Conjugate upward gaze paralysis with unilateral ptosis caused by a unilateral midbrain infarction

A 73-year-old woman with atrial fibrillation presented with a sudden right hemiparesis, with diplopia and left ptosis, and was admitted at an Emergency Unit. The neurological examination found fluctuations on consciousness level, predominant crural right hemiparesis and right central facial paralysis without sensitive abnormalities. The first ophthalmological evaluation showed normal pupillary reflexes, total left ptosis and paresis of adduction of the left eye, with conjugated horizontal palsy for right gaze and conjugated vertical palsy for upward and downward gaze on saccadic and smooth pursuit eye movements. The convergence showed paresis of left eye, with reactive pupils, and oculocephalic test was normal. A head CT had no acute ischaemic signs, and after 4 days, she was discharged. The brain magnetic resonance (MR) performed 15 days after the ictus showed a clearly defined left paramedian tegmental mesencephalic infarct (figure 1). Two months after the stroke, the patient had a remarkable improvement of ocular motility, presenting paresis of levator palpebrae, medial and inferior …