Asymmetric Bilateral Fourth Nerve Palsies: Observations and Considerations

Abstract

Acquired bilateral superior oblique paralyses are most often caused by antecedent head injuries. The spectrum of bilateral involvement ranges from complete symmetry to such asymmetry that the condition may be mistaken for unilateral paralysis.

Asymmetry may be present at the onset or occur during the course of recovery. Patients often do not volunteer complaints of torsion, and therefore excyclotorsion is frequently overlooked.

Some observations regarding the clinical findings in these bilateral presentations, particularly the asymmetric cases, are given. The authors believe that the presence of contralateral excyclotorsion is suggestive of bilateral involvement, in seemingly unilateral paralysis of the superior oblique.

• Cranial nerve IV palsy
• superior oblique palsy
• diplopia
• torsion
• paradoxical excyclotorsion