Hand disorders: palmar cutaneous branch in carpal tunnel: 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.

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Orthopaedics · Hand disorders: palmar cutaneous branch in carpal tunnel

Sample item

A woman with carpal tunnel syndrome has numbness of the thumb, index and middle fingers but normal sensation over the thenar eminence. What explains this?

AThe recurrent motor branch is sparedBThe ulnar nerve supplies the thenar eminence skinCThe palmar cutaneous branch arises proximal to and passes superficial to the flexor retinaculumDThe anterior interosseous nerve supplies the thenar skin

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

The answer and the reasoning

C. The palmar cutaneous branch arises proximal to and passes superficial to the flexor retinaculum

The palmar cutaneous branch of the median nerve leaves the main trunk about 5 cm above the wrist and runs over the flexor retinaculum, so carpal tunnel compression does not affect it. Thenar eminence sensation is therefore spared. Loss of thenar sensation suggests a more proximal median nerve lesion.

Option by option

A. The recurrent motor branch is spared
The recurrent motor branch supplies muscle, not skin.
B. The ulnar nerve supplies the thenar eminence skin
The thenar skin is median, not ulnar, territory.
C. The palmar cutaneous branch arises proximal to and passes superficial to the flexor retinaculum (correct)
Correct. The branch bypasses the carpal tunnel, sparing the thenar skin.
D. The anterior interosseous nerve supplies the thenar skin
The anterior interosseous nerve has no cutaneous branch to the hand.

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.

Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is C, The palmar cutaneous branch arises proximal to and passes superficial to the flexor retinaculum. The palmar cutaneous branch of the median nerve leaves the main trunk about 5 cm above the wrist and runs over the flexor retinaculum, so carpal tunnel compression does not affect it.

Why is "The recurrent motor branch is spared" not the answer?

The recurrent motor branch supplies muscle, not skin.

Why is "The ulnar nerve supplies the thenar eminence skin" not the answer?

The thenar skin is median, not ulnar, territory.

Why is "The anterior interosseous nerve supplies the thenar skin" not the answer?

The anterior interosseous nerve has no cutaneous branch to the hand.

What concept does this question test?

It tests Hand disorders: palmar cutaneous branch in carpal tunnel in Orthopaedics. Thenar eminence sensation is therefore spared. Loss of thenar sensation suggests a more proximal median nerve lesion.

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 Hand disorders: palmar cutaneous branch in carpal tunnel?

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.