One-and-a-half syndrome following intravenous morphine injection in a drug user

A 25-year-old man presented with a history of headache; dizziness and diplopia after intravenous injection of dissolved morphine sulphate tablets. He had no other symptoms of cerebellar or brainstem dysfunction. On examination, a left one-and-a-half syndrome, right paralytic pontine exotropia and left partial lower facial nerve palsy were found. Radiological examination with M.R.I, brain scan showed a pontine infarct at the level of the facial and auditory nerve complex. Gradual recovery after dexamethasone therapy.