Stroke
| Stroke | |
|---|---|
| Other names | Cerebrovascular accident (CVA), cerebrovascular insult (CVI), brain attack |
 | |
| CT scan of the brain showing a massive, prior right-sided ischemic stroke from blockage of an artery. Changes on a CT may not be visible early on. | |
| Specialty | Neurology, emergency medicine |
| Symptoms | Facial drooping, inability to walk, move, or feel on one side of the body, problems understanding or speaking, trouble seeing |
| Complications | Persistent vegetative state |
| Causes | Ischemic (blockage) and hemorrhagic (bleeding) |
| Risk factors | Age, high blood pressure, smoking, obesity, high cholesterol, diabetes, previous TIA, atrial fibrillation, air pollution |
| Diagnostic method | Based on symptoms and medical imaging |
| Differential diagnosis | Low blood sugar |
| Treatment | Thrombolysis, thrombectomy (if ischemic), supportive care, surgery (if hemorrhagic) |
| Medication | Alteplase, tenecteplase (if ischemic) |
| Frequency | 13.2 million (2023) |
| Deaths | 6.8 million (2023) |
A stroke is a medical condition in which blood flow to a part of the brain is reduced or blocked causing cell death. There are two main types of stroke: ischemic, due to lack of blood flow, and hemorrhagic, due to bleeding. Both cause parts of the brain to stop functioning properly.
Signs and symptoms of a stroke may include facial drooping, inability to walk, move or feel on one side of the body, problems understanding or speaking, dizziness, or loss of vision to one side. Signs and symptoms often appear soon after the stroke has occurred. If symptoms last less than 24 hours, the stroke is a transient ischemic attack (TIA), also called a mini-stroke. A hemorrhagic stroke may also be associated with a severe headache. The symptoms of a stroke can be permanent. Long-term complications may include pneumonia and loss of bladder control.
The biggest risk factor for a stroke is high blood pressure. Other risk factors include high cholesterol, smoking, obesity, diabetes, a previous TIA, atrial fibrillation and air pollution. An ischemic stroke is typically caused by blockage of a blood vessel, though there are also less common causes. A hemorrhagic stroke is caused by either bleeding directly into the brain or into the space between the brain's membranes. Bleeding may occur due to a ruptured brain aneurysm. Diagnosis is typically based on a physical exam and supported by medical imaging such as a CT scan or MRI scan. A CT scan can rule out bleeding, but may not necessarily rule out ischemia, which early on typically does not show up on a CT scan. Low blood sugar may cause similar symptoms.
Prevention includes decreasing risk factors, surgery to open up the arteries to the brain in those with problematic carotid narrowing, and anticoagulant medication in people with atrial fibrillation. Aspirin or statins may be recommended by physicians for prevention. A stroke is a medical emergency. Ischemic strokes, if detected within three to four-and-a-half hours, may be treatable with medication that can break down the clot, while hemorrhagic strokes sometimes benefit from surgery. Treatment to attempt recovery of lost function is called stroke rehabilitation, and ideally takes place in a stroke unit; however, these are not available in much of the world.
In 2023, 13.2 million people worldwide had a stroke. Strokes were the second biggest cause of death. Some 105 million people who had previously had a stroke and were still alive. About 3.2 million deaths resulted from an ischemic stroke and 3.5 million deaths from a hemorrhagic stroke. Overall, two thirds of cases of a stroke occurred in those over 65 years old.