DrE: Upper limb nerves

Question 1

Radial nerve examination: inspection

Answer 1

• Patient opposite, hanges resting on table/pillow/ Expose to above elbow/entire upper torso / Aids e.g. splint
• Ask re pain
• Inspect:
  
  • Scars - penetrating trauma of upper limb e.g. upper arm - #humerus, radial side of elbow - #radial head
  • Swelling - soft tissue/bony mass
  • Symmetry - symmetrical RA
  • Deformity ‘hold hands and arms out straight’ - wrist drop
  • Erythema - inflammation
  • Sinus - post op infection
  • muscle wasting - wrist extensors

Question 2

Radial nerve examination: sensation

Answer 2

Feel - temperature changes dorsal/ventral - with back of hand

• 1st dorsal web space - superficial radial nerve
• Dorsal forearm - high lesion

Question 3

Radial nerve examination: motor

Answer 3

• triceps - extension - high lesion nerve br proximal to spiral groove
• Brachioradialis - elbow flexion - nreve br above elbow distal to radial groove
• supinator - posterior interosseous nerve - br at level of elbow, passes deep between 2 heads of supinator
• MCPJ Extension - note R nerve supplies all long digital extensors
• Extensor pollicis longus - palmar surface flat on table, lift thumb -> EPL visible and palpable

Question 4

Radial nerve examination: Special test

Answer 4

Functional assessment

-Assess global and fine functions

Question 5

Radial nerve examination: completion

Answer 5

• QoL Impingement and sleeep - ask patient about impact on life and in turn necessity for intervention
• Help patient dress - functional limitation
• Upper limb neurovascular status:
  
  • full examination
  • focus on pulses, dermatomes, myotomes
• Neck examination - cervical spine pathology
• Radiology - humerus # / cervical spine (MRI)
• Nerve conduction studies

Question 6

Median nerve examination: Inspection

Answer 6

• Patient opposite, hanges resting on table/pillow/ Expose to above elbow/entire upper torso / Aids e.g. splint
• Ask re pain
• Inspect:
  
  • Scars - carpal tunnel decompression/previous trauma
  • swelling - soft tissue/bony mass
  • symmetry - symmetrical disease = RA
  • Deformity
    
    • Benediction sign - make a fist-> infability to flex thumb, index finger, AIN palsy, c.4-6cm below elbow, entire motor to FPL/FDP (radial), PQ. ?compression from tendinous band - accessory muscles, vascular pathology, pain/weakness of pinch
    • ape hand - loss of abduction of thumb
    • Simian thumb
  • Erythema - inflammation
  • sinus - post op, infective
  • Muscle wasting - thenar eminence/forearm flexors

Question 7

Median nerve examination: sensation

Answer 7

Feel

• temperature changes dorsal/ventral - with back of hand
• reduced sweating
• Thenar eminence - palmar cutaneous branch (over floor of retinaculum br proximal to carpal tunnel)
• Digital nerves - ulnar and radial difital nerves, radial 31/1 digits after passing through carpal tunnel

Question 8

Median nerve examination: motor

Answer 8

• Pronator teres - affected with high lesion
• Opponens pollicis - touch each finger in succession
• Abductor pollicis brevis - palm up, point thumb to ceiling, stop pushing down
• Flexor pollicis longus - pincer grip/paper pull - thumb flattens if FPL affected (adductor pollicis of ulnar nerve)

Question 9

Median nerve examination: special tests

Answer 9

• Tinel’s test - CTS
• Phalen’s Test - CTS
• Functional Assessment - global & fine function

Question 10

Median nerve examination: completion

Answer 10

• QoL Impingement and sleeep - ask patient about impact on life and in turn necessity for intervention
• Help patient dress - functional limitation
• Upper limb neurovascular status:
  
  • full examination
  • focus on pulses, dermatomes, myotomes
• Neck examination - cervical spine pathology
• Radiology - cervical spine (MRI)
• Nerve conduction studies - degeneration/demyelination/conduction block

Question 11

Ulnar nerve examination: inspection

Answer 11

• Patient opposite, hanges resting on table/pillow/ Expose to above elbow/entire upper torso / Aids e.g. splint
• Ask re pain
• Inspect:
  
  • Scars - cubital tunnel decompressionscar posterior to medial epicondyle/previous trauma
  • swelling - soft tissue/bony mass
  • symmetry - symmetrical disease = RA
  • Deformity
    
    • Claw hand - when patient extends their fingers
  • Erythema - inflammation
  • Sinus - post op, infective
  • Muscle wasting - hypothenar eminence, interosseous muscles (intermetecarpal wasting)

Question 12

Ulnar nerve examination: sensation

Answer 12

• Ask about pain
• Feel temp changes/reduced sweating
• Palpate ulnar nerve behind medial epicondyle
• Sensation:
  
  • All digital nerves:
    
    • Ulnar and radial digital nerves
    • Superficial cutaneous branch of ulnar nerve classically supplies sensation to ulnar 1 1/2 digits via digital nerves after passing through guyon’s canal
  • Little finger
    
    • innervated by dorsal sensory branch, branches from ulnar nerve c.1 hand’s bredth proximal to wrist

Question 13

Ulnar nerve examination: motor

Answer 13

• FDP (ulnar): ulnar 1/2 of FD{ (ring & little fingers) by testing distal interphalengeal joint flexion (DIPJ)
• Palmar interossei - adduct fingers, placing sheet between PAD
• Dorsal interossei - abduct fingers, against resistance DAB

Question 14

Ulnar nerve examination: special test

Answer 14

• Froment’s test - fists with thumbs up, sheet between thumbs and fist, hold paper - weak adductor poll -> flex thumb to prevent pull (FPL supplied by median nerve)
• Guyon’s canal percussion - reproduce ulnar nerve symptoms, if compression is within Guyon’s canal
• Cubital tunnel syndrome - fully flex elow, tuck closely into sides, reproduce ulnar nerve symptoms, if compression is within ctubital tunnel (also percussion)

Question 15

Ulnar nerve examination: completion

Answer 15

• QoL Impingement and sleeep - ask patient about impact on life and in turn necessity for intervention
• Help patient dress - functional limitation
• Upper limb neurovascular status:
  
  • full examination
  • focus on pulses, dermatomes, myotomes
• Neck examination - cervical spine pathology
• Radiology - cervical spine (MRI)
• Nerve conduction studies - degeneration/demyelination/conduction block

Question 16

What is the course of the radial nerve?

Answer 16

• Roots C5-T1
• Arise from posterior cord of brachial plexus
• Pass through triangular space
• Descends on posterior humerus in spiral groove between medial and lateral heads of triceps
• Nerve br to triceps and anconeus
• Nerve br to brachioradialis (above elbow)
• At levels of lateral epicondyle:
  
  • Superficial radial nerve: superficial br
    
    • descends on dorsal radial aspect of forearm, beneath brachioradialis
    • Emerges to subcutaneous position at junction of middle and distral 3rds
    • Supplies sensation to dorsal 1st web space
  • Posterior interosseous nerve (PIN): deep br
    
    • Winds around neck of radius, passes between superficial and deep heads of supinator - arcade of frohse
    • Supplies wrist extensors and supinators, hand extensors and APL
    • Supplies ECRL and ECRB
      *

Question 17

What is the typical appearance of the hand in radial nerve palsy?

Answer 17

Dependent on level of nerve injury

• High radial nerve injury:
  
  • Complete wrist drop due to loss of extensors
• Lower radial nerve injury - afffecting e.g. PIN alone:
  
  • Loss of extension of all digits with preserved wrist extension - ERCL still functioning via ECRL via superficial radial nerve
  • Small patch of sensory loss on dorsal 1st web space

Question 18

What is the course of the median nerve?

Answer 18

• Roots C6-T1
• Arises from medial and lateral cords of brachial plexus
• Passes with brachial artery
• Passes through/under pronator teres and continues beneath FDS
• Supplies: PT, Palmaris longus, FCR, FDS
• Gives off:
  
  • Anterior interosseous nerve AID: FPL, Radial 1/2 FDP, PQ
  • Palmar cutaenous brach c.5cm proximal to wris: sensation to palm of hand (in line with radial 3.5 digits)

Enters the carpal tunnel and gives off…

• Recurrent motor branch:
  
  • Lateral Lumbricals
  • Opponens pollicis
  • Abductor pollicis brevis
  • Flexor pollicis brevis
• Digital cutaenous branches: sensation to radial 31/2 digits

Question 19

What is the appearance of the hand in a high median nerve palsy?

Answer 19

• Thenar eminence wasting: lose innervation to abductor pollicis breevis, flexor pollicis brevis, opponens pollicis
• Benediction sign: index and middle fingers remain extended when patient tries to make a fist
• Ape hand deformity: wasting of thenar muscles results in thumb coming to lie in line with remaning digits and movement to become limitted to flexion, extension (LOSS of abduction and opposition)

Question 20

What is the course of the ulnar nerve?

Answer 20

• Roots C8 and T1
• medial cord
• descends posterior- medial aspect of humerus
• Pierces medial intermuscular septum
• Passes posterior to medial epicondyle in cubital tunnel
• Passes between 2 heads of FCU to enter anterior compartment of forearm, gives branch to FCU and FDP (ulnar 1/2)
• Gives off
  
  • dorsal sensory branch at distal 1/3 of forearm, it perforates deep fascia and runs on ulnar side of dorcum of wrist and hand -> sensation to dorsal ulnar aspect of hand
• Ulnar nerve continues through guyon’s canal (medial to ulnar artery) & gives off:
  
  • Deep motor branch:
    
    • all intrinsic hand muscles except LOAF (median)
  • Superficial sensory branch:
    
    • sensation to ulnar 1 1/2 digits

Question 21

What is the typical appearance of the hand in ulnar nerve palsy?

Answer 21

• Ulnar clawing of ring and little finger
  
  • MCPJ hyper-extension (lumbrical paralysis) & flexion at PIPJ & DIPJ
  • Clawing -> more obvious when patient is asked to straighten their fingers
  • Middle and index fingers are not affected as those 2 lumbrical are supplies by medial nerve (LOAF)

Question 22

What is the ulnar paradox?

Answer 22

Clawing appears worse in lower less severe ulnar injury

• clawing is due to ulnar 2 lumbrical paralysis
  
  • lumbrical flex the MCPJ and extend DIPJ & PIPJ
• FDP and FPS flex the DIPJ and PIPJ in fingers
  
  • FDP to little and ring fingers = ulnar nerve (flexes DIPJ)
  • FPS - median nerve - flexes PIPJ
• High ulnar nerve injury (e.g. at elbow) loss of FDP function so no flexion at DIPJ so less excentuated looking claw
• Lower ulnar nerve injury e.g. at wrist FDP is spared, flexion at DIPJ, more excentuated looking claw

Question 23

What is the tardy ulnar nerve palsy?

Answer 23

• Valgus deformity in the area of the medial epicondule
  
  • e.g. malnutrition/non-union of condylar #
  • e.g. epiphyseal injury to lateral side of elbow
• -> chronic stretching of ulnar nerve
• -> late/tardy ulnar nerve palsy

Question 24

What are the common sites of radial nerve compression?

Answer 24

• Thoracic outlet
• Axilla
• Radial tunnel syndrome
• Arcade of Frohse
• ECRB
• Supinator

Question 25

What are the cmmon sites of median nerve compression?

Answer 25

• Medial intermuscular septum
• Ligament of Struthers
• Pronator teres
• Anterior interosseous syndrome
• Carpal tunnel syndrome

Question 26

What are the common sites of ulnar nerve compression?

Answer 26

• Medial intermuscular septum
• Cubital tunnel
• Guyon’s canal

Question 27

what fractures may be associated with radial nerve injuries?

Answer 27

humeral shaft fractures

Question 28

What fractures may be associated with median nerve injury?

Answer 28

Wrist fractures

Question 29

What fractures may be associated with ulnar nerve injuries?

Answer 29

Supra-condylar humeral fractures