Stroke
• Stroke is the most common cause of epilepsy in the elderly, but younger patients can also suffer strokes.
• How many types of stroke are there?
- Ischemic (when there is lack of blood supply to part of the brain which results in an infarct of part of the brain tissue) and
- Hemorrhagic (when there is a bleed in the brain).
• How likely is it that a person who has a stroke will develop seizures?
- About 10% (1 out of 10) for ischemic strokes
- About 20 to 30% (2 to 3 out of 10) for hemorrhagic strokes
• The likelihood of developing epilepsy increases with strokes that are:
- Hemorrhagic
- Large
- Involve the cortex (the superficial/outer part) of the brain.
• Why do patients who have a stroke have a greater chance of developing epilepsy?
o A stroke damages a specific part of the brain by killing brain cells. Once that happens, brain tissue swells and scar tissue develops. The scar tissue affects the normal flow of electrical activity in the brain which then causes seizures.
• Not all patients that have a stroke require treatment unless they have repetitive seizures.
• An important confounding factor that the doctor needs to look out for: transitory strokes (TIAs) could be mistaken with seizures and need to be properly diagnosed.