CASE 17405 Published on 23.09.2021

Möbius Syndrome Neuroimaging Evaluation: a Rare but Accurate Diagnosis

Section

Neuroradiology

Case Type

Clinical Cases

Authors

Caio Tasso Oliveira Rêgo, Héber Samuel Colares Costa, Pedro Neves Paiva de Castro, Roberto Queiroz dos Santos, Elissandra Melo Lima, Dequitier Carvalho Machado

Radiology Department, Hospital das Américas. Américas Serviços Médicos, Rio de Janeiro, Brazil

Patient

14 years, female

Categories
Area of Interest Neuroradiology brain ; Imaging Technique MR
Clinical History

A 14-year-old female presented permanent convergent strabismus and absence of facial mimic in the neurological evaluation. The patient's parents reported that she always had that "facial expression" and had difficulties ingesting and talking. During her development, she also presented a slight cognition delay.

Imaging Findings

The investigation consisted of magnetic resonance imaging (MRI), emphasizing the posterior fossa, including the volumetric gradient echo sequence FIESTA (fast imaging employing steady-state acquisition) for cranial nerves anatomical delineation.

The MRI demonstrated the absence of the cisternal segment of the abducens and facial nerves, bilaterally, as also the absence of the inner ear canal segment of the facial nerve. Additionally, MRI showed flattening on the floor of the fourth ventricle in the pons, which represents the hypoplasia of the facial colliculus. Trigeminal and vestibulocochlear nerves presented normal thickness and course.  Further, there was a Blake's pouch remnant posterior to the cerebellum (Figs. 1-7).

Discussion

The Möbius syndrome is a genetic disturbance characterized by the absence of the lateral ocular movement, resulting in convergent strabismus, associated with facial paralyzes [1,2]. In addition, other cranial and musculoskeletal anomalies could be associated [2]. The precise etiological mechanism of the condition is unknown; however, there are reports of association with hypoxia during gestation and drugs like thalidomide [1,2]. In this case, the patient's mother related a high-risk pregnancy with a suspect of placental abruption.

Although other cranial nerves could be affected, the absence of the sixth and seventh nerves is the syndrome's hallmark [3,4]. Besides that, other findings such as flattening of the IV ventricle floor, representing the hypoplasia of the facial colliculus, supra and infratentorial cerebrospinal fluid cysts, thalamic fusion, dysgenesis of the callosum body, alterations on the brainstem and other anomalies are described in this disease [3].

In this case, the clinical presentation associated with the imaging assessment showing absence of abducens and facial nerves, flattening of the IV ventricle floor, and infratentorial Blake's pouch remnant corroborate the diagnosis [3-5].

Conclusively, the MRI assessment of Möbius syndrome with volumetric sequences allows accurate anatomical evaluation of cranial nerves, enabling the diagnosis and changing the patient's multidisciplinary approach and prognosis.

Differential Diagnosis List
Moebius Syndrome
Duane syndrome
Tubulinopathies
Pontine tegmental cap dysplasia
Pontinocerebellum cistern tumors compromising the brainstem and nerves
Final Diagnosis
Moebius Syndrome
Case information
URL: https://www.eurorad.org/case/17405
DOI: 10.35100/eurorad/case.17405
ISSN: 1563-4086
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