Types of stroke
An ischemic stroke is caused by a blocked blood vessel in the brain.
The reasons for the blockage of the blood vessel can vary:
- A blood clot (thrombus) is formed directly in the brain.
- Deposits on the vessel walls of the brain cause the obstruction.
Information can be found here.
It is possible that a blood clot has formed outside the brain and has been transported by the regular blood flow into the brain. If the clot settles at a narrowing artery blocking blood flow this type of stroke is called embolic stroke. They usually result from heart-, lung-, or venous diseases or appear after heart surgeries. They strike fast and usually without any warning signs.
Transitory ischemic attack (TIA)
The „small“ stroke does not really exist. According to the latest evidence a transitory circulatory disorder lasts only a few minutes and resolves itself spontaneously. The accompanying deficits are also only transient (e.g. sensory disorders in arms or legs, visual disturbances, vertigo) and resolve completely. After imaging diagnosis no defined lesion can be detected. However, if the symptoms last 10 minutes or longer the probability increases that a it is a “real stroke” with detectable brain damage exists.
Keep in mind that a TIA has to be treated as an emergency!
A transient ischemic attack is an important warning signal even if – fortunately – no damage remains. This is because one in ten patients develops an ischemic stroke within three months later, then mostly with permanent consequences.
Strokes without typical symptoms are called silent strokes. They affect brain regions in which important functions are not located or only general symptoms like vertigo are caused.
A silent stroke can be a warning sign for an impending ischemic stroke.