Back to Blog
Flashcard hero slow speech6/15/2023 ![]() TIAs are a warning sign of progressive cerebrovascular disease. TIAs may be due to microemboli that temporarily block the blood flow. In general, one third of individuals who experience a TIA do not experience another event, one third have additional TIAs, and one third progress to stroke. However, it is important to teach the patient to seek treatment for any stroke symptoms, since there is no way to predict if a TIA will resolve or if it is in fact the development of a stroke. In the past, TIAs were operationally defined as any focal cerebral ischemic event with symptoms lasting less than 24 hours. Clinical symptoms typically last less than 1 hour. A TIA is a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischemia, but without acute infarction of the brain. Recurrence of embolic stroke is common unless the underlying cause is aggressively treated.Īnother risk factor associated with stroke is a past history of a transient ischemic attack (TIA). Smaller emboli then continue to obstruct smaller vessels, which in turn involve smaller portions of the brain with fewer deficits noted. The effects of the emboli are initially characterized by severe neurologic deficits, which can be temporary if the clot breaks up and allows blood to flow. Prognosis is related to the amount of brain tissue deprived of its blood supply. The patient usually remains conscious, although he or she may have a headache. The embolic stroke often occurs rapidly, giving little time to accommodate by developing collateral circulation. Warning signs are less common with embolic than with thrombotic stroke. An embolus arising from an atherosclerotic plaque is more common in older adults. Rheumatic heart disease is one cause of embolic stroke in young to middle-aged adults. ![]() Embolic strokes can affect any age-group. The patient with an embolic stroke commonly has severe clinical symptoms that occur suddenly. Less common causes of emboli include air and fat from long bone (e.g., femur) fractures. Heart conditions associated with emboli include atrial fibrillation, myocardial infarction, infective endocarditis, rheumatic heart disease, valvular prostheses, and atrial septal defects. ![]() The embolus travels upward to the cerebral circulation and lodges where a vessel narrows or bifurcates (splits). Most emboli originate in the endocardial (inside) layer of the heart, with plaque breaking off from the endocardium and entering the circulation. Embolism is the second most common cause of stroke, accounting for about 24% of strokes. A stroke that occurs when an embolus lodges in and occludes a cerebral artery, resulting in infarction and edema of the area supplied by the involved vessel.
0 Comments
Read More
Leave a Reply. |