UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 1158
Question:
A 57 year old woman is driving home from work one evening and makes a left hand turn. She is completely unaware of a car approaching from behind on the left and she causes a minor traffic accident. She is brought to an emergency room. Her history is unremarkable, other than a complaint of chronic headaches.
On physical exam, she is found to have a defect in her peripheral field of vision, but her central field of vision is fine. What would explain a loss of the field of vision on the periphery, but not a loss of the central vision?

a) pituitary adenoma
b) embolus from the internal carotid artery
c) multiple sclerosis
d) hysteria
e) chronic alcoholism