From the Guidelines
There are two main types of strokes: ischemic strokes and hemorrhagic strokes, with ischemic strokes further divided into large-artery atherosclerosis, cardioembolism, small-artery or lacunar stroke, and other subtypes. Ischemic strokes, which account for about 87% of all strokes, occur when blood flow to the brain is blocked by a clot or narrowed blood vessels 1. These can be further divided into:
- Large-artery atherosclerosis: occurs in patients with a cortical infarct in the distribution of a large cerebral artery demonstrated to have luminal occlusion, or narrowing of 50%, of atherosclerotic origin
- Cardioembolism: cortical or large subcortical infarctions with a recognized high-risk cardiac source are presumed to be caused by cardioembolism
- Small-artery or lacunar stroke: usually diagnosed when a patient has symptoms consistent with a lacunar syndrome, such as pure motor hemiparesis and a small (<1.5 cm) lesion found on neuroimaging Hemorrhagic strokes happen when a blood vessel in the brain ruptures and bleeds into surrounding tissue, including intracerebral hemorrhages and subarachnoid hemorrhages 1. A third category is a transient ischemic attack (TIA), often called a "mini-stroke," which involves temporary blockage of blood flow to the brain with symptoms that typically resolve within 24 hours 1. Understanding these stroke types is crucial for proper diagnosis and treatment, as management approaches differ significantly between ischemic and hemorrhagic strokes.
Some key points to consider:
- Ischemic stroke subtype is a strong predictor of long-term survival, with patients with small-vessel disease appearing to be at lower risk 1
- Determining the most probable ischemic stroke subtype may provide useful prognostic information that may be helpful when deciding whether to study a stroke patient for the presence of unrecognized CHD 1
- Children with stroke have remarkable differences in presentation compared with older patients, with 55% of strokes being ischemic and the remainder being hemorrhagic 1
From the Research
Types of Strokes
- Ischemic strokes: occur when a blood vessel in the brain is blocked by a clot or other substance, reducing blood flow to the brain 2, 3
- Hemorrhagic strokes: occur when a blood vessel in the brain ruptures, causing bleeding in the brain 2, 3, 4
Subtypes of Hemorrhagic Strokes
- Intracerebral hemorrhage (ICH): the most common type of hemorrhagic stroke, which occurs when a blood vessel in the brain bursts and bleeds into the surrounding tissue 4
- Subarachnoid hemorrhage: occurs when a blood vessel on the surface of the brain ruptures and bleeds into the space between the brain and the skull 3
- Cerebral venous thrombosis: a rare type of hemorrhagic stroke that occurs when a blood clot forms in the veins of the brain 4
Other Types of Strokes
- Transient ischemic attack (TIA): a temporary blockage of a blood vessel in the brain that does not cause permanent damage 3
- Venous stroke: a rare type of stroke that occurs when a blood clot forms in the veins of the brain 4