Orthopedic Manifestations of Mobius Syndrome: Case Series and Survey Study

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.

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.

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

Characterization of Hand Anomalies Associated With Möbius Syndrome

PURPOSE

To investigate the distinguishing morphological characteristics of the upper extremities in children with Möbius syndrome.

METHODS

Twenty-seven involved extremities in 14 patients with a diagnosis of Möbius syndrome were identified at 2 institutions. Medical records, radiographs, and clinical photographs were evaluated. Congenital hand differences were classified according to the Oberg, Manske, and Tonkin classification, and hands with symbrachydactyly were classified by the Blauth and Gekeler classification. The presence of other congenital anomalies was catalogued.

RESULTS

There was bilateral involvement in 93% of patients with congenital hand anomalies. Twelve patients demonstrated congenital hand anomalies and 2 patients had been diagnosed with arthrogryposis. Among the 12 patients with congenital hand anomalies, 21 hands were classifiable as symbrachydactyly by the Oberg, Manske, and Tonkin classification and could be categorized by the Blauth and Gekeler classification. Short finger type was the most common subtype of symbrachydactyly, present in 13 hands. Eleven of these 13 patients (85%) were primarily affected on the radial side of the hand. Proximal arm involvement was identified in 2 patients with symbrachydactyly, both of whom had Poland syndrome and an absent pectoralis major.

CONCLUSIONS

Symbrachydactyly in Möbius syndrome differs from the typical presentation of symbrachydactyly. Characteristically, there is a bilateral presentation with a strong predilection for radially based brachydactyly. These described characteristics may help the hand surgeon appropriately assess patients, especially those with radial-sided symbrachydactyly.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic III.

Moebius Syndrome with Hypoglossal Palsy, Syndactyly, Brachydactyly, and Anisometropic Amblyopia

Moebius syndrome is a rare cause of congenital facial and abducens palsy. It is sometimes associated with musculoskeletal abnormalities and other cranial nerve palsies. Genetics and ischemic insults to the fetus are considered to be the cause of this syndrome. We report here a 12-year-old female patient who was presented to us with poor cosmesis of her face, with associated decreased vision and lagophthalmos in her left eye. She didn't have any signs of exposure keratopathy in the affected eye. Her best-corrected vision was 20/20 and 20/60 in right and left eyes respectively. The cause of decreased vision in her left eye was found to be anisometropic amblyopia, due to asymmetric hyperopic astigmatism in her eyes. She did not report diplopia in any gaze position. Examination of her cranial nerve revealed left facial, abducens, and hypoglossal nerve palsy, leading us to the diagnosis of Moebius syndrome. Apart from that, she had syndactyly in one of her hands, and brachydactyly in both. Since the eyes were straight in their primary position, no surgical intervention was carried out for her lagophthalmos, which was measured to be only 2 mm. This was to prevent any post-operative iatrogenic ptosis. The condition requires a multidisciplinary approach involving the opinions of a neuro-ophthalmologist, strabismologist, and oculoplastics for the management of the complications associated with the disease.

Trimorphic extreme clubfoot deformities and their management by triple surgical skin expanders- DOLAR, DOLARZ and DOLARZ-E (evidence based mega-corrections without arthrodesis)

AIM/PURPOSE

Extreme congenital club foot deformities are common in developing countries, presenting at birth, persisting in children, adolescents and adults; as untreated/under-corrected by conservative and/or surgical means. Scores of confusing names exist in literature for such deformities with no good treatment available; mostly advocating unacceptable arthrodesis. The author researched this grey area for more than 40 years and successfully innovated improved surgical corrections, more acceptable to patients.

METHODS

All were given a generic name: "extreme deformities", with 3 hierarchic grades. each 3D (trimorphic) because of their common aim: a good correction. The author started with anatomical dissections in clubfeet (zero cost), consistently reinforced with solid clinical background. Heterogeneous skin contractures, congenital with/without scars, were discovered as the primary cause with cramped deeper tissues and evolved, evidence based, 3D enlargement of skin chamber by triple expanding incisions: DOrso-LAteral Rotation skin flap (DOLAR- acronym) for grade I, DOLAR + Z-plasty (DOLARZ) for grade II and DOLAR + Z + VY-plasty (DOLARZ-E) for grade III, E means Extended. Patient satisfaction level (excellent, good, fair/poor) had been considered for grading results, rather than scoring systems because each clubfoot is different with countless variables.

RESULTS & CONCLUSIONS

The author operated 1080 feet during the last 40 years with long term follow up, six months to 30 years, with an average of 12½ years. The results obtained were: excellent/good (96%) and fair/poor (4% including superficial skin necrosis only in 3%, evidence based). Triple surgical skin expansion consistently resulted in longer, flexible, joints sparing, good shaped, better functioning foot; even in adults.

An interesting case of systemic lupus erythematosus in a patient with Moebius syndrome

Moebius' syndrome (MS) is characterized by a nonprogressive facial palsy associated with impairment in eye abduction, which can be uni- or bilateral. Some authors raise the possibility that patients with MS may suffer from social stigmatism due to their facial dysmorphism and that constant teasing and bullying perpetrated by people in the same social circle are adjuvants in the development of low self-esteem, behavioral problems, and even psychiatric disorders. Psychological stress, anxiety, and depression are factors contributing to both development and impairment of autoimmune diseases, such as systemic lupus erythematosus (SLE). The objective of this work is to report the case of a patient with MS who developed SLE. In the present case report, we have emphasized the importance of both clinical dental examination and surgeon-dentist in the early diagnosis of systemic diseases by considering that these conditions can affect both syndromic and normoreactive patients.

Mobius Syndrome: A 35-Year Single Institution Experience

BACKGROUND

Mobius syndrome is a rare syndrome that is known to be associated with a variety of orthopaedic conditions including scoliosis, clubfoot, transverse limb deficiencies, Poland syndrome, and a myriad of hand conditions. To date, no large series exist to characterize the orthopaedic manifestations of Mobius syndrome.

METHODS

Medical records at a single tertiary pediatric institution were reviewed for all patients diagnosed with Mobius syndrome from January 1, 1980 to December 31, 2015. Records and radiographs were reviewed for associated orthopaedic conditions and their management.

RESULTS

In total, 44 patients with Mobius syndrome were identified. Age at presentation ranged from 6 days to 14 years. When compared with the general population, patients with Mobius syndrome had an increased incidence of clubfoot (41%), Poland syndrome (20%), and scoliosis (14%). Clubfoot treated both before and after the institution of Ponseti casting had a high rate of requiring posteromedial release, with a significant rate of subsequent revision. Hip dysplasia was noted in 1 patient and required surgical correction. Other associated syndromes included arthrogryposis, Pierre Robin syndrome, and chromosome 10 defect.

CONCLUSIONS

Mobius syndrome is accompanied by an increased rate of several orthopaedic problems; most notably clubfoot, scoliosis, and upper extremity differences that often require surgical treatment. The management of clubfoot in the setting of Mobius syndrome often requires surgical intervention due to failure of casting, and seems to have a higher rate of need for revision. Early involvement of orthopaedists in the care of patients with Mobius syndrome is often necessary. Orthopaedist should counsel families that treatment may be more complex than that of idiopathic disease.

LEVEL OF EVIDENCE

Level IV-case series.

Update on 13 Syndromes Affecting Craniofacial and Dental Structures

Care of individuals with syndromes affecting craniofacial and dental structures are mostly treated by an interdisciplinary team from early childhood on. In addition to medical and dental specialists that have a vivid interest in these syndromes and for whom these syndromes are of evident interest, experts of scientific background-like molecular and developmental geneticists, but also computational biologists and bioinformaticians-, become more frequently involved in the refined diagnostic and etiological processes of these patients. Early diagnosis is often crucial for the effective treatment of functional and developmental aspects. However, not all syndromes can be clinically identified early, especially in cases of absence of known family history. Moreover, the treatment of these patients is often complicated because of insufficient medical knowledge, and because of the dental and craniofacial developmental variations. The role of the team is crucial for the prevention, proper function, and craniofacial development which is often combined with orthognathic surgery. Although the existing literature does not provide considerable insight into this topic, this descriptive review aims to provide tools for the interdisciplinary team by giving an update on the genetics and general features, and the oral and craniofacial manifestations for early diagnosis. Clinical phenotyping together with genetic data and pathway information will ultimately pave the way for preventive strategies and therapeutic options in the future. This will improve the prognosis for better functional and aesthetic outcome for these patients and lead to a better quality of life, not only for the patients themselves but also for their families. The aim of this review is to promote interdisciplinary interaction and mutual understanding among all specialists involved in the diagnosis and therapeutic guidance of patients with these syndromal conditions in order to provide optimal personalized care in an integrated approach.