All patients

Full blood count

ESR or C-reactive protein (if raised, consider vasculitis, infective endocarditis, cardiac myxoma or systemic infection)

INR (if taking warfarin)

Sickle cell test (if sickle cell disease considered)

Electrolytes and creatinine

Lipid profile

Blood glucose (exclude hypoglycaemia and diabetes mellitus)

Blood culture if febrile or infective endocarditis suspected (e.g. prosthetic heart valve)

ECG (atrial fibrillation, previous myocardial infarction, left ventricular hypertrophy)

Chest X-ray (exclude lung neoplasm, assess heart size)

Selected patients

Neuroimaging

• MRI is indicated for the following in the first instance unless the patient cannot tolerate this, in which case CT should be done:
  • Diagnosis is unclear
  • Exclude structural intracranial lesion such as meningioma, subdural haematoma
  • When vascular territory is unclear (diffusion-weighted MRI)
  • When duration of focal neurological symptoms was >1 h (diffusion-weighted MRI)
  • If the patient may be suitable for carotid endarterectomy and need to be certain whether anterior or posterior circulation

Arterial imaging

• Carotid duplex scan, following carotid territory TIA or transient monocular visual loss
• CT or MR angiography if carotid dissection or large-vessel vasculitis is suspected

Echocardiography

• When cardiac embolic source is suspected or must be excluded:
  • Transthoracic echocardiography (TTE) where a cardio-embolic cause for stroke is being considered. Use to look for endocarditis, aortic dissection, atrial myxoma or where there is an undiagnosed cardiac murmur or abnormal ECG.
  • Use transthoracic echocardiography with bubble injection where patent foramen ovale is suspected.
  • Consider transoesophageal echocardiography (TOE) for patients with possible endocarditis and a normal TTE, mechanical heart valve prosthesis and for unexplained stroke in patients <50 years.

Ambulatory ECG monitoring

• Ambulatory monitoring for 24 h if paroxysmal atrial fibrillation (AF) is suspected
• If ECG monitoring for 24 h does not reveal paroxysmal AF, but clinical suspicion is high, consider 7-day recording