Abstract

Vertical gaze palsy is usually associated with lesions of the rostral midbrain and thalamo-mesencephalic junction. The rostral interstitial nucleus of the medial longitudinal fasciculus (riMLF), the interstitial nucleus of Cajal, and the posterior commissure located in the midbrain are the critical area in supranuclear control of vertical eye movements. We describe a case of vertical one-and-a-half syndrome accompanying contralateral abduction and incomplete depression palsy due to thalamo-mesencephalic infarction. These vertical eye movement abnormalities are presumed to be caused by damage to the ipsilateral riMLF, interstitial nucleus of Cajal, and oculomotor fascicles.

• Keywords: Vertical one-and-a-half syndrome; Gaze palsy; Midbrain;