Hand Nerves

Question 1

What forms the median nerve

Answer 1

Lateral and medial brachial plexus (C5, C6, C7) and (C8 + T1)

Question 2

Path of the median nerve

Answer 2

Passes anterior to the third part of the axillary artery
Descends lateral to the brachial artery
Crosses to the medial side and passes deep to the bicipital aponeurosis and medial cubital vein at the elbow

Question 3

What branches does the median nerve has in the forearm

Answer 3

Pronator teres
Flexor carpi radialis
Palmaris longus
Flexor digitorum superficialis
Flexor pollicis longus
Flexor digitorum profundus
Palmar cutaneous branch

Question 4

What does the median nerve supply in the hands (motor)

Answer 4

LOAF

Lateral 2 lumbricals
Opponens pollicis
Abductor pollicis brevis
Flexor pollicis brevis

Question 5

What does the median nerve supply in the hand (sensory)

Answer 5

Thumb and lateral 2.5 fingers

Question 6

What happens if the median nerve is damaged at the wrist

Answer 6

E.g. carpal tunnel

Paralysis and wasting of thenar eminence muscles + opponens pollicis (ape hand deformity)

Sensory loss to palmar aspect of lateral 2.5 fingers

Question 7

What happens to median nerve if damage at the elbow

Answer 7

Same as in carpal tunnel, but with:
Difficulty pronating forearm
Weak wrist flexion
Ulnar deviation of wrist

Question 8

What happens if anterior interosseous nerve is damaged

Answer 8

(This is a branch of the median nerve that leaves just below the elbow)

It results in loss of pronation of the forearm and weakness of long flexors of thumb and index

Question 9

Symptoms of carpal tunnel

Answer 9

Pain/pins needles in thumb, index, middle finger

Shaking hands gives relief

Question 10

What is Tinel’s sign

Answer 10

Tapping causes paraesthesia in carpal tunnel

Question 11

What is Phalen’s sign

Answer 11

Flexion of the wrist causes symptoms in carpal tunel

Question 12

Examination findings in carpal tunnel

Answer 12

Weakness of thumb abduction (abductor pollicis brevis)

Wasting of thenar eminence (NOT hypothenar)

Question 13

Treatment of carpal tunnel

Answer 13

Analgesia
Wrist splints at night
Corticosteroid injection
Surgical decompression

Question 14

Ulnar nerve brachial plexus

Answer 14

Arises from medial cord of brachial plexus C8 and T1

Question 15

Motor supply of ulnar nerve

Answer 15

Medial two lumbricals
Adductor pollicis
Interossei
Hypothenar muscles: abductor digiti minimi, flexor digiti minimi
Flexor carpi ulnaris

Question 16

Sensory supply of ulnar nerve

Answer 16

Medial 1.5 fingers (palmar and dorsal aspects)

Question 17

Path of ulnar nerve

Answer 17

Posterio-medially down the upper arm, then down the medial aspect of forearm through Guyon’s canal into the hand

Question 18

What is Froment’s sign

Answer 18

An assessment for ulnar nerve palsy
It tests adductor pollicis
Hold a piece of paper between thumb and index finger (will flex pollicis longus to compensate if adductor pollicis problems)

Question 19

What is cubital tunnel syndrome

Answer 19

Compression of the ulnar nerve as it passes through the cubital tunnel

Question 20

Features of cubital tunnel syndrome

Answer 20

Tingling and numbess of 4th/5th finger, intermittent > constant
Weakness and muscle wasting
More painful if you lean on affected elbow

Question 21

Treatment of cubital tunnel syndrome

Answer 21

Avoid aggravation
Physiotherapy
Steroid injections
Surgery