**Core Concept**
Pseudo-Foster-Kennedy syndrome is a clinical entity that mimics the classical Foster-Kennedy syndrome, which is characterized by ipsilateral optic atrophy and contralateral papilledema due to a frontal lobe tumor. However, pseudo-Foster-Kennedy syndrome is caused by a different set of conditions, primarily involving the optic nerves or chiasm.

**Why the Correct Answer is Right**
Pseudo-Foster-Kennedy syndrome typically involves conditions that affect the optic nerve or chiasm, such as optic neuritis, glaucoma, or optic nerve sheath meningioma. These conditions lead to ipsilateral optic atrophy and contralateral optic nerve dysfunction, resulting in pseudo-Foster-Kennedy syndrome. The key pathophysiological mechanism is the involvement of the optic nerve or chiasm, which disrupts the normal visual pathway.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because it does not specify the underlying cause of pseudo-Foster-Kennedy syndrome. While tumors can cause Foster-Kennedy syndrome, they are not the primary cause of pseudo-Foster-Kennedy syndrome.
* **Option B:** This option is incorrect because it is a characteristic of pseudo-Foster-Kennedy syndrome, not an exception.
* **Option C:** This option is incorrect because it is a characteristic of pseudo-Foster-Kennedy syndrome, not an exception.
* **Option D:** This option is incorrect because it is a characteristic of pseudo-Foster-Kennedy syndrome, not an exception.

**Clinical Pearl / High-Yield Fact**
To remember the key difference between Foster-Kennedy syndrome and pseudo-Foster-Kennedy syndrome, recall that Foster-Kennedy syndrome is characterized by a frontal lobe tumor, while pseudo-Foster-Kennedy syndrome involves conditions that affect the optic nerve or chiasm.

**Correct Answer:** D.