Moebius syndrome: clinical features, diagnosis, management and early intervention

Moebius syndrome and hypopituitarism: a case of multiple pituitary hormone deficiency and revision of the literature

OBJECTIVES

Moebius syndrome (MS) is a rare congenital non-progressive rhombencephalic disorder mostly characterised by abducens and facial nerve palsy, but with a multifaceted clinical presentation. Isolated or multiple pituitary hormone deficiencies in the setting of MS have been occasionally reported, but the simultaneous involvement of three or more hypothalamic-pituitary axes has never been described. We hereby report the case of a girl with MS that showed a co-occurrence of GH-, TSH- and ACTH-deficiency. In addition, we provide a systematic revision of all the published cases of hypopituitarism among patients with MS.

CASE PRESENTATION

A 6-year-old patient with a MS was referred to our outpatient clinic for faltering growth. The combination of stature below -3.0 SDS, impaired height velocity and pathological response to two GH-stimulation tests prompted the diagnosis of GH deficiency and therefore recombinant human GH was undertaken. Brain MRI highlighted a thin infundibular stalk. By the age of 10 years, she started to complain progressive fatigue and the co-occurrence of remarkably decreased fT4 levels in the setting of non-increased TSH led to diagnose central hypothyroidism. Accordingly, she was started on levothyroxine replacement therapy with timely clinical improvement. At the age of 11.3 years, recurrent symptoms consistent with morning hypoglycaemia prompted the prescription of a low-dose ACTH test, that confirmed an ACTH deficiency, in the setting of a multiple pituitary hormonal impairment.

CONCLUSIONS

Patients with MS are potentially at risk for either isolated or multiple pituitary hormones deficiency. Clinicians should lower the threshold for prescribing a dedicated endocrine assessment.

Moebius Syndrome associated with syringomyelia: a case report

BACKGROUND

Moebius Syndrome is a genetic condition that results in inability for facial mimicry due to palsy of cranial nerves VI and VII. Syringomyelia is characterized by a dilation of the central canal in the spinal cord, and is generally asymptomatic. Both disorders are diagnosed using imaging tests. A newborn with no facial movements upon physical examination was admitted to the delivery room of our hospital. A specialist confirmed the condition to be Moebius Syndrome. Further investigation using magnetic resonance imaging indicated that syringomyelia was associated with Moebius Syndrome. Given that syringomyelia is a silent myelopathy with a possible impact on the future health of the patient, careful analysis is recommended when diagnosing Moebius Syndrome. Few similar cases have been reported to date. Further studies are warranted to determine the actual association between these two conditions. Since syringomyelia diagnoses are often made when testing for other conditions, as in this study, neurological examinations of the brain should be expanded to include the spinal cord, in order to verify the presence of coexisting disorders.

Successful Outcome of Two-Stage Strabismus Surgery in a Rare Case of Unilateral Möbius Syndrome: A Case Report

Möbius syndrome (MBS) is a rare congenital disorder characterized by facial and abducens palsy which is usually bilateral and may involve multiple cranial nerves. Additional features, such as craniofacial anomalies, tongue malformations, and limb defects, may also be present. The etiology of this syndrome is not well established but the ischemic necrosis of the brainstem leading to hypoplasia of the cranial nerve nuclei is the supposed to be most likely one. MBS leads to a large angle esotropia along with bilateral limitation of abduction with delayed diagnosis, which is very challenging to correct with a single procedure. There are only a few reports illustrating the surgical outcome of strabismus in MBS. In this case report, we describe an unusual case of unilateral MBS who presented with large esotropia since childhood and was managed by two-stage strabismus surgery, including unilateral medial rectus (MR) muscle recession followed by vertical recti transposition. The final primary position alignment was satisfactory. Therefore, MR muscle recession alone is an effective first procedure of choice for mild-to-moderate esotropia in patients with MBS, whereas severe cases may further require the transposition of vertical recti. As it is a congenital condition, early surgical intervention may prevent amblyopia and provide an opportunity for the development of binocular single vision. Hence, prompt diagnosis and early surgical intervention are of utmost importance in these cases.

A rare case of pontine tegmental cap dysplasia

Pontine Tegmental Cap Dysplasia (PTCD) is a rare hindbrain malformation characterized by cranial nerve dysfunction, cerebellar abnormalities, and developmental delays of varying severity. This case report presents a 12-month-old female with significant developmental delays, hypotonia, and cranial nerve abnormalities. The findings underscore the critical role of radiology and neuroimaging in diagnosing and managing PTCD. Additionally, this case highlights the importance of neuroimaging in differentiating PTCD from other possible diagnoses and malformations.

Sleep health of adults and children with Moebius syndrome

INTRODUCTION

Moebius syndrome is a rare congenital disorder with frequent anecdotal reports of sleep disturbances not sufficiently categorized by prior literature. The present mixed-methods, two-phase study aimed to characterize the sleep health and symptoms of a cohort of adults and children (via parent proxies) with Moebius syndrome.

METHODS

In Phase 1, participants were 46 adults with Moebius Syndrome (Mage=33.5[13.0]; 72 % female) and 17 parent-proxies for children with Moebius Syndrome (child Mage=10.47[3.4]; 53 % female). Participants completed a self-reported questionnaire battery. In Phase 2, five adults (Mage=25.4[6.5]; 100 % female) from Phase 1 completed 2 weeks of sleep diary and actigraphy, 2 nights of single-channel EEG, and diagnostic and qualitative interviews.

RESULTS

Adults endorsed elevated rates of self-reported sleep disorder symptoms including sleep apnea (26 %), insomnia (56 %), nightmares (35 %), excessive daytime sleepiness (30 %), cataplexy (26 %), REM sleep behavior disorder (61 %), and parasomnias (100 %). Children had elevated rates of sleep disturbances (71 %), sleep-related daytime impairment (82 %), parasomnias (76 %) and daytime sleepiness (53 %). Qualitative interviews revealed participants endorsed a history of sleep problems dating to childhood and continuing into adulthood that impacted social relationships and quality of life and had experienced little treatment success.

DISCUSSION

These findings shed light on the constellation of sleep health experiences among individuals with Moebius syndrome. Poor sleep health may represent a modifiable treatment target to improve health and well-being in individuals with Moebius syndrome. The heterogenous nature of sleep problems among people with Moebius syndrome may not respond well to a one-size-fits-all intervention, instead necessitating personalized approaches.

Overview of Unilateral and Bilateral Pediatric Facial Paralysis: Workup, Treatment, and Frontiers

Pediatric facial nerve paralysis can present significant challenges based on its various etiologies, unique approach to treatment options, and overall outcomes. It can impact both the child and parent when regarding function, appearance, and psychosocial implications. The etiology of facial nerve palsy can include congenital, traumatic, iatrogenic, and idiopathic causes. In some, the paralysis is transient while others have permanent loss of function. A thorough evaluation and differential diagnosis are essential to guide treatment planning. The purpose of this paper is to review facial paralysis in children with a focus on surgical management.

Psychosocial functioning in patients with altered facial expression: a scoping review in five neurological diseases

PURPOSE

To perform a scoping review to investigate the psychosocial impact of having an altered facial expression in five neurological diseases.

METHODS

A systematic literature search was performed. Studies were on Bell's palsy, facioscapulohumeral muscular dystrophy (FSHD), Moebius syndrome, myotonic dystrophy type 1, or Parkinson's disease patients; had a focus on altered facial expression; and had any form of psychosocial outcome measure. Data extraction focused on psychosocial outcomes.

RESULTS

Bell's palsy, myotonic dystrophy type 1, and Parkinson's disease patients more often experienced some degree of psychosocial distress than healthy controls. In FSHD, facial weakness negatively influenced communication and was experienced as a burden. The psychosocial distress applied especially to women (Bell's palsy and Parkinson's disease), and patients with more severely altered facial expression (Bell's palsy), but not for Moebius syndrome patients. Furthermore, Parkinson's disease patients with more pronounced hypomimia were perceived more negatively by observers. Various strategies were reported to compensate for altered facial expression.

CONCLUSIONS

This review showed that patients with altered facial expression in four of five included neurological diseases had reduced psychosocial functioning. Future research recommendations include studies on observers' judgements of patients during social interactions and on the effectiveness of compensation strategies in enhancing psychosocial functioning.

Exploring the Impact of Genetics in a Large Cohort of Moebius Patients by Trio Whole Exome Sequencing

Moebius syndrome (MBS) is a rare congenital disorder characterized by non-progressive facial palsy and ocular abduction paralysis. Most cases are sporadic, but also rare familial cases with autosomal dominant transmission and incomplete penetrance/variable expressivity have been described. The genetic etiology of MBS is still unclear: de novo pathogenic variants in REV3L and PLXND1 are reported in only a minority of cases, suggesting the involvement of additional causative genes. With the aim to uncover the molecular causative defect and identify a potential genetic basis of this condition, we performed trio-WES on a cohort of 37 MBS and MBS-like patients. No de novo variants emerged in REV3L and PLXND1. We then proceeded with a cohort analysis to identify possible common causative genes among all patients and a trio-based analysis using an in silico panel of candidate genes. However, identified variants emerging from both approaches were considered unlikely to be causative of MBS, mainly due to the lack of clinical overlap. In conclusion, despite this large cohort, WES failed to identify mutations possibly associated with MBS, further supporting the heterogeneity of this syndrome, and suggesting the need for integrated omics approaches to identify the molecular causes underlying MBS development.

Physiopathologic Bases of Moebius Syndrome: Combining Genetic, Vascular, and Teratogenic Theories

Moebius syndrome (MBS) is a congenital cranial dysinnervation disorder (CCDD) characterized by a bilateral palsy of abducens and facial cranial nerves, which may coexist with other cranial nerves palsies, mostly those found in the dorsal pons and medulla oblongata. MBS is considered a "rare" disease, occurring in only 1:50,000 to 1:500,000 live births, with no gender predominance. Three independent theories have been described to define its etiology: the vascular theory, which talks about a transient blood flow disruption; the genetic theory, which takes place due to mutations related to the facial motor nucleus neurodevelopment; and last, the teratogenic theory, associated with the consumption of agents such as misoprostol during the first trimester of pregnancy. Since the literature has suggested the existence of these theories independently, this review proposes establishing a theory by matching the MBS molecular bases. This review aims to associate the three etiopathogenic theories at a molecular level, thus submitting a combined postulation. MBS is most likely an underdiagnosed disease due to its low prevalence and challenging diagnosis. Researching other elements that may play a key role in the pathogenesis is essential. It is common to assume the difficulty that patients with MBS have in leading an everyday social life. Research by means of PubMed and Google Scholar databases was carried out, same in which 94 articles were collected by using keywords with the likes of "Moebius syndrome," "PLXND1 mutations," "REV3L mutations," "vascular disruption AND teratogens," and "congenital facial nerve palsy." No exclusion criteria were applied.

Oral findings and comprehensive dental management of Moebius syndrome: a systematic review

BACKGROUND

Moebius syndrome (MS) is a rare, non-progressive, neuromuscular, congenic disease involving the oral maxillofacial region. The present study aimed to describe the oral and extraoral findings in MS patients and their comprehensive dental management.

METHODS

A digital search was carried out in PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar, restricted to articles in English from Jan 01, 2000, to Apr 02, 2023, following PRISMA guidelines. The methodological quality of the studies was evaluated following the JBI guidelines. Qualitative analysis was carried out on the overall result, extraoral and intraoral manifestations, considering dental management as appropriate.

RESULTS

Twenty-three studies were included, and a total of 124 cases of patients with MS were analyzed. The 82% of patients with MS were younger than 15 years of age. The most frequent extraoral manifestations were blinking and visual problems (78,22%), malformations of the upper and lower limbs (58,22%), bilateral facial paralysis (12,90%), lack of facial expression (12.09%), and unilateral facial paralysis (6,45%). On the other hand, the most frequent oral manifestations were tongue deformities (78,22%), micrognathia (37,90%), labial incompetence (36,29%), cleft palate (22,87%), gothic palate (16,12%), microstomia (15,32%), anterior open bite (15,32%), dental caries (8,87%), and periodontal disease (8,06%). The majority of MS patients were treated by pediatric dentistry (60,86%), using a surgical approach (56,52%), and orthodontic and orthopedic maxillary (43,47%) followed by restorative (39,13%), and periodontal treatments (21,73%).

CONCLUSIONS

This systematic review demonstrates that patients with MS present a wide variety of oral and extraoral manifestations, for which dental treatments are planned and tailored to each patient in accordance with oral manifestations. These treatments encompass problem resolution and oral health maintenance, incorporating recent techniques in managing and treating patients with MS.

Case report: Identification of a novel variant p.Gly215Arg in the CHN1 gene causing Moebius syndrome

Background: Moebius Syndrome (MBS) is a rare congenital neurological disorder characterized by paralysis of facial nerves, impairment of ocular abduction and other variable abnormalities. MBS has been attributed to both environmental and genetic factors as potential causes. Until now only two genes, PLXND1 and REV3L have been identified to cause MBS. Results: We present a 9-year-old male clinically diagnosed with MBS, presenting facial palsy, altered ocular mobility, microglossia, dental anomalies and congenital torticollis. Radiologically, he lacks both abducens nerves and shows altered symmetry of both facial and vestibulocochlear nerves. Whole-exome sequence identified a de novo missense variant c.643G>A; p.Gly215Arg in CHN1, encoding the α2-chimaerin protein. The p.Gly215Arg variant is located in the C1 domain of CHN1 where other pathogenic gain of function variants have been reported. Bioinformatic analysis and molecular structural modelling predict a deleterious effect of the missense variant on the protein function. Conclusion: Our findings support that pathogenic variants in the CHN1 gene may be responsible for different cranial congenital dysinnervation syndromes, including Moebius and Duane retraction syndromes. We propose to include CHN1 in the genetic diagnoses of MBS.

Treatment Approaches for Altered Facial Expression: A Systematic Review in Facioscapulohumeral Muscular Dystrophy and Other Neurological Diseases

Background

Facial weakness is a key feature of facioscapulohumeral muscular dystrophy (FSHD) and may lead to altered facial expression and subsequent psychosocial impairment. There is no cure and supportive treatments focus on optimizing physical fitness and compensation of functional disabilities.

Objective

We hypothesize that symptomatic treatment options and psychosocial interventions for other neurological diseases with altered facial expression could be applicable to FSHD. Therefore, the aim of this review is to collect symptomatic treatment approaches that target facial muscle function and psychosocial interventions in various neurological diseases with altered facial expression in order to discuss the applicability to FSHD.

Methods

A systematic search was performed. Selected studies had to include FSHD, Bell's palsy, Moebius syndrome, myotonic dystrophy type 1, or Parkinson's disease and treatment options which target altered facial expression. Data was extracted for study and patients' characteristics, outcome assessment tools, treatment, outcome of facial expression and or psychosocial functioning.

Results

Forty studies met the inclusion criteria, of which only three studies included FSHD patients exclusively. Most, twenty-one, studies were performed in patients with Bell's palsy. Studies included twelve different therapy categories and results were assessed with different outcomes measures.

Conclusions

Five therapy categories were considered applicable to FSHD: training of (non-verbal) communication compensation strategies, speech training, physical therapy, conference attendance, and smile restoration surgery. Further research is needed to establish the effect of these therapies in FSHD. We recommend to include outcome measures in these studies that cover at least cosmetic, functional, communication, and quality of life domains.

Monozygotic twins discordant for a congenital cranial dysinnervation disorder with features of Moebius syndrome

Moebius syndrome is a congenital cranial dysinnervation disorder (CCDD) that presents with nonprogressive cranial nerve (CN) VI and VII palsies resulting in facial weakness and inability to abduct the eye(s). While many CCDDs have an underlying genetic cause, the etiology of Moebius syndrome remains unclear as most cases are sporadic. Here, we describe a pair of monochorionic, diamniotic twin girls; one with normal growth and development, and one with micrognathia, reduced facial expression, and poor feeding. Magnetic resonance imaging of the brain performed on the affected twin at 19 months of age showed severely hypoplastic or absent CN IV bilaterally, left CN VI smaller than right, and bilateral hypoplastic CN VII and IX, consistent with a diagnosis of a CCDD, most similar to that of Moebius syndrome. Genomic sequencing was performed on each twin and data was assessed for discordant variants, as well as variants in novel and CCDD-associated genes. No pathogenic, likely pathogenic, or variants of uncertain significance were identified in genes known to be associated with CCDDs or other congenital facial weakness conditions. This family provides further evidence in favor of a stochastic event as the etiology in Moebius syndrome, rather than a monogenic condition.

Prenatal diagnosis of Poland-Möbius syndrome by multimodality fetal imaging

We describe prenatal diagnosis of Poland-Möbius syndrome using a combination of ultrasound and MRI. Poland syndrome was diagnosed based on absence of the pectoralis muscles associated with dextroposition of the fetal heart and elevation of the left diaphragm. Associated brain anomalies that led to the diagnosis of Poland-Möbius syndrome, included ventriculomegaly, hypoplastic cerebellum, tectal beaking, and a peculiar flattening of the posterior aspect of the pons and medulla oblongata, which has been reported by postnatal diffusion tensor imaging studies as a reliable neuroimaging marker for Möbius syndrome. Since abnormalities of cranial nerves VI and VII may be difficult to detect prenatally, careful attention to the appearance of the brain stem as illustrated in the current report may aid in the prenatal diagnosis of Möbius syndrome.

Impact of Social Determinants of Health in the Care of Moebius Syndrome: A Case Report

Moebius syndrome is a rare congenital disorder characterized by nonprogressive uni- or bilateral abducens nerve (VI) and facial nerve (VII) palsy. Other cranial nerves (CN) such as CN III, IV, and IX-XII may be involved leading to varied presentations. Speech development, communication, and psychomotor complications are common. Given the complexity of the disease, patients require an individualized, multidisciplinary care plan involving many medical specialists. Accessing this level of care without insurance poses seemingly insurmountable challenges and places immense financial strain on both patients with Moebius syndrome and their families. Physicians must advocate for patients with Moebius syndrome and be knowledgeable about the community resources available to them such as non-profit organizations. This report presents a case of Moebius syndrome in an uninsured, immigrant, 13-year-old male and the barriers to providing him with adequate care.

The interaction between the nervous system and the stomatognathic system: from development to diseases

The crosstalk between the nerve and stomatognathic systems plays a more important role in organismal health than previously appreciated with the presence of emerging concept of the "brain-oral axis". A deeper understanding of the intricate interaction between the nervous system and the stomatognathic system is warranted, considering their significant developmental homology and anatomical proximity, and the more complex innervation of the jawbone compared to other skeletons. In this review, we provide an in-depth look at studies concerning neurodevelopment, craniofacial development, and congenital anomalies that occur when the two systems develop abnormally. It summarizes the cross-regulation between nerves and jawbones and the effects of various states of the jawbone on intrabony nerve distribution. Diseases closely related to both the nervous system and the stomatognathic system are divided into craniofacial diseases caused by neurological illnesses, and neurological diseases caused by an aberrant stomatognathic system. The two-way relationships between common diseases, such as periodontitis and neurodegenerative disorders, and depression and oral diseases were also discussed. This review provides valuable insights into novel strategies for neuro-skeletal tissue engineering and early prevention and treatment of orofacial and neurological diseases.

Diagnosis and Dental Management of a Child with Moebius Syndrome: A Case Report

Moebius syndrome (MBS) is a rare congenital nonprogressive neuromuscular disorder characterized by partial or complete, unilateral or bilateral paralysis of the facial (VII) and abducens (VI) cranial nerves (CNs). In this syndrome bilateral facial palsy may occur with the involvement of VII CN and impaired eye movements can be there because of the involvement of VI CN. It can also be associated with other CN palsies, orofacial anomalies, and limb defects. MBS is diagnosed exclusively on the basis of clinical criteria, although causative genetic patterns are being documented in recent studies. The present case report describes the dental management of a 5-year-old child diagnosed with MBS. The child presented with the abnormal shape of legs, incomplete eye closure during sleep, inability to smile, lingual hypoplasia, microstomia, and hypoplastic teeth among other dental-skeletal abnormalities, and a clinical diagnosis of MBS was made.

How to cite this article

Mittal M, Kumar A, Chopra R, et al. Diagnosis and Dental Management of a Child with Moebius Syndrome: A Case Report. Int J Clin Pediatr Dent 2023;16(S-1):S109-S112.

Moebius Syndrome: What We Know So Far

Moebius syndrome (MBS) is a rare congenital cranial nerve disorder characterized by unilateral, bilateral symmetrical, or asymmetrical facial (VII) and abducens (VI) nerve palsies. Genetics and rhombencephalon vascular disturbances from intrauterine environmental exposures have been attributed to its development. It can present with various orofacial abnormalities. Although the diagnosis is purely clinical, certain characteristic features are present in the brain's images. With no cure, it is essential to devise management on a personalized basis. We discuss etiology, presentation, diagnostic approaches, and effective management in the existing literature. This comprehensive review examines the clinic-pathological aspects of Moebius syndrome. The authors employed the PUBMED base index to identify pertinent literature and reference it according to research keywords. Findings suggest the most popular etiology is the theory of intrauterine vascular disruption to the brainstem during embryogenesis, followed by the genetic hypothesis. Intrauterine environmental exposures have been implicated as potential risk factors. Facial and abducens nerve palsies are the most common presenting features. However, clinical manifestations of lower cranial nerves (IX, X, XI, XII) may be present with orthopedic anomalies and intellectual deficiencies. The diagnosis is clinical with minimal defined diagnostic criteria. Characteristic radiological manifestations involving the brainstem and cerebellum can be observed in imaging studies. With no definitive treatment options, a multidisciplinary approach is employed to provide supportive care. Despite radiological manifestations, Moebius syndrome is diagnosed clinically. Although incurable, a multidisciplinary approach, with personalized rehabilitative measures, can manage physical and psychological deficits; however, standard guidelines need to be established.

Echoencephalography of Möbius sequence: A congenital cranial dysinnervation disorder with brainstem calcifications

BACKGROUND AND PURPOSE

Möbius sequence (MBS) previously known as Möbius syndrome is a rare nonprogressive developmental defect of the rhombencephalon leading to congenital abducens (VIth) and facial (VIIth) nerve palsy. Echoencephalography is the first, safe, noninvasive, and cost-effective imaging modality available at bedside. No study on the use of echoencephalography in neonates for the diagnosis of MBS has been previously reported.

METHODS

In this single tertiary center study, more than 18,000 neonates underwent echoencephalographic imaging over the span of two decades. Imaging was performed through the anterior, posterior, and lambdoid fontanelles. All neonates found to have calcifications of brainstem tegmental nuclei underwent additional imaging studies. Each neonate with MBS was carefully examined by the same investigator.

RESULTS

Five neonates were shown to have punctate, bilateral, symmetrical tegmental pontine calcifications through all three acoustic windows. These calcifications extended caudally in most patients, and rostrally in 2 patients. Brainstem hypoplasia was best seen through the posterior fontanelle. Three out of five infants were noted to have brainstem hypoplasia with straightening of the floor of the fourth ventricle. In two children, facial collicular bulges and hypoglossal eminences were present. All five infants fulfilled clinical diagnostic criteria of MBS. In addition, a wide array of cerebral defects is identified. Echoencephalographic findings were confirmed by other imaging modalities.

CONCLUSION

Knowledge of echoencephalographic features of MBS should improve its early recognition. A detailed description of the various imaging phenotypes of MBS is necessary to characterize the etiology of this heterogeneous congenital cranial dysinnervation disorder.

Moebius Syndrome: An Updated Review of Literature

Moebius Syndrome, is a rare, non-progressive congenital neuropathological syndrome characterized primarily by the underdevelopment of the facial (CN VII) and abducens nerve (CN VI). Other features of Moebius Syndrome include facial nerve paresis, ophthalmoplegias, orthodontic deficiencies (including crowded dentition, swollen and hyperplastic gingiva, dental calculus, etc.), musculoskeletal abnormalities, and impaired mental function. Due to the rarity of the disorder, very few case studies have been reported in the literature. This article summarizes the significant features of the disease according to commonalities in reported cases, along with several newly recognized features cited in recent literature. We have explored the different diagnostic criteria and the newly recognized imaging modalities that may be used. Understandably, the condition detrimentally affects a patient's quality of life; thus, treatment measures have also been outlined. This study aims to provide updated literature on Moebius Syndrome MBS and improve understanding of the condition.

Poland-Möbius syndrome: a case report implicating a novel mutation of the PLXND1 gene and literature review

BACKGROUND

Möbius (Moebius) and Poland's syndromes are two rare congenital syndromes characterized by non-progressive bilateral (and often asymmetric) dysfunction of the 6^th and 7^th cranial nerves and hypoplasia of the pectoral muscles associated with chest wall and upper limb anomalies respectively. Manifest simultaneously as Poland-Möbius (Poland-Moebius) syndrome, debate continues as to whether this is a distinct nosological entity or represents phenotypic variation as part of a spectrum of disorders of rhomboencephalic development. Etiological hypotheses implicate both genetic and environmental factors. The PLXND1 gene codes for a protein expressed in the fetal central nervous system and vascular endothelium and is thus involved in embryonic neurogenesis and vasculogenesis. It is located at chromosome region 3q21-q22, a locus of interest for Möbius syndrome.

CASE PRESENTATION

We present the first report of a patient with Poland-Möbius syndrome and a mutation in the PLXND1 gene. A child with Poland-Möbius syndrome and a maternally inherited missense variant (NM_015103.2:ex14:c.2890G > Ap.V964M) in the PLXND1 gene is described. In order to contextualize these findings, the literature was examined to identify other confirmed cases of Poland-Möbius syndrome for which genetic data were available. Fourteen additional cases of Poland-Möbius syndrome with genetic studies are described in the literature. None implicated the PLXND1 gene which has previously been implicated in isolated Möbius syndrome.

CONCLUSIONS

This report provides further evidence in support of a role for PLXND1 mutations in Möbius syndrome and reasserts the nosological link between Möbius and Poland's syndromes.

LEVEL OF EVIDENCE

Level V, Descriptive Study.

Moebius syndrome-Case report

Moebius Syndrome is a rare multifactorial condition defined by congenital complete or partial VII and VIth cranial nerves palsy and other physical abnormalities. We present the case of a 3 months old infant with Moebius sequence and breathing and eating difficulties, managed by tracheostomy and laryngoplasty.

Simultaneous Bilateral Proximal Femur Implant Failure: A Case Report

A seven-year-old boy with Moebius syndrome and bilateral hip dysplasia underwent left-sided adductor lengthening, bilateral proximal femur varus derotational osteotomies, and internal fixation with proximal femur blade plates, and left-sided Dega pelvic osteotomy. Postoperatively, he was immobilized in a Petrie cast. A month later, the child presented with bilateral proximal femur blade plate implant failure. Simultaneous bilateral proximal femur implant failure in a child, to our knowledge, has not yet been reported. Implant failure in the absence of significant trauma is rare. We describe various contributory factors that may lead to implant failure which must be carefully considered while managing a non-ambulatory child.

Prevalence of Hand Malformations in Patients With Moebius Syndrome and Their Management

BACKGROUND

Moebius syndrome is a disorder characterized by facial and abducens nerve paralysis. Patients can present a wide range of upper extremity malformations. Literature focused on orthopedic manifestations of Moebius syndrome shows variability in the prevalence and clinical presentation of upper extremity anomalies. The aim of this work is to evaluate the prevalence of upper extremity malformations in patients with Moebius syndrome, clarify its various clinical presentations, and present treatment strategies for their management.

METHODS

This is a retrospective, cross-sectional study including patients with Moebius syndrome and upper extremity malformations between 2012 and 2019. Data include demographic characteristics, Moebius syndrome subtype, type of malformation, affected extremity, and surgical procedures underwent. Quantitative data were recorded as mean (standard deviation [SD]), and qualitative data were expressed in terms of totals and percentages. Statistical association between Moebius syndrome subtype and development of upper extremity anomalies was evaluated using binary logistic regression.

RESULTS

Twenty-five out of 153 patients (16.3%) presented upper extremity malformations (48% male). Mean age of presentation was 9.08 ± 9.43 years. Sixty-eight percent of the malformations were unilateral. The most common presentations included Poland syndrome and simple syndactyly with 8 cases each (32%), followed by 5 cases of brachysyndactyly (20%), 3 cases of amniotic band syndrome (12%), and 1 case of cleft hand (4%). No statistical association was found between Moebius syndrome subtype and odds ratio for development of upper extremity anomalies. Thirteen patients (52%) underwent reconstructive procedures.

CONCLUSION

Poland syndrome and syndactyly are the most common anomalies in patients with Moebius syndrome. Patients may present with a wide range of hand malformations, each patient should be carefully evaluated in order to determine whether surgical treatment is needed and to optimize rehabilitation protocols.

Acute Respiratory Distress in a Pediatric Patient With Prader-Willi and Moebius Syndromes

Although acute respiratory infections or diseases such as asthma commonly cause respiratory distress in a pediatric patient, neuromuscular disorders must be considered as a possible etiology in patients with significant hypotonia, neurological deficits, and gross developmental delay. We present a case where a patient’s lack of response to initial asthma exacerbation therapy led to a reconsideration of the original diagnosis and adaptation of the management plan. Our patient presented with a rare combination of two congenital disorders that cause hypotonia: Prader-Willi syndrome and Moebius syndrome. This case underlines the importance of considering atypical etiologies in pediatric patients with respiratory distress, while also illustrating the effectiveness of the atypical use of Dornase alfa in a patient with underlying neuromuscular disorders.

Facial Expression Time Processing in Typical Development and in Patients with Congenital Facial Palsy

Temporal dynamics of behavior, particularly facial expressions, are fundamental for communication between individuals from very early in development. Facial expression processing has been widely demonstrated to involve embodied simulative processes mediated by the motor system. Such processes may be impaired in patients with congenital facial palsy, including those affected by Moebius syndrome (MBS). The aims of this study were to investigate (a) the role of motor mechanisms in the processing of dynamic facial expression timing by testing patients affected by congenital facial palsy and (b) age-dependent effects on such processing. Accordingly, we recruited 38 typically developing individuals and 15 individuals with MBS, ranging in age from childhood to adulthood. We used a time comparison task where participants were asked to identify which one of two dynamic facial expressions was faster. Results showed that MBS individuals performed worse than controls in correctly estimating the duration of facial expressions. Interestingly, we did not find any performance differences in relation to age. These findings provide further evidence for the involvement of the motor system in processing facial expression duration and suggest that a sensorimotor matching mechanism may contribute to such timing perception from childhood.

Facial Asymmetry: A Narrative Review of the Most Common Neurological Causes

Symmetry of the face is one of the most important features for the perception of attractiveness. Asymmetry of the face means that the right and left sides of the face are not identical. Subclinical facial asymmetry is very common in the general population. Most people have some slight facial asymmetry, and this is the normal biological situation in humans. Abnormalities from soft tissue, dental, and skeletal elements lead to facial asymmetry. Asymmetry has many causal factors, and its aetiology includes both congenital and acquired conditions. Neurological facial asymmetry is scarcely addressed in the dental literature. In this narrative review, we focus on the most common neurological causes of facial asymmetry. From a neurological point of view, facial asymmetry can result from disturbances of the cranial nerves, developmental disorders, or myopathies. In the broad range of differential diagnostics of facial asymmetry, neurological abnormalities should be taken into consideration. The treatment must be related to the underlying cause. Complete knowledge of the aetiological factors and the character of the asymmetry plays a crucial role in formulating a treatment plan.

Neurogenic bladder as a lurking complication in Moebius syndrome

Moebius syndrome (MBS) is a congenital disorder characterized by facial and abducens palsy, sometimes accompanied with other cranial nerve palsies and comorbid conditions. Anatomical anomalies of the brainstem are assumed to be major etiologies of MBS. Its phenotypic presentation can be variable. We report a female patient with MBS who presented with neurogenic bladder (NB). She was born via normal vaginal delivery. At birth, she showed bilateral abducens palsy and right facial palsy. We diagnosed MBS by cranial computed tomography scan and magnetic resonance imaging. She had recurrent urinary tract infection. Hydronephrosis was noted on ultrasonography and bilateral vesicoureteral reflux (grade 5) on voiding cystourethrography. Urodynamic investigation showed detrusor overactivity and detrusor-sphincter dyssynergia, which follow the pattern of NB resulting from infrapontine-suprasacral lesions. Patients with MBS have lower brainstem dysfunction, and accordingly we should be aware of NB.

Approach to Facial Weakness

Facial palsy is a common neurologic concern and is the most common cranial neuropathy. The facial nerve contains motor, parasympathetic, and special sensory functions. The most common form of facial palsy is idiopathic (Bell's palsy). A classic presentation requires no further diagnostic measures, and generally improves with a course of corticosteroid and antiviral therapy. If the presentation is atypical, or concerning features are present, additional studies such as brain imaging and cerebrospinal fluid analysis may be indicated. Many conditions may present with facial weakness, either in isolation or with other neurologic signs (e.g., multiple cranial neuropathies). The most important ones to recognize include infections (Ramsay-Hunt syndrome associated with herpes zoster oticus, Lyme neuroborreliosis, and complications of otitis media and mastoiditis), inflammatory (demyelination, sarcoidosis, Miller-Fisher variant of Guillain-Barré syndrome), and neoplastic. No matter the cause, individuals may be at risk for corneal injury, and, if so, should have appropriate eye protection. Synkinesis may be a bothersome residual phenomenon in some individuals, but it has a variety of treatment options including neuromuscular re-education and rehabilitation, botulinum toxin chemodenervation, and surgical intervention.

Infranuclear Eye Movement Disorders

Infranuclear motility disorders are such of the cranial nerves, the extraocular muscles or changes in the orbit but definitely peripheral to the nuclei of the cranial nerves. Characteristic are movement deficits, a compensatory head posture and the pattern of incomitancy. The secondary angle of deviation is usually larger than the primary. Combined pareses suggest a lesion in the cavernous sinus, orbital apex or a multilocular event. It is essential to rule out supranuclear disorders, especially if the motility deficit is atypical. For clarification, an individual risk assessment is recommended, paying particular attention to risk factors.

Dental management of a patient with Moebius syndrome: A case report

BACKGROUND

Moebius syndrome (MBS) is a nonprogressive and rare congenital neuromuscular disorder involving the facial nerve and abductor nerve; it mainly manifests as facial paralysis and eye strabismus paralytic symptoms. Tissues in the oral cavity are also compromised, characterized by microstomia, micrognathia, tongue malformation, cleft lip, high arched palate or cleft palate, bifid uvula, and dental malocclusion. Therefore, dentistry plays a fundamental and crucial role in caring for these individuals. However, there is limited available data on MBS treatment, particularly regarding dental management.

CASE SUMMARY

This case report presents dental treatment of a 21-year-old man with MBS and discusses crucial interactions among oral complications of MBS. In this case, the patient was clinically characterized by congenital neuromuscular disorder, occlusal disorders, and tooth and gum problems. It is noteworthy that the patient presented early eruption of deciduous teeth 2 mo after birth, which has not been reported in other MBS cases and suggests a potentially new clinical manifestation of this syndrome. It is important to note that MBS cannot be cured, and oral manifestations of this syndrome can be managed by a multidisciplinary health care team that helps the patient maintain oral hygiene and dental health. After a series of oral treatments, no obvious poor oral hygiene, swollen gums, or abnormal imaging results were observed after 2 years of follow-up.

CONCLUSION

This case addressed the oral clinical manifestations of MBS and difficulties experienced during dental management, and suggested early tooth eruption as a potentially new clinical manifestation of this syndrome. Knowledge of the loop-mediated association among oral complications of this syndrome is essential to perfecting treatments.

MRPS17 promotes invasion and metastasis through PI3K/AKT signal pathway and could be potential prognostic marker for gastric cancer

In this study, the molecular mechanisms through which Mitochondrial Ribosomal Protein S17 (MRPS17) contributes to gastric cancer (GC) and its prognostic significance in GC have been explored. As a protein encoding gene, MRPS17 encodes a 28s proteins belonging the ribosomal protein S17P family. The specific roles and molecular mechanisms of MRPS17 in cancers remain ambiguous. It was revealed by analyzing data from TCGA and GEO that elevated expression of MRPS17 was significantly associated with invasion of GC and poor survival of GC patients. Then through univariate and multivariate Cox regression analyses it was demonstrated that MRPS17 an independent prognostic factor for GC patients (P<0.001). It was demonstrated by differentially expressed gene analysis and functional enrichment analysis that MPRS17 is related to PI3K/AKT pathway and Cell adhesion molecules (CAMs), while its function is mediated by collagen-containing extracellular matrix and receptor ligand/regulator activity. Then it was proven by in-vitro experiments that knocking down of MRPS17 gene in AGS and SGC7901 cells would significantly inhibit proliferation and invasion capability of these cells. Furthermore, it was revealed by cell immunofluorescence assay that as a ribosomalprotein, MRPS17 was mainly distributed in the cytoplasmic surface of cell membrane. Additionally, activation of PI3K/AKT pathway is responsible for malignant progression of glioma that was promoted by MRPS17.

In conclusion, it was revealed in the present study that MRPS17 promoted invasion and metastasis of GC and potential molecular mechanisms through which it exerted its influences on GC were explored, suggesting its potential as a novel prognostic biomarker for GC.

Embryology, Malformations, and Rare Diseases of the Cochlea

Despite the low overall prevalence of individual rare diseases, cochlear dysfunction leading to hearing loss represents a symptom in a large proportion. The aim of this work was to provide a clear overview of rare cochlear diseases, taking into account the embryonic development of the cochlea and the systematic presentation of the different disorders. Although rapid biotechnological and bioinformatic advances may facilitate the diagnosis of a rare disease, an interdisciplinary exchange is often required to raise the suspicion of a rare disease. It is important to recognize that the phenotype of rare inner ear diseases can vary greatly not only in non-syndromic but also in syndromic hearing disorders. Finally, it becomes clear that the phenotype of the individual rare diseases cannot be determined exclusively by classical genetics even in monogenetic disorders.

Surgical Treatment of Clubfoot in Children with Moebius Syndrome

Moebius syndrome (MS) is a rare disease, with paralysis of the VI and VII cranial nerves, frequently associated with clubfoot (CF). The aim of this study was to evaluate surgical treatment of CF in MS, providing its peculiarities. Between 1990 and 2019, we collected data of 11 MS patients with unilateral (n = 5) or bilateral (n = 6) CF, for a total of 17 feet (9R,8L). Six patients (3M,3F) for a total of 10 feet (6R,4L) were treated elsewhere, performing first surgery at an average age of nine months, and in our hospital for relapse surgery at an average age of 4.5 years (Group 1). Five patients (3M, 2F), for a total of seven feet (3R,4L), were primarily treated in our hospital with a peritalar release according to McKay at an average age of 9.4 months (Group 2). Diméglio score was used to assess CF severity. Three questionnaires were submitted for evaluation of subjective and functional results: American Orthopedics Foot and Ankle Society for Hindfoot (AOFAS), Foot and Ankle Outcome Score (FAOS), and Foot and Ankle Ability Measure (FAAM). Average AOFAS/FAOS/FAMM scores were 82.8, 84.8, and 82.3 for Group 1, and 93.2, 94.7, and 95.1 for Group 2 at an average follow-up of 16.9 and 13.3 years, respectively. The average Diméglio score improved from 15.5 to 4.8 in the long-term follow-up in Group 1 and from 14.6 to 3.8 in Group 2. The comparison between the groups showed better results for AOFAS, FAOS, and FAAM scores for Group 2, particularly for pain, function, and foot alignment and for the post-surgical Diméglio score. CF in MS is more severe and presented a higher relapse rate (58.8%) than idiopathic CF. Peritalar release showed no relapse and better subjective and functional results in the long-term follow-up compared to other surgical techniques

The epidemiology of Moebius syndrome in Italy

Background

The epidemiology of Moebius syndrome (MBS) is difficult to assess. In the present study, we investigated the epidemiology of MBS in a well-defined population within a precise geographical area.

Materials and methods

Our university hospital is the only national referral center for the diagnosis and treatment of MBS. Participants in this cross-sectional study were patients affected by MBS who had been periodically followed by our medical staff since 1998. Most of the patients were referred to our hospital by the Italian Association of Moebius Syndrome (AISMO). Demographic data necessary for study purposes were made available in the AISMO database, updated to April 2018. Subjects were assigned to geographical macroareas that are conventionally used in surveys and epidemiological investigations by the Italian National Institute of Statistics. The rates and prevalence of MBS cases were calculated on the basis of the last available survey of the Italian population. Each study parameter was then calculated with reference to the whole country and macroarea partition. The sex rate and the corresponding prevalence were calculated with respect to the weighted whole population and to the respective sex population. Chi-square analysis was adopted to investigate possible differences among geographical regions and/or sexes. A p value < 0.05 was considered statistically significant.

Results

One hundred and sixty-four out of 212 MBS patients fulfilled our inclusion criteria. All cases occurred in Caucasian patients and were sporadic. The median age at diagnosis was 3.6 years, ranging from 0 to 55 years; this range was significantly reduced to 0–5 years (median age at diagnosis: 2.2 years) in patients included after 2007. The calculated prevalence at birth was 0.06 cases per 10,000 live births, with an overall prevalence of 0.27/100,000, without any sex or geographical predominance.

Conclusions

The prevalence of MBS observed herein, rounded for possible underestimation, was 0.3/100,000 people, without any regional difference in the distribution of cases. Our data confirm the rarity of the disease on a national level.

A New Neurorehabilitative Postsurgery Intervention for Facial Palsy Based on Smile Observation and Hand-Mouth Motor Synergies

Objective

To perform a preliminary test of a new rehabilitation treatment (FIT-SAT), based on mirror mechanisms, for gracile muscles after smile surgery.

Method

A pre- and postsurgery longitudinal design was adopted to study the efficacy of FIT-SAT. Four patients with bilateral facial nerve paralysis (Moebius syndrome) were included. They underwent two surgeries with free muscle transfers, one year apart from each other. The side of the face first operated on was rehabilitated with the traditional treatment, while the second side was rehabilitated with FIT-SAT. The FIT-SAT treatment includes video clips of an actor performing a unilateral or a bilateral smile to be imitated (FIT condition). In addition to this, while smiling, the participants close their hand in order to exploit the overlapped cortical motor representation of the hand and the mouth, which may facilitate the synergistic activity of the two effectors during the early phases of recruitment of the transplanted muscles (SAT). The treatment was also aimed at avoiding undesired movements such as teeth grinding. Discussion. Results support FIT-SAT as a viable alternative for smile rehabilitation after free muscle transfer. We propose that the treatment potentiates the effect of smile observation by activating the same neural structures responsible for the execution of the smile and therefore by facilitating its production. Closing of the hand induces cortical recruitment of hand motor neurons, recruiting the transplanted muscles, and reducing the risk of associating other unwanted movements such as teeth clenching to the smile movements.

Long-term results of facial animation surgery in patients with Moebius syndrome

Gracilis neuromuscular transplant is considered the gold standard for facial animation in Moebius syndrome patients. However, long-term evaluation of the results has not been critically examined in the international literature. Thus, it remains unknown how the transplanted flap changes with facial growth, and whether contraction (smiling) is maintained. Pediatric patients with Moebius syndrome who underwent facial animation surgery with at least 5 years of follow-up were retrospectively examined. Photographs taken at the 1-year and most recent follow-up visits were analyzed and compared using Emotrics software. Analyses focused on the rest position, and on gentle and maximum smiles. Eighteen patients were enrolled. Seven patients had bilateral and 11 unilateral Moebius syndrome; therefore, 25 gracilis transplants were analyzed. The latest follow-ups ranged from 5 to 13.2 years (mean 7.6 years). The three principal facial expressions that were examined did not differ significantly between 1 year and a mean of 7.6 years after surgery, but tended to improve in most patients. Commissure excursion and smile angle for the maximum smile did improve significantly (p = 0.002 and 0.029, respectively). The series examined in this study supports the limited literature regarding the long-term stability of gracilis transplantation to animate the faces of Moebius syndrome children.

Intracranial calcifications in childhood: Part 2

This article is the second of a two-part series on intracranial calcification in childhood. In Part 1, the authors discussed the main differences between physiological and pathological intracranial calcification. They also outlined histological intracranial calcification characteristics and how these can be detected across different neuroimaging modalities. Part 1 emphasized the importance of age at presentation and intracranial calcification location and proposed a comprehensive neuroimaging approach toward the differential diagnosis of the causes of intracranial calcification. Pathological intracranial calcification can be divided into infectious, congenital, endocrine/metabolic, vascular, and neoplastic. In Part 2, the chief focus is on discussing endocrine/metabolic, vascular, and neoplastic intracranial calcification etiologies of intracranial calcification. Endocrine/metabolic diseases causing intracranial calcification are mainly from parathyroid and thyroid dysfunction and inborn errors of metabolism, such as mitochondrial disorders (MELAS, or mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes; Kearns-Sayre; and Cockayne syndromes), interferonopathies (Aicardi-Goutières syndrome), and lysosomal disorders (Krabbe disease). Specific noninfectious causes of intracranial calcification that mimic TORCH (toxoplasmosis, other [syphilis, varicella-zoster, parvovirus B19], rubella, cytomegalovirus, and herpes) infections are known as pseudo-TORCH. Cavernous malformations, arteriovenous malformations, arteriovenous fistulas, and chronic venous hypertension are also known causes of intracranial calcification. Other vascular-related causes of intracranial calcification include early atherosclerosis presentation (children with risk factors such as hyperhomocysteinemia, familial hypercholesterolemia, and others), healed hematoma, radiotherapy treatment, old infarct, and disorders of the microvasculature such as COL4A1- and COL4A2-related diseases. Intracranial calcification is also seen in several pediatric brain tumors. Clinical and familial information such as age at presentation, maternal exposure to teratogens including viruses, and association with chromosomal abnormalities, pathogenic genes, and postnatal infections facilitates narrowing the differential diagnosis of the multiple causes of intracranial calcification.

Splenogonadal fusion: a radiologic-pathologic correlation and review of the literature

We present the case of a 29-year-old male who presented to his General Practitioner with a left testicular lump. Scrotal ultrasound examination revealed 4 well-defined, homogenous, mildly hypoechoic extratesticular mass lesions. He was referred for an urgent urological opinion and underwent local excision. Histologic analysis revealed splenic tissue resulting in the diagnosis of splenogonadal fusion.

A Systematic Review of the Psychosocial Adjustment of Children and Adolescents with Facial Palsy: The Impact of Moebius Syndrome

Introduction: Facial palsy is often associated with impaired facial function and altered appearance. However, the literature with regards to the psychological adjustment of children and adolescents with facial palsy has not been systematically reviewed to date. This paper aimed to review all published research with regards to psychosocial adjustment for children and adolescents with facial palsy. Methods: MEDLINE, CINAHL, Embase, PsychInfo and AMED databases were searched and data was extracted with regards to participant characteristics, study methodology, outcome measures used, psychosocial adjustment and study quality. Results: Five studies were eligible for inclusion, all of which investigated psychosocial adjustment in participants with Moebius syndrome, a form of congenital facial palsy. Many parents reported their children to have greater social difficulties than general population norms, with difficulties potentially increasing with age. Other areas of psychosocial adjustment, including behaviour, anxiety and depression, were found to be more comparable to the general population. Discussion: Children and adolescents with Moebius syndrome may experience social difficulties. However, they also demonstrate areas of resilience. Further research including individuals with facial palsy of other aetiologies is required in order to determine the psychosocial adjustment of children and adolescents with facial palsy.

Sleep-related breathing disorders associated with the characteristics of underlying congenital rare diseases of Moebius syndrome and Poland syndrome

A 24-year-old woman was referred to us with daytime sleepiness. She has two congenital intractable and rare diseases, namely, Moebius syndrome and Poland syndrome. Physiological examinations and a detailed usage analysis under a ventilation device helped to conclude that hypoglossal nerve paralysis and thoracic deformity from her two underlying diseases were associated closely with her final diagnosis of obstructive sleep apnoea and sleep-related hypoventilation due to medical disorders. Bilevel positive pressure ventilation with auto-titrating expiratory positive airway pressure was effective. This is the first report that describes in detail the causal interactions between underlying two intractable and rare diseases and sleep-related breathing disorders.

Isolated Chromosome 6q27 Terminal Deletion Syndrome

Any change in either the short (p) or long (q) arm of chromosome six can result in a variety of disorders. 

A two-year-old female child came to us with a history of sudden onset generalized tonic-clonic seizure. She had a syndromic face with frontal bossing and palpable thinning of the right lower lip and an apparent facial asymmetry while crying due to the hypoplasia of the right depressor angularis oris. Her joints were hypermobile and hypotonic. Chromosomal karyotyping exhibited a normal female karyotype, but pathogenic microarray genetic evaluation showed a loss of approximately 783 kb of the 6q27 terminus. She was diagnosed with chromosome 6q27 terminal deletion and managed with anti-seizure medications. 

Chromosome 6q27 terminal deletion can present with an array of structural and developmental anomalies. It is, therefore, necessary to understand the typical phenotypic and distinctive clinical features of congenital chromosome 6q27 terminal deletion syndrome for early diagnosis and intervention.

Orofacial motor dysfunction in Moebius syndrome

AIM

To review orofacial disabilities and their consequences in children with Moebius syndrome (MBS).

METHOD

We retrospectively analysed the records of 32 patients (21 males, 11 females) with non-progressive bilateral facial and abducens palsies who had been examined before 6 months of age.

RESULTS

All facial muscles were severely involved in 17 patients; in the 15 others, partial movements were found in the lower face. Most patients (n=24) were unable to smile. Patients frequently presented with congenital trismus (n=20) and drooling (n=18). Additional palsies involved cranial nerves IX and X (n=18) and XII (n=25). Sucking was absent or weak in 30 patients; swallowing was impaired in 25. During the first month of life, feeding disorders were graded as severe/moderate in 25. Respiratory complications occurred in 17. Severe feeding disorders were associated with congenital trismus (p=0.01) and with cranial nerve IX and X palsy (p=0.01). Growth failure between 1 and 6 months of age, followed by catch-up growth between 6 and 12 months, was observed in 20 patients. Between 2 and 5 years of age, 25 out of 32 patients attained normal oral diet and 28 out of 29 showed normal growth.

INTERPRETATION

Children with MBS frequently require adjusted therapeutic options to prevent failure to thrive. Congenital trismus, cranial nerve IX and X palsy, and laryngeal-tracheal dysfunctions are predictors of severe feeding disorders.

WHAT THIS PAPER ADDS

Moebius syndrome frequently induces reduced oral intake and early failure to thrive. Normal oral diet and growth parameters are attained at 2 to 5 years of age. Congenital trismus, pharyngeal palsy, and laryngeal disorders predict dysphagia.

A Mouse Model of Dysphagia After Facial Nerve Injury

OBJECTIVE

Dysphagia is common following facial nerve injury; however, research is sparse regarding swallowing-related outcomes and targeted treatments. Previous animal studies have used eye blink and vibrissae movement as measures of facial nerve impairment and recovery. The purpose of this study was to create a mouse model of facial nerve injury that results in dysphagia to enhance translational research outcomes.

STUDY DESIGN

Prospective animal study.

METHODS

Twenty C57BL/6J mice underwent surgical transection of the main trunk (MT) (n = 10) or marginal mandibular branch (MMB) (n = 10) of the left facial nerve. Videofluoroscopic swallow study (VFSS) assays for drinking and eating were performed at baseline and 14 days postsurgery to quantify several deglutition-related outcome measures.

RESULTS

VFSS analysis revealed that MT transection resulted in significantly slower lick and swallow rates during drinking (P ≤ .05) and significantly slower swallow rates and longer inter-swallow intervals during eating (P ≤ .05), congruent with oral and pharyngeal dysphagia. After MMB transection, these same VFSS metrics were not statistically significant (P > .05).

CONCLUSION

The main finding of this study was that transection of the facial nerve MT leads to oral and pharyngeal stage dysphagia in mice; MMB transection does not. These results from mice provide novel insight into specific VFSS metrics that may be used to characterize dysphagia in humans following facial nerve injury. We are currently using this surgical mouse model to explore promising treatment modalities such as electrical stimulation to hasten recovery and improve outcomes following various iatrogenic and idiopathic conditions affecting the facial nerve.

LEVEL OF EVIDENCE

NA Laryngoscope, 131:17-24, 2021.