19 July 2010
Posted in Pearls in Ophthalmology
PIO congratulates Srinivas Iyengar, MD, winner of the Volume 5 Issue 1 Photo Quiz! Dr. Iyengar wins a $100 Amazon.com gift card.
Answer: One-and-a-half syndrome
The one and a half syndrome is characterized by a conjugate horizontal gaze palsy in one direction and an internuclear ophthalmoplegia in the other. The most common manifestation of this syndrome is limitation of horizontal eye movement to abduction of one eye with no horizontal movement of the other eye. Nystagmus is present when the eye on the opposite side of the lesion is abducted. Convergence is classically spared as Cranial Nerve III and its nucleus is spared bilaterally. Differential diagnoses include: pontine hemorrhage, ischemia, tumors, mass lesions, and multiple sclerosis.