Dorsal midbrain (Parinaud) syndrome

A 52-year-old man presented with sudden onset of vertical diplopia, limited vertical gaze (figure 1), vertical oscillopsia, taste changes and lip numbness. His family had noted left-sided facial changes, with flattening of the nasolabial fold (figure 2). He had no significant medical or family history. He worked as a bus driver, drank 21 units of alcohol per week and had a smoking history of 9 pack-year. Figure 1 Limitation of vertical gaze. Figure 2 Left facial nerve palsy. On examination, there was subtle unilateral upper motor neurone facial weakness. He had normal visual acuity, colour vision, visual fields and fundus examination. Eye movement examination showed completely absent voluntary up and down gaze, both saccadic and pursuit, with some vertical gaze on the doll’s head manoeuvre. Pupil examination identified loss of pupillary contraction to light with …