Quiz week 27

Q1. Which of the following scenarios is typical of diabetic complication (as opposed to a different cause)?

1. Internuclear ophthalmoplegia
2. 3rd nerve paralysis but sparing of the pupillary reflex
3. Absent pupillary reflex to light
4. Loss of taste in the anterior 2/3rd part of the tongue
5. Homonymous central hemianopia

The answer is choice 2. Almost everyone got this question right. The parasympathetic fibers travel with the 3rd nerve on its outer surface. The blood supply to this area is derived from the meningeal surface. The vasa nervosum that gets affected by diabetes causes damage in the core of the nerve but spares the pupillary reflex.

Q2. Of the following patterns of hemianopia, which one best describes the presentation of a pituitary tumor? (This one is not simple - but do not hesitate)

1. Homonymous bitemporal hemianopia
2. Homonymous left lateral hemianopia
3. Heteronymous hemianopia
4. Unilateral blindness
5. Inferior quadrantic hemianopia

The correct answer was choice 3 (Heteronymous hemianopia).This question was tough. It was based on terminology. A question or one like it showed up in 1999 boards. It tests ones knowledge of the term homonymous. Homonymous means corresponding fields and is used as follows - left homonymous hemianopia and right homonymous hemianopia. the former means that the nasal field on the  right side and the temporal field on the left are damaged thus not allowing the person to view on the left field.

The defect with pituitary lesions is bitemporal typically but that makes it heteronymous hemianopia. I personally dislike this question because it only clarifies terminology (not concepts) but the quiz - as you already know - is supposed to be difficult.