A new type of Duane's syndrome: Twitch abduction on attempted upgaze and V-incomitance due to misinnervation of the lateral rectus by superior rectus neurons

Abstract

A patient with V-incomitance and twitch abduction of the left eye on attempted upward saccades is described. Twitch abduction is accompanied by a slight retraction of the globe. The findings are compatible with congenital misinnervation of the left lateral rectus muscle by high threshold neurons originally intended to serve elevator muscles, i.e., the superior rectus and/or the inferior oblique. It is suggested that this unique ocular motor abnormality represents a new type of Duane's retraction syndrome.

Key Words:

• Duane's retraction syndrome
• congenital ocular motor abnormality
• misinnervation of lateral rectus muscle