Cervico-Oculo-Acoustic Syndrome

At a glance

A congenital condition affecting mostly females and consisting of the triad of ☞Klippel-Feil Syndrome, ☞Duane Retraction Syndrome, and Congenital Sensorineural Deafness.

Synonyms

COA Syndrome; Wildervanck Syndrome.

History

It bears the name of the Dutch geneticist L.S. Wildervanck who described this disorder in 1952, but previous reports exist.

Incidence

Approximately 100 cases have been described.

Genetic inheritance

Most cases appear to be sporadic; however, polygenic and X-linked dominant inheritance have been discussed due to the overwhelming female predominance in these patients, which might also suggest that the disorder is typically lethal males. The described vertebral anomalies originate during the third and eighth week of embryogenesis as a result of abnormal segmentation of mesodermal somites. This process may also be responsible for the occasionally associated cardiovascular anomalies (eg, single coronary artery, persistent left superior vena cava, patent foramen ovale). Deafness is caused by a bony malformation of the inner ear.

Diagnosis

Based on clinical findings of the (sometimes incomplete) triad of bilateral abducens paresis with ☞Duane retraction syndrome, deafness, and Klippel-Feil Syndrome. Diagnostic imaging is used to confirm the vertebral anomalies.

Clinical aspects

Deafness may be sensorineural, conductive, or mixed, and bi- or unilateral. The neck is short, has a webbed appearance, and there is a variable degree of fusion and segmentation defects of the upper cervical spine, but may also involve other parts of the cervical, thoracic, and/or lumbar spine (Klippel-Feil Syndrome). Abducens nerve palsy with globe retraction manifesting on medial gaze is present (Duane retraction syndrome). Additional abnormalities may include proportionate short stature, microcephaly, hydrocephalus, brainstem and cerebellar hypoplasia, ☞Arnold-Chiari malformation, occipital meningocele, structural facial asymmetry, facial palsy, low-posterior hairline, preauricular skin tags, ptosis, strabismus, pseudopapilledema, cleft palate, kyphoscoliosis, spina bifida, and Sprengel deformity (elevated, hypoplastic scapulae). Facial asymmetry is usually progressive until adulthood with increasing growth discrepancy between the normal and the non- or slow-growing side. This also means that a previously “manageable or easy airway” could later turn into a “difficult airway.” Occasionally, abnormal bony masses in the region of the mandibular rami can further limit mouth opening. Mirror movement disorder has been reported in some patients. One case report describes ☞Diastematomyelia of the lower medulla and cervical cord that was accompanied by vermian hypoplasia and tonsillar herniation of the cerebellum resulting in triventricular hydrocephalus. Cardiac defects such as atrial and/or ventricular septal defects may be present. Intelligence is usually normal, but some patients with mental retardation have been reported.

Precautions before anesthesia

Patients with the Klippel-Feil Syndrome are vulnerable to cervical cord injury during laryngoscopy secondary to head and neck movements. Evaluate the spine clinically and obtain conventional radiographs and/or ...