A 65-year-old woman, who has been attending her GP for many years, is being treated for hyperlipidaemia. She has a family history of coronary artery disease.

On this occasion, she presents with a one-month history of intermittent, bilateral headaches, episodes of blurred vision and weakness of her left arm. The record of the examination states no limb weakness and normal reflexes.

Being concerned about a cerebral tumour, the GP arranges a CT of her brain, and this is reported as showing no significant abnormality.

Two weeks later, the woman is re-examined by the GP, who records no further symptoms and no carotid bruits, and refers the patient to a neurologist.