Spine: conus medullaris versus cauda equina: practice question

A Orthopaedics 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.

Try it

Orthopaedics · Spine: conus medullaris versus cauda equina

Sample item

A patient with a L1 burst fracture has early loss of bladder control, symmetrical saddle anaesthesia, mild bilateral leg weakness and little radicular pain. Which lesion fits best?

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

The answer and the reasoning

A. Conus medullaris syndrome

Conus medullaris syndrome, from injury at the L1 level, tends to cause early and prominent sphincter dysfunction, symmetrical saddle loss, limited motor deficit and little pain, with possible upper motor neuron signs. Cauda equina lesions give asymmetric lower motor neuron weakness, severe radicular pain and later sphincter loss. Both need urgent imaging and decompression.

Option by option

  • A. Conus medullaris syndrome (correct)

    Correct. Early sphincter loss with symmetrical saddle anaesthesia suggests a conus lesion.

  • B. Cauda equina syndrome

    Cauda equina syndrome is typically asymmetric with severe radicular pain.

  • C. Anterior cord syndrome

    Anterior cord syndrome causes motor loss with loss of pain and temperature below the lesion and preserved dorsal column function.

  • D. Central cord syndrome

    Central cord syndrome affects the arms more than the legs in cervical injuries.

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.

More Orthopaedics questions

Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is A, Conus medullaris syndrome. Conus medullaris syndrome, from injury at the L1 level, tends to cause early and prominent sphincter dysfunction, symmetrical saddle loss, limited motor deficit and little pain, with possible upper motor neuron signs.

Why is "Cauda equina syndrome" not the answer?

Cauda equina syndrome is typically asymmetric with severe radicular pain.

Why is "Anterior cord syndrome" not the answer?

Anterior cord syndrome causes motor loss with loss of pain and temperature below the lesion and preserved dorsal column function.

Why is "Central cord syndrome" not the answer?

Central cord syndrome affects the arms more than the legs in cervical injuries.

What concept does this question test?

It tests Spine: conus medullaris versus cauda equina in Orthopaedics. Cauda equina lesions give asymmetric lower motor neuron weakness, severe radicular pain and later sphincter loss. Both need urgent imaging and decompression.

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 Spine: conus medullaris versus cauda equina?

Pair each fracture with its classic complication and nerve injured. Then use the flashcards and the other Orthopaedics 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.