Final answer:
The embolus causing transient blindness in a 66-year-old woman is likely from an embolic stroke due to a blood clot or other matter that obstructs the artery to the retina. It may originate from the heart or atherosclerotic plaques, and treatment involves medication to prevent further clotting.
Step-by-step explanation:
The source of the embolus in a transient neurologic event, like the episode of blindness in the left eye experienced by a 66-year-old woman, is likely to be from an embolic stroke. This type of stroke occurs when an embolus, such as a blood clot or other foreign matter, travels through the bloodstream and becomes lodged in an artery supplying the brain, particularly in the arteries that supply the eye's retina causing transient monocular blindness. The embolus can originate from various places within the cardiovascular system, such as the heart (especially in cases of arrhythmia like atrial fibrillation) or from atherosclerotic plaques within the arteries themselves.
Treatment typically involves anticoagulant or antiplatelet medication to prevent further clots from forming. It's crucial for the patient to receive a thorough evaluation, which may involve imaging studies and cardiac assessment, to identify the precise source of the embolus and to prevent future strokes or transient ischemic attacks (TIAs).