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A 58-Year-Old Man Comes to the Emergency Department Due to a 3-Hour

question 97

Multiple Choice

A 58-year-old man comes to the emergency department due to a 3-hour history of abrupt-onset weakness and numbness of the right lower extremity, as well as urinary incontinence. Two months ago, the patient was hospitalized due to left-sided weakness that resolved spontaneously after several hours. At that time, MRI of the head and MR angiography of the head and neck were normal, but the patient was found to have atrial fibrillation. An oral anticoagulant was prescribed at discharge, but the patient has been nonadherent with therapy. Blood pressure is 162/94 mm Hg and pulse is 102/min and irregularly irregular. Physical examination shows weakness and sensory loss in the right lower extremity. Babinski sign is present on the right. Speech is normal, and there is no facial weakness. Examination of the right upper extremity and the left extremities is unremarkable. An embolic occlusion affecting which of the following vascular regions is the most likely cause of this patient's current symptoms?

Definitions:

Quartz Crystals

Hard, crystalline minerals made of silica (SiO2), used in various applications due to their piezoelectric properties.

Sinkholes

Depressions or holes in the ground caused by the collapse of a surface layer, occurring in areas where the rock below is limestone, carbonate rock, salt beds, or other rocks that can be dissolved by groundwater.

Sinkhole

A natural depression formation caused by the dissolution of soluble bedrock or substrate collapse.

Weathering

The natural process where rocks are broken down or dissolved into smaller pieces by chemical, physical, or biological factors.