A 23-year-old woman who is 15 weeks into her first pregnancy is referred to your office because of vision problems. She reports that at times she has been seeing things out of the corner of her eye....

A 23-year-old woman who is 15 weeks into her first pregnancy is referred to your office because of vision problems. She reports that at times she has been seeing things out of the corner of her eye. On further discussion, you discover that she also has been more prone to bump into things lately. Her examination is nonfocal. What is the most likely explanation?

A. An electrical disturbance of the visual cortex related to migraine

B. Substance abuse; check the urine drug screen

C. An electrical disturbance of the visual cortex related to seizure

D. Compression of the optic chiasm

E. Demyelination in the optic tracts