The Baby Who Never Smiles

Discussion

This patient's presentation is consistent with Moebius (or Möbius) syndrome.

Moebius syndrome is a rare congenital condition that was first described by German neurologist Paul Julius Möbius. The current definition varies among investigators, but some of the most common clinical components that are included are craniofacial and extremity abnormalities.^[1]

The most common cranial nerve manifestations include facial weakness consistent with cranial nerve VII palsy and weakened ocular abduction consistent with cranial nerve VI palsy.^[1] There is a range in severity and laterality of the affected muscles among affected individuals. Approximately 85% of patients with Moebius syndrome have extremity malformations, including the talipes, digital hypoplasia, or syndactyly.

Given the rarity of this syndrome (approximately 0.002%-0.0002% of births), the patient's presentation may fall along a spectrum of potential signs and symptoms.^[1] These patients can present challenges for both surgeons and anesthesiologists. The presence of craniofacial abnormalities can make routine anesthetic procedures, such as intubation, more difficult.^[2] These challenges highlight the importance of correctly diagnosing this condition to ensure careful treatment planning and evaluation for the presence of concurrent abnormalities.

The most common ophthalmologic presentation is either unilateral or bilateral esotropia as a result of reduced lateral rectus function. Cranial nerve III and IV involvement will result in vertical and torsional deficits. Cranial nerve VII palsy produces lagophthalmos and resultant exposure keratitis. The variety of ocular abnormalities in Moebius syndrome necessitates careful ophthalmologic examination to be alert to the spectrum of possible presentations when evaluating these patients.^[2]

The etiology of Moebius syndrome is not known, but it appears to be multifactorial. There has been evidence of a genetic component related to various loci on chromosomes 3, 10, and 13.^[3]

There is no definitive treatment for Moebius syndrome, but both surgical and medical treatment options allow patients to experience improved visual outcomes. These individuals are at increased risk for corneal abrasions caused by lagophthalmos requiring extra lubrication.

Musculoskeletal abnormalities can be corrected with splinting or prostheses.^[4] The surgical approach to strabismus as a result of abducens nerve palsy usually involves medial rectus muscle recession as an initial procedure. Often, these patients will require multiple surgical interventions to correct the strabismus.^[2]

Cite this: The Baby Who Never Smiles - Medscape - Apr 03, 2014.

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