Entrapment pearls

Question 1

Compression sites for Median Nerve

Answer 1

Carpal Tunnel
Pronator Teres Heads

It manifests with lateral flexor weakness and wasting of the thenar eminence (the thumb pad).

Question 2

Compression sites for Ulnar Nerve

Answer 2

Guyon’s canal
Cubital tunnel

It manifests of the medial flexor weakness and clawing of the 4th and fifth digits, the so-called ulnar claw.

Question 3

Compression Site for Radial Nerve

Answer 3

supinator muscle in the forearm
mid-shaft of the humerus at the spiral groove
axilla

It manifests with extensor muscle weakness and wrist drop.

Question 4

What muscle is innervated by the anterior interosseus nerve

Answer 4

supplies flexor digitorum profundus 2 and 3 (C7 – T1)

Question 5

what happens when the anterior interosseus nerve is injured

Answer 5

When the anterior interosseous nerve is injured in isolation (anterior interosseous syndrome or neuropathy),

patients exhibit the “OK” sign (or more aptly, the not “OK” sign); wherein, they are unable to form a circle with the thumb and index finger.

Neither the thumb’s interphalangeal joint nor the index finger’s distal interphalangeal joints will flex.

Question 6

in the carpal tunnel

The median nerve passes beneath the

Answer 6

flexor retinaculum

Question 7

T/F

in the Cubital Tunnel syndrome, only the motor components of the ulnar nerve are affected.

Answer 7

False

Both motor and sensory components are affected