Isolated pseudoabducens palsy in acute thalamic stroke.

Oculomotor abnormalities are rarely noted in thalamic strokes. We describe isolated right pseudoabducens palsy in a young patient with acute left thalamic infarction revealed by diffusion-weighted magnetic resonance imaging. The patient's horizontal diplopia and oculomotor palsy resolved within 3days. This case supports the hypothesis that a lesion can cause isolated esotropia by interrupting descending inhibitory convergence pathways that traverse the paramedian thalamus and decussate in the subthalamic region to innervate the contralateral third oculomotor nucleus. Esotropia contralateral to the thalamic lesion results from tonic activation of the medial rectus, producing pseudoabducens palsy.