A congenital condition affecting mostly females and
consisting of deafness, vertebral fusion, and abducens palsy.
COA Syndrome; Wildervanck Syndrome.
First described by the Dutch geneticist L.S. Wildervanck
Approximately 85 cases have been described.
Most cases appear to be sporadic, however,
polygenic and X-linked dominant inheritance have been discussed.
Deafness is a result of a bony malformation of the
inner ear. The Klippel-Feil Syndrome (see Clinical Aspects) may involve fusion of cervical,
thoracic, and/or lumbar vertebrae; however, fusion of C2-C3 is the most
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.
Deafness may be sensorineural, conductive, or
mixed. The neck has a webbed appearance, and there is a variable degree of
cervical fusion (Klippel-Feil syndrome). Abducens nerve palsy with globe
retraction on looking medially is present (Duane retraction syndrome).
Additional abnormalities may include short stature, microcephaly,
hydrocephalus, brainstem and cerebellar hypoplasia, occipital meningocele,
structural facial asymmetry, facial palsy, strabismus, cleft palate,
scoliosis, Sprengel deformity (elevated, hypoplastic scapula), spina bifida,
preauricular, tags and pseudopapilledema. 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 usually is normal, but some patients
with mental retardation have been reported.
Patients with the Klippel-Feil
syndrome are vulnerable to cervical cord injury during laryngoscopy and
during head and neck movements. Evaluate the spine clinically, and obtain
conventional radiographs and/or computed tomography scanning. Neurologic
lesions occur most frequently at the cervicooccipital junction. Assess for
increased intracranial pressure and congenital cardiac lesions
(echocardiography may be required). In a minority of cases, lung and/or
kidney problems have been described. In this case, lung function tests with
blood gas analysis and/or a complete blood count with serum concentrations
of electrolytes, creatinine, and blood urea nitrogen may be indicated.
Patients may have cervical instability
and are at high risk for spinal cord injury during direct laryngoscopy,
tracheal intubation, and positioning for surgery. The patient should be
managed as an unstable cervical spine and should have inline stabilization
for laryngoscopy and intubation. However, tracheal intubation may be
difficult because of restricted neck movement. Given the risk of spinal
lesions on intubation, awake fiberoptic intubation is the technique of
choice. Alternatively, asleep fiberoptic intubation or (intubating)
laryngeal mask can be used (particularly in children), however then the
“real-time” neurologic monitoring of the awake patient is not available in
this scenario. Use of continuous spinal cord monitoring (if available) is then recommended.
Intraoperatively, the head and neck should be maintained in a position that
has been determined preoperatively to be safe. Meticulous attention must be