Teaching Video NeuroImages: Almost No Eye Movements to the Left

A 31-year-old patient had acute dizziness and lateropulsion to the right. Neuro-ophthalmologic examination revealed (1) a saccade gaze palsy left (video 1, part A), (2) “half-pathologic” head-impulse test right B), but (3) bilaterally normal adduction during convergence reaction C), findings typical for abducens nuclear palsy. It was caused by histologically proven cavernoma in tegmentum pontis (figure). To differentiate an from combined lateral contralateral medial rectus muscle palsy, one must reaction, which goes via direct pathways oculomotor nucleus.1