Warning signs of an ischemic stroke may be evident as early as seven days before an attack and require urgent treatment to prevent serious damage to the brain, according to a study of stroke patients published in the March 8, 2005 issue of Neurology, the scientific journal of the American Academy of Neurology.
Wondering how to tell if you had a stroke in the past or how to tell if you had a stroke in your sleep? Unfortunately, most people don't actually find out they've suffered from a silent stroke until they see a doctor for another condition and are ordered to have an MRI or a CT scan.
MRI uses magnetic fields to detect subtle changes in the content of brain tissue. One effect of stroke is the slowing of water movement, called diffusion, through the damaged brain tissue, and MRI can show this type of damage within the first hour after the stroke symptoms start.
Blood tests for stroke. There is no blood test that can diagnose a stroke. However, in the hospital, your doctor or nurse may do a series of blood tests to learn the cause of your stroke symptoms: Complete blood count (CBC).
Computerized tomography (CT) scan – CT scans use a series of X-rays to create a detailed image of your brain. A CT scan can show a hemorrhage, tumor, stroke and other conditions. There are different types of CT scans that your doctor may use depending on your situation.
An MRI can detect brain tissue damaged by an ischemic stroke and brain hemorrhages. Your doctor may inject a dye into a blood vessel to view the arteries and veins and highlight blood flow (magnetic resonance angiography or magnetic resonance venography).
Any irregularities or causes for concern show up in a CT scan approximately six to eight hours after the onset of the first signs of a stroke. During a CT scan, the patient may be intravenously injected with dyes, which will highlight any abnormal areas in the scan, giving doctors a clearer view of the head.
You will likely have a head CT scan or brain MRI. A stroke may show changes on these tests, but TIAs will not. You may have an angiogram, CT angiogram, or MR angiogram to see which blood vessel is blocked or bleeding. You may have an echocardiogram if your doctor thinks you may have a blood clot from the heart.
The only way to tell the difference between a ministroke and a stroke is by having a doctor look at an image of your brain with either a CT scan or an MRI scan. If you've had an ischemic stroke, it's likely that it won't show up on a CT scan of your brain for 24 to 48 hours. An MRI scan usually shows a stroke sooner.
One of the most common stroke mimics is a seizure, which researchers believe account for as many as 20% of all stroke mimics. Other common stroke mimics include migraines, syncope, sepsis, brain tumor and metabolic derangement (low sodium or low blood sugar).
CT scans are excellent at detecting the bleeding in the brain that occurs in hemorrhagic stroke. However, ischemic stroke may be difficult or impossible to see in CT images, especially during the first few hours after the stroke occurs, which is the period when treatment decisions are most important.
In fact, ischemic strokes unfold over a period of 10 hours. That means that with every second you wait for treatment, the brain damage gets worse. If a stroke is untreated for the full 10 hours, the brain ages up to 36 years! With every minute you wait, the brain loses two million brain cells.
The longer a stroke goes untreated, the more damage can be done — possibly permanently — to the brain. “If you suspect you or someone you're with is having a stroke, don't hesitate to call 911,” Dr. Humbert says. “It could save a life.”
In addition to the classic stroke symptoms associated with the FAST acronym, around 7-65% of people undergoing a stroke will experience some form of a headache. People describe a stroke-related headache as a very severe headache that comes on within seconds or minutes.
Diagnosis and Tests
The doctor will do some simple quick checks to test your vision, muscle strength, and ability to think and speak. Diagnostic testing consists of either a computed tomogram (CT) or magnetic resonance imaging (MRI) scan of the brain and carotid arteries to determine the possible cause of the TIA.
Most people who have a mini-stroke feel fine after the event. In fact, many people don't even realize they've had one! Symptoms might include weakness, numbness, tingling, vision changes or difficulty speaking. Most symptoms are temporary and dissipate within minutes but sometimes can last up to 24 hours.
What Happens if a Mini Stroke Goes Untreated? A mini stroke may resolve on its own, but it's difficult to know just how serious the circumstances are without a thorough medical workup. Familiarizing yourself with these symptoms will allow you to act quickly, which is crucial for avoiding permanent brain damage.
“Ignoring any stroke sign could be a deadly mistake,” says Mitch Elkind, M.D., chair of the American Stroke Association. The Association recommends calling for emergency help immediately, even if the symptoms go away. Acting fast can improve your chances of accurate diagnosis, treatment and recovery.
When stroke occurs, the blood pressure (BP) often rises because of various factors, such as psychological stress, pain, elevated intracranial pressure, urinary retention, and hypoxemia.
Weakness or numbness of the face, arm or leg, usually on one side of the body. Trouble speaking or understanding. Problems with vision, such as dimness or loss of vision in one or both eyes. Dizziness or problems with balance or coordination.