This page compiles our content related to stroke. For further information on diagnosis and treatment, follow the links below to our full BMJ Best Practice topics on the relevant conditions and symptoms.
Stroke is defined as an acute neurologic deficit lasting more than 24 hours and caused by cerebrovascular etiology. It is subdivided into ischemic stroke (caused by vascular occlusion or stenosis) and hemorrhagic stroke (caused by vascular rupture, resulting in intraparenchymal, subarachnoid, and/or intraventricular hemorrhage). Ischemic stroke accounts for 87% of all stroke cases, hemorrhagic stroke for 10%, and subarachnoid hemorrhage for 3%.
Regardless of the specific etiology, ischemic stroke occurs when blood supply in a cerebral vascular territory is critically reduced due to occlusion or critical stenosis of a cerebral artery. A minority of ischemic strokes are caused by cerebral sinus or cortical vein thrombosis. Risk factors strongly associated with ischemic stroke include older age, history of transient ischemic attack or previous ischemic stroke, family history of stroke, hypertension, smoking, diabetes mellitus, atrial fibrillation, comorbid cardiac conditions, carotid artery stenosis, sickle cell disease, and dyslipidemia.
Cause of a minority of ischemic strokes. Atherosclerotic plaque in the cervical carotid artery is the most common cause. Plaque disruption and atheroembolization into the intracranial circulation is the most common mechanism for stroke. Strong risk factors include older age, smoking, and history of cardiovascular disease. Carotid revascularization of moderate- or high-grade recently symptomatic carotid artery stenosis prevents future stroke. The benefit of revascularization for asymptomatic stenosis is less certain.
Transient ischemic attack (TIA) should be suspected in a patient who presents with sudden-onset, focal neurologic deficit that resolves spontaneously and cannot be explained by another condition such as hypoglycemia. TIAs have considerable risk of early recurrent cerebral ischemic events. Strong risk factors for TIA include atrial fibrillation, valvular heart disease, carotid stenosis, intracranial stenosis, congestive heart failure, hypertension, hyperlipidemia, diabetes, cigarette smoking, alcohol-use disorder, and advanced age. Evaluation and initiation of secondary prevention should occur rapidly.
Intracerebral hemorrhage is caused by vascular rupture with bleeding into the brain parenchyma, resulting in a primary mechanical injury to the brain tissue. The global prevalence of intracerebral hemorrhage was 18.88 million cases in 2020. Strong risk factors include hypertension, older age, family history of ICH, hemophilia, cerebral amyloid angiopathy, anticoagulation, use of illicit sympathomimetic drugs, vascular malformations, and Moyamoya syndrome.
Typically asymptomatic until ruptured, resulting in a subarachnoid hemorrhage. Screening with noninvasive neuroangiography is recommended for at-risk populations. Strong risk factors include smoking, moderate-high level alcohol consumption, family history, previous subarachnoid hemorrhage, and heritable connective tissue disease.
A medical emergency where there is bleeding into the subarachnoid space. The most common cause of nontraumatic subarachnoid hemorrhage is rupture of an intracranial aneurysm. Strong risk factors include hypertension, smoking, family history, and autosomal dominant polycystic kidney disease.
BMJ Publishing Group
This overview has been compiled using the information in existing sub-topics.
Questions to ask your doctor if you've had a stroke
Stroke caused by a blood clot: preventing another strokeMore Patient leaflets
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