Cranial nerve defects in congenital facial palsy

Cranial nerve defects were enumerated in 29 children with congenital facial palsy presenting for reanimation via chart review with a view to determining unaffected donor nerves. The literature was searched via Medline to reveal 186 additional case reports that were complete enough in their description to allow assessment of cranial nerve defects.

The group presenting for reanimation comprised 24 females and 5 males. All of the males had unilateral isolated facial nerve paralysis. Of the females, 9 had isolated unilateral palsy and 14 had bilateral palsy, and half of these were isolated. Six had bilateral abducens nerve palsy, fulfilling the original definition of Möbius syndrome. Of these, 3 had a right-sided hypoglossal weakness, one had a bilateral oculomotor palsy, and one had a bilateral trochlear palsy. One girl had bilateral facial and auditory involvement. The literature review revealed a group that was 60% male, with 85% having bilateral facial palsy. Abducens palsy was present in 68%, glossopharyngeal in 28%, hypoglossal in 26%, and oculomotor in 20%. The group was very heterogeneous in many ways.

There are many theories of pathogenesis of this syndrome. Isolated facial palsy is in concordance with previous findings of nerve lesions within the temporal bone. Multiple cranial nerve defects are more likely to have brainstem lesions, related to prenatal ischemic events. The cranial nerve least likely to be involved was the accessory nerve, suggesting that this may be a reliable donor for reanimation procedures.