A 26-year-old man noticed a facial asymmetry and double vision on awaking and went to the emergency room. There was left eye exotropia at rest and a total horizontal gaze palsy to the right. On attempting gaze to the left, there was limited right eye adduction and horizontal nystagmus of the abducted left eye. Vertical eye movements and convergence were normal. He had a right-sided lower motor neurone facial palsy, with decreased forehead wrinkling on the right, an asymmetric smile and Bell’s sign (figure 1 and video 1). There was also right sensorineural hearing loss (by Weber and Rinne testing) and right leg ataxia.
What is probable site of the lesion?
What is its most likely cause?
This patient has the ‘eight-and-a-half syndrome’ (Eggenberger 1998), combining a one-and-a-half syndrome with an ipsilateral lower motor neurone facial (seventh) nerve palsy.1 The…