What caused this stroke

The list of potential causes is long and obviously differs for ischaemic35 and haemorrhagic stroke.36 In individual patients, even after extensive investigation it may be difficult to establish the cause: many will have competing causes (for example, atrial fibrillation (AF) and carotid disease). Thus in practice, the precise cause of stroke is often uncertain. Accepting this, we estimate that about 50% of ischaemic strokes are due to atherothromboembolism, 25% due to intracranial small vessel disease, and 20% due to cardiac embolism, with only 5% due to rarer causes. Most haemorrhagic strokes are thought to be due to small vessel disease (often associated with hypertension), although amyloid angiopathy commonly underlies lobar haemorrhages; vascular abnormalities such as aneurysms and arteriovenous malformations may also underlie haemorrhage and the risk of haemorrhage with anticoagulants increases with the international normalised ratio (INR).

The history and examination may provide important aetiological clues (for example, the use of oral anticoagulants, the presence of an irregular pulse or heart murmur). Unusual causes are considerably more likely in younger patients (for example, evidence of drug abuse or recent cervical trauma precipitating arterial dissection). Our approach to investigation aims to be reasonably cost effective. We perform some simple investigations (full blood count, ESR, plasma glucose, urea and electrolytes, random plasma cholesterol, urinalysis, 12-lead EGG, and CT brain scan) in all patients in whom we are considering active management, even if our clinical assessment strongly suggests a common cause. These tests may identify important modifiable risk factors as well as highlighting the possibility of a rarer, unexpected cause of stroke (for example, infective endocarditis, giant cell arteritis, or thrombocythaemia) which may coexist with either cardiac or degenerative vascular disease. We reserve other more specialised tests35 for patients in whom the cause of stroke is not clear (for example, young patients (less than 50 years) or those without risk factors), for those with clinical features of a rare cause, or where simple investigations show an abnormality (Table 3.1).

Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

Get My Free Ebook


Post a comment