Transient Ischemic Attack Flashcards
What are Transient ischemic attacks characterized by?
focal ischemic cerebral neurologic deficits that last for < 24 hours
How long does a TIA usually last?
less than 1-2 hours
__% of patients with stroke have a history of transient ischemic attacks
30%
What is an important cause of TIA?
embolization
What 2 locations are emboli apparent?
- heart
- extracranial arteries
What are the cardiac causes of embolic ischemic attacks?
- atrial fibrillation
- rheumatic heart disease
- mitral valve disease
- infective endocarditis
- atrial myxoma
- mural thrombi complicating myocardial infarction
What are paradoxical emboli?
Emboli that travel from the veins to the brain through atrial septal defects and patent foramen ovale
An ____ plaque on a major artery to the brain may also serve as a source of emboli
ulcerated
Where is atherosclerosis most commonly seen? What does this cause?
in the Carotid bifurcation extracranially
causes a bruit
Patients with what disease have an increased risk of developing transient ischemic deficits or strokes?
AIDS
What are 4 other less common abnormalities of blood vessels that may cause a TIA?
- Fibromuscular dysplasia
- atherosclerosis of the aortic arch
- inflammatory arterial disorders such as giant cell arteritis, SLE, polyarteritis, and granulomatous angiitis
- Meningovascular syphilis
Although hypotension may cause a reduction of cerebral artery blood flow if a major extracranially artery to the brain is stenosed, this is a ____ source of TIA
rare
Other than what has already been listed, list 4 other disorders that can cause a TIA
- polycythemia
- sickle cell disease
- hyperviscosity syndromes
- severe anemia
Subclavian ____ syndrome may lead to transient vertebrobasilar ischemia.
steal
When do symptoms of subclavian steal syndrome arise?
When there is localized stenosis or occlusion of one subclavian artery proximal to the source of the vertebral artery, so that blood is “stolen” from it.
What are the signs and symptoms of subclavian steal syndrome?
- bruit in the supraclavicular fossa
- unequal radial pulses
- difference of 20 mm Hg or more between the systolic blood pressures in the arms
What do specific symptoms of a TIA depend on?
the arterial distribution affected
The risk of stroke is high in the first _ months after an attack, particularly in the _ month and especially within the first __ hours
3
first
48
There is a higher risk for stroke with what type of attack?
carotid ischemic attacks
Stroke risk is greatest in patients __ years of older and those who have ______.
60
diabetes
Stroke risk is greatest after transient ischemic attacks that last longer than __ minutes and with symptoms or signs of weakness, speech impairment, or gait disturbance.
10
What imaging technique is indicated within the first 24 hours of symptom onset?
CT and MRI
What type of MRI is particularly sensitive for revealing acute or subacute infarction?
MRI with diffusion-weighted sequences
What imaging technique is especially useful for detecting significant stenosis of the internal carotid artery?
carotid duplex ultrasonography
