Lateral Rectus Dysfunction and “Associated Things”

Abstract

Congenital lateral rectus dysfunction primarily encompasses the following groups: lateral rectus palsy, Duane syndrome, Möbius sequence (syndrome), and horizontal gaze palsy. A true incidence of each of these ocular motility disorders is not well established. However, one of the most common conditions is Duane syndrome, which also is one of the most interesting because of the associated aberrant innervation and the presence of systemic malformations in some cases. The literature on thalidomide embryopathy strongly suggests that at least some cases of Duane syndrome can result from an insult to the developing brain stem early in the 4th week of gestation. Möbius sequence is usually a sporadic occurrence but also has many associated anomalies involving the limbs or craniofacial structures. There is a spectrum of ocular motility patterns in both of these conditions, and any given patient may show an ocular motility picture that is compatible with either Duane syndrome or Möbius sequence.

Aberrant lacrimation and facial nerve palsy have been reported with Duane syndrome, thalidomide embryopathy, and Möbius sequence, again suggesting some developmental relationship of the three conditions. One speculation about the pathophysiology of Möbius sequence is temporary vascular disruption resulting in hypoxia to a vulnerable area of the brain stem. This hypothesis is supported by clinical conditions in which episodes of vascular disruption early in the pregnancy were associated with the infant having the characteristic findings of Möbius sequence.

• Duane syndrome
• sixth nerve palsy
• thalidomide
• Wildervanck syndrome
• autism