MRCP-0636

MRCP-0636

A 48-year-old patient with diabetes is referred from the Emergency department complaining of dizziness and vomiting. On examination he is alert and orientated, his pulse is 80 irregularly irregular and BP 160/90 mmHg. There is nystagmus on left lateral gaze and his speech is slurred. On examination of the limbs, you note intention tremor and past pointing. He is ataxic when mobilised. What is the likely diagnosis?