Transient Ischemic Attack (TIA)
Transient ischemic attacks are caused when blood flow to parts of the brain are restricted for brief periods of time. Because the blood supply is restored quickly, brain tissue does not die as it does in a stroke. These attacks are often early warning signs of a stroke.
Acute Ischemic Stroke
Strokes can be either ischemic or hemorrhagic. In an ischemic stroke, the blood supply to part of the brain is cut off because atherosclerosis or a blood clot has blocked a blood vessel. Blood clots can travel to the brain from another artery (artery-to-artery embolization) or they can come from the heart (cardioemblic stroke).
Aneurysms and Subarachnoid Hemorrhages
While an ischemic stroke is caused by the blood supply to part of the brain being cut off, a hemorrhagic stroke is caused by bleeding into the brain.
A subarachnoid hemorrhage is sudden bleeding between the brain and the membranes that cover it. Besides killing the brain cells where the bleeding occurs, bleeding inside the skull can quickly raise the pressure on the brain to dangerous levels.
While ischemic strokes happen when the blood flow to a part of the brain is interrupted, a hemorrhagic stroke is caused when there is bleeding into brain tissue that kills blood cells.
A cerebral hemorrhage can take several forms:
- Intracerebral hemorrhages. This is bleeding inside the brain. The symptoms and prognosis of an intracerebral bleed vary depending on the size and location of the bleed.
- Subarachnoid hemorrhages. This is bleeding between the brain and the membranes that cover the brain.
- Subdural hemorrhages. This is bleeding between the layers of the brain’s covering (the meninges).
- Epidural hemorrhages. This is bleeding between the skull and the covering of the brain.
Since contrast angiography was developed in the 1920s, great advances have been made in diagnostic tests to determine the type of stroke and its precise location.
The types of diagnostic tests include:
- Imaging tests
- Electrical activity tests
- Blood flow tests
- Other tests
Emergency Stroke Services
Immediate emergency treatment is critical to surviving a stroke with the least amount of damage to your brain and your ability to function. Every stroke or transient ischemic attack must be treated as a life-threatening emergency.
For many stroke survivors, rehabilitation is a key way to maintain your independence and ability to manage your daily activities. Medical rehabilitation does not reverse the effects of a stroke. It is designed to build your strength, capability and confidence so that you can continue your daily activities, despite the effects of your stroke. This may mean changing how you do things, relearning certain activities or redefining how you live.