メビウス症候群

Moebius syndrome (OMIM #157900) is a rare congenital cranial dysinnervation disorder characterized by abducens (CN VI) and facial (CN VII) nerve palsies with variable craniofacial and limb anomalies. Despite advances in genomic testing, the majority of patients remain genetically unexplained. Episignature testing, which detects syndrome-specific DNA methylation patterns, has emerged as a complementary diagnostic tool for conditions with shared developmental mechanisms. We describe an 8-month-old male born prematurely with bilateral clubfoot, craniofacial dysmorphism, feeding difficulty requiring gastrostomy tube placement, and respiratory failure requiring tracheostomy. Neuroimaging demonstrated absence of bilateral abducens and facial nerves with pontocerebellar hypoplasia, supporting a clinical diagnosis of Moebius syndrome. Extensive genetic evaluation, including genome sequencing and targeted testing for hypotonia and hypoventilation syndromes, was nondiagnostic. Episignature analysis revealed a moderately positive methylation signature consistent with a recurrent constellation of embryonic malformation (RCEM), concordant with two of three previously validated RCEM classifier models. To our knowledge, this is the first report of a patient with a positive RCEM episignature and Moebius syndrome, suggesting a common embryologic pathway. Episignature testing may represent a valuable diagnostic tool in patients with Moebius syndrome and related craniofacial-limb malformation spectra when conventional genomic testing is unrevealing.

Although recognizing emotions from facial expressions appears effortless, the field is divided between vision-based accounts, which posit matching to learned visual templates, and embodied accounts, which posit recruitment of facial motor circuits. We propose an ambiguity-gated, developmentally calibrated architecture in which the recognition system draws on sensorimotor information primarily when visual evidence is insufficient, with early motor experience proposed to shape the threshold and gain of this contribution. We tested this model across three studies (N = 185) integrating dynamic prototypical and nonprototypical expressions, congenital (Moebius syndrome) and acquired facial palsy, and standardized severity grading (Sunnybrook Facial Grading System; SFGS). Neurotypical adults (N = 117) confirmed a robust prototypicality-dependent cost on recognition. Both congenital (N = 15) and acquired (N = 19) cohorts showed severity-performance coupling for nonprototypical expressions, consistent with shared reliance on sensorimotor information when visual evidence is insufficient; only the Moebius cohort showed this coupling also for prototypical expressions, consistent with undercalibrated visual templates following lifelong atypical facial motor experience. Exploratory electroencephalography (EEG) revealed reduced sensorimotor-face-network functional connectivity in Moebius, consistent with altered cross-route integration. Reanalysis of an independent dataset of ultra-ambiguous static morphs replicated severity-performance coupling and revealed Moebius-control mean differences only under high perceptual demand. Together, the findings provide strong behavioral support for an ambiguity-gated, developmentally calibrated architecture and motivate direct tests of how developmental motor experience shapes when-and how strongly-the recognition system draws on sensorimotor information.

INTRODUCTION: Chronic facial paralysis severely compromises facial symmetry and function. The free gracilis muscle flap has become the gold standard for dynamic facial reanimation. This study aims to evaluate the functional and aesthetic outcomes of gracilis free muscle flap procedures performed at the Facial Paralysis Clinic of Hospital General "Dr. Manuel Gea González," using the Terzis Functional Grading System and the eFACE (Electronic Facial Paralysis Assessment) digital assessment tool. MATERIALS AND METHODS: A retrospective, cross-sectional, and analytical study was conducted on 52 patients who underwent free gracilis muscle flap surgery for facial reanimation between 2018 and 2023. Inclusion criteria were chronic facial paralysis and complete pre- and postoperative assessments using the Terzis grading system. In unilateral cases, the eFACE scale was also used. Functional and aesthetic outcomes were analyzed using paired Student's t -tests. RESULTS: Of the 52 procedures, 62% involved unilateral paralysis. The most common etiology was classic Moebius syndrome (35%). Significant functional improvement was observed on the Terzis scale, with mean scores increasing from 1.1 to 3.1 postoperatively ( p < 0.01). In unilateral cases, the eFACE scale demonstrated significant improvements in static symmetry, dynamic movement, midface/smile, and lower face/neck domains. No significant changes were observed in synkinesis or periocular function. Postoperatively, 52% of patients achieved good outcomes (group IV), and 86% of procedures were free of complications. CONCLUSION: The free gracilis muscle flap significantly improves facial function and aesthetic in patients with chronic facial paralysis. These findings validate its effectiveness and highlight the value of objective assessment tools for outcome measurement and future research.

PURPOSE: To report the surgical outcomes of the treatment of vertical deviation in patients with Möbius syndrome. METHODS: A retrospective review of the medical records of patients diagnosed with Möbius syndrome treated at the Ricardo Gutiérrez Children's Hospital between 2010 and 2024 was performed. Age, sex, and horizontal and vertical ocular deviations before and after surgery were recorded. Ocular deviation was measured using the alternate prism and cover test or Krimsky test according to patient cooperation. RESULTS: Sixty-two children were included, of whom 18 underwent surgical treatment. Most surgically treated patients presented with esotropia and were managed with bilateral medial rectus recession, with a mean recession of 7 mm (range: 4-12 mm). The mean preoperative horizontal deviation was 53 prism diopters (PD) of esotropia (range: 25-70 PD). Only 2 of 62 patients presented with exotropia. Vertical deviation was clinically evident in 14 of 62 patients, but only 5 underwent surgical correction. In all surgically treated cases, the vertical deviation corresponded to dissociated vertical deviation (DVD). One patient underwent bilateral superior rectus recession combined with horizontal surgery, one patient underwent unilateral superior rectus recession, and three patients underwent inferior rectus plication as a second procedure, achieving excellent postoperative alignment. CONCLUSIONS: Although esotropia with bilateral abduction limitation represents the predominant pattern in Möbius syndrome, vertical deviation is clinically evident in almost one quarter of patients. Inferior rectus plication proved to be a safe and effective technique for the surgical resolution of hypertropia in these cases.

BACKGROUND: The facial vein is the standard recipient vessel in facial reanimation surgery. Its complete absence is rarely described but may cause major challenges during free functional muscle transfer (FFMT). This study aimed to determine the prevalence and predictors of facial vein absence and assess its surgical relevance in facial reanimation patients. METHODS: A retrospective analysis of 198 patients who underwent FFMT between 2005 and 2025 was performed. Facial vein presence was evaluated intraoperatively, and all patients had preoperative Doppler ultrasonography. Potential predictors were analyzed using logistic regression and Fisher's exact test. RESULTS: Facial vein aplasia occurred in 12 patients. Aplasia was significantly associated with congenital etiology and syndromic palsy, especially Moebius syndrome. No associations with age, sex, operative time, or complications were found. CONCLUSIONS: Facial vein aplasia is strongly linked to congenital and syndromic palsy. Preoperative Doppler ultrasonography is recommended for identifying venous anomalies and optimizing surgical planning. TRIAL REGISTRATION: Freiburger Register Klinischer Studien (FRKS): Number FRKS005811.