UE Peripheral Nerve Injuries

Question 1

Dermatomes C5-T1

Answer 1

Question 2

Dermatomes L2-S1

Answer 2

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Question 3

Median nerve entrapment

Answer 3

Proximal to elbow
Distal to elbow (pronator teres syndrome)
Anterior interosseous syndrome (AIN)
Carpal tunnel syndrome

Question 4

Compression under ligament of struthers

Answer 4

Median nerve
Proximal to elbow

Bone spur
Motor and sensory loss in entire distribution
Pronator teres muscle affected

Question 5

Pronator teres syndrome

Answer 5

Median nerve
Compression b/t two heads of pronator teres

MOI:
Overuse, repetitive activities involving pronation (hammering, tennis)

Sxs:
Heaviness/pain in FA
Minimal night pain

Motor impact:
FPL
Abductor pollicis brevis
FDP (dig 2-3)
Opp pollicis
Pronator quadratus
Pronator teres SPARED***

Pain reproduced w/ resisted flexion and pronation

Sensory: median n. distribution

Special tests:
(+) Pronator teres syndrome test
(+)Tinel’s sign in FA
(-) phalen’s

Question 6

Anterior interosseous syndrome

Answer 6

Median nerve
AIN compressed below pronator teres near flexor group

Pure motor

Weakness in FPL, FDP (2-3), pronator quadratus

FA pain but no sensory sxs

Unable to make OK sign

Question 7

Carpal tunnel syndrome

Answer 7

Median nerve
Compressed under transverse carpal ligament

Sensory:
Median distribution sparring thenar eminence (palmar cutaneous br. does not go thru tunnel)

Motor:
AbdPB
Opp poll
FPB
Thenar m. atrophy

Sxs:
Nocturnal pain
Reproduced w/ prolonged wrist flexion, active compression of carpal tunnel

Special tests:
(+) tinel’s at wrist
(+) phalen’s
(+) reverse phalen’s
(+) flick manuever

Question 8

Radial nerve entrapments

Answer 8

Crutch palsy
High radial nerve injury
Radial tunnel syndrome
Posterior interosseous nerve syndrome (PIN)
Wartenberg’s syndrome

Question 9

Crutch palsy

Answer 9

Radial n.
Very high n. palsy, axilla injury

Motor:
loss of elbow ext, wrist/dig ext weakness, weak supination

sensory:
radial n. distribution

Question 10

High radial nerve injury

Answer 10

Radial n.
Humerus spiral groove or shaft fx

Motor:
triceps SPARED***
wrist drop
thumb ext weakness

sensory:
radial n. distribution below impairment

Question 11

Radial tunnel syndrome

Answer 11

Radial n.
Compression of PIN in radial tunnel (supinator hypertrophy)

Pain over radial tunnel, 5 cm distal to lat epi

Pain on radial aspect of proximal FA

No sensory or motor sxs

Sxs agg by resisted supination, finger extension, FA pronation, wrist flexion

Question 12

Posterior interosseous nerve syndrome

Answer 12

Radial n.
Compression on PIN b/t two heads of supinator mm.

Pure motor
Pain in deep FA, lat elbow
Weakness of wrist ext
Dropped fingers/thumbs

ECRL SPARED*** (wrist can still ext and radially dev)

Question 13

Wartenberg’s syndrome

Answer 13

Radial n.
Cheiralgia paresthetica
Compression of superficial sensory branch under ECRL and brachialis tendons

MOI:
trauma, tight watch, handcuffs

Pain/sensory disturbances on radial side of dorsum of hand
Pain reproduced w/ flexion and ulnar dev

No motor loss

Special tests
(+) tinel’s at site of compression

Question 14

Ulnar nerve entrapments

Answer 14

Cubital tunnel syndrome
Guyon’s canal syndrome

Question 15

Cubital tunnel syndrome

Answer 15

Ulnar n.
Entrapment b/t two heads of flexor carpi ulnaris

MOI:
prolonged elbow flexion, fx, spurs, arthritis

Sensory (first): pain/sensory sxs at 4th/5th digits and hypothenar

Motor (later):
FDP 3/4
Hypothenar mm.
Ulnar interossei
Adductor pollicis

Special tests:
(+) elbow flexion test
(+) froment paper sign
(+) wartenberg sign
(+) tinel’s

Question 16

Guyon’s canal syndrome

Answer 16

Ulnar n.
Entrapment b/t hook of hamate and transverse carpal ligament

MOI:
heavy gripping, twisting, activities involving pressure

Sensory:
pain/sensory at 4/5 digits (only palmar b/c dorsal cut. does not go thru canal)
hypothenar

motor:
hypothenar mm.
ulnar interossei
adductor pollicis
FDP SPARED ***

Special tests:
(+) froments paper sign
(+) wartenberg sign
(+) tinel’s