Master the board step 3

Neurology 9
Stroke and TIA
Strokes and transient ischemic attacks (TIAs) present with the sudden onset of
weakness on one side of the body. Weakness of half of the face and aphasia are
common as well. Cases may state that there is a partial or total loss of vision,
which may be transient. The cause is decreased or altered cerebral blood flow.
Stroke
Strokes are discriminated from TIA based on time. Strokes last for ≥ 24
hours. There will be permanent residual neurologic deficits, caused by ischemia
or hemorrhage: 80 percent are ischemic in nature, and 20 percent are
hemorrhagic. Ischemic strokes can be either from emboli or from a thrombosis.
Emboli present with more sudden symptoms.
Stroke spares the upper
third of the face, from the
eyes up.
Transient Ischemic Attack (TIA)
TIAs present exactly the same as a stroke, except that the symptoms last < 24
hours and resolve completely. Cases may present only with transient loss of
vision in one eye, known as amaurosis fugax. This happens during a transient
ischemic attack because the first branch of the internal carotid artery is the
ophthalmic artery. TIAs are always caused by emboli or thrombosis. TIAs are
never due to hemorrhage; hemorrhages do not resolve in 24 hours.
A 67-year-old man with a history of hypertension and diabetes comes to the emergency
department with a sudden onset of weakness in the right arm and leg over the last
hour. On exam, he cannot lift the bottom half of the right side of his face. What is the
best initial step?
a. Head CT with contrast
b. Head CT without contrast
c. Aspirin
d. Thrombolytics
e. MRI
223