This patient presents with decreased left vision. The visual acuity measures right 6/6 and left 6/36. There is no relative afferent pupillary defect. A MRI is as shown.

a. What is this scan?

b. What abnormality is shown?

c. Why is there no relative afferent pupillary defect?

d. What is the most likely visual defect?

 

Answer to a A T-2 weighted MRI brain scan.
 

Answer to bA lesion in the pituitary fossa. This patient has a macroadenoma.
 

Answer to cBecause of involvement of the contralateral (right) optic nerve. 
 

Answer to dJunctional scotoma.

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