Strokes and seizures are two different things, although stroke victims are more at risk for seizures. Strokes involve part of the brain dying, usually due to interruption of blood flow. Seizures are neuronal disturbances and don't usually result in permanent damage to the brain. The symptoms can be similar (
Todd's paresis), but seizure victims should recover fully and fairly quickly after the event.
I agree that if Kennedy's paralysis lasts for more than a couple of weeks, then chances are he suffered a stroke.
I am aware that strokes and seizures are different but it sounded like they were describing a stroke.