Vertical 'half-and-a-half'syndrome

Abstract

The patient's behavioural impairment and right-sided ataxia improved significantly over the following week and the patient was discharged with residual anterograde amnesia, minimal word finding difficulties and vertical diplopia. [...]we suggest that the contralateral upward gaze palsy resulted from injury to the premotor fibres that innervate the contralateral superior rectus and ipsilateral inferior oblique subnuclei within the posterior commissure. 3 4 Since both the rostral interstitial medial longitudinal fasciculus and the posterior commissure are within the territory of the thalamo-subthalamic paramedian artery, 5 their simultaneous injury would explain this unique combination of vertical eye movement deficits.