Neuroanatomy: Foster Kennedy syndrome: practice question

A Anatomy question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Anatomy · Neuroanatomy: Foster Kennedy syndrome

Sample item

A patient with an olfactory groove meningioma has optic atrophy in the right eye and a swollen optic disc in the left eye. What produces the swollen disc?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

B. Raised intracranial pressure transmitted to the opposite optic nerve sheath

In the Foster Kennedy syndrome a frontal base mass compresses the ipsilateral optic nerve, causing primary optic atrophy, while the rising intracranial pressure produces papilloedema in the opposite eye. The atrophic side therefore marks the side of the tumour.

Option by option

  • A. Direct tumour compression of the optic nerve on the same side as the mass

    Direct compression explains the atrophic disc on the tumour side, not the swollen disc.

  • B. Raised intracranial pressure transmitted to the opposite optic nerve sheath (correct)

    Correct. Raised intracranial pressure produces papilloedema in the eye opposite the tumour.

  • C. Ischaemic infarction of the optic nerve head from ophthalmic artery occlusion

    Ischaemic optic neuropathy gives a pale swollen disc but is not the mechanism here.

  • D. Retrograde degeneration of retinal ganglion cell axons after chiasmal damage

    Retrograde degeneration produces pallor, not swelling of the disc.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Anatomy question

What is the answer to this Anatomy question?

The best answer is B, Raised intracranial pressure transmitted to the opposite optic nerve sheath. In the Foster Kennedy syndrome a frontal base mass compresses the ipsilateral optic nerve, causing primary optic atrophy, while the rising intracranial pressure produces papilloedema in the opposite eye.

Why is "Direct tumour compression of the optic nerve on the same side as the…" not the answer?

Direct compression explains the atrophic disc on the tumour side, not the swollen disc.

Why is "Ischaemic infarction of the optic nerve head from ophthalmic artery o…" not the answer?

Ischaemic optic neuropathy gives a pale swollen disc but is not the mechanism here.

Why is "Retrograde degeneration of retinal ganglion cell axons after chiasmal…" not the answer?

Retrograde degeneration produces pallor, not swelling of the disc.

What concept does this question test?

It tests Neuroanatomy: Foster Kennedy syndrome in Anatomy. The atrophic side therefore marks the side of the tumour.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Neuroanatomy: Foster Kennedy syndrome?

Learn every nerve by its route, its muscles and what a lesion looks like at the bedside. That one habit answers a large share of questions. Then use the flashcards and the other Anatomy questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.