stomach size measurement by ultrasound.

SETTING

The study population was selected from an academic, tertiary care center between 2003 and 2011.

PATIENTS/PARTICIPANTS

Cases were neonates undergoing CL/P repair during the study period. Cases with other known structural or chromosomal abnormalities were excluded. Controls were contemporary, nondiabetic neonates that matched gestational age (within one week) to cases. Each case measurement was matched ∼1:2 with control measurement.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

The primary outcome was difference in mean prenatal ultrasound measurement of fetal stomach size between cases and controls. We hypothesized that patients with postnatal development of GERD would have smaller mean fetal stomach size.

RESULTS

There were 32 cases including 19 patients with unilateral cleft lip and palate, 8 with unilateral cleft lip, and 4 with bilateral cleft lip and palate. Cases were noted to have smaller mean anterior-posterior and transverse fetal stomach measurements as compared to controls. This was statistically significant from 16 to 21 weeks, 25 to 27 weeks, and 28 to 36 weeks (P < .01 for all).

CONCLUSIONS

Prenatal ultrasound measurement of fetal stomach size as a surrogate marker of fetal swallowing is predictive of postnatal development of GERD in isolated CL/P.

Disrupted Coordination of Hypoglossal Motor Control in a Mouse Model of Pediatric Dysphagia in DiGeorge/22q11.2 Deletion Syndrome

We asked whether the physiological and morphologic properties of hypoglossal motor neurons (CNXII MNs) that innervate protruder or retractor tongue muscles are disrupted in neonatal LgDel mice that carry a heterozygous deletion parallel to that associated with DiGeorge/22q11.2 deletion syndrome (22q11.2DS). Disrupted coordination of tongue movement in LgDel mouse pups may contribute to suckling, feeding, and swallowing (S/F/S) disruptions that parallel pediatric dysphagia in infants and toddlers with 22q11.2DS. Using an in vitro rhythmically active medullary slice preparation, we found spontaneous firing as well as IPSC frequency differed significantly in neonatal LgDel versus wild-type (WT) protruder and retractor CNXII MNs that were identified by retrograde tracing from their target muscles. In response to respiration-related activity, initiation and decay of transiently increased firing in WT protruder MNs is delayed in LgDel, accompanied by altered excitatory/inhibitory (E/I) balance. In addition, LgDel retractor MNs have a transient increase in firing with diminished IPSC frequency that is not seen in WT. There were no significant differences in cell body volume of either XII class in WT and LgDel Sholl analysis showed the total numbers of dendritic intersections (at 50- and 90-μm radii from the cell soma) were significantly greater for LgDel versus WT retractor MNs. Thus, the physiological, synaptic and cellular properties of distinct classes of CNXII MNs that coordinate tongue movement in neonatal WT mice are altered in LgDel Such changes could contribute to sub-optimal coordination of S/F/S that underlies pediatric dysphagia in 22q11.2DS.

Variations in maternal vitamin A intake modifies phenotypes in a mouse model of 22q11.2 deletion syndrome

BACKGROUND

Vitamin A regulates patterning of the pharyngeal arches, cranial nerves, and hindbrain that are essential for feeding and swallowing. In the LgDel mouse model of 22q11.2 deletion syndrome (22q11DS), morphogenesis of multiple structures involved in feeding and swallowing are dysmorphic. We asked whether changes in maternal dietary Vitamin A intake can modify cranial nerve, hindbrain and pharyngeal arch artery development in the embryo as well as lung pathology that can be a sign of aspiration dysphagia in LgDel pups.

METHODS

Three defined amounts of vitamin A (4, 10, and 16 IU/g) were provided in the maternal diet. Cranial nerve, hindbrain and pharyngeal arch artery development was evaluated in embryos and inflammation in the lungs of pups to determine the impact of altering maternal diet on these phenotypes.

RESULTS

Reduced maternal vitamin A intake improved whereas increased intake exacerbated lung inflammation in LgDel pups. These changes were accompanied by increased incidence and/or severity of pharyngeal arch artery and cranial nerve V (CN V) abnormalities in LgDel embryos as well as altered expression of Cyp26b1 in the hindbrain.

CONCLUSIONS

Our studies demonstrate that variations in maternal vitamin A intake can influence the incidence and severity of phenotypes in a mouse model 22q11.2 deletion syndrome.

Paediatric dysphagia within the context of South Africa's quadruple burden of disease, seen at a tertiary level hospital

Purpose: To inform service provision, this study explored feeding and swallowing difficulties in children within the context of South Africa's quadruple burden of disease (BOD) (i.e. conditions characterised as communicable, non-communicable, maternal and/or perinatal and trauma).Method: A retrospective chart review of 1432 paediatric inpatients (under 12 years of age) who met the inclusion criteria of presenting with dysphagia and being referred for speech-language pathology services was conducted.Result: Participants with diagnoses within the maternal and/or perinatal BOD category were noted most frequently (61.2%), followed by non-communicable (59.7%), communicable (43.4%) and trauma (4.2%). The majority of participants were under 1 year of age (82.2%) and 56.2% presented with comorbidities in multiple BOD categories. Mortality was 5.9%, with a higher rate (67.7%) in more complex cases. Mortality was associated with non-communicable BOD (p = 0.001), and maternal and/or perinatal BOD (p = 0.003). Pharyngeal phase swallowing difficulties were a significant risk for mortality (OR = 2.96; 95% CI: 1.01-8.65, p = 0.047).Conclusion: The majority of children with dysphagia presented with multiple comorbidities and were at high risk for mortality. Education and service delivery models should be designed to improve health outcomes and reduce mortality rates.

A Multidisciplinary Approach to Pediatric Feeding Disorders: Roles of the Speech-Language Pathologist and Behavioral Psychologist

Purpose Pediatric feeding disorders (PFDs) present as a complex clinical challenge because of the heterogeneous underlying etiologies and their impact on health, safety, growth, and psychosocial development. A multidisciplinary team approach is essential for accurate diagnosis and prompt interventions to lessen the burdens associated with PFDs. The role of the speech-language pathologist (SLP) as a member of the multidisciplinary team will be highlighted. Method This clinical focus article reviews the definition of PFDs and pertinent literature on factors that contribute to the development of PFDs, the accurate diagnosis, and current interventions for infants and children. As part of the multidisciplinary team, the SLP has an integral role in determining whether a child cannot or will not eat and working with the team to identify and carryout appropriate interventions. Collaboration between SLPs and psychologists/behavioral specialists in conjunction with the parents/caregivers as part of the multidisciplinary team is essential to the advancement of therapeutic goals. Conclusions Due to their complex nature, the successful management of PFDs is only possible with the care and expertise of a multidisciplinary team, which includes parents/caregivers. SLPs are important members of these multidisciplinary teams and provide valuable input for the accurate identification and effective remediation of PFDs.

Suckling, Feeding, and Swallowing: Behaviors, Circuits, and Targets for Neurodevelopmental Pathology

All mammals must suckle and swallow at birth, and subsequently chew and swallow solid foods, for optimal growth and health. These initially innate behaviors depend critically upon coordinated development of the mouth, tongue, pharynx, and larynx as well as the cranial nerves that control these structures. Disrupted suckling, feeding, and swallowing from birth onward-perinatal dysphagia-is often associated with several neurodevelopmental disorders that subsequently alter complex behaviors. Apparently, a broad range of neurodevelopmental pathologic mechanisms also target oropharyngeal and cranial nerve differentiation. These aberrant mechanisms, including altered patterning, progenitor specification, and neurite growth, prefigure dysphagia and may then compromise circuits for additional behavioral capacities. Thus, perinatal dysphagia may be an early indicator of disrupted genetic and developmental programs that compromise neural circuits and yield a broad range of behavioral deficits in neurodevelopmental disorders.

Persistent Feeding and Swallowing Deficits in a Mouse Model of 22q11.2 Deletion Syndrome

Disrupted development of oropharyngeal structures as well as cranial nerve and brainstem circuits may lead to feeding and swallowing difficulties in children with 22q11. 2 deletion syndrome (22q11DS). We previously demonstrated aspiration-based dysphagia during early postnatal life in the LgDel mouse model of 22q11DS along with disrupted oropharyngeal morphogenesis and divergent differentiation and function of cranial motor and sensory nerves. We now ask whether feeding and swallowing deficits persist in adult LgDel mice using methods analogous to those used in human patients to evaluate feeding and swallowing dysfunction. Compared to wild-type mice, videofluoroscopic swallow study revealed that LgDel mice have altered feeding and swallowing behaviors, including slower lick rates, longer inter-lick intervals, and longer pharyngeal transit times with liquid consistency. Transoral endoscopic assessment identified minor structural anomalies of the palate and larynx in one-third of the LgDel mice examined. Video surveillance of feeding-related behaviors showed that LgDel mice eat and drink more frequently. Furthermore, LgDel animals engage in another oromotor behavior, grooming, more frequently, implying that divergent craniofacial and cranial nerve structure and function result in altered oromotor coordination. Finally, LgDel mice have significantly increased lung inflammation, a potential sign of aspiration-based dysphagia, consistent with results from our previous studies of early postnatal animals showing aspiration-related lung inflammation. Thus, oromotor dysfunction, feeding, and swallowing difficulties and their consequences persist in the LgDel 22q11DS mouse model. Apparently, postnatal growth and/or neural plasticity does not fully resolve deficits due to anomalous hindbrain, craniofacial, and cranial nerve development that prefigure perinatal dysphagia in 22q11DS. This new recognition of persistent challenges with feeding and swallowing may provide opportunities for improved therapeutic intervention for adolescents and adults with 22q11DS, as well as others with a history of perinatal feeding and swallowing disorders.

Nutritive sucking abnormalities and brain microstructural abnormalities in infants with established brain injury: a pilot study

OBJECTIVE

To determine the relationship between nutritive sucking and microstructural integrity of sensorimotor tracts in newborns with brain injury.

STUDY DESIGN

Diffusion imaging was performed in ten newborns with brain injury. Nutritive sucking was assessed using Nfant®. The motor, sensory, and corpus callosum tracts were reconstructed via tractography. Fractional anisotropy, radial, axial, and mean diffusivity were estimated for these tracts. Multiple regression models were developed to test the association between sucking features and diffusion parameters.

RESULTS

Low-sucking smoothness correlated with low-fractional anisotropy of motor tracts (p = 0.0096). High-sucking irregularity correlated with high-mean diffusivity of motor (p = 0.030) and corpus callosum tracts (p = 0.032). For sensory tracts, high-sucking irregularity (p = 0.018) and low-smoothness variability (p = 0.002) correlated with high-mean diffusivity.

INTERPRETATION

We show a correlation between neuroimaging-demonstrated microstructural brain abnormalities and variations in sucking patterns of newborns. The consistency of this relationship should be shown on larger cohorts.

Swallowing problems in children with a tracheostomy tube

INTRODUCTION

Swallowing problems in children with a tracheostomy tube seem to be a common problem, although exact prevalence is not known. The aim of this study is to identify the prevalence and type of swallowing problems in children with a tracheostomy tube.

METHODS

We retrospectively included 44 children having a tracheostomy tube at Erasmus MC-Sophia Children's hospital. Assessment by a specialized speech and language therapist, the Modified Evans Blue Dye test, Video Fluoroscopic Swallowing Study and a Fiber-optic Endoscopic Evaluation of Swallowing were reviewed with regard to the different phases of swallowing, in particular signs of aspiration.

RESULTS

In our cohort, 31 (70%) children with a tracheostomy tube presented with problems in the oral and/or the pharyngeal phase of swallowing. Overall 19 (43%) children aspirated.

CONCLUSIONS

The majority of children with a tracheostomy tube have swallowing problems in the different swallowing phases with a high risk for aspiration.

RDH10 function is necessary for spontaneous fetal mouth movement that facilitates palate shelf elevation

Cleft palate is a common birth defect, occurring in approximately 1 in 1000 live births worldwide. Known etiological mechanisms of cleft palate include defects within developing palate shelf tissues, defects in mandibular growth and defects in spontaneous fetal mouth movement. Until now, experimental studies directly documenting fetal mouth immobility as an underlying cause of cleft palate have been limited to models lacking neurotransmission. This study extends the range of anomalies directly demonstrated to have fetal mouth movement defects correlated with cleft palate. Here, we show that mouse embryos deficient in retinoic acid (RA) have mispatterned pharyngeal nerves and skeletal elements that block spontaneous fetal mouth movement in utero. Using X-ray microtomography, in utero ultrasound video, ex vivo culture and tissue staining, we demonstrate that proper retinoid signaling and pharyngeal patterning are crucial for the fetal mouth movement needed for palate formation. Embryos with deficient retinoid signaling were generated by stage-specific inactivation of retinol dehydrogenase 10 (Rdh10), a gene crucial for the production of RA during embryogenesis. The finding that cleft palate in retinoid deficiency results from a lack of fetal mouth movement might help elucidate cleft palate etiology and improve early diagnosis in human disorders involving defects of pharyngeal development.

Summary: Fetal mouth immobility and defects in pharyngeal patterning underlie cleft palate in retinoid-deficient Rdh10 mutant mouse embryos.

In the line-up: deleted genes associated with DiGeorge/22q11.2 deletion syndrome: are they all suspects?

BACKGROUND

22q11.2 deletion syndrome (22q11DS), a copy number variation (CNV) disorder, occurs in approximately 1:4000 live births due to a heterozygous microdeletion at position 11.2 (proximal) on the q arm of human chromosome 22 (hChr22) (McDonald-McGinn and Sullivan, Medicine 90:1-18, 2011). This disorder was known as DiGeorge syndrome, Velo-cardio-facial syndrome (VCFS) or conotruncal anomaly face syndrome (CTAF) based upon diagnostic cardiovascular, pharyngeal, and craniofacial anomalies (McDonald-McGinn and Sullivan, Medicine 90:1-18, 2011; Burn et al., J Med Genet 30:822-4, 1993) before this phenotypic spectrum was associated with 22q11.2 CNVs. Subsequently, 22q11.2 deletion emerged as a major genomic lesion associated with vulnerability for several clinically defined behavioral deficits common to a number of neurodevelopmental disorders (Fernandez et al., Principles of Developmental Genetics, 2015; Robin and Shprintzen, J Pediatr 147:90-6, 2005; Schneider et al., Am J Psychiatry 171:627-39, 2014).

RESULTS

The mechanistic relationships between heterozygously deleted 22q11.2 genes and 22q11DS phenotypes are still unknown. We assembled a comprehensive "line-up" of the 36 protein coding loci in the 1.5 Mb minimal critical deleted region on hChr22q11.2, plus 20 protein coding loci in the distal 1.5 Mb that defines the 3 Mb typical 22q11DS deletion. We categorized candidates based upon apparent primary cell biological functions. We analyzed 41 of these genes that encode known proteins to determine whether haploinsufficiency of any single 22q11.2 gene-a one gene to one phenotype correspondence due to heterozygous deletion restricted to that locus-versus complex multigenic interactions can account for single or multiple 22q11DS phenotypes.

CONCLUSIONS

Our 22q11.2 functional genomic assessment does not support current theories of single gene haploinsufficiency for one or all 22q11DS phenotypes. Shared molecular functions, convergence on fundamental cell biological processes, and related consequences of individual 22q11.2 genes point to a matrix of multigenic interactions due to diminished 22q11.2 gene dosage. These interactions target fundamental cellular mechanisms essential for development, maturation, or homeostasis at subsets of 22q11DS phenotypic sites.

The strengths of the genetic approach to understanding neural systems development and function: Ray Guillery's synthesis

The organization and function of sensory systems, especially the mammalian visual system, has been the focus of philosophers and scientists for centuries-from Descartes and Newton onward. Nevertheless, the utility of understanding development and its genetic foundations for deeper insight into neural function has been debated: Do you need to know how something is assembled-a car, for example-to understand how it works or how to use it-to turn on the ignition and drive? This review addresses this issue for sensory pathways. The pioneering work of the late Rainer W. (Ray) Guillery provides an unequivocal answer to this central question: Using genetics for mechanistic exploration of sensory system development yields essential knowledge of organization and function. Ray truly built the foundation for this now accepted tenet of modern neuroscience. His work on the development and reorganization of visual pathways in albino mammals-all with primary genetic mutations in genes for pigmentation-defined the genetic approach to neural systems development, function and plasticity. The work that followed his lead in a variety of sensory systems, including my own work in the developing olfactory system, proceeds directly from Ray's fundamental contributions.

A Novel Three-Dimensional Analysis of Tongue Movement During Water and Saliva Deglutition: A Preliminary Study on Swallowing Patterns

Deglutition is a complex oral function, and the study of the whole process requires a precise analysis of the elements involved, especially of the tongue biomechanics. We described a three-dimensional analysis of tongue movements during both saliva and water deglutition in participants with normal occlusion. Fourteen participants (25.36 ± 4.85 years) were evaluated, and the movements of anterior, middle, and posterior portions of the tongue were recorded using AG501 3D-electromagnetic articulograph. An average volume (AVS) for water deglutition was determined for each participant. Saliva deglutition was classified according to Bourdiol et al. 35.71% was type I, 14.29% type II, and 50% type III. The greatest displacement on the inferior-superior axis was in the posterior portion, followed by the middle and anterior portions. In the posterior-anterior axis, smallest movement was in the anterior portion. During water deglutition, on the inferior-superior axis, there were statistical differences for 1-AVS between the anterior/middle and anterior/posterior portions of the tongue. There were statistical differences for both ½-AVS and ¼-AVS between the anterior/posterior portions of the tongue. On the posterior-anterior axis, there were no statistical differences among any volume-portion relations. On the medial-lateral axis, there was statistical difference for the ½-AVS between middle and posterior portions. The movement of the tongue portions was influenced by the volume and the element to be swallowed. The amplitude of the movement was directly proportional to the volume of water swallowed.

Otolaryngological features in a cohort of patients affected with 22q11.2 deletion syndrome: A monocentric survey

Otorhinolaryngologic manifestations are common in 22q11.2 deletion syndrome (22q11.2DS), but poorly described. This study aimed to better define the ear-nose-throat (ENT) phenotype of 22q11.2DS patients, in the attempt to best detect subjects requiring subspecialist intervention. We enrolled 25 patients affected with 22q11.2DS. Anatomic and functional ENT findings were investigated using clinical, laboratory, and instrumental data. Immunophenotype and frequency of infections were evaluated. Univariate and multivariate analyses were performed. ENT anomalies were found in 88% of patients, and in 20% congenital palate defects required surgery. Adenoid or palatine tonsil hypertrophy was noted in 80% and 48%. Forty-eight percent of subjects had rhinolalia/phonia, severe in half of these. We also found nasal regurgitation or laryngeal penetration/aspiration in 20% and 16%, respectively. Instrumental exams revealed a mild conductive hearing loss in 32% (bilateral in most cases), tympanometric anomalies in 28%, and swallowing abnormalities in 16%. Statistical univariate analysis showed a direct association between rhinolalia/phonia and episodes of laryngeal aspiration (p = .016) and between tympanometric anomalies and increased adenoid volume (p = .044). No association between episodes of food aspiration and palatal anomalies was found. Moreover, no statistically significant association was observed between the number of airway infections and the ENT findings. This study contributes to better define the ENT phenotype in patients with 22q11.2DS, helpful to prevent potential complications. Furthermore, the identification of a subcategory of patients may allow the early adoption of specific speech therapy programs to improve the clinical outcome of 22q11.2DS patients.

Wired for eating: how is an active feeding circuitry established in the postnatal brain?

From birth, mammals have to find food and maximize caloric intake to ensure growth and survival. Suckling must be initiated quickly after birth and then maintained and controlled until weaning. It is a complex process involving interactions between sensory and motor neuronal pathways. Meanwhile, the control of food intake and energy homeostasis is progressively established via the development of hypothalamic circuits. The development of these circuits is influenced by hormonal and nutritional signals and can be disturbed in a variety of developmental disorders leading to long-term metabolic, behavioral and cognitive dysfunctions. This review summarizes our current knowledge of the neuronal circuits involved in early postnatal feeding processes.

LVC Timing in Infant Pig Swallowing and the Effect of Safe Swallowing

Recurrent laryngeal nerve (RLN) injury in neonates, a complication of head and neck surgeries, leads to increased aspiration risk and swallowing dysfunction. The severity of resulting sequelae range from morbidity, such as aspiration pneumonia, to mortality from infection and failure to thrive. The timing of airway protective events including laryngeal vestibule closure (LVC) is implicated in aspiration. We unilaterally transected the RLN in an infant pig model to observe changes in the timing of swallowing kinematics with lesion and aspiration. We recorded swallows using high-speed video-fluoroscopic swallow studies (VFSS) and scored them using the Infant Mammalian Penetration and Aspiration Scale (IMPAS). We hypothesized that changes would occur in swallowing kinematics (1) between RLN lesion and control animals, and (2) among safe swallows (IMPAS 1), penetration swallows (IMPAS 3), and aspiration swallows (IMPAS 7). We observed numerous changes in timing following RLN lesion in safe and unsafe swallows, suggesting pervasive changes in the coordination of oropharyngeal function. The timing of LVC, posterior tongue, and hyoid movements differed between pre- and post-lesion in safe swallows. Posterior tongue kinematics differed for post-lesion swallows with penetration. The timing and duration of LVC and posterior tongue movement differed between aspiration swallows pre- and post-lesion. After lesion, safe swallows and swallows with aspiration differed in timing of LVC, laryngeal vestibule opening, and posterior tongue and hyoid movements. The timing of thyrohyoid muscle activity varied with IMPAS, but not lesion. Further study into the pathophysiology of RLN lesion-induced swallowing dysfunction is important to developing novel therapies.

[Feeding, eating, and swallowing disorders in infants and children : An overview]

Swallowing is a dynamic process that requires more than 30 muscles in the recruitment/coordination of the lips, tongue, palate, pharynx, larynx and esophagus. The eating and swallowing procedure is learned in sensitive or critical periods: when a certain degree of maturation has been achieved, the appropriate stimulus permits a certain milestone of development to occur. The swallowing procedure occurs in three main stages oral, pharyngeal, and esophageal. Therefore, swallowing disorders may present in any, some, or all of these stages in addition to feeding problems. Adult dysphagia, or difficulty swallowing, has long been reported in the literature. Infants and children also experience feeding disorders and swallowing problems, either because of developmental disorders, syndromes, behavioral or neurological conditions, respiratory problems, and/or gastroesophageal reflux, eosinophilic esophagitis or anatomical deficits. Feeding problems or dysphagia are seen in up to 25% of all children; approximately 40% of prematurely born infants have swallowing disorders, up to 64-78% with developmental disorders and up to 99% with cerebral palsy. Diagnostic options include health status, broad social environment, parent-child interactions, and parental concerns. Evaluation of dysphagia and feeding disorders involves a multifactorial approach. Imaging studies may include videofluoroscopy and/or fiberoptic evaluation of swallowing (FEES). Successful oral feeding must be measured in quality of meal time experiences with best possible oral sensorimotor skills and safe swallowing while not jeopardizing a child's functional health status or the parent-child relationship. An interdisciplinary team approach enables coordinated global assessment and therapy planning.

Altered neurobiological function of brainstem hypoglossal neurons in DiGeorge/22q11.2 Deletion Syndrome

DiGeorge/22q11.2 Deletion Syndrome (22q11DS) is a common genetic microdeletion syndrome that underlies several neurodevelopmental disorders including autism, attention deficit/hyperactivity disorder, and schizophrenia. In addition to cognitive impairments, those with 22q11DS have disrupted feeding and swallowing from birth onward. This perinatal dysphagia significantly compromises nutritional status, impairs appropriate weight gain, and can lead to life threatening aspiration-based infections. Appropriately timed excitation and inhibition of brainstem hypoglossal motor neurons, which innervate tongue muscles, is essential for proper feeding and swallowing. In this study we have examined changes in hypoglossal motor neuron function in the LgDel mouse model of 22q11DS. Hypoglossal motor neurons from LgDel mouse pups have action potentials with afterhyperpolarizations, mediated by a large conductance charybdotoxin-sensitive Ca-activated K current, that are significantly shorter in duration and greater in magnitude than those in wild-type pups. In addition, the amplitude, but not frequency, of glutamatergic excitatory glutamatergic postsynaptic currents (EPSCs) is diminished, and GABAergic, but not glycinergic, neurotransmission to hypoglossal motor neurons was reduced in LgDel animals. These observations provide a foundation for understanding the neurological changes in hypoglossal motor neuron function and their contribution to swallowing abnormalities that occur in DiGeorge/22q11.2 Deletion Syndrome.