This question tests our understanding of the various abnormal fundoscopic findings.
This fundoscopy is consistent with papilledema, a sign of increased intracranial pressure. The only answer choice that can cause this of the choices given is E, normal pressure hydrocephalus.
Retinopathy is not likely because it would not be associated with headache. Additionally, fundoscopic findings in retinopathy are usually of hemorrhage, fluffy spots (cotton-wool spots), occluded vessels, or neovascularization
Glaucoma is not possible because in glaucoma, the optic disc margins are still visible! This is the key to ruling out B&C. Cerebral edema causes these margins to be blurred, as in this case. The key in glaucoma is an increased cup/disc ratio. The cup is the inner, brighter area and the disc is the outer, more translucent ring. A cup disc ratio greater than about 0.5, then think glaucoma (the bright part should be less than half the diameter of the dimmer part)
Finally D, Retinoblastoma would present with a mass on the retina, plus this patient is not in the right age group.
So we are left with E, normal pressure hydrocephalus. It is not an ideal answer choice because this is not a typical presentation, I would have liked to see gait disturbance, dementia, or urinary incontinence. But the key here is realizing that even though the pressure measured by LP is normal, the increased fluid is still putting pressure on the brain and this is the reason for the classical symptoms associated with NPH.
This is actually a classic presentation of a brain tumor. When we had our ophtho block, we learned that headache + papilledema is most likely to be a brain tumor and this patient fits that description. I would have liked to see some sort of brain tumor as an answer choice, but unfortunately none was given.
Hope that helps