1. Where in the visual pathway would you localize the lesion in this case (optic nerve, optic chiasma, optic tract, optic radiations, or occipital cortex)?
Optic nerve (II)
2. What is an afferent pupillary defect (Marcus Gunn pupil), what is its anatomical basis, and what localizing significance does it have?
Paradoxical dilation of a pupil ipsilateral to an optic nerve lesion, when the light is shined back onto that pupil during the “swinging flashlight test”. An APD is due to an impaired direct light reflex with an intact consensual light reflex. It localizes the lesion to the ipsilateral optic nerve (or widespread retinal disease).
3. What side of the nervous system is involved in this case? What specific structure(s) is involved by the pathologic process?
Right optic nerve (II)
4. In general, what type of pathologic process is involved in this case?
Probably a relatively silent optic nerve process (optic or retrobulbar neuritis, optic nerve compression or inflammation).
An MRI scan showed 2 small hyperintensities in the subcortical white matter on T2W images. Therefore, the patient probably had either demyelinating disease (i.e., MS) or an autoimmune disease such as SLE.
5. Are the visual findings and the patient’s headache problem related in this case?
Probably not
6. How would you classify the patient’s headache problem?
Migraine without aura (common migraine)
7. What diagnostic procedure(s) would you undertake at this point?
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